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Sample records for polyploid lake sturgeon

  1. Inheritance of microsatellite loci in the polyploid lake sturgeon (Acipenser fulvescens)

    Science.gov (United States)

    Pyatskowit, J.D.; Krueger, C.C.; Kincaid, H.L.; May, B.

    2001-01-01

    Inheritance in the expression of amplicons for four microsatellite primer pairs was determined using 10 families created from gametes of wild lake sturgeon (Acipenser fulvescens). Loci Afu34 and Afu68 expressed a maximum of two even-intensity bands per individual and had progeny genotype ratios that fit disomic inheritance (P > 0.05). Some variation exhibited at Afu34 and Afu68 was attributable to a null allele. Genotype expression at both loci also indicated that one female parent had transmitted unreduced gametes. Primer Afu39 amplified products that exhibited four gene doses, where genotype counts fit expected ratios for disomic inheritance (P > 0.05) indicating amplification of products from two disomic loci that share alleles. Meiotic drive was evident at the Afu39 loci based on a test for random segregation (P inheritance based on a single progeny potentially produced by a double reduction gamete. No evidence for proposed octoploid inheritance was observed.

  2. Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

    Science.gov (United States)

    Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

  3. Best management practices guide for waterpower projects: lake sturgeon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    There are challenges and potential risks inherent in waterpower generation activities and this guide focuses on the fish species of lake sturgeon in Ontario and provides a synthesis of industry-wide knowledge and best available science indicators regarding hydropower impacts. This manual is written as guidance to proponents and practitioners but also to owners and operators, and provides them with tools and approaches to implement management strategies that will minimize potential impacts of waterpower generation installations on lake sturgeon and its habitat.

  4. Lake Sturgeon, Acipenser fulvescens, movements in Rainy Lake, Minnesota and Ontario

    Science.gov (United States)

    Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake, Minnesota-Ontario, contains a native population of Lake Sturgeon (Acipenser fulvescens) that has gone largely unstudied. The objective of this descriptive study was to summarize generalized Lake Sturgeon movement patterns through the use of biotelemetry. Telemetry data reinforced the high utilization of the Squirrel Falls geographic location by Lake Sturgeon, with 37% of the re-locations occurring in that area. Other spring aggregations occurred in areas associated with Kettle Falls, the Pipestone River, and the Rat River, which could indicate spawning activity. Movement of Lake Sturgeon between the Seine River and the South Arm of Rainy Lake indicates the likelihood of one integrated population on the east end of the South Arm. The lack of re-locations in the Seine River during the months of September and October may have been due to Lake Sturgeon moving into deeper water areas of the Seine River and out of the range of radio telemetry gear or simply moving back into the South Arm. Due to the movements between Minnesota and Ontario, coordination of management efforts among provincial, state, and federal agencies will be important.

  5. Mattagami River Lake sturgeon entrainment : Little Long generating station facilities

    International Nuclear Information System (INIS)

    Seyler, J.; Evers, J.; McKinley, S.; Evans, R.R.; Prevost, G.; Carson, R.; Phoenix, D.

    1996-01-01

    This project and publication is the result of a collaborative effort by other Large River Ecosystem Unit of Northeast Science (NEST), Ontario Hydro in Kapuskasing, and the New Post First Nation in Cochrane, Ontario, designed to investigate potential solutions to minimize or eliminate the problem of trapped lake sturgeon in the Adam Creek Diversion. The Adam Creek Dam is used to divert excess water from the Mattagami River hydroelectric complex which consists of the Little Long, Smoky Falls, Harmon and Kipling generating stations. The lake sturgeon entrainment problem in the area was discovered in 1990. Potential solutions to the problem include the redirection of flows to mainstream, the placement of a rope barrier, electrical deterrents, physical/electrical guidance systems, sound deterrents, gate modifications, and the continued relocation of fish. The advantages and disadvantages of each of these potential solutions are discussed. Results of the analysis indicated that perceptual and physical barriers have the greatest potential to minimize lake sturgeon entrainment in Adam Creek. 25 refs., 2 tabs., 3 figs., 6 appendices

  6. Use of navigation channels by Lake Sturgeon: Does channelization increase vulnerability of fish to ship strikes?

    Directory of Open Access Journals (Sweden)

    Darryl W Hondorp

    Full Text Available Channelization for navigation and flood control has altered the hydrology and bathymetry of many large rivers with unknown consequences for fish species that undergo riverine migrations. In this study, we investigated whether altered flow distributions and bathymetry associated with channelization attracted migrating Lake Sturgeon (Acipenser fulvescens into commercial navigation channels, potentially increasing their exposure to ship strikes. To address this question, we quantified and compared Lake Sturgeon selection for navigation channels vs. alternative pathways in two multi-channel rivers differentially affected by channelization, but free of barriers to sturgeon movement. Acoustic telemetry was used to quantify Lake Sturgeon movements. Under the assumption that Lake Sturgeon navigate by following primary flow paths, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River were expected to choose navigation channels over alternative pathways and to exhibit greater selection for navigation channels than conspecifics in the less-channelized lower St. Clair River. Consistent with these predictions, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River selected the higher-flow and deeper navigation channels over alternative migration pathways, whereas in the less-channelized lower St. Clair River, individuals primarily used pathways alternative to navigation channels. Lake Sturgeon selection for navigation channels as migratory pathways also was significantly higher in the more-channelized lower Detroit River than in the less-channelized lower St. Clair River. We speculated that use of navigation channels over alternative pathways would increase the spatial overlap of commercial vessels and migrating Lake Sturgeon, potentially enhancing their vulnerability to ship strikes. Results of our study thus demonstrated an association between channelization and the path use of migrating Lake Sturgeon that could prove

  7. Comparison of select hematology and serum chemistry analtyes between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens)

    Science.gov (United States)

    DiVincenti, Louis; Priest, Heather; Walker, Kyle J.; Wyatt, Jeffrey D.; Dittman, Dawn

    2013-01-01

    Hematology and serum chemistry analytes were compared between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens) to potentially improve understanding of medical issues in lake sturgeon. Blood samples were taken from 30 lake sturgeon exhibited in 11 institutions in the United States and from 23 experimentally stocked lake sturgeon caught in gill nets in the lower Genesee River in Rochester, New York, USA. For hematology, only segmented neutrophil count was significantly different, with wild-caught fish having a higher number of circulating neutrophils. For clinical chemistry analytes, chloride, uric acid, calcium, phosphate, glucose, aspartate aminotransferase, triglycerides, and creatine kinase were significantly different between the two cohorts. These differences are likely not clinically significant and are attributable to handling stress, variability in environmental parameters, or differences in nutritional status. This is the first report of hematology and serum chemistry values in aquarium-housed lake sturgeon and provides useful reference intervals for clinicians.

  8. Lake sturgeon response to a spawning reef constructed in the Detroit river

    Science.gov (United States)

    Roseman, Edward F.; Manny, B.; Boase, J.; Child, M.; Kennedy, G.; Craig, J.; Soper, K.; Drouin, R.

    2011-01-01

    Prior to the First World War, the bi-national Detroit River provided vast areas of functional fish spawning and nursery habitat. However, ongoing conflicting human uses of these waters for activities such as waste disposal, water withdrawals, shoreline development, shipping, recreation, and fishing have altered many of the chemical, physical, and biological processes of the Detroit River. Of particular interest and concern to resource managers and stakeholders is the significant loss and impairment of fish spawning and nursery habitat that led to the decline in abundance of most fish species using this ecosystem. Lake sturgeon (Acipenser fulvescens) populations for example, were nearly extirpated by the middle of the 20th century, leaving only a small fraction of their former population. Fisheries managers recognized that the loss of suitable fish spawning habitat is a limiting factor in lake sturgeon population rehabilitation in the Detroit River. In efforts to remediate this beneficial water use impairment, a reef consisting of a mixture of natural rock and limestone was constructed at the upstream end of Fighting Island in 2008. This paper focuses on the response by lake sturgeon to the different replicates of suitable natural materials used to construct the fish spawning habitat at Fighting Island in the Detroit River. Pre-construction fisheries assessment during 2006–2008 showed that along with the presence of adult lake sturgeon, spawning conditions were favorable. However, no eggs were found in assessments conducted prior to reef construction. The 3300 m2 Fighting Island reef was placed at the upstream end of the island in October of 2008. The construction design included 12 spawning beds of three replicates each consisting of either round rock, small or large (shot-rock) diameter limestone or a mixture thereof. An observed response by spawning lake sturgeon occurred the following year when spawning-ready adults (ripe), viable eggs, and larvae were

  9. Assessment of whether upstream passage for Lake Sturgeon is needed at the Pointe du Bois Generating Station (Winnipeg River)

    International Nuclear Information System (INIS)

    Pratt, T.

    2010-01-01

    This document reviewed Manitoba Hydro's proposal to modernize the Pointe du Bois Generating Station (GS) on the Winnipeg River, with particular reference to the potential impacts on Lake Sturgeon in Management Unit 5 (MU5) where large numbers of the fish spawn at the base of the falls. The modernization will involve replacing the spillway, dam segments and replacing or repairing the powerhouse. The pros and cons of providing upstream fish passage for Lake Sturgeon and the generating station were outlined. The only spawning area in the MU5 area may be altered considerably due to changes in water flow, depending on the design chosen for modernization. A potential benefit of providing upstream fish passage for Lake Sturgeon would be to increase genetic diversity within the Winnipeg River. Another potential benefit would be to allow Lake Sturgeon, from the relatively dense population below the GS, to move upstream into MU4 where unfilled habitat may be available and Lake Sturgeon abundance is lower. A potential disadvantage of providing fish passage would be the loss of individual Lake Sturgeon from the healthy population in MU5 with no accompanying benefit to MU4. There would be no net gain to MU4 or MU5 if migrating Lake Sturgeon returned to MU5 rather than proceeding upstream. It was concluded that these current gaps in knowledge must be filled in order to fully assess the environmental impacts. 2 figs.

  10. Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor

    Science.gov (United States)

    Kessel, Steven T.; Hondorp, Darryl W.; Holbrook, Christopher; Boase, James C.; Chiotti, Justin A.; Thomas, Michael V.; Wills, Todd C.; Roseman, Edward; Drouin, Richard; Krueger, Charles C.

    2018-01-01

    Population structure, distribution, abundance, and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations is an important aspect of the ecology of highly-mobile animals, allowing populations to exploit spatially- or temporally-distributed food and space resources.This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes.Over six years (2011 – 2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 yr battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use.Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assign to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 “contingents” (spatiotemporally segregated subgroups).Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

  11. Sex assignment of lake sturgeon (Acipenser fluvescens) based on plasma sex hormone and vitellogenin levels

    Science.gov (United States)

    Craig, J.M.; Papoulias, D.M.; Thomas, M.V.; Annis, M.L.; Boase, J.

    2009-01-01

    This study focused on identifying the sex of lake sturgeon by measuring the sex hormones estradiol and testosterone, and the phosphoprotein vitellogenin (Vtg) in blood plasma by radioimmunoassay and enzyme-linked immunosorbent assay, respectively, and evaluating these techniques as tools in lake sturgeon population management. Surveys of the St Clair River (SCR) lake sturgeon population have characterized it as rebounding by having steady or increasing recruitment since 1997. However, researchers have not been able to effectively determine the sex for most of the sturgeon they capture because few fish caught during surveys are releasing gametes. A total of 115 fish were sampled from May through June in 2004 and 2005 from the SCR, Michigan, USA. Of these, only four females and eight males were verified (i.e. they were releasing gametes at time of capture), resulting in very few fish with which to validate blood hormone and Vtg biomarkers of sex. Fifty-six percent of the fish were assigned a sex designation based on biomarker criteria. Correspondence between actual gonadal sex and biomarker-directed classification was good for the small subset of fish for which gonadal sex was definitively determined. Moreover, application of the steroid values in a predictive sex assignment model developed for white sturgeon misclassified only the same two fish that were misclassified with the steroid and Vtg biomarkers. The experimental results suggest a sex ratio of 1 : 2.7 (F:M), however more conclusive methods are needed to confirm this ratio because so few fish were available for sex validation. Of the 43 males, 14 were within the legal slot limit, 11 were smaller than 1067 mm total length (TL), and 18 were larger than 1270 mm TL. All 15 females were larger than 1270 mm TL, and thus protected by the slot limit criteria. Considering that lake sturgeon are threatened in Michigan, an advantage to using blood plasma assays was that fish were not harmed, and sample collection was

  12. Lake Roosevelt White Sturgeon Recovery Project : Annual Progress Report, January 2003 – March 2004.

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Matthew D.; McLellan, Jason G. [Washington Department of Fish and Wildlife

    2009-07-15

    This report summarizes catch data collected from white sturgeon Acipenser transmontanus in Lake Roosevelt during limited setlining and gill netting activities in the fall of 2003, and documents progress toward development of a U.S. white sturgeon conservation aquaculture program for Lake Roosevelt. From 27-30 October, 42 overnight small mesh gill net sets were made between Marcus and Northport, WA for a total catch of 15 juvenile white sturgeon (275-488 mm FL). All sturgeon captured were of Canadian hatchery origin. These fish had been previously released as sub-yearlings into the Canadian portion (Keenleyside Reach) of the Transboundary Reach of the Columbia River during 2002 and 2003. Most sturgeon (n=14) were caught in the most upstream area sampled (Northport) in low velocity eddy areas. Five fish exhibited pectoral fin deformities (curled or stunted). Growth rates were less than for juvenile sturgeon captured in the Keenleyside Reach but condition factor was similar. Condition factor was also similar to that observed in juvenile sturgeon (ages 1-8) captured in the unimpounded Columbia River below Bonneville Dam between 1987-92. From 10-14 November, 28 overnight setline sets were made in the Roosevelt Reach between the confluence of the Spokane River and Marcus Island for a total catch of 17 white sturgeon (94-213 cm FL). Catch was greatest in the most upstream areas sampled, a distribution similar to that observed during a WDFW setline survey in Lake Roosevelt in 1998. The mean W{sub r} index of 110% for fish captured this year was higher than the mean W{sub r} of 91% for fish captured in 1998. Excellent fish condition hindered surgical examination of gonads as lipid deposits made the ventral body wall very thick and difficult to penetrate with available otoscope specula. Acoustic tags (Vemco model V16 coded pingers, 69 kHz, 48-month life expectancy) were internally applied to 15 fish for subsequent telemetry investigations of seasonal and reproductively

  13. Assessment of lake sturgeon (Acipenser fulvescens) spawning efforts in the lower St. Clair River, Michigan

    Science.gov (United States)

    Nichols, S. Jerrine; Kennedy, Gregory; Crawford, Eric; Allen, Jeffrey; French, John; Black, Glen; Blouin, Marc; Hickey, James P.; Chernyak, Sergei; Haas, Robert; Thomas, Michael

    2003-01-01

    One of the most threatened remaining populations of lake sturgeon in the Great Lakes is found in the connecting channels between Lake Huron and Lake Erie. Only two spawning grounds are presently known to be active in this region, and both are in the St. Clair River. The spawning reef in the St. Clair River delta has been recently colonized by round gobies (Neogobius melanostomus) in densities up to 25/m2, raising concerns regarding predation on the benthic-oriented eggs and larvae of the sturgeon. Investigations in 1998–1999 showed that while round goby predation does occur, a number of other factors may be equally affecting sturgeon spawning success, including few spawning adults (noted in either year. There were factors other than predation affecting larval survival in 1999. There was a higher silt load on the reef than in 1998 and large numbers of dead larvae were found. Recruitment success from this site could be improved by utilizing techniques to increase the number of eggs on the reef, such as reducing the illegal take of adult fish and by placing eggs in predator-exclusion chambers to increase hatch rate.

  14. Assigning sex and reproductive stage to adult Lake Sturgeon using ultrasonography and common morphological measurements

    Science.gov (United States)

    Chiotti, Justin A.; Boase, James C.; Hondorp, Darryl W.; Briggs, Andrew S.

    2016-01-01

    Sex determination of fish species is difficult to assess when sexual dimorphism and gametes are not apparent. For threatened and endangered fish species, noninvasive techniques are needed when determining sex to minimize stress and the potential for mortality. We evaluated the use of a portable ultrasound unit to determine sex of Lake Sturgeon Acipenser fulvescens in the field. Ultrasound images were collected from 9 yellow-egg (F2, F3), 32 black-egg (F4, F5), and 107 fully developed male (M2) Lake Sturgeon. Two readers accurately assigned sex to 88–96% of fish, but accuracy varied in relation to maturity stage. Black-egg females and fully developed males were correctly identified for 89–100% of the fish sampled, while these two readers identified yellow-egg females only 33% and 67% of the time. Time spent collecting images ranged between 2 and 3 min once the user was comfortable with operating procedures. Discriminant analysis revealed the total length : girth ratio was a strong predictor of sex and maturity, correctly classifying 81% of black-egg females and 97% of the fully developed males. However, yellow-egg females were incorrectly classified on all occasions. This study shows the utility of using ultrasonography and a total length : girth ratio for sex determination of Lake Sturgeon in later reproductive stages around the spawning season.

  15. Efficacy of iodine for disinfection of Lake Sturgeon eggs from the St. Lawrence River, New York

    Science.gov (United States)

    Chalupnicki, Marc A.; Dittman, Dawn E.; Starliper, Clifford E.; Iwanowicz, Deborah

    2014-01-01

    Optimal fish husbandry to reduce the risk of disease is particularly important when using wild fish as the source for gametes. The propagation and reestablishment of Lake Sturgeon Acipenser fulvescens in New York waters to become a viable self-sustaining population is considered a high priority by managers. While standard hatchery egg disinfection practices have been used to prevent the transmission of diseases, data on the bacterial loads present on egg surfaces following iodine disinfection is lacking. Our study investigated the bacteria present on the outer surface of Lake Sturgeon eggs and the effectiveness of an iodine disinfection treatment in eliminating bacteria that could pose a threat to egg survival and cause hatchery disease outbreaks. During the springs of 2011–2013, 12 to 41 different species of bacteria were recovered from the outer egg surfaces prior to an iodine treatment; Aeromonas, Pseudomonas, Shewanella, and Chryseobacterium were the most common genera identified. Cohort eggs treated using the standard protocol of a single treatment of 50 mg/L iodine for 30 min resulted in an average of 57.8% reduction in bacterial CFU/g. While this is a significant reduction, bacteria were not completely eliminated and hatchery managers should be aware that pathogens could remain on Lake Sturgeon eggs following the standard iodine disinfection treatment.

  16. Exposure-related effects of Zequanox on juvenile lake sturgeon (Acipenser fulvescens) and lake trout (Salvelinus namaycush)

    Science.gov (United States)

    Luoma, James A.; Severson, Todd J.; Wise, Jeremy K.; Barbour, Matthew

    2018-01-01

    The environmental fate, persistence, and non-target animal impacts of traditional molluscicides for zebra, Dreissena polymorpha, and quagga, D. bugensis, mussel control led to the development of the biomolluscicide Zequanox. Although previous research has demonstrated the specificity of Zequanox, one study indicated sensitivity of salmonids and lake sturgeon, Acipenser fulvescens, following non-label compliant exposures to Zequanox. This study was conducted to evaluate sublethal and lethal impacts of Zequanox exposure on juvenile lake sturgeon and lake trout, Salvelinus namaycush, following applications that were conducted in a manner consistent with the Zequanox product label. Fish were exposed to 50 or 100 mg/L of Zequanox as active ingredient for 8 h and then held for 33 d to evaluate latent impacts. No acute mortality was observed in either species; however, significant latent mortality (P < 0.01, df = 9; 46.2%) was observed in lake trout that were exposed to the highest dose of Zequanox. Statistically significant (P < 0.03, df = 9), but biologically minimal differences were observed in the weight (range 20.17 to 21.49 g) of surviving lake sturgeon at the termination of the 33 d post-exposure observation period. Statistically significant (P < 0.05, df = 9) and biologically considerable differences were observed in the weight (range 6.19 to 9.55 g) of surviving lake trout at the termination of the 33 d post-exposure observation period. Histologic evaluation of lake trout gastrointestinal tracts suggests that the mode of action in lake trout is different from the mode of action that induces zebra and quagga mussel mortality. Further research could determine the sensitivity of other salmonid species to Zequanox and determine if native fish will avoid Zequanox treated water.

  17. Electronic archival tags provide first glimpse of bathythermal habitat use by free-ranging adult lake sturgeon Acipenser fulvescens

    Science.gov (United States)

    Briggs, Andrew S.; Hondorp, Darryl W.; Quinlan, Henry R.; Boase, James C.; Mohr, Lloyd C.

    2016-01-01

    Information on lake sturgeon (Acipenser fulvescens) depth and thermal habitat use during non-spawning periods is unavailable due to the difficulty of observing lake sturgeon away from shallow water spawning sites. In 2002 and 2003, lake sturgeon captured in commercial trap nets near Sarnia, Ontario were implanted with archival tags and released back into southern Lake Huron. Five of the 40 tagged individuals were recaptured and were at large for 32, 57, 286, 301, and 880 days. Temperatures and depths recorded by archival tags ranged from 0 to 23.5 ºC and 0.1 to 42.4 m, respectively. For the three lake sturgeon that were at large for over 200 days, temperatures occupied emulated seasonal fluctuations. Two of these fish occupied deeper waters during winter than summer while the other occupied similar depths during non-spawning periods. This study provides important insight into depth and thermal habitat use of lake sturgeon throughout the calendar year along with exploring the feasibility of using archival tags to obtain important physical habitat attributes during non-spawning periods.

  18. Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor.

    Science.gov (United States)

    Kessel, Steven T; Hondorp, Darryl W; Holbrook, Christopher M; Boase, James C; Chiotti, Justin A; Thomas, Michael V; Wills, Todd C; Roseman, Edward F; Drouin, Richard; Krueger, Charles C

    2018-01-01

    Population structure, distribution, abundance and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations are an important aspect of the ecology of highly mobile animals, allowing populations to exploit spatially or temporally distributed food and space resources. This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes. Over 6 years (2011-2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 years battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use. Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assigned to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 "contingents" (spatiotemporally segregated subgroups). Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

  19. Lake Sturgeon, Lake Whitefish, and Walleye egg deposition patterns with response to fish spawning substrate restoration in the St. Clair–Detroit River system

    Science.gov (United States)

    Fischer, Jason L.; Pritt, Jeremy J.; Roseman, Edward; Prichard, Carson G.; Craig, Jaquelyn M.; Kennedy, Gregory W.; Manny, Bruce A.

    2018-01-01

    Egg deposition and use of restored spawning substrates by lithophilic fishes (e.g., Lake Sturgeon Acipenser fulvescens, Lake Whitefish Coregonus clupeaformis, and Walleye Sander vitreus) were assessed throughout the St. Clair–Detroit River system from 2005 to 2016. Bayesian models were used to quantify egg abundance and presence/absence relative to site-specific variables (e.g., depth, velocity, and artificial spawning reef presence) and temperature to evaluate fish use of restored artificial spawning reefs and assess patterns in egg deposition. Lake Whitefish and Walleye egg abundance, probability of detection, and probability of occupancy were assessed with detection-adjusted methods; Lake Sturgeon egg abundance and probability of occurrence were assessed using delta-lognormal methods. The models indicated that the probability of Walleye eggs occupying a site increased with water velocity and that the rate of increase decreased with depth, whereas Lake Whitefish egg occupancy was not correlated with any of the attributes considered. Egg deposition by Lake Whitefish and Walleyes was greater at sites with high water velocities and was lower over artificial spawning reefs. Lake Sturgeon eggs were collected least frequently but were more likely to be collected over artificial spawning reefs and in greater abundances than elsewhere. Detection-adjusted egg abundances were not greater over artificial spawning reefs, indicating that these projects may not directly benefit spawning Walleyes and Lake Whitefish. However, 98% of the Lake Sturgeon eggs observed were collected over artificial spawning reefs, supporting the hypothesis that the reefs provided spawning sites for Lake Sturgeon and could mitigate historic losses of Lake Sturgeon spawning habitat.

  20. Accelerometer-derived activity correlates with volitional swimming speed in lake sturgeon (Acipenser fulvescens)

    Science.gov (United States)

    Thiem, J.D.; Dawson, J.W.; Gleiss, A.C.; Martins, E.G.; Haro, Alexander J.; Castro-Santos, Theodore R.; Danylchuk, A.J.; Wilson, R.P.; Cooke, S.J.

    2015-01-01

    Quantifying fine-scale locomotor behaviours associated with different activities is challenging for free-swimming fish.Biologging and biotelemetry tools can help address this problem. An open channel flume was used to generate volitionalswimming speed (Us) estimates of cultured lake sturgeon (Acipenser fulvescens Rafinesque, 1817) and these were paired withsimultaneously recorded accelerometer-derived metrics of activity obtained from three types of data-storage tags. This studyexamined whether a predictive relationship could be established between four different activity metrics (tail-beat frequency(TBF), tail-beat acceleration amplitude (TBAA), overall dynamic body acceleration (ODBA), and vectorial dynamic body acceleration(VeDBA)) and the swimming speed of A. fulvescens. Volitional Us of sturgeon ranged from 0.48 to 2.70 m·s−1 (0.51–3.18 bodylengths (BL) · s−1). Swimming speed increased linearly with all accelerometer-derived metrics, and when all tag types werecombined, Us increased 0.46 BL·s−1 for every 1 Hz increase in TBF, and 0.94, 0.61, and 0.94 BL·s−1 for every 1g increase in TBAA,ODBA, and VeDBA, respectively. Predictive relationships varied among tag types and tag-specific parameter estimates of Us arepresented for all metrics. This use of acceleration data-storage tags demonstrated their applicability for the field quantificationof sturgeon swimming speed.

  1. Rethinking the influence of hydroelectric development on gene flow in a long-lived fish, the Lake Sturgeon Acipenser fulvescens.

    Directory of Open Access Journals (Sweden)

    Craig A McDougall

    Full Text Available Many hydroelectric dams have been in place for 50 - >100 years, which for most fish species means that enough generations have passed for fragmentation induced divergence to have accumulated. However, for long-lived species such as Lake Sturgeon, Acipenser fulvescens, it should be possible to discriminate between historical population structuring and contemporary gene flow and improve the broader understanding of anthropogenic influence. On the Winnipeg River, Manitoba, two hypotheses were tested: 1 Measureable quantities of former reservoir dwelling Lake Sturgeon now reside downstream of the Slave Falls Generating Station, and 2 genetically differentiated populations of Lake Sturgeon occur upstream and downstream, a result of historical structuring. Genetic methods based on ten microsatellite markers were employed, and simulations were conducted to provide context. With regards to contemporary upstream to downstream contributions, the inclusion of length-at-age data proved informative. Both pairwise relatedness and Bayesian clustering analysis substantiated that fast-growing outliers, apparently entrained after residing in the upstream reservoir for several years, accounted for ~15% of the Lake Sturgeon 525-750 mm fork length captured downstream. With regards to historical structuring, upstream and downstream populations were found to be differentiated (FST = 0.011, and 0.013-0.014 when fast-growing outliers were excluded, and heterozygosity metrics were higher for downstream versus upstream juveniles. Historical asymmetric (downstream gene flow in the vicinity of the generating station was the most logical explanation for the observed genetic structuring. In this section of the Winnipeg River, construction of a major dam does not appear to have fragmented a previously panmictic Lake Sturgeon population, but alterations to habitat may be influencing upstream to downstream contributions in unexpected ways.

  2. Simulation of hydrodynamics, water quality, and lake sturgeon habitat volumes in Lake St. Croix, Wisconsin and Minnesota, 2013

    Science.gov (United States)

    Smith, Erik A.; Kiesling, Richard L.; Ziegeweid, Jeffrey R.; Elliott, Sarah M.; Magdalene, Suzanne

    2018-01-05

    Lake St. Croix is a naturally impounded, riverine lake that makes up the last 40 kilometers of the St. Croix River. Substantial land-use changes during the past 150 years, including increased agriculture and urban development, have reduced Lake St. Croix water-quality and increased nutrient loads delivered to Lake St. Croix. A recent (2012–13) total maximum daily load phosphorus-reduction plan set the goal to reduce total phosphorus loads to Lake St. Croix by 20 percent by 2020 and reduce Lake St. Croix algal bloom frequencies. The U.S. Geological Survey, in cooperation with the National Park Service, developed a two-dimensional, carbon-based, laterally averaged, hydrodynamic and water-quality model, CE–QUAL–W2, that addresses the interaction between nutrient cycling, primary production, and trophic dynamics to predict responses in the distribution of water temperature, oxygen, and chlorophyll a. Distribution is evaluated in the context of habitat for lake sturgeon, including a combination of temperature and dissolved oxygen conditions termed oxy-thermal habitat.The Lake St. Croix CE–QUAL–W2 model successfully reproduced temperature and dissolved oxygen in the lake longitudinally (from upstream to downstream), vertically, and temporally over the seasons. The simulated water temperature profiles closely matched the measured water temperature profiles throughout the year, including the prediction of thermocline transition depths (often within 1 meter), the absolute temperature of the thermocline transitions (often within 1.0 degree Celsius), and profiles without a strong thermocline transition. Simulated dissolved oxygen profiles matched the trajectories of the measured dissolved oxygen concentrations at multiple depths over time, and the simulated concentrations matched the depth and slope of the measured concentrations.Additionally, trends in the measured water-quality data were captured by the model simulation, gaining some potential insights into the

  3. Adaption of egg and larvae sampling techniques for lake sturgeon and broadcast spawning fishes in a deep river

    Science.gov (United States)

    Roseman, Edward F.; Kennedy, Gregory W.; Craig, Jaquelyn; Boase, James; Soper, Karen

    2011-01-01

    In this report we describe how we adapted two techniques for sampling lake sturgeon (Acipenser fulvescens) and other fish early life history stages to meet our research needs in the Detroit River, a deep, flowing Great Lakes connecting channel. First, we developed a buoy-less method for sampling fish eggs and spawning activity using egg mats deployed on the river bottom. The buoy-less method allowed us to fish gear in areas frequented by boaters and recreational anglers, thus eliminating surface obstructions that interfered with recreational and boating activities. The buoy-less method also reduced gear loss due to drift when masses of floating aquatic vegetation would accumulate on buoys and lines, increasing the drag on the gear and pulling it downstream. Second, we adapted a D-frame drift net system formerly employed in shallow streams to assess larval lake sturgeon dispersal for use in the deeper (>8 m) Detroit River using an anchor and buoy system.

  4. Identifying temporal bottlenecks for the conservation of large-bodied fishes: Lake Sturgeon (Acipenser fulvescens show highly restricted movement and habitat use over-winter

    Directory of Open Access Journals (Sweden)

    Donnette Thayer

    2017-04-01

    Full Text Available The relationship between species’ size and home range size has been well studied. In practice, home range may provide a good surrogate of broad spatial coverage needed for species conservation, however, many species can show restricted movement during critical life stages, such as breeding and over-wintering. This suggests the existence of either a behavioral or habitat mediated ‘temporal bottleneck,’ where restricted or sedentary movement can make populations more susceptible to harm during specific life stages. Here, we study over-winter movement and habitat use of Lake Sturgeon (Acipenser fulvescens, the largest freshwater fish in North America. We monitored over-winter movement of 86 fish using a hydro-acoustic receiver array in the South Saskatchewan River, Canada. Overall, 20 fish remained within our study system throughout the winter. Lake Sturgeon showed strong aggregation and sedentary movement over-winter, demonstrating a temporal bottleneck. Movement was highly restricted during ice-on periods (ranging from 0.9 km/day in November and April to 0.2 km/day in mid-November to mid-March, with Lake Sturgeon seeking deeper, slower pools. We also show that Lake Sturgeon have strong aggregation behavior, where distance to conspecifics decreased (from 575 to 313 m in preparation for and during ice-on periods. Although the Lake Sturgeon we studied had access to 1100 kilometers of unfragmented riverine habitat, we show that during the over-winter period Lake Sturgeon utilized a single, deep pool (<0.1% of available habitat. The temporal discrepancy between mobile and sedentary behaviors in Lake Sturgeon suggest adaptive management is needed with more localized focus during periods of temporal bottlenecks, even for large-bodied species.

  5. Decision 99-18: Range Petroleum Corporation application for a well licence, Sturgeon Lake Area

    International Nuclear Information System (INIS)

    1999-07-01

    Range Petroleum Corporation (Range) applied to the Alberta Energy and Utilities Board (EUB) pursuant to Section 2.020 of the Oil and Gas Conservation Regulations for a well licence to drill a sour oil well from a surface location in Legal Subdivision 4, Section 34, West of the fifth Meridian, directionally to a bottom-hole location under Sturgeon Lake. The purpose of the proposed well would be to obtain sour oil production from the Leduc Formation. The well would be a Level 1 well because it would have a potential maximum hydrogen sulphide release rate of 0.0412 cubic m/s. The EUB received objections to the application from landowners, cattle ranchers, farmers, residents, and cottage owners in the area of the proposed well. The application and intervention were considered at a public hearing on 26 January 1999 in Grande Prairie, Alberta, and the Board viewed the proposed surface location, the previous Lds 3-2 surface location, and the surrounding area prior to the hearing. Having carefully considered the evidence, the Board believed that it would be possible to drill the proposed well safely and with minimal risk, subject to attached conditions. But in light of the unique setting of the area, including the residences and the road and lake configurations, and the difficulty that would exist preparing an effective environmental review process (ERP), the Board deferred its decision on the well licence application until an approved ERP is in place

  6. Seasonal variation in plasma nonesterified fatty acids of Lake Sturgeon (Acipenser fulvescens) in the vicinity of hydroelectric facilities

    International Nuclear Information System (INIS)

    McKinley, R.S.; Power, G.; Singer, T.D.; Ballantyne, J.S.

    1993-01-01

    To establish the effects of hydroelectric generation on the health of lake sturgeon (Acipenser fulvescens), seasonal variations in plasma nonesterified fatty acids (NEFAs) upstream and downstream from hydroelectric stations were measured over a 2-y period. Plasma NEFA profiles were also compared up- and downstream of the stations for differences in utilization of individual NEFA species as substrates for lipid oxidation. Significantly higher levels of total plasma NEFA were found in lake sturgeon upstream (2355 ± 395.9 nmole/ml) compared with those downstream (798 ± 133.5 nmole/ml) of the generating stations during the spring. The NEFA profiles for several key fatty acid species differed significantly among seasons up- and downstream of the facilities. In particular, during spring and summer, the levels of oleic acid (18:1n9) were highest upstream of the stations and levels of a polyunsaturated fatty acid, docosahexaenoic acid (22:6n3), were higher below rather than above the stations. The differences in plasma NEFA concentration may be attributed to altered nutritional status due to the varying flow regime located downstream of the hydroelectric stations. 33 refs., 4 figs., 1 tab

  7. Sensitivity of lake sturgeon (Acipenser fulvescens) early life stages to 2,3,7,8-tetrachlorodibenzo-P-dioxin and 3,3′,4,4′,5-pentachlorobiphenyl

    Science.gov (United States)

    Tillitt, Donald E.; Buckler, Justin A.; Nicks, Diane; Candrl, James; Claunch, Rachel; Gale, Robert W.; Puglis, Holly J.; Little, Edward E.; Linbo, Tiffany L.; Baker, Mary

    2017-01-01

    The aquatic food web of the Great Lakes has been contaminated with polychlorinated biphenyls (PCBs) since the mid-20th century. Threats of PCB exposures to long-lived species of fish, such as lake sturgeon (Acipenser fulvescens), have been uncertain because of a lack of information on the relative sensitivity of the species. The objective of the present study was to evaluate the sensitivity of early–life stage lake sturgeon to 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. Mortality, growth, morphological and tissue pathologies, swimming performance, and activity levels were used as assessment endpoints. Pericardial and yolk sac edema, tubular heart, yolk sac hemorrhaging, and small size were the most commonly observed pathologies in both TCDD and PCB-126 exposures, beginning as early as 4 d postfertilization, with many of these pathologies occurring in a dose-dependent manner. Median lethal doses for PCB-126 and TCDD in lake sturgeon were 5.4 ng/g egg (95% confidence interval, 3.9–7.4 ng/g egg) and 0.61 ng/g egg (0.47–0.82 ng/g egg), respectively. The resulting relative potency factor for PCB-126 (0.11) was greater than the World Health Organization estimate for fish (toxic equivalency factor = 0.005), suggesting that current risk assessments may underestimate PCB toxicity toward lake sturgeon. Swimming activity and endurance were reduced in lake sturgeon survivors from the median lethal doses at 60 d postfertilization. Threshold and median toxicity values indicate that lake sturgeon, like other Acipenser species, are more sensitive to PCB and TCDD than the other genus of sturgeon, Scaphirhynchus, found in North America. Indeed, lake sturgeon populations in the Great Lakes and elsewhere are susceptible to PCB/TCDD-induced developmental toxicity in embryos and reductions in swimming performance.

  8. Reintroduction of Lake Sturgeon (Acipenser fulvescens) into the St. Regis River, NY: Post-release assessment of habitat use and growth

    Science.gov (United States)

    Dittman, Dawn E.; Chalupnicki, Marc A.; Johnson, James H.; Snyder, James

    2015-01-01

    One of the depleted endemic fish species of the Great Lakes, Acipenser fulvescens (Lake Sturgeon), has been the target of extensive conservation efforts. One strategy is reintroduction into historically productive waters. The St. Regis River, NY, represents one such adaptive-management effort, with shared management between New York and the St. Regis Mohawk Tribe. Between 1998 and 2004, a total of 4977 young-of-year Lake Sturgeon were released. Adaptive management requires intermediate progress metrics. During 2004 and 2005, we measured growth, habitat use, and survivorship metrics of the released fish. We captured a total of 95 individuals of all stocked ages. Year-class minimal-survival rates ranged from 0.19–2.1%. The size-at-age and length/biomass relationships were comparable to those reported for juveniles in other Great Lakes waters. These intermediate assessment metrics can provide feedback to resource managers who make restoration-program decisions on a much shorter time-scale than the time-frame in which the ultimate goal of a self-sustaining population can be attained.

  9. Predicted effects of future climate warming on thermal habitat suitability for Lake Sturgeon (Acipenser fulvescens, Rafinesque, 1817) in rivers in Wisconsin, USA

    Science.gov (United States)

    Lyons, John D.; Stewart, Jana S.

    2015-01-01

    The Lake Sturgeon (Acipenser fulvescens, Rafinesque, 1817) may be threatened by future climate warming. The purpose of this study was to identify river reaches in Wisconsin, USA, where they might be vulnerable to warming water temperatures. In Wisconsin, A. fulvescens is known from 2291 km of large-river habitat that has been fragmented into 48 discrete river-lake networks isolated by impassable dams. Although the exact temperature tolerances are uncertain, water temperatures above 28–30°C are potentially less suitable for this coolwater species. Predictions from 13 downscaled global climate models were input to a lotic water temperature model to estimate amounts of potential thermally less-suitable habitat at present and for 2046–2065. Currently, 341 km (14.9%) of the known habitat are estimated to regularly exceed 28°C for an entire day, but only 6 km (0.3%) to exceed 30°C. In 2046–2065, 685–2164 km (29.9–94.5%) are projected to exceed 28°C and 33–1056 km (1.4–46.1%) to exceed 30°C. Most river-lake networks have cooler segments, large tributaries, or lakes that might provide temporary escape from potentially less suitable temperatures, but 12 short networks in the Lower Fox and Middle Wisconsin rivers totaling 93.6 km are projected to have no potential thermal refugia. One possible adaptation to climate change could be to provide fish passage or translocation so that riverine Lake Sturgeon might have access to more thermally suitable habitats.

  10. Passage and behaviour of cultured Lake Sturgeon in a prototype side-baffle fish ladder: I. Ladder hydraulics and fish ascent

    Science.gov (United States)

    Kynard, B.; Pugh, D.; Parker, T.

    2011-01-01

    Research and development of a fish ladder for sturgeons requires understanding ladder hydraulics and sturgeon behaviour in the ladder to insure the ladder is safe and provides effective passage. After years of research and development, we designed and constructed a full-scale prototype side-baffle ladder inside a spiral flume (38.3m long??1m wide??1m high) on a 6% (1:16.5) slope with a 1.92-m rise in elevation (bottom to top) to test use by sturgeons. Twenty-eight triangular side baffles, each extending part way across the flume, alternated from inside wall to outside wall down the ladder creating two major flow habitats: a continuous, sinusoidal flow down the ladder through the vertical openings of side-baffles and an eddy below each side baffle. Ascent and behaviour was observed on 22 cultured Lake Sturgeon=LS (Acipenser fulvescens) repeatedly tested in groups as juveniles (as small as 105.1cm TL, mean) or as adults (mean TL, 118cm) during four periods (fall 2002 and 2003; spring 2003 and 2007). Percent of juveniles entering the ladder that ascended to the top was greater in spring (72.7%) than in fall (40.9-45.5%) and 90.9% of 11 adults, which ascended as juveniles, ascended to the top. Six LS (27.3%) never swam to the top and seven (31.8%) swam to the top in all tests, indicating great variability among individuals for ascent drive. Some LS swam directly to the top in <1min, but most rested in an eddy during ascent. Juveniles swimming through outside wall baffle slots (mean velocity, 1.2ms-1) swam at 1.8-2.2body lengthss-1 and 3.2-3.3tail beatss-1, either at or approaching prolonged swimming speed. The side-baffle ladder was stream-like and provided key factors for a sturgeon ladder: a continuous flow and no full cross-channel walls, abundant eddies for resting, an acceptable water depth, and a water velocity fish could ascend swimming 2bls-1. A side-baffle ladder passes LS and other moderate-swimming fishes. ?? 2011 Blackwell Verlag, Berlin.

  11. Characterization of the contents and histology of the gastrointestinal tracts of White Sturgeon (Acipenser transmontanus) captured from Upper Lake Roosevelt, Washington, October 2008

    Science.gov (United States)

    Parsley, Michael J.; van der Leeuw, Bjorn K.; Elliott, Diane G.

    2010-01-01

    The gastrointestinal tracts of 37 juvenile white sturgeon (Acipenser transmontanus) captured from the upper part of Lake Roosevelt during October 2008, were examined to identify prey taxa and to determine if the fish were consuming smelter slag along with other sediments. Histological examination of the gastrointestinal tract tissues and comparison with similar tissues from hatchery-reared fish also was performed. The contents of the gastro-intestinal tracts (guts) indicated that white sturgeon were actively foraging on various benthic invertebrates and the diet was quite diverse, with more than 50 percent of the fish feeding on five or more different taxa. Slag was present in 76 percent of the guts examined. Although not all guts contained slag particles, larger fish tended to have greater amounts of slag in their guts. Histology of the gut tissues showed the presence of a chronic inflammatory response, and the severity of the response had a significant positive correlation (P = 0.01) with fish length and weight suggesting that the inflammation represented a response to long-term exposure to one or more stressors. However, additional work is needed to determine if the physical or chemical properties of slag contributed to this response.

  12. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Directory of Open Access Journals (Sweden)

    Jon C Svendsen

    Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

  13. Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Rust, Pete; Wakkinen, Virginia (Idaho Department of Fish and Game, Boise, ID)

    2005-06-01

    The objective of this research was to determine the environmental requirements for successful spawning and recruitment of the Kootenai River white sturgeon Acipenser transmontanus population. Annual tasks include monitoring and evaluating the various life stages of Kootenai River white sturgeon. Sampling for adult Kootenai River white sturgeon in 2003 began in March and continued through April. Eighty-one adult white sturgeon were captured with 3,576 hours of angling and set-lining effort in the Kootenai River. Discharge from Libby Dam and river stage at Bonners Ferry in 2003 peaked in May and early June. Flows remained above 500 m{sup 3}/s throughout June, decreased rapidly through mid July, and increased back to near 500 m{sup 3}/s after mid July and through mid August. By late August, flows had decreased to below 400 m{sup 3}/s. We monitored the movements of 24 adult sturgeon in Kootenay Lake, British Columbia (BC) and the Kootenai River from March 15, 2003 to August 31, 2003. Some of the fish were radio or sonic tagged in previous years. Twelve adult white sturgeon were moved upstream to the Hemlock Bar reach (rkm 260.0) and released as part of the Set and Jet Program. Transmitters were attached to seven of these fish, and their movements were monitored from the time of release until they moved downstream of Bonners Ferry. Eight additional radio-tagged white sturgeon adults were located in the traditional spawning reach (rkm 228-240) during May and June. Sampling with artificial substrate mats began May 21, 2003 and ended June 30, 2003. We sampled 717 mat d (a mat d is one 24 h set) during white sturgeon spawning. Three white sturgeon eggs were collected near Shortys Island on June 3, 2003, and five eggs were collected from the Hemlock Bar reach on June 5, 2003. Prejuvenile sampling began June 17, 2003 and continued until July 31, 2003. Sampling occurred primarily at Ambush Rock (rkm 244.0) in an attempt to document any recruitment that might have occurred from

  14. 76 FR 28309 - Drawbridge Operation Regulation; Sturgeon Bay Ship Canal, Sturgeon Bay, WI

    Science.gov (United States)

    2011-05-17

    ... vehicular traffic congestion would not develop on downtown Sturgeon Bay streets due to unscheduled bridge... schedules during the peak tourist and navigation seasons to provide for the efficient movement of vehicular... between Lake Michigan and Green Bay. The area experiences a significant increase in vehicular and vessel...

  15. Spontaneous polyploidization in cucumber.

    Science.gov (United States)

    Ramírez-Madera, Axel O; Miller, Nathan D; Spalding, Edgar P; Weng, Yiqun; Havey, Michael J

    2017-07-01

    This is the first quantitative estimation of spontaneous polyploidy in cucumber and we detected 2.2% polyploids in a greenhouse study. We provide evidence that polyploidization is consistent with endoreduplication and is an on-going process during plant growth. Cucumber occasionally produces polyploid plants, which are problematic for growers because these plants produce misshaped fruits with non-viable seeds. In this study, we undertook the first quantitative study to estimate the relative frequency of spontaneous polyploids in cucumber. Seeds of recombinant inbred lines were produced in different environments, plants were grown in the field and greenhouse, and flow cytometry was used to establish ploidies. From 1422 greenhouse-grown plants, the overall relative frequency of spontaneous polyploidy was 2.2%. Plants possessed nuclei of different ploidies in the same leaves (mosaic) and on different parts of the same plant (chimeric). Our results provide evidence of endoreduplication and polysomaty in cucumber, and that it is an on-going and dynamic process. There was a significant effect (p = 0.018) of seed production environment on the occurrence of polyploid plants. Seed and seedling traits were not accurate predictors of eventual polyploids, and we recommend that cucumber producers rogue plants based on stature and leaf serration to remove potential polyploids.

  16. Toxicity of smelter slag-contaminated sediments from Upper Lake Roosevelt and associated metals to early life stage White Sturgeon (Acipenser transmontanus Richardson, 1836)

    Science.gov (United States)

    Little, E.E.; Calfee, R.D.; Linder, G.

    2014-01-01

    The toxicity of five smelter slag-contaminated sediments from the upper Columbia River and metals associated with those slags (cadmium, copper, zinc) was evaluated in 96-h exposures of White Sturgeon (Acipenser transmontanus Richardson, 1836) at 8 and 30 days post-hatch. Leachates prepared from slag-contaminated sediments were evaluated for toxicity. Leachates yielded a maximum aqueous copper concentration of 11.8 μg L−1 observed in sediment collected at Dead Man's Eddy (DME), the sampling site nearest the smelter. All leachates were nonlethal to sturgeon that were 8 day post-hatch (dph), but leachates from three of the five sediments were toxic to fish that were 30 dph, suggesting that the latter life stage is highly vulnerable to metals exposure. Fish maintained consistent and prolonged contact with sediments and did not avoid contaminated sediments when provided a choice between contaminated and uncontaminated sediments. White Sturgeon also failed to avoid aqueous copper (1.5–20 μg L−1). In water-only 96-h exposures of 35 dph sturgeon with the three metals, similar toxicity was observed during exposure to water spiked with copper alone and in combination with cadmium and zinc. Cadmium ranging from 3.2 to 41 μg L−1 or zinc ranging from 21 to 275 μg L−1 was not lethal, but induced adverse behavioral changes including a loss of equilibrium. These results suggest that metals associated with smelter slags may pose an increased exposure risk to early life stage sturgeon if fish occupy areas contaminated by slags.

  17. Polyploidization of liver cells.

    Science.gov (United States)

    Celton-Morizur, Séverine; Desdouets, Chantal

    2010-01-01

    Eukaryotic organisms usually contain a diploid complement of chromosomes. However, there are a number of exceptions. Organisms containing an increase in DNA content by whole number multiples of the entire set of chromosomes are defined as polyploid. Cells that contain more than two sets of chromosomes were first observed in plants about a century ago and it is now recognized that polyploidy cells form in many eukaryotes under a wide variety of circumstance. Although it is less common in mammals, some tissues, including the liver, show a high percentage of polyploid cells. Thus, during postnatal growth, the liver parenchyma undergoes dramatic changes characterized by gradual polyploidization during which hepatocytes of several ploidy classes emerge as a result of modified cell-division cycles. This process generates the successive appearance of tetraploid and octoploid cell classes with one or two nuclei (mononucleated or binucleated). Liver cells polyploidy is generally considered to indicate terminal differentiation and senescence and to lead both to the progressive loss of cell pluripotency and a markedly decreased replication capacity. In adults, liver polyploidization is differentially regulated upon loss of liver mass and liver damage. Interestingly, partial hepatectomy induces marked cell proliferation followed by an increase in liver ploidy. In contrast, during hepatocarcinoma (HCC), growth shifts to a nonpolyploidizing pattern and expansion of the diploid hepatocytes population is observed in neoplastic nodules. Here we review the current state of understanding about how polyploidization is regulated during normal and pathological liver growth and detail by which mechanisms hepatocytes become polyploid.

  18. Green Sturgeon Acoustic Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database is used to hold tracking data for green sturgeon tagged in Central California. The data collection began in late 2002 and is ongoing.

  19. DNA damage and polyploidization.

    Science.gov (United States)

    Chow, Jeremy; Poon, Randy Y C

    2010-01-01

    A growing body of evidence indicates that polyploidization triggers chromosomal instability and contributes to tumorigenesis. DNA damage is increasingly being recognized for its roles in promoting polyploidization. Although elegant mechanisms known as the DNA damage checkpoints are responsible for halting the cell cycle after DNA damage, agents that uncouple the checkpoints can induce unscheduled entry into mitosis. Likewise, defects of the checkpoints in several disorders permit mitotic entry even in the presence of DNA damage. Forcing cells with damaged DNA into mitosis causes severe chromosome segregation defects, including lagging chromosomes, chromosomal fragments and chromosomal bridges. The presence of these lesions in the cleavage plane is believed to abort cytokinesis. It is postulated that if cytokinesis failure is coupled with defects of the p53-dependent postmitotic checkpoint pathway, cells can enter S phase and become polyploids. Progress in the past several years has unraveled some of the underlying principles of these pathways and underscored the important role of DNA damage in polyploidization. Furthermore, polyploidization per se may also be an important determinant of sensitivity to DNA damage, thereby may offer an opportunity for novel therapies.

  20. Polyploidization in liver tissue.

    Science.gov (United States)

    Gentric, Géraldine; Desdouets, Chantal

    2014-02-01

    Polyploidy (alias whole genome amplification) refers to organisms containing more than two basic sets of chromosomes. Polyploidy was first observed in plants more than a century ago, and it is known that such processes occur in many eukaryotes under a variety of circumstances. In mammals, the development of polyploid cells can contribute to tissue differentiation and, therefore, possibly a gain of function; alternately, it can be associated with development of disease, such as cancer. Polyploidy can occur because of cell fusion or abnormal cell division (endoreplication, mitotic slippage, or cytokinesis failure). Polyploidy is a common characteristic of the mammalian liver. Polyploidization occurs mainly during liver development, but also in adults with increasing age or because of cellular stress (eg, surgical resection, toxic exposure, or viral infections). This review will explore the mechanisms that lead to the development of polyploid cells, our current state of understanding of how polyploidization is regulated during liver growth, and its consequence on liver function. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  1. The Gulf Sturgeon in the Suwannee River - Questions and Answers

    Science.gov (United States)

    Sulak, Kenneth J.; Randall, Michael T.

    2009-01-01

    Sturgeons and paddlefishes are modern descendants of an ancient group of freshwater fishes, the Chondrostei (a group of bony fishes with mostly cartilaginous skeletons). Sturgeons evolved during the Age of the Dinosaurs, and have prospered in the large rivers and lakes of North America, Europe and Asia for 200 million years. Together with alligators and crocodiles, they survived the mass extinction at the end of the Mesozoic Era, when the dinosaurs and many other groups of animals disappeared forever. They originated prior to the creation of the Atlantic Ocean, when the Northern Hemisphere supercontinent Pangea broke into North America and Eurasia. Most sturgeons are highly specialized to feed in the sediment on small invertebrate prey, a radical evolutionary departure from most of their fish-eating ancestors.

  2. Morphology, chemical contents and physiology of chondrostean fish sperm: a comparative study between Siberian sturgeon (Acipenser baerii) and sterlet (Acipenser ruthenus)

    Czech Academy of Sciences Publication Activity Database

    Pšenička, M.; Hadi Alavi, S.M.; Číčová, Zdeňka; Gela, D.; Cosson, J.; Nebesářová, Jana; Linhart, O.

    2008-01-01

    Roč. 24, č. 4 (2008), s. 371-377 ISSN 0175-8659 Grant - others:GA ČR(CZ) GA524/06/0817 Program:GA Institutional research plan: CEZ:AV0Z60220518 Keywords : NORTH-AMERICAN STURGEONS * TRANSMISSION ELECTRON-MICROSCOPY * CELL ULTRASTRUCTURE * SHOVELNOSE STURGEON * LAKE STURGEON * MOTILITY * SPERMATOZOA * PADDLEFISH * SALMON * OSMOLALITY Subject RIV: EC - Immunology Impact factor: 0.638, year: 2008

  3. Megakaryocyte and polyploidization.

    Science.gov (United States)

    Mazzi, Stefania; Lordier, Larissa; Debili, Najet; Raslova, Hana; Vainchenker, William

    2018-01-01

    In mammals, platelets are produced in the blood by cytoplasmic fragmentation of megakaryocytes (MKs). Platelet production is thus dependent on both the MK number and size. During differentiation, MKs switch from a division by mitosis to polyploidization by endomitosis to increase their size. The endomitotic process includes several successive rounds of DNA replication with an entry in mitosis with a failure in late cytokinesis and a defect in karyokinesis. This leads to a giant cell with a modal ploidy at 16N and one multilobulated nucleus. The entire genome is duplicated several times and all alleles remain functional producing a hypermetabolic cell. A defect in abscission explains the cytokinesis failure and is related to an altered accumulation of actomyosin at the cleavage furrow as a consequence of both a low local RhoA activity and silencing of the MYH10 gene. This mechanism is regulated by transcription factors that govern differentiation explaining the intricacies of both processes. However, the endomitotic cell cycle regulation is still incompletely understood, particularly mitosis entry, escape to the tetraploid checkpoint, and defect in karyokinesis. Polyploidization is regulated during ontogeny, the first embryonic MKs being 2N. The molecular mechanism of this embryo-fetal/adult transition is beginning to be understood. In physiological conditions, MK ploidy is increased by an enhanced platelet demand through the thrombopoietin/myeloproliferative leukemia axis. In numerous hematologic malignancies, MK ploidy decreases, but it is always associated with a defect in MK differentiation. It has been proposed that polyploidization induction could be a treatment for some malignant MK disorders. Copyright © 2018 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  4. Physiological significance of polyploidization in mammalian cells.

    Science.gov (United States)

    Pandit, Shusil K; Westendorp, Bart; de Bruin, Alain

    2013-11-01

    Programmed polyploidization occurs in all mammalian species during development and aging in selected tissues, but the biological properties of polyploid cells remain obscure. Spontaneous polyploidization arises during stress and has been observed in a variety of pathological conditions, such as cancer and degenerative diseases. A major challenge in the field is to test the predicted functions of polyploidization in vivo. However, recent genetic mouse models with diminished polyploidization phenotypes represent novel, powerful tools to unravel the biological function of polyploidization. Contrary to a longstanding hypothesis, polyploidization appears to not be required for differentiation and has no obvious impact on proliferation. Instead, polyploidization leads to increased cell size and genetic diversity, which could promote better adaptation to chronic injury or stress. We discuss here the consequences of reducing polyploidization in mice and review which stress responses and molecular signals trigger polyploidization during development and disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. 162.125 Section 162.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.125 Sturgeon Bay and the Sturgeon Bay Ship...

  6. White Sturgeon Bibliography, 1985 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fickeisen, Duane H. (Pacific Northwest National Laboratory, Richland, WA)

    1986-03-01

    This bibliography presents citations to the majority of published materials on white sturgeon (Acipenser transmontanus). The purpose was to assist in planning and implementing research on white sturgeon in the Columbia River system. (ACR)

  7. North American sturgeon otolith morphology

    Science.gov (United States)

    Chalupnicki, Marc A.; Dittman, Dawn E.

    2016-01-01

    Accurate expedient species identification of deceased sturgeon (Acipenseridae) when external physical characteristic analysis is inconclusive has become a high priority due to the endangered or threatened status of sturgeon species around the world. Examination of otoliths has provided useful information to aid in population management, age and size-class analysis, understanding predator–prey interactions, and archeological research in other fish species. The relationship between otolith characteristics and sturgeon species has remained unknown. Therefore, we analyzed the shape of otoliths from the eight species of sturgeon found in North America to test the utility of otolith characteristic morphology in species identification. There were distinct differences in the size and shape of the otoliths between species of sturgeon with little shape variation among individuals of the same species. The relationship between otolith length axes was linear, and most of the variability was explained by a Log (axis + 1) transformation of the x and y axes (r2 = 0.8983) using the equation y = 0.73x + 0.0612. Images of otoliths from all eight North American species are presented to assist in the identification process.

  8. Columbia River White Sturgeon Genetics and Early Life History: Population Segregation and Juvenile Feeding Behavior, 1987 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, Ernest L.

    1988-06-01

    The geographic area of the genetics study broadly covered the distribution range of sturgeon in the Columbia from below Bonneville Dam at Ilwaco at Lake Roosevelt, the Upper Snake River, and the Kootenai River. The two remote river sections provided data important for enhancement considerations. There was little electrophoretic variation seen among individuals from the Kootenai River. Upper Snake river sturgeon showed a higher percentage of polymorphic loci than the Kootenai fish, but lower than the other areas in the Columbia River we sampled. Sample size was increased in both Lake Roosevelt and at Electrophoretic variation was specific to an individual sampling area in several cases and this shaped our conclusions. The 1987 early life history studies concentrated on the feeding behavior of juvenile sturgeon. The chemostimulant components in prey attractive to sturgeon were examined, and the sensory systems utilized by foraging sturgeon were determined under different environmental conditions. These results were discussed with regard to the environmental changes that have occurred in the Columbia River. Under present river conditions, the feeding mechanism of sturgeon is more restricted to certain prey types, and their feeding range may be limited. In these situations, enhancement measures cannot be undertaken without consideration given to the introduction of food resources that will be readily available under present conditions. 89 refs., 7 figs., 11 tabs.

  9. Contaminants in Atlantic sturgeon and shortnose sturgeon recovered from the Penobscot and Kennebec rivers, Maine.

    Data.gov (United States)

    Department of the Interior — In the Gulf of Maine, the shortnose sturgeon (Acipenser brevirostrum) is a federally‐listed endangered species and the Atlantic sturgeon (Acipenser oxyrinchus) is a...

  10. Site heteroplasmy in the mitochondrial cytochrome b gene of the sterlet sturgeon Acipenser ruthenus

    Directory of Open Access Journals (Sweden)

    Andreea Dudu

    2012-01-01

    Full Text Available Sturgeons are fish species with a complex biology. They are also characterized by complex aspects including polyploidization and easiness of hybridization. As with most of the Ponto-Caspian sturgeons, the populations of Acipenser ruthenus from the Danube have declined drastically during the last decades. This is the first report on mitochondrial point heteroplasmy in the cytochrome b gene of this species. The 1141 bp sequence of the cytb gene in wild sterlet sturgeon individuals from the Lower Danube was determined, and site heteroplasmy evidenced in three of the 30 specimens collected. Two nucleotide sequences were identified in these heteroplasmic individuals. The majority of the heteroplasmic sites are synonymous and do not modify the sequence of amino acids in cytochrome B protein. To date, several cases of point heteroplasmy have been reported in animals, mostly due to paternal leakage of mtDNA. The presence of specific point heteroplasmic sites might be interesting for a possible correlation with genetically distinct groups in the Danube River.

  11. 77 FR 21890 - Drawbridge Operation Regulation; Sturgeon Bay Ship Canal, Sturgeon Bay, WI

    Science.gov (United States)

    2012-04-12

    ... Street and Maple-Oregon Bridges so vehicular traffic congestion would not develop on downtown Sturgeon... the efficient movement of vehicular traffic in Sturgeon Bay. The Sturgeon Bay Ship Canal is... experiences a significant increase in vehicular and vessel traffic during the peak tourist and navigation...

  12. 77 FR 44140 - Drawbridge Operation Regulation; Sturgeon Bay Ship Canal, Sturgeon Bay, WI

    Science.gov (United States)

    2012-07-27

    ... Maple-Oregon Bridges so vehicular traffic congestion would not develop on downtown Sturgeon Bay streets... movement of vehicular traffic in Sturgeon Bay. The Sturgeon Bay Ship Canal is approximately 8.6 miles long... significant increase in vehicular and vessel traffic during the peak tourist and navigation season between...

  13. Intergenomic rearrangements after polyploidization of Kengyilia thoroldiana (Poaceae: Triticeae) affected by environmental factors.

    Science.gov (United States)

    Wang, Qiuxia; Liu, Huitao; Gao, Ainong; Yang, Xinming; Liu, Weihua; Li, Xiuquan; Li, Lihui

    2012-01-01

    Polyploidization is a major evolutionary process. Approximately 70-75% species of Triticeae (Poaceae) are polyploids, involving 23 genomes. To investigate intergenomic rearrangements after polyploidization of Triticeae species and to determine the effects of environmental factors on them, nine populations of a typical polyploid Triticeae species, Kengyilia thoroldiana (Keng) J.L.Yang et al. (2n = 6x = 42, StStPPYY), collected from different environments, were studied using genome in situ hybridization (GISH). We found that intergenomic rearrangements occurred between the relatively large P genome and the small genomes, St (8.15%) and Y (22.22%), in polyploid species via various types of translocations compared to their diploid progenitors. However, no translocation was found between the relatively small St and Y chromosomes. Environmental factors may affect rearrangements among the three genomes. Chromosome translocations were significantly more frequent in populations from cold alpine and grassland environments than in populations from valley and lake-basin habitats (P<0.05). The relationship between types of chromosome translocations and altitude was significant (r = 0.809, P<0.01). Intergenomic rearrangements associated with environmental factors and genetic differentiation of a single basic genome should be considered as equally important genetic processes during species' ecotype evolution.

  14. Intergenomic rearrangements after polyploidization of Kengyilia thoroldiana (Poaceae: Triticeae affected by environmental factors.

    Directory of Open Access Journals (Sweden)

    Qiuxia Wang

    Full Text Available Polyploidization is a major evolutionary process. Approximately 70-75% species of Triticeae (Poaceae are polyploids, involving 23 genomes. To investigate intergenomic rearrangements after polyploidization of Triticeae species and to determine the effects of environmental factors on them, nine populations of a typical polyploid Triticeae species, Kengyilia thoroldiana (Keng J.L.Yang et al. (2n = 6x = 42, StStPPYY, collected from different environments, were studied using genome in situ hybridization (GISH. We found that intergenomic rearrangements occurred between the relatively large P genome and the small genomes, St (8.15% and Y (22.22%, in polyploid species via various types of translocations compared to their diploid progenitors. However, no translocation was found between the relatively small St and Y chromosomes. Environmental factors may affect rearrangements among the three genomes. Chromosome translocations were significantly more frequent in populations from cold alpine and grassland environments than in populations from valley and lake-basin habitats (P<0.05. The relationship between types of chromosome translocations and altitude was significant (r = 0.809, P<0.01. Intergenomic rearrangements associated with environmental factors and genetic differentiation of a single basic genome should be considered as equally important genetic processes during species' ecotype evolution.

  15. The Analysis of Polyploid Genetic Data

    NARCIS (Netherlands)

    Meirmans, P.G.; Liu, S.; van Tienderen, P.H.

    2018-01-01

    Though polyploidy is an important aspect of the evolutionary genetics of both plants and animals, the development of population genetic theory of polyploids has seriously lagged behind that of diploids. This is unfortunate since the analysis of polyploid genetic data—and the interpretation of the

  16. Bacterial flora of sturgeon fingerling

    International Nuclear Information System (INIS)

    Arani, A.S.; Mosahab, R.

    2008-01-01

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  17. Functional reprogramming of polyploidization in megakaryocytes.

    Science.gov (United States)

    Trakala, Marianna; Rodríguez-Acebes, Sara; Maroto, María; Symonds, Catherine E; Santamaría, David; Ortega, Sagrario; Barbacid, Mariano; Méndez, Juan; Malumbres, Marcos

    2015-01-26

    Polyploidization is a natural process that frequently accompanies differentiation; its deregulation is linked to genomic instability and cancer. Despite its relevance, why cells select different polyploidization mechanisms is unknown. Here we report a systematic genetic analysis of endomitosis, a process in which megakaryocytes become polyploid by entering mitosis but aborting anaphase. Whereas ablation of the APC/C cofactor Cdc20 results in mitotic arrest and severe thrombocytopenia, lack of the kinases Aurora-B, Cdk1, or Cdk2 does not affect megakaryocyte polyploidization or platelet levels. Ablation of Cdk1 forces a switch to endocycles without mitosis, whereas polyploidization in the absence of Cdk1 and Cdk2 occurs in the presence of aberrant re-replication events. Importantly, ablation of these kinases rescues the defects in Cdc20 null megakaryocytes. These findings suggest that endomitosis can be functionally replaced by alternative polyploidization mechanisms in vivo and provide the cellular basis for therapeutic approaches aimed to discriminate mitotic and polyploid cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Kootenai River white sturgeon investigations. Chapter 1: Kootenai River white sturgeon spawning and recruitment evaluation; Annual report, January 1--December 31, 1996

    International Nuclear Information System (INIS)

    Paragamian, V.L.; Kruse, G.; Wakkinen, V.

    1997-09-01

    Test flows for Kootenai River white sturgeon Acipenser transmontanus spawning, scheduled for June 1996, were postponed until July. However, an estimated 126% snow pack and unusually heavy precipitation created conditions for sturgeon spawning that were similar to those occurring before construction of Libby Dam. Discharge in the Kootenai River at Bonners Ferry rose to nearly 1,204 m 3 /s (42,500 cfs) during May and water temperature ranged from 5.8 C to 8.4 C (42 F to 47 F). Migration of adult white sturgeon into spawning areas occurred in late May during a rising hydrograph. Discharge and water temperature were rising and had reached approximately 1,077 m 3 /s (38,000 cfs) and 8 C (46 F). Discharge at Bonners Ferry peaked at about 1,397 m 3 /s (49,300 cfs) on June 5. A total of 348 eggs (and one egg shell) were collected with 106,787 h of mat effort during the flow events. The first white sturgeon eggs were collected on June 8 and continued through June 30. Staging of eggs and back-calculating to spawning dates indicated there were at least 18 spawning episodes between June 6 and June 25. Discharge on June 6 was 1,196 m 3 /s (42,200 cfs) and decreased steadily to 850 m 3 /s (30,000 cfs) by June 26. Although sturgeon spawned in the same reach of river that they had during 1994 and 1995, the majority of eggs were found significantly (P = 0.0001) farther upstream than 1994 and 1995 and this in turn may be related to elevation of Kootenay Lake

  19. Dual annual spawning races in Atlantic sturgeon.

    Directory of Open Access Journals (Sweden)

    Matthew T Balazik

    Full Text Available Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus, Acipenseridae populations in the United States were listed as either endangered or threatened under the Endangered Species Act in 2012. Because of the endangered/threatened status, a better understanding of Atlantic sturgeon life-history behavior and habitat use is important for effective management. It has been widely documented that Atlantic sturgeon reproduction occurs from late winter to early summer, varying clinally with latitude. However, recent data show Atlantic sturgeon also spawn later in the year. The group that spawns later in the year seems to be completely separate from the spring spawning run. Recognition of the later spawning season has drastically modified estimates of the population status of Atlantic sturgeon in Virginia. With the combination of new telemetry data and historical documentation we describe a dual spawning strategy that likely occurs in various degrees along most, if not all, of the Atlantic sturgeon's range. Using new data combined with historical sources, a new spawning strategy emerges which managers and researchers should note when determining the status of Atlantic sturgeon populations and implementing conservation measures.

  20. The Analysis of Polyploid Genetic Data.

    Science.gov (United States)

    Meirmans, Patrick G; Liu, Shenglin; van Tienderen, Peter H

    2018-03-16

    Though polyploidy is an important aspect of the evolutionary genetics of both plants and animals, the development of population genetic theory of polyploids has seriously lagged behind that of diploids. This is unfortunate since the analysis of polyploid genetic data-and the interpretation of the results-requires even more scrutiny than with diploid data. This is because of several polyploidy-specific complications in segregation and genotyping such as tetrasomy, double reduction, and missing dosage information. Here, we review the theoretical and statistical aspects of the population genetics of polyploids. We discuss several widely used types of inferences, including genetic diversity, Hardy-Weinberg equilibrium, population differentiation, genetic distance, and detecting population structure. For each, we point out how the statistical approach, expected result, and interpretation differ between different ploidy levels. We also discuss for each type of inference what biases may arise from the polyploid-specific complications and how these biases can be overcome. From our overview, it is clear that the statistical toolbox that is available for the analysis of genetic data is flexible and still expanding. Modern sequencing techniques will soon be able to overcome some of the current limitations to the analysis of polyploid data, though the techniques are lagging behind those available for diploids. Furthermore, the availability of more data may aggravate the biases that can arise, and increase the risk of false inferences. Therefore, simulations such as we used throughout this review are an important tool to verify the results of analyses of polyploid genetic data.

  1. Chemical characteristics and antithrombotic effect of chondroitin sulfates from sturgeon skull and sturgeon backbone.

    Science.gov (United States)

    Gui, Meng; Song, Juyi; Zhang, Lu; Wang, Shun; Wu, Ruiyun; Ma, Changwei; Li, Pinglan

    2015-06-05

    Chondroitin sulfates (CSs) were extracted from sturgeon skull and backbone, and their chemical composition, anticoagulant, anti-platelet and thrombolysis activities were evaluated. The average molecular weights of CS from sturgeon skull and backbone were 38.5kDa and 49.2kDa, respectively. Disaccharide analysis indicated that the sturgeon backbone CS was primarily composed of disaccharide monosulfated in position four of the GalNAc (37.8%) and disaccharide monosulfated in position six of the GalNAc (59.6%) while sturgeon skull CS was primarily composed of nonsulfated disaccharide (74.2%). Sturgeon backbone CS showed stronger antithrombotic effect than sturgeon skull CS. Sturgeon backbone CS could significantly prolong activated partial thromboplastin time (APTT) and thrombin time (TT), inhibited ADP-induced platelet aggregation and dissolved platelet plasma clots in vitro. The results suggested that sturgeon backbone CS can be explored as a functional food with antithrombotic function. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Students Collaborating to Undertake Tracking Efforts for Sturgeon(SCUTES)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Students Collaborating to Undertake Tracking Efforts for Sturgeon (SCUTES) is a collaboration between NOAA Fisheries, sturgeon researchers, and teachers/educators in...

  3. FEATURES DIGESTION OF STURGEON SPECIES (ACIPENSERIDAE (REVIEW

    Directory of Open Access Journals (Sweden)

    M. Simon

    2016-09-01

    Full Text Available Purpose. To review scientific sources are about the anatomical, physiological and biochemical characteristics of the digestive system and proper digestion process in the sturgeon species (Acipenseridae. Outline the common anatomical and morphological characteristics of the gastrointestinal tract. Consider the activity of digestive enzymes and the influence of various factors. Findings. Review of scientific papers reveals that although the digestion of sturgeon are broadly similar to those of the cartilaginous and bony fish, there are a number of species specificity. In particular, sturgeon enzymes have a wider temperature and hydrogen ranges. It is confirmed that temperature adaptations of digestive system poikilothermic organ-isms are realised mainly thanks to reorganisations of fermental systems. It is shown that enzymes in sturgeons are adjustable, as their activity level significantly changes under the influence of divalent metal ions (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+. The assumption that evolutionary adaptation of hydrolytic function of intestines of fishes to temperature conditions of an inhabitancy takes place, apparently, is made. The paper describes the effect of sex and age factors on the level of activity of enzymes of sturgeons. Set out the regularities of circadian rhythms of the fish of this family. Showed specific features of the liver and its involvement in lipid metabolism and antioxidant defense system. Practical value. The knowledge of hydrolysis characteristics of a diet of sturgeon species is important for the efficiency estimation of feeding and understanding of evolutionary and ecological aspects of digestion physiology. Systematized data on the digestive system of fish sturgeon species are of interest a wide range of research in two main areas. Firstly, although the sturgeon are relict species, but the adaptation of their digestive system is still going on, allowing you to analyze the evolutionary development of the

  4. Molecular Cytogenetics in Artificial Hybrid and Highly Polyploid Sturgeons: An Evolutionary Story Narrated by Repetitive Sequences

    Czech Academy of Sciences Publication Activity Database

    Symonová, Radka; Flajšhans, M.; Sember, Alexandr; Havelka, M.; Gela, D.; Kořínková, Tereza; Rodina, M.; Rábová, Marie; Ráb, Petr

    2013-01-01

    Roč. 141, 2-3 (2013), s. 153-162 ISSN 1424-8581 R&D Projects: GA ČR GA523/08/0824; GA ČR(CZ) GPP506/11/P596 Institutional support: RVO:67985904 Keywords : Acipenser * GISH * Hybridization * Macrochromosomes Subject RIV: EG - Zoology Impact factor: 1.905, year: 2013

  5. Atypical E2f functions are critical for pancreas polyploidization

    NARCIS (Netherlands)

    Matondo, Ramadhan B; Moreno, Eva; Toussaint, Mathilda J M; Tooten, Peter C J; van Essen, Saskia C; van Liere, Elsbeth A; Youssef, Sameh A; Bongiovanni, Laura; de Bruin, Alain

    2018-01-01

    The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of

  6. Decidual cell polyploidization necessitates mitochondrial activity.

    Directory of Open Access Journals (Sweden)

    Xinghong Ma

    Full Text Available Cellular polyploidy has been widely reported in nature, yet its developmental mechanism and function remain poorly understood. In the present study, to better define the aspects of decidual cell polyploidy, we isolated pure polyploid and non-polyploid decidual cell populations from the in vivo decidual bed. Three independent RNA pools prepared for each population were then subjected to the Affymetrix gene chip analysis for the whole mouse genome transcripts. Our data revealed up-regulation of 1015 genes and down-regulation of 1207 genes in the polyploid populations, as compared to the non-polyploid group. Comparative RT-PCR and in situ hybridization results indeed confirmed differential expressional regulation of several genes between the two populations. Based on functional enrichment analyses, up-regulated polyploidy genes appeared to implicate several functions, which primarily include cell/nuclear division, ATP binding, metabolic process, and mitochondrial activity, whereas that of down-regulated genes primarily included apoptosis and immune processes. Further analyses of genes that are related to mitochondria and bi-nucleation showed differential and regional expression within the decidual bed, consistent with the pattern of polyploidy. Consistently, studies revealed a marked induction of mitochondrial mass and ATP production in polyploid cells. The inhibition of mitochondrial activity by various pharmacological inhibitors, as well as by gene-specific targeting using siRNA-mediated technology showed a dramatic attenuation of polyploidy and bi-nucleation development during in vitro stromal cell decidualization, suggesting mitochondria play a major role in positive regulation of decidual cell polyploidization. Collectively, analyses of unique polyploidy markers and molecular signaling networks may be useful to further characterize functional aspects of decidual cell polyploidy at the site of implantation.

  7. Polyploidization increases meiotic recombination frequency in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Rehmsmeier Marc

    2011-04-01

    Full Text Available Abstract Background Polyploidization is the multiplication of the whole chromosome complement and has occurred frequently in vascular plants. Maintenance of stable polyploid state over generations requires special mechanisms to control pairing and distribution of more than two homologous chromosomes during meiosis. Since a minimal number of crossover events is essential for correct chromosome segregation, we investigated whether polyploidy has an influence on the frequency of meiotic recombination. Results Using two genetically linked transgenes providing seed-specific fluorescence, we compared a high number of progeny from diploid and tetraploid Arabidopsis plants. We show that rates of meiotic recombination in reciprocal crosses of genetically identical diploid and autotetraploid Arabidopsis plants were significantly higher in tetraploids compared to diploids. Although male and female gametogenesis differ substantially in meiotic recombination frequency, both rates were equally increased in tetraploids. To investigate whether multivalent formation in autotetraploids was responsible for the increased recombination rates, we also performed corresponding experiments with allotetraploid plants showing strict bivalent pairing. We found similarly increased rates in auto- and allotetraploids, suggesting that the ploidy effect is independent of chromosome pairing configurations. Conclusions The evolutionary success of polyploid plants in nature and under domestication has been attributed to buffering of mutations and sub- and neo-functionalization of duplicated genes. Should the data described here be representative for polyploid plants, enhanced meiotic recombination, and the resulting rapid creation of genetic diversity, could have also contributed to their prevalence.

  8. Haplotype-Based Genotyping in Polyploids

    Directory of Open Access Journals (Sweden)

    Josh P. Clevenger

    2018-04-01

    Full Text Available Accurate identification of polymorphisms from sequence data is crucial to unlocking the potential of high throughput sequencing for genomics. Single nucleotide polymorphisms (SNPs are difficult to accurately identify in polyploid crops due to the duplicative nature of polyploid genomes leading to low confidence in the true alignment of short reads. Implementing a haplotype-based method in contrasting subgenome-specific sequences leads to higher accuracy of SNP identification in polyploids. To test this method, a large-scale 48K SNP array (Axiom Arachis2 was developed for Arachis hypogaea (peanut, an allotetraploid, in which 1,674 haplotype-based SNPs were included. Results of the array show that 74% of the haplotype-based SNP markers could be validated, which is considerably higher than previous methods used for peanut. The haplotype method has been implemented in a standalone program, HAPLOSWEEP, which takes as input bam files and a vcf file and identifies haplotype-based markers. Haplotype discovery can be made within single reads or span paired reads, and can leverage long read technology by targeting any length of haplotype. Haplotype-based genotyping is applicable in all allopolyploid genomes and provides confidence in marker identification and in silico-based genotyping for polyploid genomics.

  9. Columbia River White Sturgeon (Acipenser Transmontanus) Population Genetics and Early Life History Study, January 1, 1986 to December 31, 1986, Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, Ernest L.

    1986-12-01

    The 1986 Columbia River white sturgeon investigations continued to assess genetic variability of sturgeon populations isolated in various areas of the Columbia River, and to examine environmental factors in the habitat that may affect early life history success. Baseline data have been collected for three character sets. Twenty-eight loci have been analyzed for differences using electrophoresis, snout shapes were assessed for multivariate distinction, and scute counts have been examined as an index of variability. Fish that reside in the mid-Columbia and lower river have been sufficiently characterized by electrophoresis to compare with up-river areas. To date, few electrophoretic differences have been identified. However, Lake Roosevelt sturgeon sample size will be increased to determine if some of the observed differences from lower river fish are significant. Snout shape has been shown to be easily quantifiable using the digitizing technique. Scute count data initially indicate that variability exists within as well as between areas. Patterns of differentiation of one or more of these data sets may be used to formulate stock transplant guidelines essential for proper management or enhancement of this species. The historical habitat available to sturgeon in the Columbia River has changed through the development of hydroelectric projects. Dams have reduced the velocity and turbulence, and increased light penetration in the water column from less silt. These changes have affected the ability of sturgeon to feed and have made them more vulnerable to predation, which appear to have altered the ability of populations isolated in the reservoirs to sustain themselves. Present studies support the theory that both the biological and physical habitat characteristics of the Columbia River are responsible for reduced sturgeon survival, and justify consideration of enhancement initiatives above Bonneville to improve sturgeon reproductive success.

  10. How Low Can You Go? Determining a Size Threshold for Implantation of a New Acoustic Transmitter in Age-0 White Sturgeon

    Energy Technology Data Exchange (ETDEWEB)

    Ashton, Neil K.; Liss, Stephanie A.; Walker, Ricardo W.; Brown, Richard S.; Klassen, Cheryl; Backhouse, Stephanie; Bates, Phil; Townsend, Richard L.

    2017-01-01

    Telemetry studies are often used to investigate sturgeon habitat use and movement patterns; however, existing acoustic transmitters are generally too large to implant into age-0 sturgeon without harming the fish. Recent development of a miniaturized acoustic transmitter (cylindrical, 0.7 g in air, 24.2 mm long, 5.0 mm diameter) with up to 365 d battery life has the potential to advance our understanding of age-0 sturgeon ecology in rivers and lakes. Prior to use in field studies, it is essential to conduct experiments evaluating potential adverse transmitter effects on fish. We tested transmitter retention, fish survival, and growth of a broad size range of age-0 white sturgeon (Acipenser transmontanus; 158–277 mm fork length; 26–126 g; 0.6–2.6% transmitter burden) in an 84 d laboratory study, with an ultimate goal of determining a minimum size threshold of sturgeon that can be implanted with this acoustic transmitter. At 84 d post-implantation, transmitter retention and fish survival were 100%. Specific growth rates were reduced at 7 and 14 d post-implantation, resulting in minimum fork length thresholds of 250 and 171 mm, respectively. Juveniles implanted with transmitters regained their growth potential by 28 d post-implantation and no size differences were detected in comparisons with unmarked control fish. This study demonstrates the ability to implant small age-0 sturgeon with high transmitter retention and fish survival, and only minor growth effects. Use of new miniaturized acoustic transmitters may give researchers a means to address questions about young-of-the-year fish recruitment, ecological patterns, and potentially advance conservation management of sturgeon populations.

  11. Ontogenetic behavior and migration of Atlantic sturgeon, Acipenser oxyrinchus oxyrinchus, and shortnose sturgeon, A. brevirostrum, with notes on social behavior

    Science.gov (United States)

    Kynard, B.; Horgan, M.

    2002-01-01

    Ontogenetic behavior of Hudson River Atlantic sturgeon and Connecticut River shortnose sturgeon early life intervals were similar during laboratory observations. After hatching, free embryos were photonegative and sought cover. When embryos developed into larvae, fish left cover, were photopositive, and initiated downstream migration. Free embryos may remain at the spawning site instead of migrating downstream because the risk of predation at spawning sites is low. The two species are sympatric, but not closely related, so the similarities in innate behaviors suggest common adaptations, not phylogenetlc relationship. Atlantic sturgeon migrated downstream for 12 days (peak, first 6 days), shortnose sturgeon migrated for 3 days, and year-0 juveniles of both species did not resume downstream migration. Short or long migrations of larvae may reflect different styles related to the total migratory distance from spawning sites to juvenile rearing areas. Atlantic sturgeon need to move a short distance to reach rearing areas and they had a long 1-step migration of 6-12 days. In contrast, shortnose sturgeon need to move a long distance to reach all rearing areas. This may be accomplished by a 2-step migration, of which the brief migration of larvae is only the first step. Early migrant Atlantic sturgeon were nocturnal, while late migrants were diurnal, and shortnose sturgeon were diurnal. These diel differences may also be adaptations for long (Atlantic sturgeon) or short (shortnose sturgeon) migrations. Cultured shortnose sturgeon, and possibly Atlantic sturgeon, have a dominance hierarchy with large fish dominant when competing for limited foraging space. Social behavior may be more important in the life history of wild sturgeons than is generally recognized.

  12. On the mechanisms of induction of the cells polyploidization

    International Nuclear Information System (INIS)

    Kair, M.B.; Gil'yano, N.Ya.; Malinovskij, O.V.

    1992-01-01

    In rats liver hepatocytes two mechanisms of polyploidization, induced by ionizing radiation have been shown; polyploidization of cells takes place in the result of mitosis blocking, whereas during the irradiation by dense ionizing radiation polyploidization is realized at the expense of cells confluence. It is supposed that in case of polyploidization induction by dense ionizing radiation the target is the cellular membrane. The evidence of this suggestion has been recorded.Induction of hepatocytes confluence by neutrons with various energies, as well as age dependent changes in the effect of hepatocytes confluence, induced by neutrons were obtained. (author). 7 refs., 6 figs

  13. Atypical E2f functions are critical for pancreas polyploidization.

    Directory of Open Access Journals (Sweden)

    Ramadhan B Matondo

    Full Text Available The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of polyploidization in the pancreas are still unknown. We discovered that atypical E2f activity is essential for polyploidization in the pancreas, using an inducible Cre/LoxP approach in new-born mice to delete ubiquitously the atypical E2f transcription factors, E2f7 and E2f8. In contrast to its critical role in embryonic survival, conditional deletion of both of both atypical E2fs in newborn mice had no impact on postnatal survival and mice lived until old age. However, deficiency of E2f7 or E2f8 alone was sufficient to suppress polyploidization in the pancreas and associated with only a minor decrease in blood serum levels of glucose, insulin, amylase and lipase under 4 hours starvation condition compared to wildtype littermates. In mice with fewer pancreatic polyploid cells that were fed ad libitum, no major impact on hormones or enzymes levels was observed. In summary, we identified atypical E2fs to be essential for polyploidization in the pancreas and discovered that postnatal induced loss of both atypical E2fs in many organs is compatible with life until old age.

  14. DNA Damage Signaling Instructs Polyploid Macrophage Fate in Granulomas

    DEFF Research Database (Denmark)

    Herrtwich, Laura; Nanda, Indrajit; Evangelou, Konstantinos

    2016-01-01

    to a chronic stimulus, though critical for disease outcome, have not been defined. Here, we delineate a macrophage differentiation pathway by which a persistent Toll-like receptor (TLR) 2 signal instructs polyploid macrophage fate by inducing replication stress and activating the DNA damage response. Polyploid...

  15. Atypical E2f functions are critical for pancreas polyploidization.

    Science.gov (United States)

    Matondo, Ramadhan B; Moreno, Eva; Toussaint, Mathilda J M; Tooten, Peter C J; van Essen, Saskia C; van Liere, Elsbeth A; Youssef, Sameh A; Bongiovanni, Laura; de Bruin, Alain

    2018-01-01

    The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of polyploidization in the pancreas are still unknown. We discovered that atypical E2f activity is essential for polyploidization in the pancreas, using an inducible Cre/LoxP approach in new-born mice to delete ubiquitously the atypical E2f transcription factors, E2f7 and E2f8. In contrast to its critical role in embryonic survival, conditional deletion of both of both atypical E2fs in newborn mice had no impact on postnatal survival and mice lived until old age. However, deficiency of E2f7 or E2f8 alone was sufficient to suppress polyploidization in the pancreas and associated with only a minor decrease in blood serum levels of glucose, insulin, amylase and lipase under 4 hours starvation condition compared to wildtype littermates. In mice with fewer pancreatic polyploid cells that were fed ad libitum, no major impact on hormones or enzymes levels was observed. In summary, we identified atypical E2fs to be essential for polyploidization in the pancreas and discovered that postnatal induced loss of both atypical E2fs in many organs is compatible with life until old age.

  16. Relevance of sexual polyploidization for crop improvement - A review

    NARCIS (Netherlands)

    Ramanna, M.S.; Jacobsen, E.

    2003-01-01

    Colchicine induced polyploids have not directly contributed for crop improvement in the past. On the other hand, the so-called natural polyploids, derived from the functioning of numerically unreduced (2n) gametes have been shown to be more relevant for crop improvement in many cases. Different

  17. Tools for Genetic Studies in Experimental Populations of Polyploids

    Directory of Open Access Journals (Sweden)

    Peter M. Bourke

    2018-04-01

    Full Text Available Polyploid organisms carry more than two copies of each chromosome, a condition rarely tolerated in animals but which occurs relatively frequently in the plant kingdom. One of the principal challenges faced by polyploid organisms is to evolve stable meiotic mechanisms to faithfully transmit genetic information to the next generation upon which the study of inheritance is based. In this review we look at the tools available to the research community to better understand polyploid inheritance, many of which have only recently been developed. Most of these tools are intended for experimental populations (rather than natural populations, facilitating genomics-assisted crop improvement and plant breeding. This is hardly surprising given that a large proportion of domesticated plant species are polyploid. We focus on three main areas: (1 polyploid genotyping; (2 genetic and physical mapping; and (3 quantitative trait analysis and genomic selection. We also briefly review some miscellaneous topics such as the mode of inheritance and the availability of polyploid simulation software. The current polyploid analytic toolbox includes software for assigning marker genotypes (and in particular, estimating the dosage of marker alleles in the heterozygous condition, establishing chromosome-scale linkage phase among marker alleles, constructing (short-range haplotypes, generating linkage maps, performing genome-wide association studies (GWAS and quantitative trait locus (QTL analyses, and simulating polyploid populations. These tools can also help elucidate the mode of inheritance (disomic, polysomic or a mixture of both as in segmental allopolyploids or reveal whether double reduction and multivalent chromosomal pairing occur. An increasing number of polyploids (or associated diploids are being sequenced, leading to publicly available reference genome assemblies. Much work remains in order to keep pace with developments in genomic technologies. However, such

  18. Tools for Genetic Studies in Experimental Populations of Polyploids.

    Science.gov (United States)

    Bourke, Peter M; Voorrips, Roeland E; Visser, Richard G F; Maliepaard, Chris

    2018-01-01

    Polyploid organisms carry more than two copies of each chromosome, a condition rarely tolerated in animals but which occurs relatively frequently in the plant kingdom. One of the principal challenges faced by polyploid organisms is to evolve stable meiotic mechanisms to faithfully transmit genetic information to the next generation upon which the study of inheritance is based. In this review we look at the tools available to the research community to better understand polyploid inheritance, many of which have only recently been developed. Most of these tools are intended for experimental populations (rather than natural populations), facilitating genomics-assisted crop improvement and plant breeding. This is hardly surprising given that a large proportion of domesticated plant species are polyploid. We focus on three main areas: (1) polyploid genotyping; (2) genetic and physical mapping; and (3) quantitative trait analysis and genomic selection. We also briefly review some miscellaneous topics such as the mode of inheritance and the availability of polyploid simulation software. The current polyploid analytic toolbox includes software for assigning marker genotypes (and in particular, estimating the dosage of marker alleles in the heterozygous condition), establishing chromosome-scale linkage phase among marker alleles, constructing (short-range) haplotypes, generating linkage maps, performing genome-wide association studies (GWAS) and quantitative trait locus (QTL) analyses, and simulating polyploid populations. These tools can also help elucidate the mode of inheritance (disomic, polysomic or a mixture of both as in segmental allopolyploids) or reveal whether double reduction and multivalent chromosomal pairing occur. An increasing number of polyploids (or associated diploids) are being sequenced, leading to publicly available reference genome assemblies. Much work remains in order to keep pace with developments in genomic technologies. However, such technologies

  19. Oxidative stress promotes pathologic polyploidization in nonalcoholic fatty liver disease.

    Science.gov (United States)

    Gentric, Géraldine; Maillet, Vanessa; Paradis, Valérie; Couton, Dominique; L'Hermitte, Antoine; Panasyuk, Ganna; Fromenty, Bernard; Celton-Morizur, Séverine; Desdouets, Chantal

    2015-03-02

    Polyploidization is one of the most dramatic changes that can occur in the genome. In the liver, physiological polyploidization events occur during both liver development and throughout adult life. Here, we determined that a pathological polyploidization takes place in nonalcoholic fatty liver disease (NAFLD), a widespread hepatic metabolic disorder that is believed to be a risk factor for hepatocellular carcinoma (HCC). In murine models of NAFLD, the parenchyma of fatty livers displayed alterations of the polyploidization process, including the presence of a large proportion of highly polyploid mononuclear cells, which are rarely observed in normal hepatic parenchyma. Biopsies from patients with nonalcoholic steatohepatitis (NASH) revealed the presence of alterations in hepatocyte ploidy compared with tissue from control individuals. Hepatocytes from NAFLD mice revealed that progression through the S/G2 phases of the cell cycle was inefficient. This alteration was associated with activation of a G2/M DNA damage checkpoint, which prevented activation of the cyclin B1/CDK1 complex. Furthermore, we determined that oxidative stress promotes the appearance of highly polyploid cells, and antioxidant-treated NAFLD hepatocytes resumed normal cell division and returned to a physiological state of polyploidy. Collectively, these findings indicate that oxidative stress promotes pathological polyploidization and suggest that this is an early event in NAFLD that may contribute to HCC development.

  20. Myocardial Polyploidization Creates a Barrier to Heart Regeneration in Zebrafish.

    Science.gov (United States)

    González-Rosa, Juan Manuel; Sharpe, Michka; Field, Dorothy; Soonpaa, Mark H; Field, Loren J; Burns, Caroline E; Burns, C Geoffrey

    2018-02-26

    Correlative evidence suggests that polyploidization of heart muscle, which occurs naturally in post-natal mammals, creates a barrier to heart regeneration. Here, we move beyond a correlation by demonstrating that experimental polyploidization of zebrafish cardiomyocytes is sufficient to suppress their proliferative potential during regeneration. Initially, we determined that zebrafish myocardium becomes susceptible to polyploidization upon transient cytokinesis inhibition mediated by dominant-negative Ect2. Using a transgenic strategy, we generated adult animals containing mosaic hearts composed of differentially labeled diploid and polyploid-enriched cardiomyocyte populations. Diploid cardiomyocytes outcompeted their polyploid neighbors in producing regenerated heart muscle. Moreover, hearts composed of equivalent proportions of diploid and polyploid cardiomyocytes failed to regenerate altogether, demonstrating that a critical percentage of diploid cardiomyocytes is required to achieve heart regeneration. Our data identify cardiomyocyte polyploidization as a barrier to heart regeneration and suggest that mobilizing rare diploid cardiomyocytes in the human heart will improve its regenerative capacity. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. True polyploid meiosis in the human male.

    Science.gov (United States)

    Pearson, Peter L; Madan, Kamlesh

    2018-05-21

    Polyploidy does not usually occur in germinal cells of mammals and other higher vertebrates. We describe a unique example of mosaic autotetraploidy in the meiosis of a human male. Although the original observations were made in the late 1960s, we did not publish them at that time, because we expected to detect further examples that could be described together. However, this did not occur and we have now decided to make the observations available to demonstrate that polyploidy in mammalian male meiosis can arise at a higher frequency than expected by random polyploidization of individual meiotic cells, by either DNA duplication or cell fusion prior to synapsis. This is the first description of a population of primary spermatocytes exhibiting multivalent formation at leptotene /diakinesis in human spermatogenesis, with ring, chain, frying pan and other types of quadrivalents, typical of autotetraploidy. As many of the polyploid configurations showed apoptotic breakdown, it is likely that diploid and/or aneuploid spermatozoa would have rarely or never resulted from this mosaic autotetraploid meiosis.

  2. NEW BIOTECHNOLOGICAL METHODS FOR CRYOPRESERVATION OF REPRODUCTIVE CELLS OF STURGEON

    Directory of Open Access Journals (Sweden)

    E. N. Ponomareva

    2016-01-01

    Full Text Available The aim of the research is to increase the survivability of reproductive cells of sturgeon at cryopreservation and developing reliable technology suitable for use on an industrial scale.Methods. We have used standard methods of freezing, thawing reproductive cells, fertilization and incubation of eggs and larval rearing of sturgeon. Fundamentally new is cryoprotective composition: for sperm we have adjusted the composition of cryoprotective medium (for beluga 3% of dimethyl sulfoxide, for Russian sturgeon 4% of dimethyl sulfoxide; for freezing the eggs we have used cryoprotective mixture of unrefined vegetable and animal oils.Results. Survivability of defrosted sperm sturgeon has been increased: for Beluga it is up to 20%, for Russian sturgeon - 47%. At insemination of cryopreserved eggs of Russian sturgeon with native sperm the fertilization rate has made 41%.Main conclusions. The research proves the effectiveness of reducing the toxic effect of cryoprotective substances, thus leading to increased survivability of reproductive cells of sturgeon. During the insemination of eggs, stored in liquid nitrogen, the resulting offspring were viable and by the reactivity of the central nervous system and receptor complex it does not differ from the young obtained by conventional technology.

  3. Reproductive physiology of Missouri River gravid pallid sturgeon and shovelnose sturgeon during the 2005 and 2006 spawning seasons: Chapter C in Factors affecting the reproduction, recruitment, habitat, and population dynamics of pallid sturgeon and shovelnose sturgeon in the Missouri River

    Science.gov (United States)

    Papoulias, Diana M.; Annis, Mandy L.; Delonay, Aaron J.; Tillitt, Donald E.

    2007-01-01

    In a natural, unaltered river, the location and timing of sturgeon spawning will be dictated by the prevailing environmental conditions to which the sturgeon have adapted. A goal of the Comprehensive Sturgeon Research Program (CSRP; see chap. A) at the U.S. Geological Survey Columbia Environmental Research Center is to identify where, when, and under what conditions shovelnose sturgeon (Scaphirhynchus platorynchus) and pallid sturgeon (S. albus) spawn in the altered Missouri River so that those conditions necessary for spawning success can be defined. One approach to achieving this goal is to exploit what is known about fish reproductive physiology to develop and apply a suite of diagnostic indicators of readiness to spawn. In 2005 and 2006, gravid shovelnose sturgeon and a limited number of pallid sturgeon were fitted with transmitters and tracked on their spawning migration. A suite of physiological indicators of reproductive state such as reproductive hormones and oocyte development were measured. These same measurements were made on tissues collected from additional fish, presumably migrating to spawn, that were not tagged or tracked. The data presented here indicating the sturgeons’ readiness to spawn are to be evaluated together with their behavior and the environmental conditions. The U.S. Army Corps of Engineers (ACOE) Sturgeon Response to Flow Modification (SRFM; see chap. A) study, initiated in 2006, provides additional opportunities to experimentally evaluate the sturgeon reproductive response indicators relative to changes in flow. In this chapter, we report progress made on identifying and developing the physiological indicators and summarize 2 years’ worth of indicator data collected thus far.

  4. Radionuclide concentrations in white sturgeon from the Columbia River

    International Nuclear Information System (INIS)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1993-11-01

    The objectives of this study were to (1) review and summarize historical data on radionuclide concentrations in white sturgeon from the Columbia River, (2) determine present-day radionuclide tissue burdens from different locations in the Columbia River, and (3) compare historical data with current data. We first reviewed and summarized the historical literature on radionuclide concentrations in white sturgeon from the Hanford Reach. Field studies were then conducted to evaluate the relationship among sample locations, age/length of white sturgeon, and present radionuclide tissue burdens. Results and comparisons are discussed in the remainder of this report

  5. REFERENCED TECHNOLOGICAL PERFORMANCES FOR STURGEON FINGERLING BREEDING IN INTENSIVE SYSTEM

    Directory of Open Access Journals (Sweden)

    MARILENA TALPES

    2008-10-01

    Full Text Available Work objective is to present an oversight regarding the modality to rearing the descendents of anadromous sturgeon species, Acipenser stellatus, Acipenser gueldenstaedti and Huso huso, obtained trough artificial reproduction, indicating successively, the production system, its management, alimentation strategy for sturgeon species and technological performances registered by these. Experiments developed during two phases, respectively the post-embryonary one and sapling rearing during of a 168 days period. Registered performances of sturgeon species material were assessed in conformity with specifically biotechnological indicators.

  6. Factors affecting the reproduction, recruitment, habitat, and population dynamics of pallid sturgeon and shovelnose sturgeon in the Missouri River

    Science.gov (United States)

    Korschgen, Carl E.

    2007-01-01

    For more than a hundred years, human activities have modified the natural forces that control the Missouri River and its native fish fauna. While the ecological effects of regulation and channel engineering are understood in general, the current understanding is not sufficient to guide river restoration and management. The U.S. Geological Survey (USGS) is in the third year of a multiagency research effort to determine the ecological requirements for reproduction and survival of the endangered pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorhynchus) in the Missouri River. The multidisciplinary research strategy includes components of behavior, physiology, habitat use, habitat availability, and population modeling of all life stages. Shovelnose sturgeon are used to design the strategy because they are closely related to the pallid sturgeon and are often used as a surrogate species to develop new research tools or to examine the effects of management actions or environmental variables on sturgeon biology and habitat use. During fiscal years 2005 and 2006, the U.S. Army Corps of Engineers (USACE) provided funds to USGS for tasks associated with the Comprehensive Sturgeon Research Program (CSRP) and for tasks associated with evaluation of the Sturgeon Response to Flow Modifications (SRFM). Because work activities of CSRP and SRFM are so integrated, we are providing information on activities that have been consolidated at the task level. These task activities represent chapters in this report.

  7. Polyploidization facilitates biotechnological in vitro techniques in the genus Cucumis.

    Science.gov (United States)

    Skálová, Dagmar; Ondřej, Vladan; Doležalová, Ivana; Navrátilová, Božena; Lebeda, Aleš

    2010-01-01

    Prezygotic interspecific crossability barrier in the genus Cucumis is related to the ploidy level of the species (cucumber (C. sativus), x = 7; muskmelon (C. melo) and wild Cucumis species, x = 12). Polyploidization of maternal plants helps hybridization among other Cucumis species by overcoming prezygotic genetic barriers. The main objective of this paper is to compare the results of several methods supporting interspecific crosses in cucumber without and with polyploidization (comparison between diploid (2x) and mixoploid (2x/4x) cucumber maternal plants). Mixoploid plants were obtained after in vivo and in vitro polyploidization by colchicine and oryzalin. Ploidy level was estimated by flow cytometry. Embryo rescue, in vitro pollination, and isolation of mesophyll protoplast were tested and compared. Positive effect of polyploidization was observed during all experiments presented by higher regeneration capacity of cultivated mixoploid cucumber embryos, ovules, and protoplasts. Nevertheless, the hybrid character of putative hybrid accessions obtained after cross in vivo and in vitro pollination was not confirmed.

  8. Hepatocyte polyploidization and its association with pathophysiological processes

    OpenAIRE

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-01-01

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as ...

  9. Hepatocyte polyploidization and its association with pathophysiological processes.

    Science.gov (United States)

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-05-18

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as much as 90% of the hepatocytes in mice and 40% in humans. Hepatocyte polyploidization is generally considered an indicator of terminal differentiation and cellular senescence, and related to the dysfunction of insulin and p53/p21 signaling pathways. Interestingly, the high prevalence of hepatocyte polyploidization in the aged mouse liver can be reversed when the senescent hepatocytes are serially transplanted into young mouse livers. Here we review the current knowledge on the mechanism of hepatocytes polyploidization during postnatal growth, aging, and liver diseases. The biologic significance of polyploidization in senescent reversal, within the context of new ways to think of liver aging and liver diseases is considered.

  10. Adhesion signaling promotes protease‑driven polyploidization of glioblastoma cells.

    Science.gov (United States)

    Mercapide, Javier; Lorico, Aurelio

    2014-11-01

    An increase in ploidy (polyploidization) causes genomic instability in cancer. However, the determinants for the increased DNA content of cancer cells have not yet been fully elucidated. In the present study, we investigated whether adhesion induces polyploidization in human U87MG glioblastoma cells. For this purpose, we employed expression vectors that reported transcriptional activation by signaling networks implicated in cancer. Signaling activation induced by intercellular integrin binding elicited both extracellular signal‑regulated kinase (ERK) and Notch target transcription. Upon the prolonged activation of both ERK and Notch target transcription induced by integrin binding to adhesion protein, cell cultures accumulated polyploid cells, as determined by cell DNA content distribution analysis and the quantification of polynucleated cells. This linked the transcriptional activation induced by integrin adhesion to the increased frequency of polyploidization. Accordingly, the inhibition of signaling decreased the extent of polyploidization mediated by protease‑driven intracellular invasion. Therefore, the findings of this study indicate that integrin adhesion induces polyploidization through the stimulation of glioblastoma cell invasiveness.

  11. Molecular Tools for Exploring Polyploid Genomes in Plants

    Directory of Open Access Journals (Sweden)

    Domenico Carputo

    2012-08-01

    Full Text Available Polyploidy is a very common phenomenon in the plant kingdom, where even diploid species are often described as paleopolyploids. The polyploid condition may bring about several advantages compared to the diploid state. Polyploids often show phenotypes that are not present in their diploid progenitors or exceed the range of the contributing species. Some of these traits may play a role in heterosis or could favor adaptation to new ecological niches. Advances in genomics and sequencing technology may create unprecedented opportunities for discovering and monitoring the molecular effects of polyploidization. Through this review, we provide an overview of technologies and strategies that may allow an in-depth analysis of polyploid genomes. After introducing some basic aspects on the origin and genetics of polyploids, we highlight the main tools available for genome and gene expression analysis and summarize major findings. In the last part of this review, the implications of next generation sequencing are briefly discussed. The accumulation of knowledge on polyploid formation, maintenance, and divergence at whole-genome and subgenome levels will not only help plant biologists to understand how plants have evolved and diversified, but also assist plant breeders in designing new strategies for crop improvement.

  12. Effects of Exposure to the Sound from Seismic Airguns on Pallid Sturgeon and Paddlefish.

    Directory of Open Access Journals (Sweden)

    Arthur N Popper

    Full Text Available This study examined the effects of exposure to a single acoustic pulse from a seismic airgun array on caged endangered pallid sturgeon (Scaphirhynchus albus and on paddlefish (Polyodon spathula in Lake Sakakawea (North Dakota, USA. The experiment was designed to detect the onset of physiological responses including minor to mortal injuries. Experimental fish were held in cages as close as 1 to 3 m from the guns where peak negative sound pressure levels (Peak- SPL reached 231 dB re 1 μPa (205 dB re 1 μPa2·s sound exposure level [SEL]. Additional cages were placed at greater distances in an attempt to develop a dose-response relationship. Treatment and control fish were then monitored for seven days, euthanized, and necropsied to determine injuries. Necropsy results indicated that the probability of delayed mortality associated with pulse pressure following the seven day monitoring period was the same for exposed and control fish of both species. Exposure to a single pulse from a small air gun array (10,160 cm3 was not lethal for pallid sturgeon and paddlefish. However, the risks from exposure to multiple sounds and to sound exposure levels that exceed those reported here remain to be examined.

  13. Gulf sturgeon Critical Habitat Units 1-7

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent the critical habitat for Gulf Sturgeon as designated by Federal Register Vol. 68, No. 53, Wednesday, March 19, 2003, Rules and Regulations.

  14. White Sturgeon Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for WHITE STURGEON contained in the StreamNet database. This feature class was created based on linear...

  15. Biology and control of reproduction of sturgeons in fish farm

    OpenAIRE

    Billard, R.

    2000-01-01

    Over the last century the reproduction of sturgeon has been intensively studied par Russian scientists who established a technology for the ranching of alevins which included artificial fertilization of gametes taken from wild broodfish and larvae rearing. More recently, since 1970, major contributions originated from teams in the USA, the EU, Japan and Iran. A rather good knowledge of the reproductive physiology of sturgeon is now available: gametogenesis, reproductive cycle, ovulation, sper...

  16. Population Viability Analysis of the Endangered Shortnose Sturgeon

    Science.gov (United States)

    2011-12-01

    ll- 1 ) 0.0 0.2 0.4 0.6 0.8 Sturgeon ( left ) Prey ( right ) Figure 11. Model-simulated shortnose sturgeon population dynamics and prey dynamics over a...indicate low substrate diversity dominated by silt/sand substrate. ix ACRONYMS DO Dissolved oxygen DOC Dissolved organic carbon EFDC...fewer fish than the largest known population in the Hudson River ( Bain et al. 2007). Population estimates for this population have varied between 75

  17. Environmental contaminants in shortnose sturgeon from Bears Bluff National Fish Hatchery, Wadmalaw Island, South Carolina

    Data.gov (United States)

    Department of the Interior — The shortnose sturgeon (Acipenser brevirostrum) is a federally‐listed endangered species. In 2008, eleven shortnose sturgeon, reared at the Bears Bluff National Fish...

  18. Reconnecting fragmented sturgeon populations in North American rivers

    Science.gov (United States)

    Jager, Henriette; Parsley, Michael J.; Cech, Joseph J. Jr.; McLaughlin, R.L.; Forsythe, Patrick S.; Elliott, Robert S.

    2016-01-01

    The majority of large North American rivers are fragmented by dams that interrupt migrations of wide-ranging fishes like sturgeons. Reconnecting habitat is viewed as an important means of protecting sturgeon species in U.S. rivers because these species have lost between 5% and 60% of their historical ranges. Unfortunately, facilities designed to pass other fishes have rarely worked well for sturgeons. The most successful passage facilities were sized appropriately for sturgeons and accommodated bottom-oriented species. For upstream passage, facilities with large entrances, full-depth guidance systems, large lifts, or wide fishways without obstructions or tight turns worked well. However, facilitating upstream migration is only half the battle. Broader recovery for linked sturgeon populations requires safe “round-trip” passage involving multiple dams. The most successful downstream passage facilities included nature-like fishways, large canal bypasses, and bottom-draw sluice gates. We outline an adaptive approach to implementing passage that begins with temporary programs and structures and monitors success both at the scale of individual fish at individual dams and the scale of metapopulations in a river basin. The challenge will be to learn from past efforts and reconnect North American sturgeon populations in a way that promotes range expansion and facilitates population recovery.

  19. Detection of Adult Green Sturgeon Using Environmental DNA Analysis.

    Directory of Open Access Journals (Sweden)

    Paul S Bergman

    Full Text Available Environmental DNA (eDNA is an emerging sampling method that has been used successfully for detection of rare aquatic species. The Identification of sampling tools that are less stressful for target organisms has become increasingly important for rare and endangered species. A decline in abundance of the Southern Distinct Population Segment (DPS of North American Green Sturgeon located in California's Central Valley has led to its listing as Threatened under the Federal Endangered Species Act in 2006. While visual surveys of spawning Green Sturgeon in the Central Valley are effective at monitoring fish densities in concentrated pool habitats, results do not scale well to the watershed level, providing limited spatial and temporal context. Unlike most traditional survey methods, environmental DNA analysis provides a relatively quick, inexpensive tool that could efficiently monitor the presence and distribution of aquatic species. We positively identified Green Sturgeon DNA at two locations of known presence in the Sacramento River, proving that eDNA can be effective for monitoring the presence of adult sturgeon. While further study is needed to understand uncertainties of the sampling method, our study represents the first documented detection of Green Sturgeon eDNA, indicating that eDNA analysis could provide a new tool for monitoring Green Sturgeon distribution in the Central Valley, complimenting traditional on-going survey methods.

  20. E2F8 is essential for polyploidization in mammalian cells

    NARCIS (Netherlands)

    Pandit, Shusil K.; Westendorp, Bart; Nantasanti, Sathidpak; van Liere, Elsbeth; Tooten, Peter C. J.; Cornelissen, Peter W. A.; Toussaint, Mathilda J. M.; Lamers, Wouter H.; de Bruin, Alain

    2012-01-01

    Polyploidization is observed in all mammalian species and is a characteristic feature of hepatocytes, but its molecular mechanism and biological significance are unknown. Hepatocyte polyploidization in rodents occurs through incomplete cytokinesis, starts after weaning and increases with age. Here,

  1. MicroRNA-122 regulates polyploidization in the murine liver.

    Science.gov (United States)

    Hsu, Shu-Hao; Delgado, Evan R; Otero, P Anthony; Teng, Kun-Yu; Kutay, Huban; Meehan, Kolin M; Moroney, Justin B; Monga, Jappmann K; Hand, Nicholas J; Friedman, Joshua R; Ghoshal, Kalpana; Duncan, Andrew W

    2016-08-01

    A defining feature of the mammalian liver is polyploidy, a numerical change in the entire complement of chromosomes. The first step of polyploidization involves cell division with failed cytokinesis. Although polyploidy is common, affecting ∼90% of hepatocytes in mice and 50% in humans, the specialized role played by polyploid cells in liver homeostasis and disease remains poorly understood. The goal of this study was to identify novel signals that regulate polyploidization, and we focused on microRNAs (miRNAs). First, to test whether miRNAs could regulate hepatic polyploidy, we examined livers from Dicer1 liver-specific knockout mice, which are devoid of mature miRNAs. Loss of miRNAs resulted in a 3-fold reduction in binucleate hepatocytes, indicating that miRNAs regulate polyploidization. Second, we surveyed age-dependent expression of miRNAs in wild-type mice and identified a subset of miRNAs, including miR-122, that is differentially expressed at 2-3 weeks, a period when extensive polyploidization occurs. Next, we examined Mir122 knockout mice and observed profound, lifelong depletion of polyploid hepatocytes, proving that miR-122 is required for complete hepatic polyploidization. Moreover, the polyploidy defect in Mir122 knockout mice was ameliorated by adenovirus-mediated overexpression of miR-122, underscoring the critical role miR-122 plays in polyploidization. Finally, we identified direct targets of miR-122 (Cux1, Rhoa, Iqgap1, Mapre1, Nedd4l, and Slc25a34) that regulate cytokinesis. Inhibition of each target induced cytokinesis failure and promoted hepatic binucleation. Among the different signals that have been associated with hepatic polyploidy, miR-122 is the first liver-specific signal identified; our data demonstrate that miR-122 is both necessary and sufficient in liver polyploidization, and these studies will serve as the foundation for future work investigating miR-122 in liver maturation, homeostasis, and disease. (Hepatology 2016

  2. Columbia River White Sturgeon (Acipenser Transmontanus) Early Life History and Genertics Study, August 1, 1984 to December 31, 1985 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, Ernest L.

    1985-12-01

    Research on Columbia River white sturgeon has been directed at their early life history as it may apply to production and enhancement strategies for management of the species. The river environment in which sturgeon historically migrated, spawned, and reared has changed through development. Habitat changes are expected to precipitate genetic changes in the fish, as well as reduce the fitness in populations. Genetic analysis of samples taken from various locations over the length of the Columbia River have indicated that observed gene frequencies in all areas sampled were not in Hardy-Weinburg equilibrium, which could suggest that the general population is experiencing perturbation in the system. Analysis thus far has exposed few differences between samples from the lower, middle, and upper portions of the system. Allelic differences were identified in fish from the Roosevelt Lake, which may be evidence of unique characteristics among fish from that general area.

  3. Optimizing megakaryocyte polyploidization by targeting multiple pathways of cytokinesis.

    Science.gov (United States)

    Avanzi, Mauro P; Chen, Amanda; He, Wu; Mitchell, W Beau

    2012-11-01

    Large-scale in vitro production of platelets (PLTs) from cord blood stem cells is one goal of stem cell research. One step toward this goal will be to produce polyploid megakaryocytes capable of releasing high numbers of PLTs. Megakaryocyte polyploidization requires distinct cytoskeletal and cellular mechanisms, including actin polymerization, myosin activation, microtubule formation, and increased DNA production. In this study we variably combined inhibition of these principal mechanisms of cytokinesis with the goal of driving polyploidization in megakaryocytes. Megakaryocytes were derived from umbilical cord blood and cultured with reagents that inhibit distinct mechanisms of cytokinesis: Rho-Rock inhibitor (RRI), Src inhibitor (SI), nicotinamide (NIC), aurora B inhibitor (ABI), and myosin light chain kinase inhibitor (MLCKI). Combinations of reagents were used to determine their interactions and to maximize megakaryocyte ploidy. Treatment with RRI, NIC, SI, and ABI, but not with MLCKI, increased the final ploidy and RRI was the most effective single reagent. RRI and MLCKI, both inhibitors of MLC activation, resulted in opposite ploidy outcomes. Combinations of reagents also increased ploidy and the use of NIC, SI, and ABI was as effective as RRI alone. Addition of MLCKI to NIC, SI, and ABI reached the highest level of polyploidization. Megakaryocyte polyploidization results from modulation of a combination of distinct cytokinesis pathways. Reagents targeting distinct cytoskeletal pathways produced additive effects in final megakaryocyte ploidy. The RRI, however, showed no additive effect but produced a high final ploidy due to overlapping inhibition of multiple cytokinesis pathways. © 2012 American Association of Blood Banks.

  4. Polyploid response of Artemisia annua L. to colchicine treatment

    Science.gov (United States)

    Yunus, A.; Parjanto; Samanhudi; Hikam, M. P.; Widyastuti, Y.

    2018-03-01

    Artemisia (Artemisia annua) is a a medicinal herb originated from Asia, its contains Artemisinin for malaria (caused by Plasmodium falciparum) treatment. Artemisinin content in A. annua are relatively low, ranging from 0.01% -0.5%. In order to increase the Artemisinin content, polyploid induction could be one effort to be done. For that, this experiment aims to examine the effect of colchicine on morphological characteristics and the induction of polyploidization in Artemisia plants. Polyploid induction on Artemisia annua L. seeds was performed by soaking the Artemisia seeds in colchicine (0%, 0,05%, 0,1% and 0,2%; concentration based) for 2 hours. The experimental design was Completely Randomized Design, one factor, 4 colchicine treatments and in each treatment 7 replicate. The results showed that polyploid occur in plants treated with 0.05% colchicine concentration and its morphological characteristic are 89.4 cm height, 30 branches, 15.9 CCI chlorophyll content, 0.78 cm stem diameter, and chromosome number 2n = 27. In the stomata density of polyploid plants (treated by 0.05% colchicine) was 130 number/mm2 with stomata diameter of 22.8 μm.

  5. Induced polyploidization in Brassica campestris L. (Brassicaceae).

    Science.gov (United States)

    Kumar, G; Dwivedi, K

    2014-01-01

    Present experimental design has been made up to obtain crop with higher ploidy level via synthetic polyploidization. Since ploidy manipulation is generally associated with the obtainment of some increased enviable traits of the crop and also provides them greater adaptability to unfavorable or harsh circumstances as compared to its diploids counterparts. Thus, herein present research autotetraploids of Brassica campestris L. have been lucratively achieved by the application of colchicine. Two methods of treatment were utilized i.e. seed treatment and seedling treatment. No polyploidy could be obtained through seed treatment while seedling treatment responded well towards polyploidy. However, the status of autotetraploidy has been confirmed by cytomorphological investigations of treated plants as against its diploids counterparts. For the purpose, morphological parameters such as increased stomata size, pollen diameter, flower size, reproductive organs whereas reduction in plant height, leaf length, leaf breadth, stomata frequency, number of flowers/inflorescence etc. were appraised. Further, cytological observations were made that had clearly revealed the doubling of genome in the autotetraploids as compared to diploids. Meanwhile, pollen fertility and size of pollen grains were evaluated as well.

  6. Megakaryocyte Polyploidization and Proplatelet Formation in Low-Attachment Conditions.

    Science.gov (United States)

    Schlinker, Alaina C; Duncan, Mark T; DeLuca, Teresa A; Whitehead, David C; Miller, William M

    2016-07-15

    In vitro -derived platelets (PLTs), which could provide an alternative source of PLTs for patient transfusions, are formed from polyploid megakaryocytes (MKs) that extend long cytoplasmic projections, termed proplatelets (proPLTs). In this study, we compared polyploidization and proPLT formation (PPF) of MKs cultured on surfaces that either promote or inhibit protein adsorption and subsequent cell adhesion. A megakaryoblastic cell line exhibited increased polyploidization and arrested PPF on a low-attachment surface. Primary human MKs also showed low levels of PPF on the same surface, but no difference in ploidy. Importantly, both cell types exhibited accelerated PPF after transfer to a surface that supports attachment, suggesting that pre-culture on a non-adhesive surface may facilitate synchronization of PPF and PLT generation in culture.

  7. The pallid sturgeon: Scientific investigations help understand recovery needs

    Science.gov (United States)

    DeLonay, Aaron J.

    2010-01-01

    Understanding of the pallid sturgeon (Scaphirhynchus albus) has increased significantly since the species was listed as endangered over two decades ago. Since 2005, scientists at the U.S. Geological Survey (USGS) Columbia Environmental Research Center (CERC) have been engaged in an interdisciplinary research program in cooperation with the U.S. Army Corps of Engineers Missouri River Recovery Program, U.S. Fish and Wildlife Service, Nebraska Game and Parks Commission, and numerous other State and Federal cooperators to provide managers and policy makers with the knowledge needed to evaluate recovery options. During that time, the USGS has worked collaboratively with river scientists and managers to develop methods, baseline information, and research approaches that are critical contributions to recovery success. The pallid sturgeon is endangered throughout the Missouri River because of insufficient reproduction and survival of early life stages. Primary management actions on the Missouri River designed to increase reproductive success and survival have focused on flow regime, channel morphology, and propagation. The CERC research strategies have, therefore, been designed to examine the linkages among flow regime, re-engineered channel morphology, and reproductive success and survival. Specific research objectives include the following: (1) understanding reproductive physiology of pallid sturgeon and relations to environmental conditions; (2) determining movement, habitat use, and reproductive behavior of pallid sturgeon; and (3) quantifying availability and dynamics of aquatic habitats needed by pallid sturgeon for all life stages.

  8. The origin and migration of primordial germ cells in sturgeons.

    Directory of Open Access Journals (Sweden)

    Taiju Saito

    Full Text Available Primordial germ cells (PGCs arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts.

  9. Management applications of genetic structure of anadromous sturgeon populations in the Lower Danube River (LDR, Romania

    Directory of Open Access Journals (Sweden)

    ONĂRĂ Dalia Florentina

    2013-12-01

    Full Text Available During the last decades, the over-exploitation of sturgeon stocks for caviar production simultaneously with severe habitat deteriorations has led to drastic declines in the natural populations of the Danube River. As a result of (i decrease of sturgeon catches from 37.5 tons in year 2002 to 11.8 tons in year 2005, (ii disrupted age class structure of sturgeon adult cohorts in years 2003 and 2004, and (iii lack or low recruitment in the period 2001 – 2004, in 2005 the Romanian Government started the Supportive Stocking Program of Lower Danube River with hatchery-produced young sturgeons in Romania. Subsequently, in 2006 the commercial sturgeon fishing in Romania was banned for a 10-year period. Genetic investigations were undertaken as an attempt to assess the genetic variability of the sturgeon brood fish, captured from the wild, used in two aquaculture facilities in Romania for obtaining juveniles for supportive stocking of LDR with young sturgeons produced by artificial propagation in year 2007. Our data indicate strong genetic diversity in case of stellate sturgeon and lack of diversity within the batch of beluga sturgeon brood fish captured in 2007, analyzed in the current study. Specific measures that could improve the management plan of sturgeon brood fish in the Romanian part of LDR in the light of recent FAO guidelines regarding the sturgeon hatchery practices and management for release were suggested

  10. Development of polysomic microsatellite markers for characterization of population structuring and phylogeography in the shortnose sturgeon (Acipenser brevirostrum)

    Science.gov (United States)

    Henderson, Anne P.; King, Tim L.

    2012-01-01

    Shortnose sturgeon Acipenser brevirostrum is an endangered polyploid fish species for which no nuclear DNA markers previously existed. To address this need, 86 polysomic loci were developed and characterized in 20 A. brevirostrum from five river systems and eight members (parents and six progeny) of a captive-bred family. All markers proved to be polymorphic, polysomic, and demonstrated direct inheritance when tested in a captive family. Eleven loci were included in a range-wide survey of 561 fish sampled from 17 geographic collections. Allelic diversity at these markers ranged from 7 to 24 alleles/locus and averaged 16.5 alleles/locus; sufficient diversity to produce unique multilocus genotypes. In the range-wide survey, a Mantel comparison of an ecological (1-Jaccard’s) and genetic (ΦPT; an analog to FST) distance metrics, identified a strong positive correlation (r = 0.98, P PT represents a viable metric for assessing genetic relatedness using this class of marker.

  11. Polyploidization of glia in neural development links tissue growth to blood-brain barrier integrity.

    Science.gov (United States)

    Unhavaithaya, Yingdee; Orr-Weaver, Terry L

    2012-01-01

    Proper development requires coordination in growth of the cell types composing an organ. Many plant and animal cells are polyploid, but how these polyploid tissues contribute to organ growth is not well understood. We found the Drosophila melanogaster subperineurial glia (SPG) to be polyploid, and ploidy is coordinated with brain mass. Inhibition of SPG polyploidy caused rupture of the septate junctions necessary for the blood-brain barrier. Thus, the increased SPG cell size resulting from polyploidization is required to maintain the SPG envelope surrounding the growing brain. Polyploidization likely is a conserved strategy to coordinate tissue growth during organogenesis, with potential vertebrate examples.

  12. Liver physiological polyploidization: MicroRNA-122 a key regulator.

    Science.gov (United States)

    Celton-Morizur, Séverine; Desdouets, Chantal

    2017-03-01

    Polyploidy is defined as an increase in genome DNA content and is observed in all mammalian species. Polyploidy is a common characteristic of hepatocytes. Polyploidization occurs mainly during liver development, but also in adults with increasing age or due to cellular stress. During liver development, hepatocytes polyploidization occurs through cytokinesis failure leading to the genesis of binucleate hepatocytes. Recently, Hsu et al. demonstrated that miR-122 is a key regulator of hepatic binucleation. In fact, during liver development, miR-122 directly antagonizes procytokinesis targets and thus induces cytokinesis failure leading to the genesis of binucleate hepatocytes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Features oxidative processes in sturgeons fish (Acipenseridae (review

    Directory of Open Access Journals (Sweden)

    M. Symon

    2016-12-01

    Full Text Available Purpose. To anayze scientific sources on physiological-biochemical pecularities of reducing-oxidizing processes, including peroxide oxidation of lipids and work of the system of antioxidant protection system in sturgeon species (Acipenseridae. The initiation and process of the oxidative stress have been described. The main products of peroxide oxidation of lipids, antioxidants of natural and artificial origin, organs and tissues for the studies of reducing-oxidizing processes have been examined. Findings. The work generalizes the processes of lipid peroxidation. Briefly outlined the main mechanism of action of antioxidant enzymes. Antioxidant defense system plays one of key role in the life of organism due regulating its series of metabolic processes, use of assessing of its state gives an opportunity obtain quantitative information on the progress of these processes. The products of free radical peroxidation (dien conjugates and malonic dialdehyde can also act as a sort of biomarkers of tissue damage, because their content can judge about the intensity of the flow of free radical processes in the various systems in organism. The review contains a description of the peculiarities of the liver and its involvement in lipid metabolism and antioxidant defense system. It is shown the most common antioxidants used in the feeding of sturgeon. Organs and tissues, which should be used for studying the processes of peroxide oxidation of lipids in sturgeon species, have been examined. Practical value. The systematized data regarding peroxide oxidation of lipids, oxidative stress and antioxidant protection system allow finding a balance between these processes. The data on antioxidants, which are used in feeds for sturgeon species, will be useful for sturgeon culturists. The array of the generalized information will be important for scientists who study the pecularities of the processes of peroxide oxidation of lipids and antioxidant protection system in

  14. Phylogenetic evidence for cladogenetic polyploidization in land plants.

    Science.gov (United States)

    Zhan, Shing H; Drori, Michal; Goldberg, Emma E; Otto, Sarah P; Mayrose, Itay

    2016-07-01

    Polyploidization is a common and recurring phenomenon in plants and is often thought to be a mechanism of "instant speciation". Whether polyploidization is associated with the formation of new species (cladogenesis) or simply occurs over time within a lineage (anagenesis), however, has never been assessed systematically. We tested this hypothesis using phylogenetic and karyotypic information from 235 plant genera (mostly angiosperms). We first constructed a large database of combined sequence and chromosome number data sets using an automated procedure. We then applied likelihood models (ClaSSE) that estimate the degree of synchronization between polyploidization and speciation events in maximum likelihood and Bayesian frameworks. Our maximum likelihood analysis indicated that 35 genera supported a model that includes cladogenetic transitions over a model with only anagenetic transitions, whereas three genera supported a model that incorporates anagenetic transitions over one with only cladogenetic transitions. Furthermore, the Bayesian analysis supported a preponderance of cladogenetic change in four genera but did not support a preponderance of anagenetic change in any genus. Overall, these phylogenetic analyses provide the first broad confirmation that polyploidization is temporally associated with speciation events, suggesting that it is indeed a major speciation mechanism in plants, at least in some genera. © 2016 Botanical Society of America.

  15. Whole-body γ-irradiation decelerates rat hepatocyte polyploidization.

    Science.gov (United States)

    Ikhtiar, Adnan M

    2015-07-01

    To characterize hepatocyte polyploidization induced by intermediate dose of γ-ray. Male Wistar strain rats were whole-body irradiated (WBI) with 2 Gy of γ-ray at the age of 1 month, and 5-6 rats were sacrificed monthly at 0-25 months after irradiation. The nuclear DNA content of individual hepatocytes was measured by flow cytometry, then hepatocytes were classified into various ploidy classes. Survival percentage, after exposure up to the end of the study, did not indicate any differences between the irradiated groups and controls. The degree of polyploidization in hepatocytes of irradiated rats, was significantly lower than that for the control after 1 month of exposure, and it continued to be lower after up to 8 months. Thereafter, the degree of polyploidization in the irradiated group slowly returned to the control level when the irradiated rats reached the age of 10 months. Intermediate dose of ionizing radiation, in contrast to high doses, decelerate hepatocyte polyploidization, which may coincides with the hypothesis of the beneficial effects of low doses of ionizing radiation.

  16. Dietary regulation of hypodermal polyploidization in C. elegans

    Directory of Open Access Journals (Sweden)

    Lozano Encarnación

    2008-03-01

    Full Text Available Abstract Background Dietary restriction (DR results in increased longevity, reduced fecundity and reduced growth in many organisms. Though many studies have examined the effects of DR on longevity and fecundity, few have investigated the effects on growth. Results Here we use Caenorhabditis elegans to determine the mechanisms that regulate growth under DR. We show that rather than a reduction in cell number, decreased growth in wild type C. elegans under DR is correlated with lower levels of hypodermal polyploidization. We also show that mutants lacking wild type sensory ciliated neurons are small, exhibit hypo-polyploidization and more importantly, when grown under DR, reduce their levels of endoreduplication to a lesser extent than wild type, suggesting that these neurons are required for the regulation of hypodermal polyploidization in response to DR. Similarly, we also show that the cGMP-dependent protein kinase EGL-4 and the SMA/MAB signalling pathway regulate polyploidization under DR. Conclusion We show C. elegans is capable of actively responding to food levels to regulate adult ploidy. We suggest this response is dependent on the SMA/MAB signalling pathway.

  17. Dietary regulation of hypodermal polyploidization in C. elegans.

    Science.gov (United States)

    Tain, Luke S; Lozano, Encarnación; Sáez, Alberto G; Leroi, Armand M

    2008-03-12

    Dietary restriction (DR) results in increased longevity, reduced fecundity and reduced growth in many organisms. Though many studies have examined the effects of DR on longevity and fecundity, few have investigated the effects on growth. Here we use Caenorhabditis elegans to determine the mechanisms that regulate growth under DR. We show that rather than a reduction in cell number, decreased growth in wild type C. elegans under DR is correlated with lower levels of hypodermal polyploidization. We also show that mutants lacking wild type sensory ciliated neurons are small, exhibit hypo-polyploidization and more importantly, when grown under DR, reduce their levels of endoreduplication to a lesser extent than wild type, suggesting that these neurons are required for the regulation of hypodermal polyploidization in response to DR. Similarly, we also show that the cGMP-dependent protein kinase EGL-4 and the SMA/MAB signalling pathway regulate polyploidization under DR. We show C. elegans is capable of actively responding to food levels to regulate adult ploidy. We suggest this response is dependent on the SMA/MAB signalling pathway.

  18. Production of polyploids from cultured shoot tips of Eucalyptus ...

    African Journals Online (AJOL)

    Polyploids from cultured shoot tips of Eucalyptus globulus were produced by treatment with colchicine. Results showed that the combination of 0.5% colchicine and treating multiple shoot clumps for 4 days was the most appropriate conditions for E. globulus polyploidy induction and the effect of the use of multiple shoot ...

  19. Growth, food consumption, and energy status of juvenile pallid sturgeon fed natural or artificial diets

    Science.gov (United States)

    Meyer, Hilary A.; Chipps, Steven R.; Graeb, Brian D. S.; Klumb, Robert A.

    2016-01-01

    Stocking of hatchery-raised fish is an important part of the pallid sturgeon Scaphirhynchus albus recovery program. In the wild, juvenile pallid sturgeon consume primarily aquatic insects, although little is known about specific dietary needs. In hatchery settings, pallid sturgeon are fed commercial diets that are formulated for salmonids. To compare food consumption, growth, and energy status of pallid sturgeon fed artificial or natural diets, we conducted a laboratory study using 24 juvenile pallid sturgeon (initial fork length 153–236 mm). Pallid sturgeon were fed a daily ration of either commercial pellets (1 mm, slow sinking; 45% protein, 19% fat) or chironomid larvae for 5 wk. Natural-fed pallid sturgeon exhibited a greater specific growth rate (2.12% d−1) than pellet-fed fish (0.06% d−1). Similarly, relative condition was greater for natural-fed sturgeon (Kn = 1.11) than that observed for pellet-fed fish (Kn = 0.87). In contrast, the hepatosomatic index was significantly higher in pellet-fed fish (2.5%), indicating a high lipid diet compared with natural-fed sturgeon (1.4%). Given the importance of natural diets to fish digestion and growth, it is suggested that a more holistic approach be applied in the development of a practical diet for pallid sturgeon that incorporates attributes of natural prey.

  20. Annual variation of hematology and plasma chemistry in shortnose sturgeon, Acipenser brevirostrum, during a dam-impeded spawning run.

    Science.gov (United States)

    Matsche, Mark A; Gibbons, Jarrett

    2012-12-01

    Shortnose sturgeon (Acipenser brevirostrum) spawning migrations on the Cooper River are impeded by Pinopolis Dam, Lake Moultrie, South Carolina. Sturgeon and other species aggregate below the dam in late winter/early spring and are subjected to a variety of stressors stemming from crowding, poor habitat quality, and injuries that appear to be caused by boat propeller or turbine strikes. Spawning has been documented in the tailrace, but reproductive success has not been verified as no juveniles have been captured. Fish within the dam tailrace were captured by gill net during winter, 2005 and 2007-2011, and physiological condition was assessed using a panel of hematologic and biochemical indices. Plasma phosphorus and calcium were significantly higher in females, while PCV and aspartate aminotransferase were significantly higher in males, indicating sex-specific physiological changes triggered during maturity. A marked leucopenia, accompanied by lymphopenia and neutrophilia, was evident in both sexes and was consistent across years, indicating that these fish were under chronic stress. Testosterone and estradiol levels and hematologic and biochemical reference intervals are provided for comparative purposes.

  1. TO THE ISSUE OF PRESERVATION AND RESTORATION OF STURGEON STOCKS IN THE VOLGA-CASPIAN BASIN

    Directory of Open Access Journals (Sweden)

    L. M. Vasilieva

    2012-01-01

    Full Text Available It is shown that for the preservation and restoration of natural sturgeon populations it is necessary to increase the eff iciency of reproduction, both natural and artificial Article determines the crucial role of artificial reproduction of sturgeon at the present stage to keep the gene pool of these valuable fish species and restoration of biological resources for commercial fishing.The article contains a set of measures for the conservation, restoration and rational use of natural resources of sturgeon.

  2. Toxicity assessment of silver nanoparticles in Persian sturgeon (Acipenser persicus) and starry sturgeon (Acipenser stellatus) during early life stages.

    Science.gov (United States)

    Banan, Ashkan; Kalbassi Masjed Shahi, Mohammad Reza; Bahmani, Mahmoud; Yazdani Sadati, Mohammad Ali

    2016-05-01

    Silver nanoparticles (AgNPs) are widely used in consumer products mainly due to their antimicrobial action. The rapidly increasing use of nanoparticles (NPs) has driven more attention to their possible ecotoxicological effects. In this study, the acute toxicity of colloidal AgNPs was evaluated during the embryonic stage of Persian sturgeon (Acipenser persicus) and starry sturgeon (Acipenser stellatus) at concentrations of 0, 0.25, 0.5, 1, 2, 4, and 8 mg/L. Fertilized eggs (75 eggs per replicate) were exposed to aforementioned concentrations for 96 h in triplicate. 96-h LC50 values in Persian sturgeon and starry sturgeon were calculated as 0.163 and 0.158 mg/L, respectively. Furthermore, in starry sturgeon, the short-term effects of AgNPs on the hatching rate, survival rate, and Ag accumulation during early life stages (before active feeding commences) were also analyzed at concentrations of 0, 0.025, 0.05, and 0.1 mg/L of colloidal AgNPs. The highest silver accumulation occurred in larvae exposed to 0.1 mg/L AgNPs; however, the body burden of silver did not alter survival rate, and there were no significant differences among treatments. Based on the obtained results from the acute toxicity exposures, AgNPs induced a concentration-dependent toxicity in both species during early life stages, while complementary studies are suggested for investigating their short-term effects in detail.

  3. Megakaryocyte polyploidization is associated with decreased expression of polo-like kinase (PLK).

    Science.gov (United States)

    Yagi, M; Roth, G J

    2006-09-01

    During differentiation, megakaryocytes (MK), the bone marrow precursors of circulating blood platelets, undergo polyploidization, repeated rounds of DNA replication without cell division. Mature normal MK may contain a DNA content of up to 128N, in contrast to normal diploid (2N) cells. The extent of polyploidy may influence the number of platelets produced by the MK. Therefore, understanding the molecular mechanisms regulating polyploidization could identify events involved in controlling both cell division and thrombopoiesis. We investigated the expression of several proteins involved in mitosis in cultured mouse MK, and tested the effect of expression on polyploidization. Western blot and immunofluorescent analyses were used to assess expression of cell cycle proteins in cultured MK. Populations of polyploidizing MK were separated on the basis of DNA content by flow cytometry. The gene encoding mouse polo-like kinase 1 (PLK-1) was introduced into MK by retroviral transduction, and its effects measured by flow cytometry. Polyploid mouse MK expressed lower levels of two proteins, p55CDC and PLK-1, whose activity is necessary for cell cycle progression and completion of mitosis. Comparison of sorted 2N/4N and polyploid MK indicated that PLK-1 expression was absent in polyploid MK, while expression of other cell cycle proteins was similar in both populations. Forced expression of PLK-1 during MK differentiation was associated with decreased polyploidization. These experiments suggest that PLK-1 is an important regulator of polyploidization in differentiating MK.

  4. E2F8 is essential for polyploidization in mammalian cells.

    Science.gov (United States)

    Pandit, Shusil K; Westendorp, Bart; Nantasanti, Sathidpak; van Liere, Elsbeth; Tooten, Peter C J; Cornelissen, Peter W A; Toussaint, Mathilda J M; Lamers, Wouter H; de Bruin, Alain

    2012-11-01

    Polyploidization is observed in all mammalian species and is a characteristic feature of hepatocytes, but its molecular mechanism and biological significance are unknown. Hepatocyte polyploidization in rodents occurs through incomplete cytokinesis, starts after weaning and increases with age. Here, we show in mice that atypical E2F8 is induced after weaning and required for hepatocyte binucleation and polyploidization. A deficiency in E2f8 led to an increase in the expression level of E2F target genes promoting cytokinesis and thereby preventing polyploidization. In contrast, loss of E2f1 enhanced polyploidization and suppressed the polyploidization defect of hepatocytes deficient for atypical E2Fs. In addition, E2F8 and E2F1 were found on the same subset of target promoters. Contrary to the long-standing hypothesis that polyploidization indicates terminal differentiation and senescence, we show that prevention of polyploidization through inactivation of atypical E2Fs has, surprisingly, no impact on liver differentiation, zonation, metabolism and regeneration. Together, these results identify E2F8 as a repressor and E2F1 as an activator of a transcriptional network controlling polyploidization in mammalian cells.

  5. The functional relevance of polyploidization in the skin.

    Science.gov (United States)

    Trakala, Marianna; Malumbres, Marcos

    2014-02-01

    Cell proliferation and differentiation are tightly coupled through the regulation of the cell division cycle. To preserve specific functional properties in differentiated cells, distinct variants of the basic mitotic cell cycle are used in various mammalian tissues, leading to the formation of polyploid cells. In this issue of Experimental Dermatology, Gandarillas and Freije discuss the evidences for polyploidization in keratinocytes, a process whose physiological relevance is now becoming evident. A better evaluation of these unconventional cell cycles is required not only to improve our understanding of the development and structure of the epidermis but also for future therapies against skin diseases. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Evolutionarily advanced ant farmers rear polyploid fungal crops

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Aanen, D.K.; Schiøtt, Morten

    2015-01-01

    to be lowly and facultatively polyploid (just over two haplotypes on average), whereas Atta and Acromyrmex symbionts are highly and obligatorily polyploid (ca. 5-7 haplotypes on average). This stepwise transition appears analogous to ploidy variation in plants and fungi domesticated by humans and in fungi...... the number of nuclei per fungal cell for 42 symbionts reared by 14 species of Panamanian fungus-growing ants. This showed that domesticated symbionts of higher attine ants are polykaryotic with 7-17 nuclei per cell, whereas nonspecialized crops of lower attines are dikaryotic similar to most free...... domesticated by termites and plants, where gene or genome duplications were typically associated with selection for higher productivity, but allopolyploid chimerism was incompatible with sexual reproduction....

  7. Comparative transmission genetics of introgressed chromatin in Gossypium (cotton) polyploids.

    Science.gov (United States)

    Waghmare, Vijay N; Rong, Junkang; Rogers, Carl J; Bowers, John E; Chee, Peng W; Gannaway, John R; Katageri, Ishwarappa; Paterson, Andrew H

    2016-04-01

    Introgression is widely acknowledged as a potential source of valuable genetic variation, and growing effort is being invested in analysis of interspecific crosses conferring transgressive variation. Experimental backcross populations provide an opportunity to study transmission genetics following interspecific hybridization, identifying opportunities and constraints to introgressive crop improvement. The evolutionary consequences of introgression have been addressed at the theoretical level, however, issues related to levels and patterns of introgression among (plant) species remain inadequately explored, including such factors as polyploidization, subgenome interaction inhabiting a common nucleus, and the genomic distribution and linkage relationships of introgressant alleles. We analyze introgression into the polyploid Gossypium hirsutum (upland cotton) from its sister G. tomentosum and compare the level and pattern with that of G. barbadense representing a different clade tracing to the same polyploidization. Across the genome, recurrent backcrossing to Gossypium hirsutum yielded only one-third of the expected average frequency of the G. tomentosum allele, although one unusual region showed preferential introgression. Although a similar rate of introgression is found in the two subgenomes of polyploid (AtDt) G. hirsutum, a preponderance of multilocus interactions were largely within the Dt subgenome. Skewed G. tomentosum chromatin transmission is polymorphic among two elite G. hirsutum genotypes, which suggests that genetic background may profoundly affect introgression of particular chromosomal regions. Only limited correspondence is found between G. hirsutum chromosomal regions that are intolerant to introgression from the two species, G. barbadense and G. tomentosum, concentrated near possible inversion polymorphisms. Complex transmission of introgressed chromatin highlights the challenges to utilization of exotic germplasm in crop improvement. © 2016

  8. Docetaxel-induced polyploidization may underlie chemoresistance and disease relapse.

    Science.gov (United States)

    Ogden, Angela; Rida, Padmashree C G; Knudsen, Beatrice S; Kucuk, Omer; Aneja, Ritu

    2015-10-28

    Although docetaxel significantly improves survival in a variety of malignancies, its clinical utility is severely restricted by acquired chemoresistance and disease relapse. To uncover the mechanisms underlying these all too common occurrences, an abundance of research has focused on mutations and gene expression patterns; however, these findings are yet to translate into improved outcomes for patients being administered this drug. These analyses have overlooked a promising lead in the quest to discern key mediators of resistance and relapse following docetaxel therapy: polyploidization. This process is manifested following docetaxel-mediated mitotic arrest by the appearance of giant, multinucleated cells, which slipped from mitosis without undergoing cytokinesis. Polyploid cells generally possess supernumerary centrosomes, are chromosomally instable, and resist chemotherapy. We thus suspect that chemoresistance and relapse following treatment with docetaxel might be combatted by co-administration of centrosome declustering drugs, which could selectively destroy polyploid cells given that normal cells do not possess amplified centrosomes, an intriguing paradigm that warrants further investigation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. A criticism of the value of midparent in polyploidization.

    Science.gov (United States)

    Gianinetti, A

    2013-11-01

    The hypothesis of genetic additivity states that the effects of different alleles, or different genes, add up to produce the phenotype. When considering the F1 progeny of a cross, the hypothesis of additivity of the genetic dosages provided by the parents is tested against the mid-parent value (MPV), which is the average of parental phenotypes and represents the reference value for genetic additivity. Non-additive effects (genetic interactions) are typically measured as deviations from MPV. Recently, however, the use of MPV has been directly transposed to the study of genetic additivity in newly synthesized plant polyploids, assuming that they should as well display mid-parent expression patterns for additive traits. It is shown here that this direct transposition is incorrect. It is suggested that, in neo-polyploids, mid-parent expression has to be reconsidered in terms of reduced genetic additivity. Homeostatic mechanisms are deemed to be the obvious ones responsible for this effect. Genomes are therefore ruled by negative epistasis, and heterosis in allopolyploids is due to a decreased interaction of the parental repressive systems. It is contended that focalizing on the right perspective has relevant theoretical consequences and makes the studies of neo-polyploids very important for our understanding of how genomes work.

  10. Hepatocytes polyploidization and cell cycle control in liver physiopathology.

    Science.gov (United States)

    Gentric, Géraldine; Desdouets, Chantal; Celton-Morizur, Séverine

    2012-01-01

    Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of "diploid-polyploid conversion" during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels), oxidative stress, toxic insult, and chronic hepatitis etc.). Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.

  11. Sexual polyploidization in plants--cytological mechanisms and molecular regulation.

    Science.gov (United States)

    De Storme, Nico; Geelen, Danny

    2013-05-01

    In the plant kingdom, events of whole genome duplication or polyploidization are generally believed to occur via alterations of the sexual reproduction process. Thereby, diploid pollen and eggs are formed that contain the somatic number of chromosomes rather than the gametophytic number. By participating in fertilization, these so-called 2n gametes generate polyploid offspring and therefore constitute the basis for the establishment of polyploidy in plants. In addition, diplogamete formation, through meiotic restitution, is an essential component of apomixis and also serves as an important mechanism for the restoration of F1 hybrid fertility. Characterization of the cytological mechanisms and molecular factors underlying 2n gamete formation is therefore not only relevant for basic plant biology and evolution, but may also provide valuable cues for agricultural and biotechnological applications (e.g. reverse breeding, clonal seeds). Recent data have provided novel insights into the process of 2n pollen and egg formation and have revealed multiple means to the same end. Here, we summarize the cytological mechanisms and molecular regulatory networks underlying 2n gamete formation, and outline important mitotic and meiotic processes involved in the ectopic induction of sexual polyploidization. © 2013 Ghent University. New Phytologist © 2013 New Phytologist Trust.

  12. Hepatocytes Polyploidization and Cell Cycle Control in Liver Physiopathology

    Directory of Open Access Journals (Sweden)

    Géraldine Gentric

    2012-01-01

    Full Text Available Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of “diploid-polyploid conversion” during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels, oxidative stress, toxic insult, and chronic hepatitis etc.. Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.

  13. Project overview: Chapter A in Factors affecting the reproduction, recruitment, habitat, and population dynamics of pallid sturgeon and shovelnose sturgeon in the Missouri River

    Science.gov (United States)

    DeLonay, Aaron J.; Papoulias, Diana M.; Jacobson, Robert B.; Wildhaber, Mark L.; Simpkins, Darin G.; Korschgen, Carl E.

    2007-01-01

    For more than a hundred years, human activities have modified the natural forces that control the Missouri River and its native fish fauna. While the ecological effects of regulation and channel engineering are understood in general, the current understanding is not sufficient to guide river restoration and management. The U.S. Geological Survey (USGS) is in the third year of a multiagency research effort to determine the ecological requirements for reproduction and survival of the endangered pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorhynchus) in the Missouri River. The multidisciplinary research strategy includes components of behavior, physiology, habitat use, habitat availability, and population modeling of all life stages. Shovelnose sturgeon are used to design the strategy because they are closely related to the pallid sturgeon and are often used as a surrogate species to develop new research tools or to examine the effects of management actions or environmental variables on sturgeon biology and habitat use. During fiscal years 2005 and 2006, the U.S. Army Corps of Engineers (USACE) provided funds to USGS for tasks associated with the Comprehensive Sturgeon Research Program (CSRP) and for tasks associated with evaluation of the Sturgeon Response to Flow Modifications (SRFM). Because work activities of CSRP and SRFM are so integrated, we are providing information on activities that have been consolidated at the task level. These task activities represent chapters in this report.

  14. Heavy metal bio-accumulation in tissues of sturgeon species of the Lower Danube River, Romania

    Directory of Open Access Journals (Sweden)

    ONĂRĂ Dalia Florentina

    2013-12-01

    Full Text Available This study investigates bio-accumulation of heavy metals in tissues of sturgeons of the North-Western Black Sea and Lower Danube River (LDR. Samples (10 – 30 gr of liver, muscle, fat, gonads and skin tissues collected in October 2003 from 21 adult specimens of three sturgeon species: Acipenser stellatus (10, A. gueldenstaedtii (2, and Huso huso (9 were analysed for content in Cd, Cu, Zn, Pb, Mn, Fe and Ni, using VARIAN Spectra A100. The highest concentrations of Zn, Cu and Cd were found in liver and the smallest in muscles of sturgeons. The highest heavy metal content was detected in tissues of stellate sturgeons, followed by Russian sturgeons. In all three species Cd and Cu content of the liver as well as of the stellate sturgeon muscle surpassed the admitted limits for human consumption (Cd – 0.05; Zn - 50; Cu – 5.0; Pb – 0.3 [mg / kg wet weight]. In view of a future re-opening of the commercial fishing of wild sturgeons it is strongly recommended testing the heavy metal level prior delivering sturgeon products to the market. Avoiding human consumption of liver of sturgeons captured in the LDR is strongly recommended as well. In the case of Cd a bio-accumulation with age of sturgeons was visible. In all species males seem to accumulate more heavy metals in their tissues. We explain this as effect of more frequent spawning migration of males in the LDR, the major contamination source. Beluga sturgeons show less heavy metal bio-accumulation of tissues.

  15. Radionuclide concentrations in white sturgeon from the Columbia River

    International Nuclear Information System (INIS)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1992-09-01

    Although radioactive releases from the US Department of Energy's Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River

  16. Radionuclide concentrations in white sturgeon from the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1992-09-01

    Although radioactive releases from the US Department of Energy`s Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River.

  17. Radionuclide concentrations in white sturgeon from the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1992-09-01

    Although radioactive releases from the US Department of Energy's Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River.

  18. The Relationship Between Acoustic Target Strength and Body Length for Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus)

    Science.gov (United States)

    2010-10-01

    sturgeon feeding portray them as opportunistic benthivores, feeding primar- ily on mollusks, polychaete worms, amphipods, isopods, shrimp and small bottom...dwelling fishes and insect larvae (Gilbert 1989; Smith 1985). The Atlantic sturgeon is anadromous, entering freshwater rivers to spawn at water...bottom (small rubble, gravel, hard clay, and limestone) is required for successful egg attachment and incubation, while also protecting larvae from

  19. 75 FR 53598 - Endangered and Threatened Wildlife and Plants; Threatened Status for Shovelnose Sturgeon Under...

    Science.gov (United States)

    2010-09-01

    ... (Service 1993, p. 3). Current known threats to the pallid sturgeon include habitat modification, small... current maximum harvest size limits for shovelnose sturgeon on the Mississippi River (81.3 cm (32 in... reduction in supply resulted in exponential increase in caviar prices subsequent to the 1978 peak (Bardi and...

  20. 78 FR 46813 - Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI

    Science.gov (United States)

    2013-08-02

    ...-AA00 Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI AGENCY: Coast Guard, DHS. ACTION.... This temporary safety zone will restrict vessels from a portion of Sturgeon Bay due to a fireworks... hazards associated with the fireworks display. DATES: This rule is effective from 8 p.m. until 10 p.m. on...

  1. PCR-mediated recombination in amplification products derived from polyploid cotton.

    Science.gov (United States)

    Richard C. Cronn; M. Cedroni; T. Haselkorn; C. Grover; Jonathan F. Wendel

    2002-01-01

    PCR recombination describes a process of in vitro chimera formation from non-identical templates. The key requirements of this process is the inclusion of two partially homologous templates in one reaction, a condition met when amplifying any locus from polyploid organisms and members of multigene families from diploid organisms. Because polyploids possess two or more...

  2. Coexistence and performance of diploid and polyploid Acacia senegal (L.) Willd

    DEFF Research Database (Denmark)

    Diallo, Adja Madjiguene

    ). Sibling relationship among and between trees from the different open pollinated progenies was tested by application of genetic markers to support the quantitative genetic analysis. The results suggested different mating systems in diploid and polyploids, and this complicated the quantitative genetic...... natural sites with different rainfall and salinity showed no simple geographical pattern in the frequency of polyploids. However, salinity was found to be positively correlated with frequency of polyploids. Analysis of population differentiation between cytotypes compared to genetic relationship among...... populations within cytotypes revealed that the studied polyploid populations were more differentiated than diploid ones. The analysis of genetic relationships further suggest multiple origins of polyploid A. senegal and provide novel information for understanding the evolutionary history of the recently...

  3. Main hematological parameters of sturgeon species (Acipenseridae (review

    Directory of Open Access Journals (Sweden)

    M. Simon

    2017-03-01

    Full Text Available Purpose. To analyze scientific sources on the physiological, biochemical, ecological and genetic features of the main hematological paremeters and patterns of their variability in sturgeon species (Acipenseridae. To examine the fundamental aspects of lipid and protein metabolism in blood serum and the effect of biotic and abiotic factors on them. To highlight the common features of serum enzymes. Findings. A review of scientific papers revealed that although hematological parameters of sturgeons are generally similar to those of teleosts and mammals, there are a number of significant differences. In addition, many hematological parameters are characterized by species specificity, even within a family. Special attention is given to the variability of hematological parameters under the effect of factors of both internal and external environment. The paper describes the effects of sex and age, as well as the seasons of the year on the compositio of sturgeon blood. The fundamentals of the use of serum proteins in genetic and population studies are outlined. The features of the functioning of hemoglobin in sturgeon’s red blood cells are examined. The main hematological parameters involved in the formation and maturation of sexual products, and their effect on fertility are reviewed. For example, the spawners, which hadn’t put reproductive product, are characterized by a low rate of hemoglobin, increase in erythrocyte sedimentation speed and also a rise of the level of crude protein in blood and β-lipoproteid serum.The biochemical parameters (total protein and fractions, glucose, creatinine, cholesterol, the activity of some enzymes (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatine kinase in serum are examined. Practical value. The systematized data on the main hematological parameters and patterns of their variability in sturgeon species will be useful for both scientits and fish farmers. This is due to the

  4. Involvement of atypical transcription factor E2F8 in the polyploidization during mouse and human decidualization.

    Science.gov (United States)

    Qi, Qian-Rong; Zhao, Xu-Yu; Zuo, Ru-Juan; Wang, Tong-Song; Gu, Xiao-Wei; Liu, Ji-Long; Yang, Zeng-Ming

    2015-01-01

    Polyploid decidual cells are specifically differentiated cells during mouse uterine decidualization. However, little is known about the regulatory mechanism and physiological significance of polyploidization in pregnancy. Here we report a novel role of E2F8 in the polyploidization of decidual cells in mice. E2F8 is highly expressed in decidual cells and regulated by progesterone through HB-EGF/EGFR/ERK/STAT3 signaling pathway. E2F8 transcriptionally suppresses CDK1, thus triggering the polyploidization of decidual cells. E2F8-mediated polyploidization is a response to stresses which are accompanied by decidualization. Interestingly, polyploidization is not detected during human decidualization with the down-regulation of E2F8, indicating differential expression of E2F8 may lead to the difference of decidual cell polyploidization between mice and humans.

  5. A novel approach to surveying sturgeon using side-scan sonar and occupancy modeling

    Science.gov (United States)

    Flowers, H. Jared; Hightower, Joseph E.

    2013-01-01

    Technological advances represent opportunities to enhance and supplement traditional fisheries sampling approaches. One example with growing importance for fisheries research is hydroacoustic technologies such as side-scan sonar. Advantages of side-scan sonar over traditional techniques include the ability to sample large areas efficiently and the potential to survey fish without physical handling-important for species of conservation concern, such as endangered sturgeons. Our objectives were to design an efficient survey methodology for sampling Atlantic Sturgeon Acipenser oxyrinchus by using side-scan sonar and to developmethods for analyzing these data. In North Carolina and South Carolina, we surveyed six rivers thought to contain varying abundances of sturgeon by using a combination of side-scan sonar, telemetry, and video cameras (i.e., to sample jumping sturgeon). Lower reaches of each river near the saltwater-freshwater interface were surveyed on three occasions (generally successive days), and we used occupancy modeling to analyze these data.We were able to detect sturgeon in five of six rivers by using these methods. Side-scan sonar was effective in detecting sturgeon, with estimated gear-specific detection probabilities ranging from 0.2 to 0.5 and river-specific occupancy estimates (per 2-km river segment) ranging from 0.0 to 0.8. Future extensions of this occupancy modeling framework will involve the use of side-scan sonar data to assess sturgeon habitat and abundance in different river systems.

  6. The aryl hydrocarbon receptor (AHR) transcription factor regulates megakaryocytic polyploidization.

    Science.gov (United States)

    Lindsey, Stephan; Papoutsakis, Eleftherios T

    2011-02-01

    We propose that the aryl hydrocarbon receptor (AHR) is a novel transcriptional regulator of megakaryopoietic polyploidization. Functional evidence was obtained that AHR impacts in vivo megakaryocytic differentiation and maturation; compared to wild-type mice, AHR-null mice had lower platelet counts, fewer numbers of newly synthesized platelets, increased bleeding times and lower-ploidy megakaryocytes (Mks). AHR mRNA increased 3·6-fold during ex vivo megakaryocytic differentiation, but reduced or remained constant during parallel isogenic granulocytic or erythroid differentiation. We interrogated the role of AHR in megakaryopoiesis using a validated Mk model of megakaryopoiesis, the human megakaryoblastic leukaemia CHRF cell line. Upon CHRF Mk differentiation, AHR mRNA and protein levels increased, AHR protein shifted from the cytoplasm to the nucleus and AHR binding to its consensus DNA binding sequence increased. Protein and mRNA levels of the AHR transcriptional target HES1 also increased. Mk differentiation of CHRF cells where AHR or HES1 was knocked-down using RNAi resulted in lower ploidy distributions and cells that were incapable of reaching ploidy classes ≥16n. AHR knockdown also resulted in increased DNA synthesis of lower ploidy cells, without impacting apoptosis. Together, these data support a role for AHR in Mk polyploidization and in vivo platelet function, and warrant further detailed investigations. © 2011 Blackwell Publishing Ltd.

  7. Wheat hybridization and polyploidization results in deregulation of small RNAs.

    Science.gov (United States)

    Kenan-Eichler, Michal; Leshkowitz, Dena; Tal, Lior; Noor, Elad; Melamed-Bessudo, Cathy; Feldman, Moshe; Levy, Avraham A

    2011-06-01

    Speciation via interspecific or intergeneric hybridization and polyploidization triggers genomic responses involving genetic and epigenetic alterations. Such modifications may be induced by small RNAs, which affect key cellular processes, including gene expression, chromatin structure, cytosine methylation and transposable element (TE) activity. To date, the role of small RNAs in the context of wide hybridization and polyploidization has received little attention. In this work, we performed high-throughput sequencing of small RNAs of parental, intergeneric hybrid, and allopolyploid plants that mimic the genomic changes occurring during bread wheat speciation. We found that the percentage of small RNAs corresponding to miRNAs increased with ploidy level, while the percentage of siRNAs corresponding to TEs decreased. The abundance of most miRNA species was similar to midparent values in the hybrid, with some deviations, as seen in overrepresentation of miR168, in the allopolyploid. In contrast, the number of siRNAs corresponding to TEs strongly decreased upon allopolyploidization, but not upon hybridization. The reduction in corresponding siRNAs, together with decreased CpG methylation, as shown here for the Veju element, represent hallmarks of TE activation. TE-siRNA downregulation in the allopolyploid may contribute to genome destabilization at the initial stages of speciation. This phenomenon is reminiscent of hybrid dysgenesis in Drosophila.

  8. Radionuclide concentrations in white sturgeon from the Columbia River. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1993-11-01

    The objectives of this study were to (1) review and summarize historical data on radionuclide concentrations in white sturgeon from the Columbia River, (2) determine present-day radionuclide tissue burdens from different locations in the Columbia River, and (3) compare historical data with current data. We first reviewed and summarized the historical literature on radionuclide concentrations in white sturgeon from the Hanford Reach. Field studies were then conducted to evaluate the relationship among sample locations, age/length of white sturgeon, and present radionuclide tissue burdens. Results and comparisons are discussed in the remainder of this report.

  9. Review of BPA funded sturgeon, resident fish and wildlife projects

    International Nuclear Information System (INIS)

    1990-12-01

    The Bonneville Power Administration (BPA) held a public meeting on November 19--21, 1991, for the purpose of review, coordination, and consultation of the BPA-funded projects for sturgeon, resident fish, and wildlife in the Columbia River Basin (Basin). The comments received after the meeting were favorable and the participants agreed that the meeting was stimulating and productive. The information exchanged should lead to better coordination with other projects throughout the Basin. This document list the projects by title, the project leaders and BPA's project officers, and an abstract of each leader's presentation

  10. Ontogenetic behavior, migration, and social behavior of pallid sturgeon, Scaphirhynchus albus, and shovelnose sturgeon, S. platorynchus, with notes on the adaptive significance of body color

    Science.gov (United States)

    Kynard, B.; Henyey, E.; Horgan, M.

    2002-01-01

    We conducted laboratory studies on the ontogenetic behavior of free embryos (first life interval after hatching) and larvae (first feeding interval) of pallid and shovelnose sturgeon. Migration styles of both species were similar for timing of migration (initiation by embryos on day 0 after hatching and cessation by larvae on days 12-13 at 236-243 cumulative temperature degree units), migration distance (about 13 km), life interval when most distance was moved (embryo), and diel behavior of embryos (diurnal). However, the species differed for two behaviors: movement characteristics of embryos (peak movement rate of pallid sturgeon was only one-half the peak rate of shovelnose sturgeon, but pallid sturgeon continued the lower rate for twice as long) and diel behavior of larvae (pallid sturgeon were diurnal and shovelnose sturgeon were nocturnal). Thus, the species used different methods to move the same distance. Migrating as poorly developed embryos suggests a migration style to avoid predation at the spawning site, but moving from spawning habitat to rearing habitat before first feeding could also be important. Migrants of both species preferred bright habitat (high illumination intensity and white substrate), a behavioral preference that may characterize the migrants of many species of sturgeon. Both species were remarkably similar for swimming height above the bottom by age, and day 7 and older migrants may swim far above the bottom and move far downstream. A migration of 12 or 13 days will probably not distribute larvae throughout the population's range, so an older life interval likely initiates a second longer downstream migration (2-step migration). By day 2, individuals of both species were a black-tail phenotype (light grey body with a black-tail that moved conspicuously during swimming). Aggregation behavior suggests that black-tail is a visual signal used for group cohesion.

  11. Akt1/PKB upregulation leads to vascular smooth muscle cell hypertrophy and polyploidization

    Science.gov (United States)

    Hixon, Mary L.; Muro-Cacho, Carlos; Wagner, Mark W.; Obejero-Paz, Carlos; Millie, Elise; Fujio, Yasushi; Kureishi, Yasuko; Hassold, Terry; Walsh, Kenneth; Gualberto, Antonio

    2000-01-01

    Vascular smooth muscle cells (VSMCs) at capacitance arteries of hypertensive individuals and animals undergo marked age- and blood pressure–dependent polyploidization and hypertrophy. We show here that VSMCs at capacitance arteries of rat models of hypertension display high levels of Akt1/PKB protein and activity. Gene transfer of Akt1 to VSMCs isolated from a normotensive rat strain was sufficient to abrogate the activity of the mitotic spindle cell–cycle checkpoint, promoting polyploidization and hypertrophy. Furthermore, the hypertrophic agent angiotensin II induced VSMC polyploidization in an Akt1-dependent manner. These results demonstrate that Akt1 regulates ploidy levels in VSMCs and contributes to vascular smooth muscle polyploidization and hypertrophy during hypertension. PMID:11032861

  12. Food habits of Atlantic sturgeon off the central New Jersey coast

    Science.gov (United States)

    Johnson, J. H.; Dropkin, D.S.; Warkentine, B.E.; Rachlin, J.W.; Andrews, W.D.

    1997-01-01

    Limited information exists on the marine diet of the Atlantic sturgeon Acipenser oxyrinchus oxyrinchus. We examined the food habits of 275 Atlantic sturgeon (total length, 106-203 cm) caught in the commercial fishery off the coast of New Jersey. Stomachs were provided by fishermen. Significantly more stomachs were empty in the spring than in the fall. Sand and organic debris were a major component in the stomachs (26.3-75.4% by weight). Polycheates were the primary pre group consumed, although the isopod Politolana conchorum was the most important individual prey eaten. Mollusks and fish contributed little to the diet. Some prey taxa (i.e., polychaetes, isopods, amphipods) exhibited seasonal variation in importance in the diet of Atlantic sturgeon. Identification of the offshore diet of Atlantic sturgeon is an important step in developing a better understanding of the life history requirements and marine ecology of this species.

  13. Polyploidization of rat hepatocytes due to cell fusion under the effect of radiation of different let

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.; Baldychev, A.S.; Smolin, V.A.

    1988-01-01

    The method of flow cytometry was used to study polyploidization of hepatocytes following X-, γ-, and neutron-irradiation. Ionizing radiation was shown to induce cell polyploidization by two different ways: (1) cells and nuclei fusion, and (2) restriction of mitosis after DNA replication. RBE of 14 MeV neutrons with respect to fusion was about 5x10 3 . With neutron irradiation, the densitivity of cells by fusion was not lower than that by chromosome mutations

  14. Polyploidization of rat hepatocytes due to cell fusion under the effect of radiation of different LET

    International Nuclear Information System (INIS)

    Khair, M.; Gil'yano, N.Ya.; Malinovskij, O.V.; Smolin, V.A.

    1991-01-01

    The method of flow cytometry was used to study polyploidization of hepatocytes following X-, γ-, and neutron-irradiation. Ionizing radiation was shown to induce cell polyploidization by two different ways: (1) cells and nuclei fusion, and (2) restriction of mitosis after DNA replication. RBE of 14 MeV neutrons with respect to fusion was about 5x10 3 . With neutron irradiation, the sensitivity of cells by fusion was not lower than that by chromosome mutations. (author). 6 refs., 6 figs

  15. Diet composition of larval and young-of-year shovelnose sturgeon in the Upper Missouri River

    Science.gov (United States)

    Braaten, P. J.; Fuller, D.B.; McClenning, N.D.

    2007-01-01

    Obtaining food following the transition from endogenous to exogenous feeding and during the first year of life is a critical event that strongly influences growth and survival of young-of-year fishes. For shovelnose sturgeon Scaphirhynchus platorynchus, limited information is available on food habits during the first year of life. The objective of this study was to quantify diet components of shovelnose sturgeon during the transition from endogenous to exogenous feeding and during the young-of-year life stage in the North Dakota and Montana portions of the Missouri River. Young-of-year shovelnose sturgeon were sampled between early August and early September 2003. Shovelnose sturgeon initiated exogenous feeding by 16 mm, and individuals 16–140 mm fed exclusively on two macroinvertebrate orders (Diptera and Ephemeroptera). Young-of-year shovelnose sturgeon exhibited an apparently high feeding success as 99 of 100 individuals contained food in the gut. The number of organisms in the gut increased exponentially with fish length for larval Diptera (r2 = 0.73, P the number of Diptera pupae in the gut was not significantly related (P = 0.55) to length of young-of-year shovelnose sturgeon. The length of ingested prey was linearly related to fish length for Diptera larvae (r2 = 0.20, P = 0.002), whereas the relationship between lengths of ingested Ephemeroptera larvae and lengths of young-of-year shovelnose sturgeon was best described by a power function (r2 = 0.50, P the first quantification of feeding dynamics for young-of-year shovelnose sturgeon in a natural river environment.

  16. Green sturgeon distribution in the Pacific Ocean estimated from modeled oceanographic features and migration behavior.

    Science.gov (United States)

    Huff, David D; Lindley, Steven T; Wells, Brian K; Chai, Fei

    2012-01-01

    The green sturgeon (Acipenser medirostris), which is found in the eastern Pacific Ocean from Baja California to the Bering Sea, tends to be highly migratory, moving long distances among estuaries, spawning rivers, and distant coastal regions. Factors that determine the oceanic distribution of green sturgeon are unclear, but broad-scale physical conditions interacting with migration behavior may play an important role. We estimated the distribution of green sturgeon by modeling species-environment relationships using oceanographic and migration behavior covariates with maximum entropy modeling (MaxEnt) of species geographic distributions. The primary concentration of green sturgeon was estimated from approximately 41-51.5° N latitude in the coastal waters of Washington, Oregon, and Vancouver Island and in the vicinity of San Francisco and Monterey Bays from 36-37° N latitude. Unsuitably cold water temperatures in the far north and energetic efficiencies associated with prevailing water currents may provide the best explanation for the range-wide marine distribution of green sturgeon. Independent trawl records, fisheries observer records, and tagging studies corroborated our findings. However, our model also delineated patchily distributed habitat south of Monterey Bay, though there are few records of green sturgeon from this region. Green sturgeon are likely influenced by countervailing pressures governing their dispersal. They are behaviorally directed to revisit natal freshwater spawning rivers and persistent overwintering grounds in coastal marine habitats, yet they are likely physiologically bounded by abiotic and biotic environmental features. Impacts of human activities on green sturgeon or their habitat in coastal waters, such as bottom-disturbing trawl fisheries, may be minimized through marine spatial planning that makes use of high-quality species distribution information.

  17. The Variable Effect of Polyploidization on the Phenotype in Escallonia.

    Science.gov (United States)

    Denaeghel, Hanne E R; Van Laere, Katrijn; Leus, Leen; Lootens, Peter; Van Huylenbroeck, Johan; Van Labeke, Marie-Christine

    2018-01-01

    To induce new variation within the Escallonia genus, chromosome doubling was performed in E. rubra, E. rosea , and E. illinita , three important species within this genus of mainly evergreen woody ornamental species. Obtained tetraploids and diploid controls were analyzed for rooting capacity, leaf and flower characteristics, and plant architecture using image analysis and cold tolerance. In the present study, a breeders' collection of 23 accessions was characterized cytogenetically and described morphologically. All analyzed species and cultivars were diploid (2n = 2x = 24), with exception of E. pendula , a tetraploid. Today, breeding in Escallonia is limited to lucky finds in seedling populations and few efforts in interspecific hybridization. Three selected Escallonia species underwent an in vitro chromosome doubling with both oryzalin and trifluralin applied as either a continuous or shock treatment. The treatments successfully induced polyploids in all three species. Image analysis revealed that tetraploid E. rosea had decreased shoot length (from 3.8 to 1.3 cm), higher circularity and more dense growth habit compared to diploids. No significant changes in cold tolerance were seen. Tetraploid E. illinita did not differ in shoot length, but an increased outgrowth of axillary buds on the main axis led to denser plants. For tetraploid E. rubra , an increase in plant height (from 4.9 to 5.5 cm) was observed together with a large decrease in circularity and density due to a more polar outgrowth of branches on the main axis. E. rubra tetraploids bore larger flowers than diploids and had an increased cold tolerance (from -7.7 to -11.8°C). Leaf width and area of tetraploids increased for both E. illinita and E. rubra , while a decrease was seen in E. rosea genotypes. For all three species, the rooting capacity of the tetraploids did not differ from the diploids. We conclude that the effect of polyploidization on Escallonia was highly variable and species dependent.

  18. RUNX1-induced silencing of non-muscle myosin heavy chain IIB contributes to megakaryocyte polyploidization.

    Science.gov (United States)

    Lordier, Larissa; Bluteau, Dominique; Jalil, Abdelali; Legrand, Céline; Pan, Jiajia; Rameau, Philippe; Jouni, Dima; Bluteau, Olivier; Mercher, Thomas; Leon, Catherine; Gachet, Christian; Debili, Najet; Vainchenker, William; Raslova, Hana; Chang, Yunhua

    2012-03-06

    Megakaryocytes are unique mammalian cells that undergo polyploidization (endomitosis) during differentiation, leading to an increase in cell size and protein production that precedes platelet production. Recent evidence demonstrates that endomitosis is a consequence of a late failure in cytokinesis associated with a contractile ring defect. Here we show that the non-muscle myosin IIB heavy chain (MYH10) is expressed in immature megakaryocytes and specifically localizes in the contractile ring. MYH10 downmodulation by short hairpin RNA increases polyploidization by inhibiting the return of 4N cells to 2N, but other regulators, such as of the G1/S transition, might regulate further polyploidization of the 4N cells. Conversely, re-expression of MYH10 in the megakaryocytes prevents polyploidization and the transition of 2N to 4N cells. During polyploidization, MYH10 expression is repressed by the major megakaryocyte transcription factor RUNX1. Thus, RUNX1-mediated silencing of MYH10 is required for the switch from mitosis to endomitosis, linking polyploidization with megakaryocyte differentiation.

  19. X-ray induced polyploidization in the male germline cells of Poekilocerus pictus (acrididoidea : orthopta)

    International Nuclear Information System (INIS)

    Gururaj, M.E.; Rajasekarasetty, M.R.

    1977-01-01

    After the irradiation of male germline cells of Poekilocerus pictus with 20r, 40r, 80r, 120r doses of X-rays, both first and second meiotic polyploid cells were recovered. While various degrees of polyploidy were encountered in first meiotic cells, second meiotic polyploid cells, second meitoic polyploid cells contained diploid number of half bivalents only. The former never progressed beyond leptotene and showed symptoms of degeneration. Among the latter, a few cells showed either emainingative tendencies like uncoiling and stickiness or failure of cellsted meiosis successfully. It has been shown that the dicentric bridges and/or laggards in anaphase-I interfere with the elongation and regression of the spindle, thereby giving rise to metaphase-II polyploid cells through restitution. The possible role of fragmentation of chromosomes in decreasing the incidence of metaphase-II polyploid cells at higher doses of irradiation and the causes for the differential fate of the first and second meiotic polyploid cells have been discussed. (author)

  20. A decrease in cyclin B1 levels leads to polyploidization in DNA damage-induced senescence.

    Science.gov (United States)

    Kikuchi, Ikue; Nakayama, Yuji; Morinaga, Takao; Fukumoto, Yasunori; Yamaguchi, Naoto

    2010-05-04

    Adriamycin, an anthracycline antibiotic, has been used for the treatment of various types of tumours. Adriamycin induces at least two distinct types of growth repression, such as senescence and apoptosis, in a concentration-dependent manner. Cellular senescence is a condition in which cells are unable to proliferate further, and senescent cells frequently show polyploidy. Although abrogation of cell division is thought to correlate with polyploidization, the mechanisms underlying induction of polyploidization in senescent cells are largely unclear. We wished, therefore, to explore the role of cyclin B1 level in polyploidization of Adriamycin-induced senescent cells. A subcytotoxic concentration of Adriamycin induced polyploid cells having the features of senescence, such as flattened and enlarged cell shape and activated beta-galactosidase activity. In DNA damage-induced senescent cells, the levels of cyclin B1 were transiently increased and subsequently decreased. The decrease in cyclin B1 levels occurred in G2 cells during polyploidization upon treatment with a subcytotoxic concentration of Adriamycin. In contrast, neither polyploidy nor a decrease in cyclin B1 levels was induced by treatment with a cytotoxic concentration of Adriamycin. These results suggest that a decrease in cyclin B1 levels is induced by DNA damage, resulting in polyploidization in DNA damage-induced senescence.

  1. Ecological requirements for pallid sturgeon reproduction and recruitment in the Lower Missouri River: Annual report 2010

    Science.gov (United States)

    DeLonay, Aaron J.; Jacobson, Robert B.; Papoulias, Diana M.; Wildhaber, Mark L.; Chojnacki, Kimberly A.; Pherigo, Emily K.; Haas, Justin D.; Mestl, Gerald E.

    2012-01-01

    The Comprehensive Sturgeon Research Project is a multiyear, multiagency collaborative research framework developed to provide information to support pallid sturgeon recovery and Missouri River management decisions. The project strategy integrates field and laboratory studies of sturgeon reproductive ecology, early life history, habitat requirements, and physiology. The project scope of work is developed annually with cooperating research partners and in collaboration with the U.S. Army Corps of Engineers, Missouri River Recovery—Integrated Science Program. The research consists of several interdependent and complementary tasks that engage multiple disciplines. The research tasks in the 2010 scope of work primarily address spawning as a probable factor limiting pallid sturgeon survival and recovery, although limited pilot studies also have been initiated to examine the requirements of early life stages. The research is designed to inform management decisions affecting channel re-engineering, flow modification, and pallid sturgeon population augmentation on the Missouri River, and throughout the range of the species. Research and progress made through this project are reported to the U.S. Army Corps of Engineers annually. This annual report details the research effort and progress made by the Comprehensive Sturgeon Research Project during 2010.

  2. Diet composition of larval and young-of-year shovelnose sturgeon in the Upper Missouri River

    Science.gov (United States)

    Braaten, P. J.; Fuller, D.B.; McClenning, N.D.

    2007-01-01

    Obtaining food following the transition from endogenous to exogenous feeding and during the first year of life is a critical event that strongly influences growth and survival of young-of-year fishes. For shovelnose sturgeon Scaphirhynchus platorynchus, limited information is available on food habits during the first year of life. The objective of this study was to quantify diet components of shovelnose sturgeon during the transition from endogenous to exogenous feeding and during the young-of-year life stage in the North Dakota and Montana portions of the Missouri River. Young-of-year shovelnose sturgeon were sampled between early August and early September 2003. Shovelnose sturgeon initiated exogenous feeding by 16 mm, and individuals 16–140 mm fed exclusively on two macroinvertebrate orders (Diptera and Ephemeroptera). Young-of-year shovelnose sturgeon exhibited an apparently high feeding success as 99 of 100 individuals contained food in the gut. The number of organisms in the gut increased exponentially with fish length for larval Diptera (r2 = 0.73, P feeding dynamics for young-of-year shovelnose sturgeon in a natural river environment.

  3. A spatial model of white sturgeon rearing habitat in the lower Columbia River, USA

    Science.gov (United States)

    Hatten, J.R.; Parsley, M.J.

    2009-01-01

    Concerns over the potential effects of in-water placement of dredged materials prompted us to develop a GIS-based model that characterizes in a spatially explicit manner white sturgeon Acipenser transmontanus rearing habitat in the lower Columbia River, USA. The spatial model was developed using water depth, riverbed slope and roughness, fish positions collected in 2002, and Mahalanobis distance (D2). We created a habitat suitability map by identifying a Mahalanobis distance under which >50% of white sturgeon locations occurred in 2002 (i.e., high-probability habitat). White sturgeon preferred relatively moderate to high water depths, and low to moderate riverbed slope and roughness values. The eigenvectors indicated that riverbed slope and roughness were slightly more important than water depth, but all three variables were important. We estimated the impacts that fill might have on sturgeon habitat by simulating the addition of fill to the thalweg, in 3-m increments, and recomputing Mahalanobis distances. Channel filling simulations revealed that up to 9 m of fill would have little impact on high-probability habitat, but 12 and 15 m of fill resulted in habitat declines of ???12% and ???45%, respectively. This is the first spatially explicit predictive model of white sturgeon rearing habitat in the lower Columbia River, and the first to quantitatively predict the impacts of dredging operations on sturgeon habitat. Future research should consider whether water velocity improves the accuracy and specificity of the model, and to assess its applicability to other areas in the Columbia River.

  4. Reconsidering residency: Characterization and conservation implications of complex migratory patterns of shortnose sturgeon (Acispenser brevirostrum)

    Science.gov (United States)

    Dionne, Phillip E.; Zydlewski, Gayle B.; Kinnison, Michael T.; Zydlewski, Joseph D.; Wippelhauser, Gail S.

    2013-01-01

    Efforts to conserve endangered species usually involve attempts to define and manage threats at the appropriate scale of population processes. In some species that scale is localized; in others, dispersal and migration link demic units within larger metapopulations. Current conservation strategies for endangered shortnose sturgeon (Acipenser brevirostrum) assume the species is river resident, with little to no movement between rivers. However we have found that shortnose sturgeon travel more than 130 km through coastal waters between the largest rivers in Maine. Indeed, acoustic telemetry shows that shortnose sturgeon enter six out of the seven acoustically monitored rivers we have monitored, with over 70% of tagged individuals undertaking coastal migrations between river systems. Four migration patterns were identified for shortnose sturgeon inhabiting the Penobscot River, Maine: river resident (28%), spring coastal emigrant (24%), fall coastal emigrant (33%), and summer coastal emigrant (15%). No shortnose sturgeon classified as maturing female exhibited a resident pattern, indicating differential migration. Traditional river-specific assessment and management of shortnose sturgeon could be better characterized using a broader metapopulation scale, at least in the Gulf of Maine, that accounts for diverse migratory strategies and the importance of migratory corridors as critical habitat.

  5. Involvement of atypical transcription factor E2F8 in the polyploidization during mouse and human decidualization

    OpenAIRE

    Qi, Qian-Rong; Zhao, Xu-Yu; Zuo, Ru-Juan; Wang, Tong-Song; Gu, Xiao-Wei; Liu, Ji-Long; Yang, Zeng-Ming

    2015-01-01

    Polyploid decidual cells are specifically differentiated cells during mouse uterine decidualization. However, little is known about the regulatory mechanism and physiological significance of polyploidization in pregnancy. Here we report a novel role of E2F8 in the polyploidization of decidual cells in mice. E2F8 is highly expressed in decidual cells and regulated by progesterone through HB-EGF/EGFR/ERK/STAT3 signaling pathway. E2F8 transcriptionally suppresses CDK1, thus triggering the polypl...

  6. Phylogenetic Structure of Plant Communities: Are Polyploids Distantly Related to Co-occurring Diploids?

    Directory of Open Access Journals (Sweden)

    Michelle L. Gaynor

    2018-04-01

    Full Text Available Polyploidy is widely acknowledged to have played an important role in the evolution and diversification of vascular plants. However, the influence of genome duplication on population-level dynamics and its cascading effects at the community level remain unclear. In part, this is due to persistent uncertainties over the extent of polyploid phenotypic variation, and the interactions between polyploids and co-occurring species, and highlights the need to integrate polyploid research at the population and community level. Here, we investigate how community-level patterns of phylogenetic relatedness might influence escape from minority cytotype exclusion, a classic population genetics hypothesis about polyploid establishment, and population-level species interactions. Focusing on two plant families in which polyploidy has evolved multiple times, Brassicaceae and Rosaceae, we build upon the hypothesis that the greater allelic and phenotypic diversity of polyploids allow them to successfully inhabit a different geographic range compared to their diploid progenitor and close relatives. Using a phylogenetic framework, we specifically test (1 whether polyploid species are more distantly related to diploids within the same community than co-occurring diploids are to one another, and (2 if polyploid species tend to exhibit greater ecological success than diploids, using species abundance in communities as an indicator of successful establishment. Overall, our results suggest that the effects of genome duplication on community structure are not clear-cut. We find that polyploid species tend to be more distantly related to co-occurring diploids than diploids are to each other. However, we do not find a consistent pattern of polyploid species being more abundant than diploid species, suggesting polyploids are not uniformly more ecologically successful than diploids. While polyploidy appears to have some important influences on species co-occurrence in

  7. Population viability analysis of the Endangered shortnose sturgeon

    Energy Technology Data Exchange (ETDEWEB)

    Jager, Yetta [ORNL; Bevelhimer, Mark S [ORNL; Peterson, Douglas L. [University of Georgia, Athens, GA

    2011-07-01

    This study used population viability analysis (PVA) to partition the influences of potential threats to the endangered shortnose sturgeon (Acipenser brevirostrum). A workshop brought together experts to help identify potential threats including groundwater withdrawal, poor water quality, saltwater intrusion, mercury effects, harvest as by-catch, and sedimentation of spawning habitat. During the course of the project, we eliminated some threats and added new ones. Groundwater withdrawal was dismissed after a study failed to identify connection with groundwater and the majority of pumping is from a confined aquifer. We also eliminated activities on Fort Stewart as influences on spawning habitat because any successful spawning must occur upstream of Fort Stewart. We added climate change to the list of threats based on our assessment of temperature effects and expectations of sea-level rise. Our study highlighted the role of populations in nearby rivers in providing metapopulation support, raising the concern that the population in the Ogeechee River acts as a demographic sink. As part of this study, we carried out a field sampling study to analyze effects of training activities on headwater streams. We developed a new methodology for sampling design as part of this effort and used a mixed-modeling approach to identify relationships between land cover-land use, including those associated with military training activity and water quality. We found that tank training was associated with higher suspended sediment and equipment training was associated with higher organic carbon) and water quality. We detected effects of training on suspended sediment and organic carbon. We also carried out a field sampling effort in the Canoochee and Ogeechee Rivers. In the Ogeechee River, we found that dissolved oxygen in 40% of measurements during summer were below 4 mg L-1. To evaluate mercury as a potential threat, we developed a mercury uptake model and analyzed mercury levels in

  8. Genetic differentiation of spring-spawning and fall-spawning male Atlantic sturgeon in the James River, Virginia.

    Directory of Open Access Journals (Sweden)

    Matthew T Balazik

    Full Text Available Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus, Acipenseridae populations are currently at severely depleted levels due to historic overfishing, habitat loss, and pollution. The importance of biologically correct stock structure for effective conservation and management efforts is well known. Recent improvements in our understanding of Atlantic sturgeon migrations, movement, and the occurrence of putative dual spawning groups leads to questions regarding the true stock structure of this endangered species. In the James River, VA specifically, captures of spawning Atlantic sturgeon and accompanying telemetry data suggest there are two discrete spawning groups of Atlantic sturgeon. The two putative spawning groups were genetically evaluated using a powerful microsatellite marker suite to determine if they are genetically distinct. Specifically, this study evaluates the genetic structure, characterizes the genetic diversity, estimates effective population size, and measures inbreeding of Atlantic sturgeon in the James River. The results indicate that fall and spring spawning James River Atlantic sturgeon groups are genetically distinct (overall FST = 0.048, F'ST = 0.181 with little admixture between the groups. The observed levels of genetic diversity and effective population sizes along with the lack of detected inbreeding all indicated that the James River has two genetically healthy populations of Atlantic sturgeon. The study also demonstrates that samples from adult Atlantic sturgeon, with proper sample selection criteria, can be informative when creating reference population databases. The presence of two genetically-distinct spawning groups of Atlantic sturgeon within the James River raises concerns about the current genetic assignment used by managers. Other nearby rivers may also have dual spawning groups that either are not accounted for or are pooled in reference databases. Our results represent the second documentation of genetically

  9. Downregulation of an Aim-1 Kinase Couples with Megakaryocytic Polyploidization of Human Hematopoietic Cells

    Science.gov (United States)

    Kawasaki, Akira; Matsumura, Itaru; Miyagawa, Jun-ichiro; Ezoe, Sachiko; Tanaka, Hirokazu; Terada, Yasuhiko; Tatsuka, Masaaki; Machii, Takashi; Miyazaki, Hiroshi; Furukawa, Yusuke; Kanakura, Yuzuru

    2001-01-01

    During the late phase of megakaryopoiesis, megakaryocytes undergo polyploidization, which is characterized by DNA duplication without concomitant cell division. However, it remains unknown by which mechanisms this process occurs. AIM-1 and STK15 belong to the Aurora/increase-in-ploidy (Ipl)1 serine/threonine kinase family and play key roles in mitosis. In a human interleukin-3–dependent cell line, F-36P, the expressions of AIM-1 and STK15 mRNA were specifically observed at G2/M phase of the cell cycle during proliferation. In contrast, the expressions of AIM-1 and STK15 were continuously repressed during megakaryocytic polyploidization of human erythro/megakaryocytic cell lines (F-36P, K562, and CMK) treated with thrombopoietin, activated ras (H-rasG12V), or phorbol ester. Furthermore, their expressions were suppressed during thrombopoietin-induced polyploidization of normal human megakaryocytes. Activation of AIM-1 by the induced expression of AIM-1(wild-type) canceled TPA-induced polyploidization of K562 cells significantly, whereas that of STK15 did not. Moreover, suppression of AIM-1 by the induced expression of AIM-1 (K/R, dominant-negative type) led to polyploidization in 25% of K562 cells, whereas STK15(K/R) showed no effect. Also, the induced expression of AIM-1(K/R) in CMK cells provoked polyploidization up to 32N. These results suggested that downregulation of AIM-1 at M phase may be involved in abortive mitosis and polyploid formation of megakaryocytes. PMID:11266445

  10. Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

    Directory of Open Access Journals (Sweden)

    Michael J Considine

    Full Text Available Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised

  11. Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

    Science.gov (United States)

    Considine, Michael J; Wan, Yizhen; D'Antuono, Mario F; Zhou, Qian; Han, Mingyu; Gao, Hua; Wang, Man

    2012-01-01

    Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised. Impacts of

  12. Sperm proteins in teleostean and chondrostean (sturgeon) fishes.

    Science.gov (United States)

    Li, Ping; Hulak, Martin; Linhart, Otomar

    2009-11-01

    Sperm proteins in the seminal plasma and spermatozoa of teleostean and chondrostean have evolved adaptations due to the changes in the reproductive environment. Analysis of the composition and functions of these proteins provides new insights into sperm motility and fertilising abilities, thereby creating possibilities for improving artificial reproduction and germplasm resource conservation technologies (e.g. cryopreservation). Seminal plasma proteins are involved in the protection of spermatozoa during storage in the reproductive system, whereas all spermatozoa proteins contribute to the swimming and fertilising abilities of sperm. Compared to mammalian species, little data are available on fish sperm proteins and their functions. We review here the current state of the art in this field and focus on relevant subjects that require attention. Future research should concentrate on protein functions and their mode of action in fish species, especially on the role of spermatozoa surface proteins during fertilisation and on a description of sturgeon sperm proteins.

  13. Untangling nucleotide diversity and evolution of the H genome in polyploid Hordeum and Elymus species based on the single copy of nuclear gene DMC1.

    Directory of Open Access Journals (Sweden)

    Dongfa Sun

    Full Text Available Numerous hybrid and polypoid species are found within the Triticeae. It has been suggested that the H subgenome of allopolyploid Elymus (wheatgrass species originated from diploid Hordeum (barley species, but the role of hybridization between polyploid Elymus and Hordeum has not been studied. It is not clear whether gene flow across polyploid Hordeum and Elymus species has occurred following polyploid speciation. Answering these questions will provide new insights into the formation of these polyploid species, and the potential role of gene flow among polyploid species during polyploid evolution. In order to address these questions, disrupted meiotic cDNA1 (DMC1 data from the allopolyploid StH Elymus are analyzed together with diploid and polyploid Hordeum species. Phylogenetic analysis revealed that the H copies of DMC1 sequence in some Elymus are very close to the H copies of DMC1 sequence in some polyploid Hordeum species, indicating either that the H genome in theses Elymus and polyploid Hordeum species originated from same diploid donor or that gene flow has occurred among them. Our analysis also suggested that the H genomes in Elymus species originated from limited gene pool, while H genomes in Hordeum polyploids have originated from broad gene pools. Nucleotide diversity (π of the DMC1 sequences on H genome from polyploid species (π = 0.02083 in Elymus, π = 0.01680 in polyploid Hordeum is higher than that in diploid Hordeum (π = 0.01488. The estimates of Tajima's D were significantly departure from the equilibrium neutral model at this locus in diploid Hordeum species (P<0.05, suggesting an excess of rare variants in diploid species which may not contribute to the origination of polyploids. Nucleotide diversity (π of the DMC1 sequences in Elymus polyploid species (π = 0.02083 is higher than that in polyploid Hordeum (π = 0.01680, suggesting that the degree of relationships between two parents of a polyploid might be a factor

  14. White Sturgeon Mitigation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam; 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ward, David L.; Kern, J. Chris; Hughes, Michele L. (Oregon Department of Fish and Wildlife)

    2004-02-01

    We report on our progress from April 2002 through March 2003 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam.

  15. White Sturgeon Mitigation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam; 2001-2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ward, David L.; Kern, J. Chris; Hughes, Michele L.

    2003-12-01

    We report on our progress from April 2001 through March 2002 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam.

  16. Desk-study on habitat quality for the European Sturgeon in the Dutch Rhine and southern North Sea

    NARCIS (Netherlands)

    Winter, H.V.; Teal, L.R.; Wolfshaar, van de K.E.; Griffioen, A.B.; Houben, B.; Breve, N.W.P.

    2015-01-01

    One of the most endangered fish species worldwide is the European sturgeon Acipenser sturio. The River Rhine was home to an important sturgeon population that went locally extinct in the first half of the 20th century. In recent decades, many improvements of the ecological quality of the Rhine have

  17. Integrative screening approach identifies regulators of polyploidization and targets for acute megakaryocytic leukemia

    Science.gov (United States)

    Wen, Qiang; Goldenson, Benjamin; Silver, Serena J.; Schenone, Monica; Dancik, Vladimir; Huang, Zan; Wang, Ling-Zhi; Lewis, Timothy; An, W. Frank; Li, Xiaoyu; Bray, Mark-Anthony; Thiollier, Clarisse; Diebold, Lauren; Gilles, Laure; Vokes, Martha S.; Moore, Christopher B.; Bliss-Moreau, Meghan; VerPlank, Lynn; Tolliday, Nicola J.; Mishra, Rama; Vemula, Sasidhar; Shi, Jianjian; Wei, Lei; Kapur, Reuben; Lopez, Cécile K.; Gerby, Bastien; Ballerini, Paola; Pflumio, Francoise; Gilliland, D. Gary; Goldberg, Liat; Birger, Yehudit; Izraeli, Shai; Gamis, Alan S.; Smith, Franklin O.; Woods, William G.; Taub, Jeffrey; Scherer, Christina A.; Bradner, James; Goh, Boon-Cher; Mercher, Thomas; Carpenter, Anne E.; Gould, Robert J.; Clemons, Paul A.; Carr, Steven A.; Root, David E.; Schreiber, Stuart L.; Stern, Andrew M.; Crispino, John D.

    2012-01-01

    Summary The mechanism by which cells decide to skip mitosis to become polyploid is largely undefined. Here we used a high-content image-based screen to identify small-molecule probes that induce polyploidization of megakaryocytic leukemia cells and serve as perturbagens to help understand this process. We found that dimethylfasudil (diMF, H-1152P) selectively increased polyploidization, mature cell-surface marker expression, and apoptosis of malignant megakaryocytes. A broadly applicable, highly integrated target identification approach employing proteomic and shRNA screening revealed that a major target of diMF is Aurora A kinase (AURKA), which has not been studied extensively in megakaryocytes. Moreover, we discovered that MLN8237 (Alisertib), a selective inhibitor of AURKA, induced polyploidization and expression of mature megakaryocyte markers in AMKL blasts and displayed potent anti-AMKL activity in vivo. This research provides the rationale to support clinical trials of MLN8237 and other inducers of polyploidization in AMKL. Finally, we have identified five networks of kinases that regulate the switch to polyploidy. PMID:22863010

  18. Aurora B is dispensable for megakaryocyte polyploidization, but contributes to the endomitotic process.

    Science.gov (United States)

    Lordier, Larissa; Chang, Yunhua; Jalil, Abdelali; Aurade, Frédéric; Garçon, Loïc; Lécluse, Yann; Larbret, Frédéric; Kawashima, Toshiyuki; Kitamura, Toshio; Larghero, Jérôme; Debili, Najet; Vainchenker, William

    2010-09-30

    Polyploidization of megakaryocytes (MKs), the platelet precursors, occurs by endomitosis, a mitotic process that fails at late stages of cytokinesis. Expression and function of Aurora B kinase during endomitosis remain controversial. Here, we report that Aurora B is normally expressed during the human MK endomitotic process. Aurora B localized normally in the midzone or midbody during anaphase and telophase in low ploidy megakaryocytes and in up to 16N rare endomitotic MKs was observed. Aurora B was also functional during cytokinesis as attested by phosphorylation of both its activation site and MgcRacGAP, its main substrate. However, despite its activation, Aurora B did not prevent furrow regression. Inhibition of Aurora B by AZD1152-HQPA decreased cell cycle entry both in 2N to 4N and polyploid MKs and induced apoptosis mainly in 2N to 4N cells. In both MK classes, AZD1152-HQPA induced p53 activation and retinoblastoma hypophosphorylation. Resistance of polyploid MKs to apoptosis correlated to a high BclxL level. Aurora B inhibition did not impair MK polyploidization but profoundly modified the endomitotic process by inducing a mis-segregation of chromosomes and a mitotic failure in anaphase. This indicates that Aurora B is dispensable for MK polyploidization but is necessary to achieve a normal endomitotic process.

  19. Identification of regulators of polyploidization presents therapeutic targets for treatment of AMKL.

    Science.gov (United States)

    Wen, Qiang; Goldenson, Benjamin; Silver, Serena J; Schenone, Monica; Dancik, Vlado; Huang, Zan; Wang, Ling-Zhi; Lewis, Timothy A; An, W Frank; Li, Xiaoyu; Bray, Mark-Anthony; Thiollier, Clarisse; Diebold, Lauren; Gilles, Laure; Vokes, Martha S; Moore, Christopher B; Bliss-Moreau, Meghan; Verplank, Lynn; Tolliday, Nicola J; Mishra, Rama; Vemula, Sasidhar; Shi, Jianjian; Wei, Lei; Kapur, Reuben; Lopez, Cécile K; Gerby, Bastien; Ballerini, Paola; Pflumio, Francoise; Gilliland, D Gary; Goldberg, Liat; Birger, Yehudit; Izraeli, Shai; Gamis, Alan S; Smith, Franklin O; Woods, William G; Taub, Jeffrey; Scherer, Christina A; Bradner, James E; Goh, Boon-Cher; Mercher, Thomas; Carpenter, Anne E; Gould, Robert J; Clemons, Paul A; Carr, Steven A; Root, David E; Schreiber, Stuart L; Stern, Andrew M; Crispino, John D

    2012-08-03

    The mechanism by which cells decide to skip mitosis to become polyploid is largely undefined. Here we used a high-content image-based screen to identify small-molecule probes that induce polyploidization of megakaryocytic leukemia cells and serve as perturbagens to help understand this process. Our study implicates five networks of kinases that regulate the switch to polyploidy. Moreover, we find that dimethylfasudil (diMF, H-1152P) selectively increased polyploidization, mature cell-surface marker expression, and apoptosis of malignant megakaryocytes. An integrated target identification approach employing proteomic and shRNA screening revealed that a major target of diMF is Aurora kinase A (AURKA). We further find that MLN8237 (Alisertib), a selective inhibitor of AURKA, induced polyploidization and expression of mature megakaryocyte markers in acute megakaryocytic leukemia (AMKL) blasts and displayed potent anti-AMKL activity in vivo. Our findings provide a rationale to support clinical trials of MLN8237 and other inducers of polyploidization and differentiation in AMKL. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Polyploidization and cell fusion contribute to wound healing in the adult Drosophila epithelium.

    Science.gov (United States)

    Losick, Vicki P; Fox, Donald T; Spradling, Allan C

    2013-11-18

    Reestablishing epithelial integrity and biosynthetic capacity is critically important following tissue damage. The adult Drosophila abdominal epithelium provides an attractive new system to address how postmitotic diploid cells contribute to repair. Puncture wounds to the adult Drosophila epidermis close initially by forming a melanized scab. We found that epithelial cells near the wound site fuse to form a giant syncytium, which sends lamellae under the scab to re-epithelialize the damaged site. Other large cells arise more peripherally by initiating endocycles and becoming polyploid, or by cell fusion. Rac GTPase activity is needed for syncytium formation, while the Hippo signaling effector Yorkie modulates both polyploidization and cell fusion. Large cell formation is functionally important because when both polyploidization and fusion are blocked, wounds do not re-epithelialize. Our observations indicate that cell mass lost upon wounding can be replaced by polyploidization instead of mitotic proliferation. We propose that large cells generated by polyploidization or cell fusion are essential because they are better able than diploid cells to mechanically stabilize wounds, especially those containing permanent acellular structures, such as scar tissue. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Polyploidization in Heuchera cylindrica (Saxifragaceae) did not result in a shift in climatic requirements.

    Science.gov (United States)

    Godsoe, William; Larson, Megan A; Glennon, Kelsey L; Segraves, Kari A

    2013-03-01

    Polyploidization is a key factor involved in the diversification of plants. Although polyploids are commonly found, there remains controversy on the mechanisms that lead to their successful establishment. One major problem that has been identified is that newly formed polyploids lack mates of the appropriate ploidy level and may experience severely reduced fertility due to nonproductive intercytotype crosses. Niche differentiation has been proposed as a primary mechanism that can alleviate this reproductive disadvantage and facilitate polyploid establishment. Here we test whether the establishment of tetraploid cytotypes of Heuchera cylindrica (Saxifragaceae) is consistent with climatic niche differentiation. • We use a combination of field surveys, flow cytometry and species distribution models to: (1) examine the distribution of diploid and tetraploid cytotypes; and (2) determine whether tetraploid Heuchera cylindrica occupy climates that differ from those of its diploid progenitors. • The geographic distributions of diploid and tetraploid cytotypes are largely allopatric as an extensive survey of 636 plants from 43 locations failed to detect any populations with both cytotypes. Although diploids and tetraploids occur in different geographic areas, polyploid Heuchera cylindrica occur almost exclusively in environments that are predicted to be suitable to diploid populations. • Climatic niche differentiation does not explain the geographic distribution of tetraploid Heuchera cylindrica. We propose instead that tetraploid lineages were able to establish by taking advantage of glacial retreat and expanding into previously unoccupied sites.

  2. Genomic Imprinting Was Evolutionarily Conserved during Wheat Polyploidization.

    Science.gov (United States)

    Yang, Guanghui; Liu, Zhenshan; Gao, Lulu; Yu, Kuohai; Feng, Man; Yao, Yingyin; Peng, Huiru; Hu, Zhaorong; Sun, Qixin; Ni, Zhongfu; Xin, Mingming

    2018-01-01

    Genomic imprinting is an epigenetic phenomenon that causes genes to be differentially expressed depending on their parent of origin. To evaluate the evolutionary conservation of genomic imprinting and the effects of ploidy on this process, we investigated parent-of-origin-specific gene expression patterns in the endosperm of diploid ( Aegilops spp), tetraploid, and hexaploid wheat ( Triticum spp) at various stages of development via high-throughput transcriptome sequencing. We identified 91, 135, and 146 maternally or paternally expressed genes (MEGs or PEGs, respectively) in diploid, tetraploid, and hexaploid wheat, respectively, 52.7% of which exhibited dynamic expression patterns at different developmental stages. Gene Ontology enrichment analysis suggested that MEGs and PEGs were involved in metabolic processes and DNA-dependent transcription, respectively. Nearly half of the imprinted genes exhibited conserved expression patterns during wheat hexaploidization. In addition, 40% of the homoeolog pairs originating from whole-genome duplication were consistently maternally or paternally biased in the different subgenomes of hexaploid wheat. Furthermore, imprinted expression was found for 41.2% and 50.0% of homolog pairs that evolved by tandem duplication after genome duplication in tetraploid and hexaploid wheat, respectively. These results suggest that genomic imprinting was evolutionarily conserved between closely related Triticum and Aegilops species and in the face of polyploid hybridization between species in these genera. © 2018 American Society of Plant Biologists. All rights reserved.

  3. Development and Applications of a High Throughput Genotyping Tool for Polyploid Crops: Single Nucleotide Polymorphism (SNP Array

    Directory of Open Access Journals (Sweden)

    Qian You

    2018-02-01

    Full Text Available Polypoid species play significant roles in agriculture and food production. Many crop species are polyploid, such as potato, wheat, strawberry, and sugarcane. Genotyping has been a daunting task for genetic studies of polyploid crops, which lags far behind the diploid crop species. Single nucleotide polymorphism (SNP array is considered to be one of, high-throughput, relatively cost-efficient and automated genotyping approaches. However, there are significant challenges for SNP identification in complex, polyploid genomes, which has seriously slowed SNP discovery and array development in polyploid species. Ploidy is a significant factor impacting SNP qualities and validation rates of SNP markers in SNP arrays, which has been proven to be a very important tool for genetic studies and molecular breeding. In this review, we (1 discussed the pros and cons of SNP array in general for high throughput genotyping, (2 presented the challenges of and solutions to SNP calling in polyploid species, (3 summarized the SNP selection criteria and considerations of SNP array design for polyploid species, (4 illustrated SNP array applications in several different polyploid crop species, then (5 discussed challenges, available software, and their accuracy comparisons for genotype calling based on SNP array data in polyploids, and finally (6 provided a series of SNP array design and genotype calling recommendations. This review presents a complete overview of SNP array development and applications in polypoid crops, which will benefit the research in molecular breeding and genetics of crops with complex genomes.

  4. Ribosomal DNA, heterochromatin, and correlation with genome size in diploid and polyploid North American endemic sagebrushes (Artemisia, Asteraceae)

    Science.gov (United States)

    Sonia Garcia; Teresa Garnatje; Jaume Pellicer; E. Durant McArthur; Sonja Siljak-Yakovlev; Joan Valles

    2009-01-01

    Subgenus Tridentatae (Artemisia, Asteraceae) can be considered a polyploid complex. Both polyploidy and hybridization have been documented in the Tridentatae. Fluorescent in situ hybridization (FISH) and fluorochrome banding were used to detect and analyze ribosomal DNA changes linked to polyploidization in this group by studying four diploidpolyploid species pairs. In...

  5. Substrate and flow characteristics associated with White Sturgeon recruitment in the Columbia River Basin

    Science.gov (United States)

    Hatten, James R.; Parsley, Michael; Barton, Gary; Batt, Thomas; Fosness, Ryan L.

    2018-01-01

    A study was conducted to identify habitat characteristics associated with age 0+ White Sturgeon (Acipenser transmontanus Richardson, 1863) recruitment in three reaches of the Columbia River Basin: Skamania reach (consistent recruitment), John Day reach (intermittent/inconsistent recruitment), and Kootenai reach (no recruitment). Our modeling approach involved numerous steps. First, we collected information about substrate, embeddedness, and hydrodynamics in each reach. Second, we developed a set of spatially explicit predictor variables. Third, we built two habitat (probability) models with Skamania reach training data where White Sturgeon recruitment was consistent. Fourth, we created spawning maps of each reach by populating the habitat models with in-reach physical metrics (substrate, embeddedness, and hydrodynamics). Fifth, we examined model accuracy by overlaying spawning locations in Skamania and Kootenai reaches with habitat predictions obtained from probability models. Sixth, we simulated how predicted habitat changed in each reach after manipulating physical conditions to more closely match Skamania reach. Model verification confirmed White Sturgeon generally spawned in locations with higher model probabilities in Skamania and Kootenai reaches, indicating the utility of extrapolating the models. Model simulations revealed significant gains in White Sturgeon habitat in all reaches when spring flow increased, gravel/cobble composition increased, or embeddedness decreased. The habitat models appear well suited to assist managers when identifying reach-specific factors limiting White Sturgeon recruitment in the Columbia River Basin or throughout its range.

  6. The Brassica oleracea genome reveals the asymmetrical evolution of polyploid genomes

    Science.gov (United States)

    Liu, Shengyi; Liu, Yumei; Yang, Xinhua; Tong, Chaobo; Edwards, David; Parkin, Isobel A. P.; Zhao, Meixia; Ma, Jianxin; Yu, Jingyin; Huang, Shunmou; Wang, Xiyin; Wang, Junyi; Lu, Kun; Fang, Zhiyuan; Bancroft, Ian; Yang, Tae-Jin; Hu, Qiong; Wang, Xinfa; Yue, Zhen; Li, Haojie; Yang, Linfeng; Wu, Jian; Zhou, Qing; Wang, Wanxin; King, Graham J; Pires, J. Chris; Lu, Changxin; Wu, Zhangyan; Sampath, Perumal; Wang, Zhuo; Guo, Hui; Pan, Shengkai; Yang, Limei; Min, Jiumeng; Zhang, Dong; Jin, Dianchuan; Li, Wanshun; Belcram, Harry; Tu, Jinxing; Guan, Mei; Qi, Cunkou; Du, Dezhi; Li, Jiana; Jiang, Liangcai; Batley, Jacqueline; Sharpe, Andrew G; Park, Beom-Seok; Ruperao, Pradeep; Cheng, Feng; Waminal, Nomar Espinosa; Huang, Yin; Dong, Caihua; Wang, Li; Li, Jingping; Hu, Zhiyong; Zhuang, Mu; Huang, Yi; Huang, Junyan; Shi, Jiaqin; Mei, Desheng; Liu, Jing; Lee, Tae-Ho; Wang, Jinpeng; Jin, Huizhe; Li, Zaiyun; Li, Xun; Zhang, Jiefu; Xiao, Lu; Zhou, Yongming; Liu, Zhongsong; Liu, Xuequn; Qin, Rui; Tang, Xu; Liu, Wenbin; Wang, Yupeng; Zhang, Yangyong; Lee, Jonghoon; Kim, Hyun Hee; Denoeud, France; Xu, Xun; Liang, Xinming; Hua, Wei; Wang, Xiaowu; Wang, Jun; Chalhoub, Boulos; Paterson, Andrew H

    2014-01-01

    Polyploidization has provided much genetic variation for plant adaptive evolution, but the mechanisms by which the molecular evolution of polyploid genomes establishes genetic architecture underlying species differentiation are unclear. Brassica is an ideal model to increase knowledge of polyploid evolution. Here we describe a draft genome sequence of Brassica oleracea, comparing it with that of its sister species B. rapa to reveal numerous chromosome rearrangements and asymmetrical gene loss in duplicated genomic blocks, asymmetrical amplification of transposable elements, differential gene co-retention for specific pathways and variation in gene expression, including alternative splicing, among a large number of paralogous and orthologous genes. Genes related to the production of anticancer phytochemicals and morphological variations illustrate consequences of genome duplication and gene divergence, imparting biochemical and morphological variation to B. oleracea. This study provides insights into Brassica genome evolution and will underpin research into the many important crops in this genus. PMID:24852848

  7. Bcl-XL represents a druggable molecular vulnerability during aurora B inhibitor-mediated polyploidization.

    Science.gov (United States)

    Shah, O Jameel; Lin, Xiaoyu; Li, Leiming; Huang, Xiaoli; Li, Junling; Anderson, Mark G; Tang, Hua; Rodriguez, Luis E; Warder, Scott E; McLoughlin, Shaun; Chen, Jun; Palma, Joann; Glaser, Keith B; Donawho, Cherrie K; Fesik, Stephen W; Shen, Yu

    2010-07-13

    Aurora kinase B inhibitors induce apoptosis secondary to polyploidization and have entered clinical trials as an emerging class of neocytotoxic chemotherapeutics. We demonstrate here that polyploidization neutralizes Mcl-1 function, rendering cancer cells exquisitely dependent on Bcl-XL/-2. This "addiction" can be exploited therapeutically by combining aurora kinase inhibitors and the orally bioavailable BH3 mimetic, ABT-263, which inhibits Bcl-XL, Bcl-2, and Bcl-w. The combination of ABT-263 with aurora B inhibitors produces a synergistic loss of viability in a range of cell lines of divergent tumor origin and exhibits more sustained tumor growth inhibition in vivo compared with aurora B inhibitor monotherapy. These data demonstrate that Bcl-XL/-2 is necessary to support viability during polyploidization in a variety of tumor models and represents a druggable molecular vulnerability with potential therapeutic utility.

  8. Wound-Induced Polyploidization: Regulation by Hippo and JNK Signaling and Conservation in Mammals.

    Science.gov (United States)

    Losick, Vicki P; Jun, Albert S; Spradling, Allan C

    2016-01-01

    Tissue integrity and homeostasis often rely on the proliferation of stem cells or differentiated cells to replace lost, aged, or damaged cells. Recently, we described an alternative source of cell replacement- the expansion of resident, non-dividing diploid cells by wound-induced polyploidization (WIP). Here we show that the magnitude of WIP is proportional to the extent of cell loss using a new semi-automated assay with single cell resolution. Hippo and JNK signaling regulate WIP; unexpectedly however, JNK signaling through AP-1 limits rather than stimulates the level of Yki activation and polyploidization in the Drosophila epidermis. We found that polyploidization also quantitatively compensates for cell loss in a mammalian tissue, mouse corneal endothelium, where increased cell death occurs with age in a mouse model of Fuchs Endothelial Corneal Dystrophy (FECD). Our results suggest that WIP is an evolutionarily conserved homeostatic mechanism that maintains the size and synthetic capacity of adult tissues.

  9. Rho kinase inhibition drives megakaryocyte polyploidization and proplatelet formation through MYC and NFE2 downregulation.

    Science.gov (United States)

    Avanzi, Mauro P; Goldberg, Francine; Davila, Jennifer; Langhi, Dante; Chiattone, Carlos; Mitchell, William Beau

    2014-03-01

    The processes of megakaryocyte polyploidization and demarcation membrane system (DMS) formation are crucial for platelet production, but the mechanisms controlling these processes are not fully determined. Inhibition of Rho kinase (ROCK) signalling leads to increased polyploidization in umbilical cord blood-derived megakaryocytes. To extend these findings we determined the effect of ROCK inhibition on development of the DMS and on proplatelet formation. The underlying mechanisms were explored by analysing the effect of ROCK inhibition on the expression of MYC and NFE2, which encode two transcription factors critical for megakaryocyte development. ROCK inhibition promoted DMS formation, and increased proplatelet formation and platelet release. Rho kinase inhibition also downregulated MYC and NFE2 expression in mature megakaryocytes, and this down-regulation correlated with increased proplatelet formation. Our findings suggest a model whereby ROCK inhibition drives polyploidization, DMS growth and proplatelet formation late in megakaryocyte maturation through downregulation of MYC and NFE2 expression. © 2014 John Wiley & Sons Ltd.

  10. Ecological Requirements for Pallid Sturgeon Reproduction and Recruitment in the Lower Missouri River: A Research Synthesis 2005-08

    Science.gov (United States)

    DeLonay, Aaron J.; Jacobson, Robert B.; Papoulias, Diana M.; Simpkins, Darin G.; Wildhaber, Mark L.; Reuter, Joanna M.; Bonnot, Tom W.; Chojnacki, Kimberly A.; Korschgen, Carl E.; Mestl, Gerald E.; Mac, Michael J.

    2009-01-01

    This report provides a synthesis of results obtained between 2005 and 2008 from the Comprehensive Sturgeon Research Program, an interagency collaboration between the U.S. Geological Survey, Nebraska Game and Parks Commission, U.S. Fish and Wildlife Service, and the U.S. Army Corps of Engineers' Missouri River Recovery - Integrated Science Program. The goal of the Comprehensive Sturgeon Research Program is to improve fundamental understanding of reproductive ecology of the pallid sturgeon with the intent that improved understanding will inform river and species management decisions. Specific objectives include: *Determining movement, habitat-use, and reproductive behavior of pallid sturgeon; *Understanding reproductive physiology of pallid sturgeon and relations to environmental conditions; *Determining origin, transport, and fate of drifting pallid sturgeon larvae, and evaluating bottlenecks for recruitment of early life stages; *Quantifying availability and dynamics of aquatic habitats needed by pallid sturgeon for all life stages; and *Managing databases, integrating understanding, and publishing relevant information into the public domain. Management actions to increase reproductive success and survival of pallid sturgeon in the Lower Missouri River have been focused on flow regime, channel morphology, and propagation. Integration of 2005-08 Comprehensive Sturgeon Research Program research provides insight into linkages among flow regime, re-engineered channel morphology, and pallid sturgeon reproduction and survival. The research approach of the Comprehensive Sturgeon Research Program integrates opportunistic field studies, field-based experiments, and controlled laboratory studies. The field study plan is designed to explore the role of flow regime and associated environmental cues using two complementary approaches. An upstream-downstream approach compares sturgeon reproductive behavior between an upstream section of the Lower Missouri River with highly

  11. Dispersal and survival of stocked juvenile hatchery-reared Atlantic sturgeon (Acipenser oxyrinchus

    Directory of Open Access Journals (Sweden)

    Kapusta Andrzej

    2016-12-01

    Full Text Available The post-stocking dispersal of juvenile Atlantic sturgeon (Acipenser oxyrinchus Mitchill in the Wis3oka River (southern Poland was investigated using biotelemetry. Thirty-five hatchery-reared juvenile A. oxyrinchus were tagged with radio or acoustic transmitters and tracked using mobile surveys and fixed receivers. Daily movement patterns were similar in 2009 and 2010. The sturgeon migrated with a mean speed of 1.42 km h-1 in 2009 and of 2.06 km h-1 in 2010. Migration rate was not regarded as being dependent on juvenile sturgeon size. The confirmed survival of individuals from the two field seasons differed slightly over the course of this study. Short-term survival of A. oxyrinchus was 86.7 and 90% in 2009 and 2010, respectively.

  12. Science information to support Missouri River Scaphirhynchus albus (pallid sturgeon) effects analysis

    Science.gov (United States)

    Jacobson, Robert B.; Parsley, Michael J.; Annis, Mandy L.; Colvin, Michael E.; Welker, Timothy L.; James, Daniel A.

    2016-01-26

    The Missouri River Pallid Sturgeon Effects Analysis (EA) was commissioned by the U.S. Army Corps of Engineers to develop a foundation of understanding of how pallid sturgeon (Scaphirhynchus albus) population dynamics are linked to management actions in the Missouri River. The EA consists of several steps: (1) development of comprehensive, conceptual ecological models illustrating pallid sturgeon population dynamics and links to management actions and other drivers; (2) compilation and assessment of available scientific literature, databases, and models; (3) development of predictive, quantitative models to explore the system dynamics and population responses to management actions; and (4) analysis and assessment of effects of system operations and actions on species’ habitats and populations. This report addresses the second objective, compilation and assessment of relevant information.

  13. Simulated Impacts of Juvenile Mortality on Gulf of Mexico Sturgeon Populations

    Directory of Open Access Journals (Sweden)

    William B. Tate

    2002-01-01

    Full Text Available We used an age-structured computer model to assess the impact of changes in juvenile mortality on the Gulf of Mexico sturgeon population in the Suwannee River, Florida. We simulated population trends under four levels of annual juvenile mortality (20, 25, 30, and 35%. As the rate of mortality increased, population size decreased, and rates of population growth shifted from positive to negative. Our models indicated that juvenile survival is important to the success of gulf sturgeon populations, and mortality estimates are needed to predict population viability. We suggest that life history studies in estuaries should be conducted, and bycatch rates for commercial fisheries should be quantified to aid in the management and conservation of gulf sturgeon.

  14. Life history and status of shortnose sturgeon (Acipenser brevirostrum) in the Potomac River

    Science.gov (United States)

    Kieffer, Micah

    2009-01-01

    We collected the first life history information on shortnose sturgeon (Acipenser brevirostrum) in any of the rivers to Chesapeake Bay, the geographic center of the species range. In the Potomac River, two telemetry-tagged adult females used 124 km of river: a saltwater/freshwater reach at river km (rkm) 63-141 was the foraging-wintering concentration area, and one female migrated to spawn at rkm 187 in Washington, DC. The spawning migration explained the life history context of an adult captured 122 years ago in Washington, DC, supporting the idea that a natal population once lived in the river. Repeated homing migrations to foraging and wintering areas suggested the adults were residents, not transient coastal migrants. All habitats that adults need to complete life history are present in the river. The Potomac River shortnose sturgeon offers a rare opportunity to learn about the natural rebuilding of a sturgeon population.

  15. Bathymetric and sediment facies maps for China Bend and Marcus Flats, Franklin D. Roosevelt Lake, Washington, 2008 and 2009

    Science.gov (United States)

    Weakland, Rhonda J.; Fosness, Ryan L.; Williams, Marshall L.; Barton, Gary J.

    2011-01-01

    The U.S. Geological Survey (USGS) created bathymetric and sediment facies maps for portions of two reaches of Lake Roosevelt in support of an interdisciplinary study of white sturgeon (Acipenser transmontanus) and their habitat areas within Franklin D. Roosevelt Lake, Washington. In October 2008, scientists from the USGS used a boat-mounted multibeam echo sounder (MBES) to describe bathymetric data to characterize surface relief at China Bend and Marcus Flats, between Northport and Kettle Falls, Washington. In March 2009, an underwater video camera was used to view and record sediment facies that were then characterized by sediment type, grain size, and areas of sand deposition. Smelter slag has been identified as having the characteristics of sand-sized black particles; the two non-invasive surveys attempted to identify areas containing black-colored particulate matter that may be elements and minerals, organic material, or slag. The white sturgeon population in Lake Roosevelt is threatened by the failure of natural recruitment, resulting in a native population that consists primarily of aging fish and that is gradually declining as fish die and are not replaced by nonhatchery reared juvenile fish. These fish spawn and rear in the riverine and upper reservoir reaches where smelter slag is present in the sediment of the river lake bed. Effects of slag on the white sturgeon population in Lake Roosevelt are largely unknown. Two recent studies demonstrated that copper and other metals are mobilized from slag in aqueous environments with concentrations of copper and zinc in bed sediments reaching levels of 10,000 and 30,000 mg/kg due to the presence of smelter slag. Copper was found to be highly toxic to 30-day-old white sturgeon with 96-h LC50 concentrations ranging from 3 to 5 (u or mu)g copper per liter. Older juvenile and adult sturgeons commonly ingest substantial amounts of sediment while foraging. Future study efforts in Lake Roosevelt should include sampling of

  16. S6K1 is involved in polyploidization through its phosphorylation at Thr421/Ser424.

    Science.gov (United States)

    Ma, Dongchu; Yu, Huiying; Lin, Di; Sun, Yinghui; Liu, Liping; Liu, Yage; Dai, Bing; Chen, Wei; Cao, Jianping

    2009-04-01

    Studies on polyploidization of megakaryocytes have been hampered by the lack of synchronized polyploid megakaryocytes. In this study, a relatively synchronized polyploid cell model was successfully established by employing Dami cells treated with nocodazole. In nocodazole-induced cells, cyclin B expression oscillated normally as in diploid cells and polyploid megakaryocytes. By using the nocodazole-induced Dami cell model, we found that 4E-BP1 and Thr421/Ser424 of ribosomal S6 kinase 1(S6K1) were phosphorylated mostly at M-phase in cytoplasm and oscillated in nocodazole-induced polyploid Dami cells, concomitant with increased expression of p27 and cyclin D3. However, phosphorylation of 4E-BP1 and S6K1 on Thr421/Ser424 was significantly decreased in differentiated Dami cells induced by phorbol 12-myristate 13-acetate (PMA), concomitant with increased expression of cyclin D1 and p21 and cyclin D3. Overexpression of the kinase dead form of S6K1 containing the mutation Lys 100 --> Gln in PMA-induced Dami cells increased ploidy whereas overexpression of rapamycin-resistant form of S6K1 containing the mutations Thr421 --> Glu and Ser424 --> Asp significantly dephosphorylated 4E-BP1 and reduced expression of cyclin D1, cyclin D3, p21 and p27, and slightly decreased the ploidy of PMA-induced Dami cells, compared with treatment with PMA alone. Moreover, overexpression of rapamycin-resistant form of S6K1 significantly reversed polyploidization of nocodazole-induced Dami cells. Furthermore, MAP (a novel compound synthesized recently) partly blocked the phosphorylation of S6K1 on Thr421/Ser424 and decreased the expression of p27 and polyploidization in nocodazole-induced Dami cells. Taken together, these data suggested that S6K1/4E-BP1 pathway may play an important role in polyploidization of megakaryocytes. (c) 2008 Wiley-Liss, Inc.

  17. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1992-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation. (authors). 8 refs., 4 figs., 5 tabs

  18. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1990-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation

  19. Radionuclide concentrations in white sturgeons from the Hanford Reach of the Columbia River

    International Nuclear Information System (INIS)

    Dauble, D.D.; Poston, T.M.

    1994-01-01

    We summarized radionuclide concentrations in white sturgeons Acipenser transmontanus from the Columbia River during a period when several plutonium-production reactors were operating at the Hanford Site in Washington State and compared these values to those measured several years after reactor shutdown. Studies conducted in the Hanford Reach of the Columbia River during 1953-1955 indicated that high concentrations of radionuclides (as total beta) were present in some internal organs on the external surface of white sturgeons. Average concentrations were about 1,480 Bq/kg for liver and kidney and exceeded 2,200 Bq/kg for fins and scutes. The principal radionuclides in the tissues of white sturgeons from the Hanford Reach during 1963-1967, the peak reactor operation interval, were 32 P, 65 Zn, and 51 Cr. Average concentrations of 32 P in muscle ranged from 925 to 2,109 Bq/kg and were typically two to seven times greater than 65 Zn. Average concentrations of radionuclides were usually in the order of gut contents much-gt carcass > muscle. Studies from 1989 to 1990 showed that radionuclide concentrations had decreased dramatically in white sturgeon tissue since the time of reactor operation. Maximum concentrations for artificial radionuclides ( 90 Sr, 60 Co, 137 Cs) in muscle and cartilage of white sturgeons in the Columbia River had declined to less than 4 Bq/kg. Formerly abundant radionuclides, including 32 P, 65 Zn, and 51 Cr, could not be detected in recent tissue samples. Further, radionuclide tissue burden in populations of sturgeons from the Hanford Reach and the upstream or downstream reference locations did not differ significantly. 34 refs., 3 figs., 4 tabs

  20. A proteomic analysis of green and white sturgeon larvae exposed to heat stress and selenium

    Science.gov (United States)

    Silvestre, Frédéric; Linares-Casenave, Javier; Doroshov, Serge I.; Kültz, Dietmar

    2012-01-01

    Temperature and selenium are two environmental parameters that potentially affect reproduction and stock recruitment of sturgeon in the San Francisco Bay / Delta Estuary. To identify proteins whose expression is modified by these environmental stressors, we performed a proteomic analysis on larval green and white sturgeons exposed to 18 or 26°C and micro-injected with Seleno-L-Methionine to reach 8 μg g-1 selenium body burden, with L-Methionine as a control. Selenium and high temperature induced mortalities and abnormal morphologies in both species, with a higher mortality in green sturgeon. Larval proteins were separated by two-dimensional gel electrophoresis and differential abundances were detected following spot quantitation and hierarchical cluster analysis. In green sturgeon, 34 of 551 protein spots detected on gels showed a variation in abundance whereas in white sturgeon only 9 of 580 protein spots were differentially expressed (P<0.01). Gel replicates were first grouped according to heat treatment. Fifteen of these spots were identified using MALDI TOF/TOF mass spectrometry. Proteins involved in protein folding, protein synthesis, protein degradation, ATP supply and structural proteins changed in abundance in response to heat and/or selenium. 40S ribosomal protein SA, FK506-binding protein 10, 65 kDa regulatory subunit A of protein phosphatase 2, protein disulfide isomerase, stress-induced-phosphoprotein 1, suppression of tumorigenicity 13 and collagen type II alpha 1, were differentially expressed in high temperature treatment only. Serine/arginine repetitive matrix protein 1, creatine kinase, serine peptidase inhibitor Kazal type 5 and HSP90 were sensitive to combined temperature and selenium exposure. Valosin-containing protein, a protein involved in aggresome formation and in protein quality control decreased more than 50% in response to selenium treatment. Potential use of such proteins as biomarkers of environmental stressors in larval sturgeons

  1. Potential for electropositive metal to reduce the interactions of Atlantic sturgeon with fishing gear.

    Science.gov (United States)

    Bouyoucos, Ian; Bushnell, Peter; Brill, Richard

    2014-02-01

    Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery-associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31-43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5-cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. © 2013 Society for Conservation Biology.

  2. Reproductive traits of shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820) in the lower Platte River, Nebraska

    Science.gov (United States)

    Hamel, M. J.; Rugg, M.L.; Pegg, M.A.; Patino, Reynaldo; Hammen, J.J.

    2015-01-01

    We assessed reproductive status, fecundity, egg size, and spawning dynamics of shovelnose sturgeon Scaphirhynchus platorynchus in the lower Platte River. Shovelnose sturgeon were captured throughout each year during 2011 and 2012 using a multi-gear approach designed to collect a variety of fish of varying sizes and ages. Fish were collected monthly for a laboratory assessment of reproductive condition. Female shovelnose sturgeon reached fork length at 50% maturity (FL50) at 547 mm and at a minimum length of 449 mm. The average female spawning cycle was 3–5 years. Mean egg count for adult females was 16 098 ± 1103 (SE), and mean egg size was 2.401 ± 0.051 (SE) mm. Total fecundity was positively correlated with length (r2 = 0.728; P  0.05). Male shovelnose sturgeon reached FL50 at 579 mm and at a minimum length of 453 mm. The average male spawning cycle was 1–2 years. Reproductively viable male and female sturgeon occurred during the spring (March–May) and autumn (September–October) in both years, indicating spring and potential autumn spawning events. Shovelnose sturgeon in the lower Platte River are maturing at a shorter length and younger age compared to populations elsewhere. Although it is unknown if the change is plastic or evolutionary, unfavorable environmental conditions or over-harvest may lead to hastened declines compared to other systems.

  3. Production of a high-efficiency TILLING population through polyploidization.

    Science.gov (United States)

    Tsai, Helen; Missirian, Victor; Ngo, Kathie J; Tran, Robert K; Chan, Simon R; Sundaresan, Venkatesan; Comai, Luca

    2013-04-01

    Targeting Induced Local Lesions in Genomes (TILLING) provides a nontransgenic method for reverse genetics that is widely applicable, even in species where other functional resources are missing or expensive to build. The efficiency of TILLING, however, is greatly facilitated by high mutation density. Species vary in the number of mutations induced by comparable mutagenic treatments, suggesting that genetic background may affect the response. Allopolyploid species have often yielded higher mutation density than diploids. To examine the effect of ploidy, we autotetraploidized the Arabidopsis (Arabidopsis thaliana) ecotype Columbia, whose diploid has been used for TILLING extensively, and mutagenized it with 50 mm ethylmethane sulfonate. While the same treatment sterilized diploid Columbia, the tetraploid M1 plants produced good seed. To determine the mutation density, we searched 528 individuals for induced mutations in 15 genes for which few or no knockout alleles were previously available. We constructed tridimensional pools from the genomic DNA of M2 plants, amplified target DNA, and subjected them to Illumina sequencing. The results were analyzed with an improved version of the mutation detection software CAMBa that accepts any pooling scheme. This small population provided a rich resource with approximately 25 mutations per queried 1.5-kb fragment, including on average four severe missense and 1.3 truncation mutations. The overall mutation density of 19.4 mutations Mb(-1) is 4 times that achieved in the corresponding diploid accession, indicating that genomic redundancy engenders tolerance to high mutation density. Polyploidization of diploids will allow the production of small populations, such as less than 2,000, that provide allelic series from knockout to mild loss of function for virtually all genes.

  4. The effect of polyploidization on tree hydraulic functioning.

    Science.gov (United States)

    De Baerdemaeker, Niels J F; Hias, Niek; Van den Bulcke, Jan; Keulemans, Wannes; Steppe, Kathy

    2018-02-01

    Recent research has highlighted the importance of living tissue in wood. Polyploidization can impact amounts and arrangements of living cells in wood, potentially leading to increased drought tolerance. Tetraploid variants were created from the apple cultivar Malus ×domestica 'Gala' (Gala-4x), and their vulnerability to drought-induced cavitation and their hydraulic capacitance were compared to those of their diploid predecessors (Gala-2x). Assuming a positive correlation between polyploidy and drought tolerance, we hypothesized lower vulnerability and higher capacitance for the tetraploid. Vulnerability to drought-induced cavitation and the hydraulic capacitance were quantified through acoustic emission and continuous weighing of shoots during a bench-top dehydration experiment. To underpin the hydraulic trait results, anatomical variables such as vessel area, conduit diameter, cell wall reinforcement, and ray and vessel-associated parenchyma were measured. Vulnerability to drought-induced cavitation was intrinsically equal for both ploidy variants, but Gala-4x proved to be more vulnerable than Gala-2x during the early phase of desiccation as was indicated by its significantly lower air entry value. Higher change in water content of the leafy shoot, higher amount of parenchyma, and larger vessel area and size resulted in a significantly higher hydraulic capacitance and efficiency for Gala-4x compared to Gala-2x. Both ploidy variants were typified as highly sensitive to drought-induced cavitation, with no significant difference in their overall drought vulnerability. But, when water deficit is short and moderate, Gala-4x may delay a drought-induced decrease in performance by trading hydraulic safety for increased release of capacitively stored water from living tissue. © 2018 Botanical Society of America.

  5. Segregation analysis of microsatellite (SSR) markers in sugarcane polyploids.

    Science.gov (United States)

    Lu, X; Zhou, H; Pan, Y-B; Chen, C Y; Zhu, J R; Chen, P H; Li, Y-R; Cai, Q; Chen, R K

    2015-12-28

    No information is available on segregation analysis of DNA markers involving both pollen and self-progeny. Therefore, we used capillary electrophoresis- and fluorescence-based DNA fingerprinting together with single pollen collection and polymerase chain reaction (PCR) to investigate simple sequence repeat (SSR) marker segregation among 964 single pollens and 288 self-progenies (S1) of sugarcane cultivar LCP 85-384. Twenty SSR DNA fragments (alleles) were amplified by five polymorphic SSR markers. Only one non-parental SSR allele was observed in 2392 PCRs. SSR allele inheritance was in accordance with Mendelian laws of segregation and independent assortment. Highly significant correlation coefficients were found between frequencies of observed and expected genotypes in pollen and S1 populations. Within the S1 population, the most frequent genotype of each SSR marker was the parental genotype of the same marker. The number of genotypes was higher in pollen than S1 population. PIC values of the five SSR markers were greater in pollen than S1 populations. Eleven of 20 SSR alleles (55%) were segregated in accordance with Mendelian segregation ratios expected from pollen and S1 populations of a 2n = 10x polyploid. Six of 20 SSR alleles were segregated in a 3:1 (presence:absence) ratio and were simplex markers. Four and one alleles were segregated in 77:4 and 143:1 ratios and considered duplex and triplex markers, respectively. Segregation ratios of remaining alleles were unexplainable. The results provide information about selection of crossing parents, estimation of seedling population optimal size, and promotion of efficient selection, which may be valuable for sugarcane breeders.

  6. Missouri River Scaphirhynchus albus (pallid sturgeon) effects analysis—Integrative report 2016

    Science.gov (United States)

    Jacobson, Robert B.; Annis, Mandy L.; Colvin, Michael E.; James, Daniel A.; Welker, Timothy L.; Parsley, Michael J.

    2016-07-15

    The Missouri River Pallid Sturgeon Effects Analysis was designed to carry out three components of an assessment of how Missouri River management has affected, and will affect, population dynamics of endangered Scaphirhynchus albus (pallid sturgeon): (1) collection of reliable scientific information, (2) critical assessment and synthesis of available data and analyses, and (3) analysis of the effects of actions on listed species and their habitats. This report is a synthesis of the three components emphasizing development of lines of evidence relating potential future management actions to pallid sturgeon population dynamics. We address 21 working management hypotheses that emerged from an expert opinion-based filtering process.The ability to quantify linkages from abiotic changes to pallid sturgeon population dynamics is compromised by fundamental information gaps. Although a substantial foundation of pallid sturgeon science has been developed during the past 20 years, our efforts attempt to push beyond that understanding to provide predictions of how future management actions may affect pallid sturgeon responses. For some of the 21 hypotheses, lines of evidence are limited to theoretical deduction, inference from sparse empirical datasets, or expert opinion. Useful simulation models have been developed to predict the effects of management actions on survival of drifting pallid sturgeon free embryos in the Yellowstone and Upper Missouri River complex (hereafter referred to as the “upper river”), and to assess the effects of flow and channel reconfigurations on habitat availability in the Lower Missouri River, tributaries, and Mississippi River downstream of Gavins Point Dam (hereafter referred to as the “lower river”). A population model also has been developed that can be used to assess sensitivity of the population to survival of specific life stages, assess some hypotheses related to stocking decisions, and explore a limited number of management

  7. High-throughput sequencing of microRNA transcriptome and expression assay in the sturgeon, Acipenser schrenckii.

    Directory of Open Access Journals (Sweden)

    Lihong Yuan

    Full Text Available Sturgeons are considered as living fossils and have very high evolutionary, economical and conservation values. The multiploidy of sturgeon that has been caused by chromosome duplication may lead to the emergence of new microRNAs (miRNAs involved in the ploidy and physiological processes. In the present study, we performed the first sturgeon miRNAs analysis by RNA-seq high-throughput sequencing combined with expression assay of microarray and real-time PCR, and aimed to discover the sturgeon-specific miRNAs, confirm the expressed pattern of miRNAs and illustrate the potential role of miRNAs-targets on sturgeon biological processes. A total of 103 miRNAs were identified, including 58 miRNAs with strongly detected signals (signal >500 and P≤0.01, which were detected by microarray. Real-time PCR assay supported the expression pattern obtained by microarray. Moreover, co-expression of 21 miRNAs in all five tissues and tissue-specific expression of 16 miRNAs implied the crucial and particular function of them in sturgeon physiological processes. Target gene prediction, especially the enriched functional gene groups (369 GO terms and pathways (37 KEGG regulated by 58 miRNAs (P<0.05, illustrated the interaction of miRNAs and putative mRNAs, and also the potential mechanism involved in these biological processes. Our new findings of sturgeon miRNAs expand the public database of transcriptome information for this species, contribute to our understanding of sturgeon biology, and also provide invaluable data that may be applied in sturgeon breeding.

  8. High-throughput sequencing of microRNA transcriptome and expression assay in the sturgeon, Acipenser schrenckii.

    Science.gov (United States)

    Yuan, Lihong; Zhang, Xiujuan; Li, Linmiao; Jiang, Haiying; Chen, Jinping

    2014-01-01

    Sturgeons are considered as living fossils and have very high evolutionary, economical and conservation values. The multiploidy of sturgeon that has been caused by chromosome duplication may lead to the emergence of new microRNAs (miRNAs) involved in the ploidy and physiological processes. In the present study, we performed the first sturgeon miRNAs analysis by RNA-seq high-throughput sequencing combined with expression assay of microarray and real-time PCR, and aimed to discover the sturgeon-specific miRNAs, confirm the expressed pattern of miRNAs and illustrate the potential role of miRNAs-targets on sturgeon biological processes. A total of 103 miRNAs were identified, including 58 miRNAs with strongly detected signals (signal >500 and P≤0.01), which were detected by microarray. Real-time PCR assay supported the expression pattern obtained by microarray. Moreover, co-expression of 21 miRNAs in all five tissues and tissue-specific expression of 16 miRNAs implied the crucial and particular function of them in sturgeon physiological processes. Target gene prediction, especially the enriched functional gene groups (369 GO terms) and pathways (37 KEGG) regulated by 58 miRNAs (P<0.05), illustrated the interaction of miRNAs and putative mRNAs, and also the potential mechanism involved in these biological processes. Our new findings of sturgeon miRNAs expand the public database of transcriptome information for this species, contribute to our understanding of sturgeon biology, and also provide invaluable data that may be applied in sturgeon breeding.

  9. Clonal evolution through loss of chromosomes and subsequent polyploidization in chondrosarcoma.

    Directory of Open Access Journals (Sweden)

    Linda Olsson

    Full Text Available Near-haploid chromosome numbers have been found in less than 1% of cytogenetically reported tumors, but seem to be more common in certain neoplasms including the malignant cartilage-producing tumor chondrosarcoma. By a literature survey of published karyotypes from chondrosarcomas we could confirm that loss of chromosomes resulting in hyperhaploid-hypodiploid cells is common and that these cells may polyploidize. Sixteen chondrosarcomas were investigated by single nucleotide polymorphism (SNP array and the majority displayed SNP patterns indicative of a hyperhaploid-hypodiploid origin, with or without subsequent polyploidization. Except for chromosomes 5, 7, 19, 20 and 21, autosomal loss of heterozygosity was commonly found, resulting from chromosome loss and subsequent duplication of monosomic chromosomes giving rise to uniparental disomy. Additional gains, losses and rearrangements of genetic material, and even repeated rounds of polyploidization, may affect chondrosarcoma cells resulting in highly complex karyotypes. Loss of chromosomes and subsequent polyploidization was not restricted to a particular chondrosarcoma subtype and, although commonly found in chondrosarcoma, binucleated cells did not seem to be involved in these events.

  10. The Role of Polyploidization and Interspecific Hybridization in the Breeding of Ornamental Crops

    NARCIS (Netherlands)

    Marasek-Ciolakowska, A.; Arens, P.F.P.; Tuyl, van J.M.

    2016-01-01

    Polyploidy and hybridisation are critical processes in plant evolution and speciation. Many current agricultural crops are either natural or agricultural hybrids or polyploids, including potato, sugarcane, wheat, strawberries, and banana. There is a great deal of potential to utilise these natural

  11. Polyploidization mechanisms: temperature environment can induce diploid gamete formation in Rosa sp.

    Science.gov (United States)

    Pécrix, Yann; Rallo, Géraldine; Folzer, Hélène; Cigna, Mireille; Gudin, Serge; Le Bris, Manuel

    2011-06-01

    Polyploidy is an important evolutionary phenomenon but the mechanisms by which polyploidy arises still remain underexplored. There may be an environmental component to polyploidization. This study aimed to clarify how temperature may promote diploid gamete formation considered an essential element for sexual polyploidization. First of all, a detailed cytological analysis of microsporogenesis and microgametogenesis was performed to target precisely the key developmental stages which are the most sensitive to temperature. Then, heat-induced modifications in sporad and pollen characteristics were analysed through an exposition of high temperature gradient. Rosa plants are sensitive to high temperatures with a developmental sensitivity window limited to meiosis. Moreover, the range of efficient temperatures is actually narrow. 36 °C at early meiosis led to a decrease in pollen viability, pollen ectexine defects but especially the appearance of numerous diploid pollen grains. They resulted from dyads or triads mainly formed following heat-induced spindle misorientations in telophase II. A high temperature environment has the potential to increase gamete ploidy level. The high frequencies of diplogametes obtained at some extreme temperatures support the hypothesis that polyploidization events could have occurred in adverse conditions and suggest polyploidization facilitating in a global change context.

  12. Frequency of polyploid cells in the bone marrow of rats fed irradiated wheat

    International Nuclear Information System (INIS)

    George, K.P.; Chaubey, R.C.; Sundaram, K.; Gopal-Ayengar, A.R.

    1976-01-01

    Diets containing different proportions of non-irradiated or irradiated wheat were fed to Wistar rats for 1 or 6 wk. Cytological analysis of the bone marrow showed no significant difference in the frequency of polyploid cells in the rats fed non-irradiated or irradiated wheat diets, even when the treated wheat was fed to the rats within 24 hr of irradiation. (author)

  13. Clonal evolution through loss of chromosomes and subsequent polyploidization in chondrosarcoma.

    Science.gov (United States)

    Olsson, Linda; Paulsson, Kajsa; Bovée, Judith V M G; Nord, Karolin H

    2011-01-01

    Near-haploid chromosome numbers have been found in less than 1% of cytogenetically reported tumors, but seem to be more common in certain neoplasms including the malignant cartilage-producing tumor chondrosarcoma. By a literature survey of published karyotypes from chondrosarcomas we could confirm that loss of chromosomes resulting in hyperhaploid-hypodiploid cells is common and that these cells may polyploidize. Sixteen chondrosarcomas were investigated by single nucleotide polymorphism (SNP) array and the majority displayed SNP patterns indicative of a hyperhaploid-hypodiploid origin, with or without subsequent polyploidization. Except for chromosomes 5, 7, 19, 20 and 21, autosomal loss of heterozygosity was commonly found, resulting from chromosome loss and subsequent duplication of monosomic chromosomes giving rise to uniparental disomy. Additional gains, losses and rearrangements of genetic material, and even repeated rounds of polyploidization, may affect chondrosarcoma cells resulting in highly complex karyotypes. Loss of chromosomes and subsequent polyploidization was not restricted to a particular chondrosarcoma subtype and, although commonly found in chondrosarcoma, binucleated cells did not seem to be involved in these events.

  14. Tempo and mode of recurrent polyploidization in the Carassius auratus species complex (Cypriniformes, Cyprinidae).

    Science.gov (United States)

    Luo, J; Gao, Y; Ma, W; Bi, X-y; Wang, S-y; Wang, J; Wang, Y-q; Chai, J; Du, R; Wu, S-f; Meyer, A; Zan, R-g; Xiao, H; Murphy, R W; Zhang, Y-p

    2014-04-01

    Polyploidization is an evolutionarily rare but important mechanism in both plants and animals because it increases genetic diversity. Goldfish of the Carassius auratus species complex can be tetraploids, hexaploids and octaploids. Polyploidization events have occurred repeatedly in goldfish, yet the extent of this phenomenon and its phyletic history are poorly understood. We explore the origin, tempo and frequency of polyploidization in Chinese and Japanese goldfish using both mitochondrial (mtDNA) and nuclear DNA sequences from up to 1202 individuals including the outgroup taxon, Cyprinus carpio. Analyses of de novo nuclear gene data resolve two clusters of alleles and the pattern supports the prior hypothesis of an ancient allotetraploidization for Carassius. Alleles shared by tetraploid and hexaploid individuals indicate recent autoploidizations within the C. auratus complex. Sympatric tetraploids and hexaploids share mtDNA haplotypes and these frequently occur independently within six well-supported lineages and sublineages on a small spatial scale. Gene flow estimates (Fst values) indicate that hexaploids differ only slightly from sympatric tetraploids, if at all. In contrast, allopatric populations of tetraploids and hexaploids differ from one another to a far greater extent. Gene flow between sampled localities appears to be limited. Coalescence-based time estimations for hexaploids reveal that the oldest lineage within any sampled locality is around one million years old, which is very young. Sympatric, recurrent autoploidization occurs in all sampled populations of the C. auratus complex. Goldfish experience polyploidization events more frequently than any other vertebrate.

  15. Repeated polyploidization of Gossypium genomes and the evolution of spinnable cotton fibres

    Science.gov (United States)

    Emergent phenotypes are common in polyploids relative to their diploid progenitors, a phenomenon exemplified by spinnable cotton fibers. Following 15-18 fold paleopolyploidy, allopolyploidy 1-2 million years ago reunited divergent Gossypium genomes, imparting new combinatorial complexity that might ...

  16. Experimental Evolution Reveals Interplay between Sch9 and Polyploid Stability in Yeast.

    Directory of Open Access Journals (Sweden)

    Yi-Jin Lu

    2016-11-01

    Full Text Available Polyploidization has crucial impacts on the evolution of different eukaryotic lineages including fungi, plants and animals. Recent genome data suggest that, for many polyploidization events, all duplicated chromosomes are maintained and genome reorganizations occur much later during evolution. However, newly-formed polyploid genomes are intrinsically unstable and often quickly degenerate into aneuploidy or diploidy. The transition between these two states remains enigmatic. In this study, laboratory evolution experiments were conducted to investigate this phenomenon. We show that robust tetraploidy is achieved in evolved yeast cells by increasing the abundance of Sch9-a protein kinase activated by the TORC1 (Target of Rapamycin Complex 1 and other signaling pathways. Overexpressing SCH9, but not TOR1, allows newly-formed tetraploids to exhibit evolved phenotypes and knocking out SCH9 diminishes the evolved phenotypes. Furthermore, when cells were challenged with conditions causing ancestral cells to evolve aneuploidy, tetraploidy was maintained in the evolved lines. Our results reveal a determinant role for Sch9 during the early stage of polyploid evolution.

  17. Synthetic polyploids of Tragopogon miscellus and T. mirus (Asteraceae): 60 Years after Ownbey's discovery.

    Science.gov (United States)

    Tate, Jennifer A; Symonds, V Vaughan; Doust, Andrew N; Buggs, Richard J A; Mavrodiev, Evgeny; Majure, Lucas C; Soltis, Pamela S; Soltis, Douglas E

    2009-05-01

    In plants, polyploidy has been a significant evolutionary force on both recent and ancient time scales. In 1950, Ownbey reported two newly formed Tragopogon allopolyploids in the northwestern United States. We have made the first synthetic lines of T. mirus and T. miscellus using T. dubius, T. porrifolius, and T. pratensis as parents and colchicine treatment of F(1) hybrids. We also produced allotetraploids between T. porrifolius and T. pratensis, which are not known from nature. We report on the crossability between the diploids, as well as the inflorescence morphology, pollen size, meiotic behavior, and fertility of the synthetic polyploids. Morphologically, the synthetics resemble the natural polyploids with short- and long-liguled forms of T. miscellus resulting when T. pratensis and T. dubius are reciprocally crossed. Synthetic T. mirus was also formed reciprocally, but without any obvious morphological differences resulting from the direction of the cross. Of the 27 original crosses that yielded 171 hybrid individuals, 18 of these lineages have persisted to produce 386 S(1) progeny; each of these lineages has produced S(2) seed that are viable. The successful generation of these synthetic polyploids offers the opportunity for detailed comparative studies of natural and synthetic polyploids within a nonmodel system.

  18. Transient Activation of Apomixis in Sexual Neotriploids May Retain Genomically Altered States and Enhance Polyploid Establishment

    Directory of Open Access Journals (Sweden)

    Diego Hojsgaard

    2018-02-01

    Full Text Available Polyploid genomes evolve and follow a series of dynamic transfigurations along with adaptation and speciation. The initial formation of a new polyploid individual within a diploid population usually involves a triploid bridge, a two-step mechanism of cell fusions between ubiquitous (reduced and rare (unreduced gametes. The primary fusion event creates an intermediate triploid individual with unbalanced genome sets, a situation of genomic-shock characterized by gene expression dysregulation, high dosage sensitivity, disturbed cell divisions, and physiological and reproductive attributes drastically altered. This near-sterile neotriploid must produce (even eupolyploids through secondary fusion events to restore genome steadiness, meiotic balance, and fertility required for the demographic establishment of a nascent lineage. Natural conditions locate several difficulties to polyploid establishment, including the production of highly unbalanced and rarely unreduced (euploid gametes, frequency-dependent disadvantages (minority cytotype exclusion, severe fitness loss, and ecological competition with diploid parents. Persistence and adaptation of neopolyploids depend upon genetic and phenotypic novelty coupled to joint selective forces that preserve shock-induced genomic changes (subgenome homeolog partitioning and drive meiotic (reproductive stabilization and ecological diversification. Thus, polyploid establishment through the triploid bridge is a feasible but not ubiquitous process that requires a number of low-probability events and singular circumstances. Yet, frequencies of polyploids suggest that polyploid establishment is a pervasive process. To explain this disparity, and supported in experimental evidence, I propose that situations like hybridization and ploidy-state transitions associated to genomic shock and substantial developmental alterations can transiently activate apomixis as a mechanism to halt genomic instability and cancel factors

  19. Divergences in hydraulic architecture form an important basis for niche differentiation between diploid and polyploid Betula species in NE China.

    Science.gov (United States)

    Zhang, Wei-Wei; Song, Jia; Wang, Miao; Liu, Yan-Yan; Li, Na; Zhang, Yong-Jiang; Holbrook, N Michele; Hao, Guang-You

    2017-05-01

    Habitat differentiation between polyploid and diploid plants are frequently observed, with polyploids usually occupying more stressed environments. In woody plants, polyploidization can greatly affect wood characteristics but knowledge of its influences on xylem hydraulics is scarce. The four Betula species in NE China, representing two diploids and two polyploids with obvious habitat differentiation, provide an exceptional study system for investigating the impact of polyploidization on environmental adaptation of trees from the point view of xylem hydraulics. To test the hypothesis that changes in hydraulic architecture play an important role in determining their niche differentiation, we measured wood structural traits at both the tissue and pit levels and quantified xylem water transport efficiency and safety in these species. The two polyploids had significantly larger hydraulic weighted mean vessel diameters than the two diploids (45.1 and 45.5 vs 25.9 and 24.5 μm) although the polyploids are occupying more stressed environments. As indicated by more negative water potentials corresponding to 50% loss of stem hydraulic conductivities, the two polyploids exhibited significantly higher resistance to drought-induced embolism than the two diploids (-5.23 and -5.05 vs -3.86 and -3.13 MPa) despite their larger vessel diameters. This seeming discrepancy is reconciled by distinct characteristics favoring greater embolism resistance at the pit level in the two polyploid species. Our results showed clearly that the two polyploid species have remarkably different pit-level anatomical traits favoring greater hydraulic safety than their congeneric diploid species, which have likely contributed to the abundance of polyploid birches in more stressed habitats; however, less porous inter-conduit pits together with a reduced leaf to sapwood area may have compromised their competitiveness under more favorable conditions. Contrasts in hydraulic architecture between diploid and

  20. Sexual Polyploidization in Medicago sativa L.: Impact on the Phenotype, Gene Transcription, and Genome Methylation.

    Science.gov (United States)

    Rosellini, Daniele; Ferradini, Nicoletta; Allegrucci, Stefano; Capomaccio, Stefano; Zago, Elisa Debora; Leonetti, Paola; Balech, Bachir; Aversano, Riccardo; Carputo, Domenico; Reale, Lara; Veronesi, Fabio

    2016-04-07

    Polyploidization as the consequence of 2n gamete formation is a prominent mechanism in plant evolution. Studying its effects on the genome, and on genome expression, has both basic and applied interest. We crossed two diploid (2n = 2x = 16) Medicago sativa plants, a subsp. falcata seed parent, and a coerulea × falcata pollen parent that form a mixture of n and 2n eggs and pollen, respectively. Such a cross produced full-sib diploid and tetraploid (2n = 4x = 32) hybrids, the latter being the result of bilateral sexual polyploidization (BSP). These unique materials allowed us to investigate the effects of BSP, and to separate the effect of intraspecific hybridization from those of polyploidization by comparing 2x with 4x full sib progeny plants. Simple sequence repeat marker segregation demonstrated tetrasomic inheritance for all chromosomes but one, demonstrating that these neotetraploids are true autotetraploids. BSP brought about increased biomass, earlier flowering, higher seed set and weight, and larger leaves with larger cells. Microarray analyses with M. truncatula gene chips showed that several hundred genes, related to diverse metabolic functions, changed their expression level as a consequence of polyploidization. In addition, cytosine methylation increased in 2x, but not in 4x, hybrids. Our results indicate that sexual polyploidization induces significant transcriptional novelty, possibly mediated in part by DNA methylation, and phenotypic novelty that could underpin improved adaptation and reproductive success of tetraploid M. sativa with respect to its diploid progenitor. These polyploidy-induced changes may have promoted the adoption of tetraploid alfalfa in agriculture. Copyright © 2016 Rosellini et al.

  1. Sexual Polyploidization in Medicago sativa L.: Impact on the Phenotype, Gene Transcription, and Genome Methylation

    Directory of Open Access Journals (Sweden)

    Daniele Rosellini

    2016-04-01

    Full Text Available Polyploidization as the consequence of 2n gamete formation is a prominent mechanism in plant evolution. Studying its effects on the genome, and on genome expression, has both basic and applied interest. We crossed two diploid (2n = 2x = 16 Medicago sativa plants, a subsp. falcata seed parent, and a coerulea × falcata pollen parent that form a mixture of n and 2n eggs and pollen, respectively. Such a cross produced full-sib diploid and tetraploid (2n = 4x = 32 hybrids, the latter being the result of bilateral sexual polyploidization (BSP. These unique materials allowed us to investigate the effects of BSP, and to separate the effect of intraspecific hybridization from those of polyploidization by comparing 2x with 4x full sib progeny plants. Simple sequence repeat marker segregation demonstrated tetrasomic inheritance for all chromosomes but one, demonstrating that these neotetraploids are true autotetraploids. BSP brought about increased biomass, earlier flowering, higher seed set and weight, and larger leaves with larger cells. Microarray analyses with M. truncatula gene chips showed that several hundred genes, related to diverse metabolic functions, changed their expression level as a consequence of polyploidization. In addition, cytosine methylation increased in 2x, but not in 4x, hybrids. Our results indicate that sexual polyploidization induces significant transcriptional novelty, possibly mediated in part by DNA methylation, and phenotypic novelty that could underpin improved adaptation and reproductive success of tetraploid M. sativa with respect to its diploid progenitor. These polyploidy-induced changes may have promoted the adoption of tetraploid alfalfa in agriculture.

  2. Integrating water flow, locomotor performance and respiration of Chinese sturgeon during multiple fatigue-recovery cycles.

    Directory of Open Access Journals (Sweden)

    Lu Cai

    Full Text Available The objective of this study is to provide information on metabolic changes occurring in Chinese sturgeon (an ecologically important endangered fish subjected to repeated cycles of fatigue and recovery and the effect on swimming capability. Fatigue-recovery cycles likely occur when fish are moving through the fishways of large dams and the results of this investigation are important for fishway design and conservation of wild Chinese sturgeon populations. A series of four stepped velocity tests were carried out successively in a Steffensen-type swimming respirometer and the effects of repeated fatigue-recovery on swimming capability and metabolism were measured. Significant results include: (1 critical swimming speed decreased from 4.34 bl/s to 2.98 bl/s; (2 active oxygen consumption (i.e. the difference between total oxygen consumption and routine oxygen consumption decreased from 1175 mgO2/kg to 341 mgO2/kg and was the primary reason for the decrease in Ucrit; (3 excess post-exercise oxygen consumption decreased from 36 mgO2/kg to 22 mgO2/kg; (4 with repeated step tests, white muscle (anaerobic metabolism began contributing to propulsion at lower swimming speeds. Therefore, Chinese sturgeon conserve energy by swimming efficiently and have high fatigue recovery capability. These results contribute to our understanding of the physiology of the Chinese sturgeon and support the conservation efforts of wild populations of this important species.

  3. 78 FR 27187 - Proposed Information Collection; Comment Request; Green Sturgeon Endangered Species Act Take...

    Science.gov (United States)

    2013-05-09

    ... Collection; Comment Request; Green Sturgeon Endangered Species Act Take Exceptions and Exemptions AGENCY...) of the Endangered Species Act (ESA) were promulgated for the species on June 2, 2010 (75 FR 30714... information collection, as required by the Paperwork Reduction Act of 1995. DATES: Written comments must be...

  4. Sensitivity of shovelnose sturgeon (Scaphirhynchus platorynchus) and pallid sturgeon (S. albus) early life stages to 3,30,4,40,5-pentachlorobiphenyl and 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure

    Science.gov (United States)

    Buckler, Justin; Candrl, James S.; McKee, Michael J.; Papoulias, Diana M.; Tillitt, Donald E.; Galat, David L.

    2015-01-01

    Concern exists that polychlorinated biphenyls (PCBs) may be contributing to the current decline of shovelnose sturgeon (Scaphirhynchus platorynchus) and the US federally endangered pallid sturgeon (Scaphirhynchus albus). Waterborne exposures with newly fertilized eggs were used to assess developmental and morphological effects of 2 of the most potent aryl hydrocarbon receptor (AhR) agonists, 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on early life stage shovelnose and pallid sturgeon. No dose-related effects of PCB-126 were observed on percent development or hatch in either species at concentrations as high as 1711 ng/g egg. Effects of TCDD on percent development were not assessed in shovelnose sturgeon. However, percent development was not affected by TCDD in pallid sturgeon, and percent hatch was unaffected by TCDD doses as high as 60 ng/g egg to 81 ng/g egg in either species. Morphological pathologies such as yolk sac edema and craniofacial deformities were typical of AhR agonist exposure and were similar in both species. Calculated PCB-126 50% lethal dose (LD50, 95% fiducial limits) values were 196 ng/g egg (188–203 ng/g) for shovelnose and 159 ng/g egg (122–199 ng/g) for pallid sturgeon. Likewise, calculated TCDD LD50 values were 13 ng/g egg (11–15 ng/g) for shovelnose and 12 ng/g egg (10–14 ng/g) for pallid sturgeon. These LD50 values are among the highest recorded in early life stage fish, suggesting that early life stage Scaphirhynchus sturgeon may be comparatively insensitive to AhR agonists.

  5. Electronic tagging of green sturgeon reveals population structure and movement among estuaries

    Science.gov (United States)

    Lindley, S.T.; Erickson, D.L.; Moser, M.L.; Williams, G.; Langness, O.P.; McCovey, B.W.; Belchik, M.; Vogel, D.; Pinnix, W.; Kelly, J.T.; Heublein, J.C.; Klimley, A.P.

    2011-01-01

    Green sturgeon Acipenser medirostris spend much of their lives outside of their natal rivers, but the details of their migrations and habitat use are poorly known, which limits our understanding of how this species might be affected by human activities and habitat degradation.We tagged 355 green sturgeon with acoustic transmitters on their spawning grounds and in known nonspawning aggregation sites and examined their movement among these sites and other potentially important locations using automated data-logging hydrophones. We found that green sturgeon inhabit a number of estuarine and coastal sites over the summer, including the Columbia River estuary, Willapa Bay, Grays Harbor, and the estuaries of certain smaller rivers in Oregon, especially the Umpqua River estuary. Green sturgeon from different natal rivers exhibited different patterns of habitat use; most notably, San Francisco Bay was used only by Sacramento River fish, while the Umpqua River estuary was used mostly by fish from the Klamath and Rogue rivers. Earlier work, based on analysis of microsatellite markers, suggested that the Columbia River mixed stock was mainly composed of fish from the Sacramento River, but our results indicate that fish from the Rogue and Klamath River populations frequently use the Columbia River as well. We also found evidence for the existence of migratory contingentswithin spawning populations.Our findings have significant implications for the management of the threatened Sacramento River population of green sturgeon, which migrates to inland waters outside of California where anthropogenic impacts, including fisheries bycatch and water pollution, may be a concern. Our results also illustrate the utility of acoustic tracking to elucidate the migratory behavior of animals that are otherwise difficult to observe. ?? American Fisheries Society 2011.

  6. Microsatellites variation in sterlet sturgeon, Acipenser ruthenus from the Lower Danube

    Directory of Open Access Journals (Sweden)

    Andreea Dudu

    2013-05-01

    Full Text Available Sturgeons represent an ancient group of fish with an important scientific and commercial value. The economical significance of these species is due to their meat and roes that are considered to be a gastronomic delicacy. Unfortunately, precisely due to their economical value the sturgeons have been overexploited by fishing and poaching and nowadays are facing extinction. Currently, in the Ponto-Caspian region is found the greatest diversity of acipenserid species and the Lower Danube is the last refuge for the sturgeons from the Black Sea. Acipenser ruthenus (sterlet is a fresh water sturgeon species which has undergone a large population decline, but local populations are still surviving in most parts of the rivers draining to Black, Azov and Caspian Seas. In order to have successful conservation programs of this species is essential to evaluate its genetic diversity. Microsatellites represent valuable markers for genetic analyses aiming the assessment of genetic variability of population. In our study we analyzed the cross-amplification and the polymorphism in A. ruthenus population from the Lower Danube of seven microsatellite loci (LS-19, LS-34, LS-54, LS-57, LS-68, Aox23 and Aox45, originally isolated in North-American sturgeon species. Among the seven loci, three (LS57, Aox23 and Aox45 have showed a tetrasomic profile. The most polymorphic loci were LS-57 with 12 alleles in population, followed by Aox23 and Aox45 with 11 alleles and LS-68 with 10 alleles. Four loci (LS-19, LS-34 and LS-54 presented a lower level of polymorphism, only three alleles being identified for the analyzed individuals.

  7. Functional C1q is present in the skin mucus of Siberian sturgeon (Acipenser baerii).

    Science.gov (United States)

    Fan, Chunxin; Wang, Jian; Zhang, Xuguang; Song, Jiakun

    2015-01-01

    The skin mucus of fish acts as the first line of self-protection against pathogens in the aquatic environment and comprises a number of innate immune components. However, the presence of the critical classical complement component C1q, which links the innate and adaptive immune systems of mammalians, has not been explored in a primitive actinopterygian fish. In this study, we report that C1q is present in the skin mucus of the Siberian sturgeon (Acipenser baerii). The skin mucus was able to inhibit the growth of Escherichia coli. The bacteriostatic activity of the skin mucus was reduced by heating and by pre-incubation with EDTA or mouse anti-human C1q antibody. We also detected C1q protein in skin mucus using the western blot procedure and isolated a cDNA that encodes the Siberian sturgeon C1qC, which had 44.7-51.4% identity with C1qCs in teleosts and tetrapods. A phylogenetic analysis revealed that Siberian sturgeon C1qC lies at the root of the actinopterygian branch and is separate from the tetrapod branch. The C1qC transcript was expressed in many tissues as well as in skin. Our data indicate that C1q is present in the skin mucus of the Siberian sturgeon to protect against water-borne bacteria, and the C1qC found in the sturgeon may represent the primitive form of teleost and tetrapod C1qCs. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  8. White sturgeon mitigation and restoration in the Columbia and Snake rivers upstream from Bonneville Dam, Annual Progress Report April 2006 - March 2007. Report C

    Science.gov (United States)

    Parsley, M.J.; Kofoot, P.

    2008-01-01

    Describe reproduction and early life history characteristics of white sturgeon populations in the Columbia River between Bonneville and Priest Rapids dams. Define habitat requirements for spawning and rearing white sturgeon and quantify the extent of habitat available in the Columbia River between Bonneville and Priest Rapids dams. Progress updates on young-of-the-year recruitment in Bonneville Reservoir and indices of white sturgeon spawning habitat for 2006 for McNary, John Day, The Dalles, and Bonneville dam tailrace spawning areas.

  9. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  10. Gonad organochlorine concentrations and plasma steroid levels in white sturgeon (Acipenser transmontanus) from the Columbia River, USA

    Science.gov (United States)

    Foster, E.P.; Fitzpatrick, M.S.; Feist, G.W.; Schreck, C.B.; Yates, J.

    2001-01-01

    Sturgeon are an important fishery resource world-wide, providing food and income through commercial, sport, and tribal fisheries. However, sturgeon populations are imperiled in many areas due to overharvest, habitat loss, and pollution. White Sturgeon (Acipenser transmontanus) are found along the west coast of North America from San Francisco Bay, USA to British Columbia, Canada. The Columbia River, located in the Pacific Northwest USA, supports active commercial, sport, and tribal white sturgeon fisheries. The white sturgeon fishery in the Columbia River estuary is one of the most productive sturgeon fisheries in the World. Despite the success of the Columbia River estuary white sturgeon fishery, the populations within the impounded sections (i.e. behind the hydroelectric dams) of the Columbia River experience poor reproductive success (Beamesderfer et al. 1995). This poor reproductive success has been attributed to hydroelectric development, but water pollution could also be a significant factor. The bottom dwelling life history and late maturing reproductive strategy for this species may make it particularly sensitive to the adverse effects of bioaccumulative pollutants.The Columbia River receives effluent from bleached-kraft pulp mills, aluminum smelters, municipal sewage treatment plants and runoff from agricultural. industrial, and urban areas. Bioaccumulative contaminants that have the potential for endocrine disruption have been detected in fish and sediments from the Columbia River (Foster et al. 1999). An integrated system of hormones control reproduction in vertebrates. Plasma steroids direct developmental events essential for reproduction. Disruption of endocrine control by contaminants has been linked to reproductive anomalies and failure in a number of vertebrate species (Guillette et al. 1996; Jobling et al. 1996). Because of this, it is important to understand if organochlorine compounds are accumulating in Columbia River white sturgeon and having

  11. Development of working hypotheses linking management of the Missouri River to population dynamics of Scaphirhynchus albus (pallid sturgeon)

    Science.gov (United States)

    Jacobson, Robert B.; Parsley, Michael J.; Annis, Mandy L.; Colvin, Michael E.; Welker, Timothy L.; James, Daniel A.

    2016-01-20

    This report documents a process of filtering of hypotheses that relate Missouri River Scaphirhynchus albus (pallid sturgeon) population dynamics to management actions including flow alterations, channel reconfigurations, and pallid sturgeon population augmentation. The filtering process was a partnership among U.S. Geological Survey, U.S. Army Corps of Engineers, and U.S. Fish and Wildlife Service to contribute to the Missouri River Recovery Management Plan process. The objective of the filtering process was to produce a set of hypotheses with high relevance to pallid sturgeon population dynamics and decision making on the Missouri River. The Missouri River Pallid Sturgeon Effects Analysis team filtered hundreds of potential hypotheses implicit in conceptual ecological models to develop a set of 40 candidate dominant hypotheses that were identified by experts as being important in pallid sturgeon population dynamics. Using a modified Delphi process and additional expert opinion, the team reduced this set of hypotheses to 23 working dominant hypotheses. We then matched the 23 hypotheses with management actions that could influence the biotic outcomes, resulting in as many as 176 potential effects between management actions and pallid sturgeon in the Missouri River. This number was consolidated to a candidate set of 53 working management hypotheses because some management actions applied to multiple life stages of the pallid sturgeon. We used an additional round of expert surveys to identify a set of 30 working management hypotheses. Finally, the set of working management hypotheses was filtered by the U.S. Army Corps of Engineers, Missouri River Recovery Program for actions that were within the agency’s authority and jurisdiction. This round resulted in a set of 21 hypotheses for initial modeling of linkages from management to pallid sturgeon population responses.

  12. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Scott R.; Tuell, Michael A. (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)

    2002-03-01

    In 1998 white sturgeon (Acipenser transmontanus) were captured, marked, and population data were collected in the Snake River between Lower Granite Dam and the mouth of the Salmon River. A total of 13,785 hours of setline effort and 389 hours of hook-and-line effort was employed in 1998. Of the 278 white sturgeon captured in the Snake River, 238 were marked for future identification. Three sturgeon were captured in the Salmon River and none were captured in the Clearwater River. Since 1997, 6.9% of the tagged fish have been recovered. Movement of recaptured white sturgeon ranged from 98.5 kilometers downstream to 60.7 kilometers upstream, however, less than 25% of the fish moved more than 16 kilometers (10 miles). In the Snake River, white sturgeon ranged in total length from 51.5 cm to 286 cm and averaged 118.9 cm. Differences were detected in the length frequency distributions of sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P < 0.05). In addition, the proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 37% since the 1970's. Analysis of the length-weight relationship indicated that white sturgeon in Lower Granite Reservoir were slightly larger than white sturgeon in the free-flowing Snake River.

  13. Ecological requirements for pallid sturgeon reproduction and recruitment in the Missouri River—A synthesis of science, 2005 to 2012

    Science.gov (United States)

    Delonay, Aaron J.; Chojnacki, Kimberly A.; Jacobson, Robert B.; Albers, Janice L.; Braaten, Patrick J.; Bulliner, Edward A.; Elliott, Caroline M.; Erwin, Susannah O.; Fuller, David B; Haas, Justin D.; Ladd, Hallie L.A.; Mestl, Gerald E.; Papoulias, Diana M.; Wildhaber, Mark L.

    2016-01-20

    This report is intended to synthesize the state of the scientific understanding of pallid sturgeon ecological requirements to provide recommendations for future science directions and context for Missouri River restoration and management decisions. Recruitment of pallid sturgeon has been low to non-existent throughout its range. Emerging understanding of the genetic structure of pallid sturgeon populations sets a broad framework for species and river management decisions, including decisions about managing the future genetic diversity of the species, but also decisions about where and what type of river restoration actions will be effective for subpopulations of this highly migratory species. Adult pallid sturgeon may migrate hundreds of kilometers (km) to spawn and their progeny may disperse even greater distances downstream as drifting free embryos. As a result of their complex life history pallid sturgeon naturally exploit a wide range of habitats during their life cycles. The construction of dams and reservoirs has fragmented habitats and may have shifted Missouri River subpopulations downstream. Research has not identified one primary biological or ecological constraint that appears to limit populations of the pallid sturgeon. With the present (2013) state of knowledge many life stages and life-stage transitions cannot be ruled out as contributing to recruitment failure.

  14. Ecological niche differentiation of polyploidization is not supported by environmental differences among species in a cosmopolitan grass genus.

    Science.gov (United States)

    Visser, Vernon; Molofsky, Jane

    2015-01-01

    Polyploidization frequently results in the creation of new plant species, the establishment of which is thought to often be facilitated by ecological niche differentiation from the diploid species. We tested this hypothesis using the cosmopolitan grass genus Phalaris (Poaceae), consisting of 19 species that range from diploid to tetraploid to hexaploid. Specifically, we tested whether (1) polyploids occupy more extreme environments and/or (2) have broader niche breadths and/or (3) whether the polyploid species' distributions indicate a niche shift from diploid species.• We employed a bootstrapping approach using distribution data for each species and eight environmental variables to investigate differences between species in the means, extremes, and breadths of each environmental variable. We used a kernel smoothing technique to quantify niche overlap between species.• Although we found some support for the three hypotheses for a few diploid-polyploid pairs and for specific environmental variables, none of these hypotheses were generally supported.• Our results suggest that these commonly held hypotheses about the effects of polyploidization on ecological distributions are not universally applicable. Correlative biogeographic studies like ours provide a necessary first step for suggesting specific hypotheses that require experimental verification. A combination of genetic, physiological, and ecological studies will be required to achieve a better understanding of the role of polyploidization in niche evolution. © 2015 Botanical Society of America, Inc.

  15. The evidence of apelin has the bidirectional effects on feeding regulation in Siberian sturgeon (Acipenser baerii).

    Science.gov (United States)

    Hao, Jin; Liu, Qing; Zhang, Xin; Wu, Yuanbing; Zhu, Jieyao; Qi, Jinwen; Tang, Ni; Wang, Shuyao; Wang, Hong; Chen, Defang; Li, Zhiqiong

    2017-08-01

    Apelin is a peptide, mainly produced in the brain, which participates in several physiologic effects. However, knowledge about the mechanism of appetite regulation in teleosts, including the role of apelin is not well understood. The aim of this study is to explore the effect of feeding status on the expression of apelin mRNA in the whole brain and the effects of injection of apelin on food intake in Siberian sturgeon (Acipenser baerii). In this study, we first cloned the apelin cDNA sequence of the Siberian sturgeon. We obtained a 1046-bp cDNA fragment, including a 237-bp open reading frame (ORF) that encoded 78 amino acids. Apelin was widely distributed in 11 tissues related to feeding regulation, with the highest expression in thewhole brain, followed by the spleen and trunk kidney. In addition, we measured the effects of periprandial (preprandial and postprandial) change, fasting and re-feeding on apelin mRNA expression in whole brain. The level of apelin mRNA was significantly decreased 1h after feeding. The results of the fasting experiment showed that the expression of apelin mRNA in the brain was significantly reduced after 1day of fasting but consistently increased throughout the 15-day food deprivation period. When the 15-day fasted fish were re-fed, apelin mRNA expression in the brain was significantly increased as compared to that of the control. These results suggest that apelin may play a bidirectional role in the regulation of food intake in the Siberian sturgeon. In order to further examine the effect of apelin on feeding regulation in Siberian sturgeons, acute and chronic intraperitoneal (i.p.) injection experiments were performed and food intakes were recorded. Results showed that acute i.p. injection of apelin-13 reduced food intake, however, chronic i.p. injection apelin-13 increased the food intake for 7days in Siberian sturgeons. In conclusion, our results show that apelin has a bidirectional effect on feeding regulation in Siberian sturgeons

  16. Whole-body X-irradiation of mice accelerates polyploidization of hepatocytes

    International Nuclear Information System (INIS)

    Shima, A.; Egami, N.

    1985-01-01

    Male C57BL/6 mice were whole-body irradiated with 4.75 gy of X-rays at the age of 2 months and killed at 2, 6, 12 and 19 months after irradiation. The percentage survival began to decline earlier and faster in the irradiated group than the controls up to 19 months after exposure when the study was terminated. The nuclear DNA content of individual hepatocytes was measured by a Feulgen-DNA microfluorometric method, and hepatocytes were classified into various ploidy classes. In the irradiated mice, the degree of polyploidization was significantly higher than the controls by 2 months after exposure and steadily increased up to 6 months after exposure. Thereafter, however, a slow return to the control level was found up to 19 months after irradiation. These results appear to support a hypothesis that radiation accelerates the ageing process as judged from hepatocyte polyploidization. (author)

  17. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Directory of Open Access Journals (Sweden)

    Marco De Santis Puzzonia

    Full Text Available In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

  18. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Science.gov (United States)

    De Santis Puzzonia, Marco; Cozzolino, Angela Maria; Grassi, Germana; Bisceglia, Francesca; Strippoli, Raffaele; Guarguaglini, Giulia; Citarella, Franca; Sacchetti, Benedetto; Tripodi, Marco; Marchetti, Alessandra; Amicone, Laura

    2016-01-01

    In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

  19. Akt1/PKB upregulation leads to vascular smooth muscle cell hypertrophy and polyploidization

    OpenAIRE

    Hixon, Mary L.; Muro-Cacho, Carlos; Wagner, Mark W.; Obejero-Paz, Carlos; Millie, Elise; Fujio, Yasushi; Kureishi, Yasuko; Hassold, Terry; Walsh, Kenneth; Gualberto, Antonio

    2000-01-01

    Vascular smooth muscle cells (VSMCs) at capacitance arteries of hypertensive individuals and animals undergo marked age- and blood pressure–dependent polyploidization and hypertrophy. We show here that VSMCs at capacitance arteries of rat models of hypertension display high levels of Akt1/PKB protein and activity. Gene transfer of Akt1 to VSMCs isolated from a normotensive rat strain was sufficient to abrogate the activity of the mitotic spindle cell–cycle checkpoint, promoting polyploidizati...

  20. Polyploidization delay in rat hepatocytes under liver growth inhibition by hypokinesia

    Science.gov (United States)

    Faktor, V. M.; Malyutin, V. F.; Li, S. Y.; Brodskiy, V. Y.

    1981-01-01

    A study of young rats, weighing 55 to 59 g, after being for 10 days in conditions of limited mobility, shows a retardation of body growth as well as that of liver growth. The decrease in the rate of growth is accompanied by a reduction of cell proliferation and by delay polyploidization of hepatocytes in the liver of experimental rats. The materials, methods, and results of research are discussed.

  1. Number of nucleoli in diploids and polyploids of the genus Achillea L.

    Directory of Open Access Journals (Sweden)

    Janina Dąbrowska

    2014-01-01

    Full Text Available Nucleoli were counted in 9228 interphase nuclei of the apical root meristem of 40 Achillea L. taxa (di-, tetra-. hexa- and octoploids. It was established that the distribution of nucleoli number in an interphase nucleus can be used as a rough practical indicator to distinguish between diploids and polyploids. The highest number of nucleoli (12 was found in an octoploid Achillea pannonica, but only in a small percentage of the nuclei (0.3% out of 283 nuclei.

  2. Sorting duplicated loci disentangles complexities of polyploid genomes masked by genotyping by sequencing

    DEFF Research Database (Denmark)

    Limborg, Morten; Seeb, Lisa W.; Seeb, J. E.

    2016-01-01

    Many plants and animals of polyploid origin are currently enjoying a genomics explosion enabled by modern sequencing and genotyping technologies. However, routine filtering of duplicated loci in most studies using genotyping by sequencing introduces an unacceptable, but often overlooked, bias when...... particularly stress the sometimes overlooked fact that basing genomic studies on dense maps provides value added in the form of locating and annotating outlier loci or colocating outliers into islands of divergenc...

  3. Transcriptome and metabolome of synthetic Solanum autotetraploids reveal key genomic stress events following polyploidization.

    Science.gov (United States)

    Fasano, Carlo; Diretto, Gianfranco; Aversano, Riccardo; D'Agostino, Nunzio; Di Matteo, Antonio; Frusciante, Luigi; Giuliano, Giovanni; Carputo, Domenico

    2016-06-01

    Polyploids are generally classified as autopolyploids, derived from a single species, and allopolyploids, arising from interspecific hybridization. The former represent ideal materials with which to study the consequences of genome doubling and ascertain whether there are molecular and functional rules operating following polyploidization events. To investigate whether the effects of autopolyploidization are common to different species, or if species-specific or stochastic events are prevalent, we performed a comprehensive transcriptomic and metabolomic characterization of diploids and autotetraploids of Solanum commersonii and Solanum bulbocastanum. Autopolyploidization remodelled the transcriptome and the metabolome of both species. In S. commersonii, differentially expressed genes (DEGs) were highly enriched in pericentromeric regions. Most changes were stochastic, suggesting a strong genotypic response. However, a set of robustly regulated transcripts and metabolites was also detected, including purine bases and nucleosides, which are likely to underlie a common response to polyploidization. We hypothesize that autopolyploidization results in nucleotide pool imbalance, which in turn triggers a genomic shock responsible for the stochastic events observed. The more extensive genomic stress and the higher number of stochastic events observed in S. commersonii with respect to S. bulbocastanum could be the result of the higher nucleoside depletion observed in this species. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  4. Massive expansion and differential evolution of small heat shock proteins with wheat (Triticum aestivum L.) polyploidization.

    Science.gov (United States)

    Wang, Xiaoming; Wang, Ruochen; Ma, Chuang; Shi, Xue; Liu, Zhenshan; Wang, Zhonghua; Sun, Qixin; Cao, Jun; Xu, Shengbao

    2017-05-31

    Wheat (Triticum aestivum), one of the world's most important crops, is facing unprecedented challenges due to global warming. To evaluate the gene resources for heat adaptation in hexaploid wheat, small heat shock proteins (sHSPs), the key plant heat protection genes, were comprehensively analysed in wheat and related species. We found that the sHSPs of hexaploid wheat were massively expanded in A and B subgenomes with intrachromosomal duplications during polyploidization. These expanded sHSPs were under similar purifying selection and kept the expressional patterns with the original copies. Generally, a strong purifying selection acted on the α-crystallin domain (ACD) and theoretically constrain conserved function. Meanwhile, weaker purifying selection and strong positive selection acted on the N-terminal region, which conferred sHSP flexibility, allowing adjustments to a wider range of substrates in response to genomic and environmental changes. Notably, in CI, CV, ER, MI and MII subfamilies, gene duplications, expression variations and functional divergence occurred before wheat polyploidization. Our results indicate the massive expansion of active sHSPs in hexaploid wheat may also provide more raw materials for evolving functional novelties and generating genetic diversity to face future global climate changes, and highlight the expansion of stress response genes with wheat polyploidization.

  5. Estrogen promotes megakaryocyte polyploidization via estrogen receptor beta-mediated transcription of GATA1.

    Science.gov (United States)

    Du, C; Xu, Y; Yang, K; Chen, S; Wang, X; Wang, S; Wang, C; Shen, M; Chen, F; Chen, M; Zeng, D; Li, F; Wang, T; Wang, F; Zhao, J; Ai, G; Cheng, T; Su, Y; Wang, J

    2017-04-01

    Estrogen is reported to be involved in thrombopoiesis and the disruption of its signaling may cause myeloproliferative disease, yet the underlying mechanisms remain largely unknown. GATA-binding factor 1 (GATA1) is a key regulator of megakaryocyte (MK) differentiation and its deficiency will lead to megakaryoblastic leukemia. Here we show that estrogen can dose-dependently promote MK polyploidization and maturation via activation of estrogen receptor beta (ERβ), accompanied by a significant upregulation of GATA1. Chromatin immunoprecipitation and a dual luciferase assay demonstrate that ERβ can directly bind the promoter region of GATA1 and activate its transcription. Steroid receptor coactivator 3 (SRC3) is involved in ERβ-mediated GATA1 transcription. The deficiency of ERβ or SRC3, similar to the inhibition of GATA1, leads to the impediment of estrogen-induced MK polyploidization and platelet production. Further investigations reveal that signal transducer and activator of transcription 1 signaling pathway downstream of GATA1 has a crucial role in estrogen-induced MK polyploidization, and ERβ-mediated GATA1 upregulation subsequently enhances nuclear factor erythroid-derived 2 expression, thereby promoting proplatelet formation and platelet release. Our study provides a deep insight into the molecular mechanisms of estrogen signaling in regulating thrombopoiesis and the pathogenesis of ER deficiency-related leukemia.

  6. BMS-777607 promotes megakaryocytic differentiation and induces polyploidization in the CHRF-288-11 cells.

    Science.gov (United States)

    Nurhayati, Retno Wahyu; Ojima, Yoshihiro; Taya, Masahito

    2015-04-01

    Introduction of a polyploidy inducer is a promising strategy to achieve a high level of polyploidization during megakaryocytic (MK) differentiation. Here, we report that a multi-kinase inhibitor, BMS-777607, is a potent polyploidy inducer for elevating high ploidy cell formation in the MK-differentiated CHRF-288-11 (CHRF) cells. Our result showed that BMS-777607 strongly inhibited cell division without affecting cell viability when detected at day 1 after treatment. As a consequence, the high ploidy (≥8N) cells were accumulated in culture for 8 days, with an increase from 16.2 to 75.2 % of the total cell population. The elevated polyploidization was accompanied by the increased expression level of MK marker, CD41 (platelet glycoprotein IIb/IIIa, GPIIb/IIIa), suggesting that BMS-777607 promoted both polyploidization and commitment of MK-differentiated CHRF cells. Platelet-like fragments (PFs) were released by mature CHRF cells. Based on a flow cytometry assay, it was found that the PFs produced from BMS-777607-treated cells tended to have larger size and higher expression of GPIIb/IIIa, a receptor for platelet adhesion. Taken together, these results suggested that BMS-777607 promoted MK differentiation of CHRF cells and increased the functional property of platelet-like fragments.

  7. Polyploidization on SK-N-MC human neuroblastoma cells infected with herpes simplex virus 1.

    Science.gov (United States)

    Karalyan, Zaven; Izmailyan, Roza; Karalova, Elena; Abroyan, Liana; Hakobyan, Lina; Avetisyan, Aida; Semerjyan, Zara

    2016-01-01

    Polyploidization is one of the most dramatic changes occurring within cell genome owing to various reasons including under many viral infections. We examined the impact of herpes simplex virus-1 (HSV-1) on SK-N-MC human neuroblastoma cell line. The infected cells were followed from 6 hours up to 96 hours post infection (hpi). A large number of polyploid cells with giant nuclei was observed under the influence of HSV-1 at 24 hpi with the DNA content of 32c to 64c or more, in comparison with control SK-N-MC cells that were characterized by relatively moderate values of ploidy, i.e. 8с to 16с (where 1c is the haploid amount of nuclear DNA found in normal diploid populations in G0/G1). After 48-96 hpi, the population of polyploid cells with giant nuclei decreased to the benchmark level. The SK-NMC cells infected with HSV-1 for 24 hours were stained with gallocyanine and monitored for cytological features. The infected cells underwent virus induced cellcell and nuclei fusion with the formation of dense nuclei syncytium. The metabolic activity of HSV-1 infected cells was higher in both nuclei and nucleoli when compared to control cells.

  8. Artificially induced polyploidization in Humulus lupulus L. and its effect on morphological and chemical traits.

    Science.gov (United States)

    Trojak-Goluch, Anna; Skomra, Urszula

    2013-12-01

    Chemically induced polyploids were obtained by the colchicine treatment of shoot tips of Humulus lupulus L. 'Sybilla'. Flow cytometry revealed that most of the treatments resulted in the production of tetraploids. The highest number of tetraploids was obtained when explants were immersed in 0.05% colchicine for 48 h. A field experiment was conducted to compare diploid and tetraploid plants and assess the effect of genome polyploidization on the morphological and chemical characteristics. Tetraploids showed significant differences in relation to diploids. They had thinner and shorter shoots. The influence of chromosome doubling was also reflected in the length, width and area of leaves. The length of female flowers in the tetraploids was significantly shorter than that observed in diploids. Tetraploids produced a diverse number of lupuline glands that were almost twice as large as those observed in diploids. The most distinct effect of genome polyploidization was a significant increase in the weight of cones and spindles. Contents of major chemical constituents of hop cones was little affected by ploidy level. Total essential oils were significantly lower than those in diploids. However there was a significant increase in the proportion of humulene, caryophyllene and farnesene, oils desired by the brewing industry.

  9. Evolutionary dynamics of 3D genome architecture following polyploidization in cotton.

    Science.gov (United States)

    Wang, Maojun; Wang, Pengcheng; Lin, Min; Ye, Zhengxiu; Li, Guoliang; Tu, Lili; Shen, Chao; Li, Jianying; Yang, Qingyong; Zhang, Xianlong

    2018-02-01

    The formation of polyploids significantly increases the complexity of transcriptional regulation, which is expected to be reflected in sophisticated higher-order chromatin structures. However, knowledge of three-dimensional (3D) genome structure and its dynamics during polyploidization remains poor. Here, we characterize 3D genome architectures for diploid and tetraploid cotton, and find the existence of A/B compartments and topologically associated domains (TADs). By comparing each subgenome in tetraploids with its extant diploid progenitor, we find that genome allopolyploidization has contributed to the switching of A/B compartments and the reorganization of TADs in both subgenomes. We also show that the formation of TAD boundaries during polyploidization preferentially occurs in open chromatin, coinciding with the deposition of active chromatin modification. Furthermore, analysis of inter-subgenomic chromatin interactions has revealed the spatial proximity of homoeologous genes, possibly associated with their coordinated expression. This study advances our understanding of chromatin organization in plants and sheds new light on the relationship between 3D genome evolution and transcriptional regulation.

  10. Small Molecule Supplements Improve Cultured Megakaryocyte Polyploidization by Modulating Multiple Cell Cycle Regulators.

    Science.gov (United States)

    Zou, Xiaojing; Qu, Mingyi; Fang, Fang; Fan, Zeng; Chen, Lin; Yue, Wen; Xie, Xiaoyan; Pei, Xuetao

    2017-01-01

    Platelets (PLTs) are produced by megakaryocytes (MKs) that completed differentiation and endomitosis. Endomitosis is an important process in which the cell replicates its DNA without cytokinesis and develops highly polyploid MK. In this study, to gain a better PLTs production, four small molecules (Rho-Rock inhibitor (RRI), nicotinamide (NIC), Src inhibitor (SI), and Aurora B inhibitor (ABI)) and their combinations were surveyed as MK culture supplements for promoting polyploidization. Three leukemia cell lines as well as primary mononuclear cells were chosen in the function and mechanism studies of the small molecules. In an optimal culture method, cells were treated with different small molecules and their combinations. The impact of the small molecules on megakaryocytic surface marker expression, polyploidy, proliferation, and apoptosis was examined for the best MK polyploidization supplement. The elaborate analysis confirmed that the combination of SI and RRI together with our MK induction system might result in efficient ploidy promotion. Our experiments demonstrated that, besides direct downregulation on the expression of cytoskeleton protein actin, SI and RRI could significantly enhance the level of cyclins through the suppression of p53 and p21. The verified small molecule combination might be further used in the in vitro PLT manufacture and clinical applications.

  11. Small Molecule Supplements Improve Cultured Megakaryocyte Polyploidization by Modulating Multiple Cell Cycle Regulators

    Directory of Open Access Journals (Sweden)

    Xiaojing Zou

    2017-01-01

    Full Text Available Platelets (PLTs are produced by megakaryocytes (MKs that completed differentiation and endomitosis. Endomitosis is an important process in which the cell replicates its DNA without cytokinesis and develops highly polyploid MK. In this study, to gain a better PLTs production, four small molecules (Rho-Rock inhibitor (RRI, nicotinamide (NIC, Src inhibitor (SI, and Aurora B inhibitor (ABI and their combinations were surveyed as MK culture supplements for promoting polyploidization. Three leukemia cell lines as well as primary mononuclear cells were chosen in the function and mechanism studies of the small molecules. In an optimal culture method, cells were treated with different small molecules and their combinations. The impact of the small molecules on megakaryocytic surface marker expression, polyploidy, proliferation, and apoptosis was examined for the best MK polyploidization supplement. The elaborate analysis confirmed that the combination of SI and RRI together with our MK induction system might result in efficient ploidy promotion. Our experiments demonstrated that, besides direct downregulation on the expression of cytoskeleton protein actin, SI and RRI could significantly enhance the level of cyclins through the suppression of p53 and p21. The verified small molecule combination might be further used in the in vitro PLT manufacture and clinical applications.

  12. polymapR - linkage analysis and genetic map construction from F1 populations of outcrossing polyploids.

    Science.gov (United States)

    Bourke, Peter M; van Geest, Geert; Voorrips, Roeland E; Jansen, Johannes; Kranenburg, Twan; Shahin, Arwa; Visser, Richard G F; Arens, Paul; Smulders, Marinus J M; Maliepaard, Chris

    2018-05-02

    Polyploid species carry more than two copies of each chromosome, a condition found in many of the world's most important crops. Genetic mapping in polyploids is more complex than in diploid species, resulting in a lack of available software tools. These are needed if we are to realise all the opportunities offered by modern genotyping platforms for genetic research and breeding in polyploid crops. polymapR is an R package for genetic linkage analysis and integrated genetic map construction from bi-parental populations of outcrossing autopolyploids. It can currently analyse triploid, tetraploid and hexaploid marker datasets and is applicable to various crops including potato, leek, alfalfa, blueberry, chrysanthemum, sweet potato or kiwifruit. It can detect, estimate and correct for preferential chromosome pairing, and has been tested on high-density marker datasets from potato, rose and chrysanthemum, generating high-density integrated linkage maps in all of these crops. polymapR is freely available under the general public license from the Comprehensive R Archive Network (CRAN) at http://cran.r-project.org/package=polymapR. Chris Maliepaard chris.maliepaard@wur.nl or Roeland E. Voorrips roeland.voorrips@wur.nl. Supplementary data are available at Bioinformatics online.

  13. PECULIARITIES OF THE TRANSITION OF EARLY STURGEON (ACIPENSERIDAE FRY TO ARTIFICIAL FORMULATED FEEDS IN RAS (A REVIEW

    Directory of Open Access Journals (Sweden)

    M. Simon

    2016-03-01

    Full Text Available Purpose. To review scientific sources on the morphological and ecophysiological peculiarities of the transition of early sturgeon fry (Acipenseridae to artificial formulated feeds. To summarize the biotechnological fundamentals of the use of artificial formulated feeds in the conditions of recirculating aquaculture systems (RAS. Findings. The transition of early sturgeon fry to artificial formulated feeds is one of the most difficult stages of their rearing, even under controlled conditions of RAS. The review contains the description of the peculiarities of sturgeon embryogenesis, their behavior and morpho-physiological changes at this stage of their development. It contains main requirements for the rearing of sturgeon larvae in RAS. We showed that the ultimate refuse from natural (live or frozen forage organisms is not advisable; the optimum is their combination with artificial feeds with gradual predominance of the latters. We provided the schemes of their feeding based on the combination of natural and artificial feeds. We reviewed the most common biologically active supplements, which contributed to better feed digestion during the periods of the transition to exogenous feeding. We highlighted the effect of feeding with brine shrimp nauplii enriched with polyunsaturated fatty acids on the growth and development of early sturgeon fry. Practical value. The array of the summarized information will be important for scientists who study the peculiarities of the transition of early sturgeon fry to artificial formulated feeds in RAS. The data on the biotechnologies of rational feeding of early sturgeon fry in RAS in this period are important in the conditions of continuous search for the most effective replacement of live forage organisms and reduction of fish fry mortality in postembryogenesis.

  14. Thrombopoietin-induced Polyploidization of Bone Marrow Megakaryocytes Is Due to a Unique Regulatory Mechanism in Late Mitosis

    Science.gov (United States)

    Nagata, Yuka; Muro, Yoshinao; Todokoro, Kazuo

    1997-01-01

    Megakaryocytes undergo a unique differentiation program, becoming polyploid through repeated cycles of DNA synthesis without concomitant cell division. However, the mechanism underlying this polyploidization remains totally unknown. It has been postulated that polyploidization is due to a skipping of mitosis after each round of DNA replication. We carried out immunohistochemical studies on mouse bone marrow megakaryocytes during thrombopoietin- induced polyploidization and found that during this process megakaryocytes indeed enter mitosis and progress through normal prophase, prometaphase, metaphase, and up to anaphase A, but not to anaphase B, telophase, or cytokinesis. It was clearly observed that multiple spindle poles were formed as the polyploid megakaryocytes entered mitosis; the nuclear membrane broke down during prophase; the sister chromatids were aligned on a multifaced plate, and the centrosomes were symmetrically located on either side of each face of the plate at metaphase; and a set of sister chromatids moved into the multiple centrosomes during anaphase A. We further noted that the pair of spindle poles in anaphase were located in close proximity to each other, probably because of the lack of outward movement of spindle poles during anaphase B. Thus, the reassembling nuclear envelope may enclose all the sister chromatids in a single nucleus at anaphase and then skip telophase and cytokinesis. These observations clearly indicate that polyploidization of megakaryocytes is not simply due to a skipping of mitosis, and that the megakaryocytes must have a unique regulatory mechanism in anaphase, e.g., factors regulating anaphase such as microtubule motor proteins might be involved in this polyploidization process. PMID:9334347

  15. A habitat suitability model for Chinese sturgeon determined using the generalized additive method

    Science.gov (United States)

    Yi, Yujun; Sun, Jie; Zhang, Shanghong

    2016-03-01

    The Chinese sturgeon is a type of large anadromous fish that migrates between the ocean and rivers. Because of the construction of dams, this sturgeon's migration path has been cut off, and this species currently is on the verge of extinction. Simulating suitable environmental conditions for spawning followed by repairing or rebuilding its spawning grounds are effective ways to protect this species. Various habitat suitability models based on expert knowledge have been used to evaluate the suitability of spawning habitat. In this study, a two-dimensional hydraulic simulation is used to inform a habitat suitability model based on the generalized additive method (GAM). The GAM is based on real data. The values of water depth and velocity are calculated first via the hydrodynamic model and later applied in the GAM. The final habitat suitability model is validated using the catch per unit effort (CPUEd) data of 1999 and 2003. The model results show that a velocity of 1.06-1.56 m/s and a depth of 13.33-20.33 m are highly suitable ranges for the Chinese sturgeon to spawn. The hydraulic habitat suitability indexes (HHSI) for seven discharges (4000; 9000; 12,000; 16,000; 20,000; 30,000; and 40,000 m3/s) are calculated to evaluate integrated habitat suitability. The results show that the integrated habitat suitability reaches its highest value at a discharge of 16,000 m3/s. This study is the first to apply a GAM to evaluate the suitability of spawning grounds for the Chinese sturgeon. The study provides a reference for the identification of potential spawning grounds in the entire basin.

  16. Effects of acclimation on poststocking dispersal and physiological condition of age-1 pallid sturgeon

    Science.gov (United States)

    Oldenburg, E.W.; Guy, C.S.; Cureton, E.S.; Webb, M.A.H.; Gardner, W.M.

    2011-01-01

    The objective of this study was to evaluate the effects of acclimation to flow and site-specific physicochemical water conditions on poststocking dispersal and physiological condition of age-1 hatchery-reared pallid sturgeon. Fish from three acclimation treatments were radio-tagged, released at two locations (Missouri River and Marias River), and monitored using passive telemetry stations. Marias treatment was acclimated to flow and site-specific physicochemical conditions, Bozeman treatment was acclimated to flow only, and controls had no acclimation (reared under traditional conservation propagation protocol). During both years, fish released in the Missouri River dispersed less than fish released in the Marias River. In 2005, Marias treatment dispersed less and nearly twice as many fish remained in the Missouri River reach as compared to control fish. In 2006, pallid sturgeon dispersed similarly among treatments and the number of fish remaining in the Missouri River reach was similar among all treatments. Differences in poststocking dispersal between years were related to fin curl which was present in all fish in 2005 and only 26% in 2006. Pallid sturgeon from all treatments in both years had a greater affinity for the lower reaches of the Missouri River than the upper reaches. Thus, release site influenced poststocking dispersal more than acclimation treatment. No difference was observed in relative growth rate among treatments. However, acclimation to flow (i.e., exercise conditioning) prevented fat accumulation from rupturing hepatocytes. Acclimation conditions used in this study did not benefit pallid sturgeon unless physiological maladies were present. Overriding all treatment effects was stocking location; thus, natural resource agencies need to consider stocking location carefully to reduce poststocking dispersal. ?? 2011 Blackwell Verlag, Berlin.

  17. Use of geometric morphometrics to identify ecophenotypic variation of juvenile Persian sturgeon Acipenser persicus

    Directory of Open Access Journals (Sweden)

    Shima Bakhshalizadeh

    2017-06-01

    Full Text Available Study of phenotypic variation is essential for identifying discrete phenotypic stocks. We sampled immature Persian sturgeon from the eastern and western portion of the southern Caspian Sea to test for morphological differences that could predict the ecophenotypic variation of Persian sturgeon. Geometric morphometric methods were used to quantify body shape. Configuration of landmark coordinates of fish body were scaled, translated and rotated using generalized Procrustes analysis, followed by univariate analysis of variance of resulting shape coordinates to evaluate potential morphological differences between regions. A principal component analysis was carried out to reduce the number of dimensions without the loss of information. The discriminate function analysis was performed to determine the efficacy of body landmarks for discrimination by geographic variants. Within-group linkage was inferred for dendrogram clusters using Pearson correlation distance on the basis of the average linkage method as a complement for discriminate analysis. Principle component analysis revealed that the largest differences were in body size. Most notable were differences in distance between head landmarks and the dorsal fin between eastern and western regions. Fish from the western region exhibited a longer distance from head landmarks to the dorsal fin than fish from the eastern region. Furthermore, the ventral portion of fish from the western region was longer than that of the eastern individuals. These findings show that juvenile Persian sturgeon already possess morphological traits that can be used to discriminate fish from different regions. Furthermore, these differences are discernible in spite of the volume of artificially-inseminated sturgeon larva that have been released during the past 40 years.

  18. Fall spawning of Atlantic sturgeon in the Roanoke River, North Carolina

    Science.gov (United States)

    Smith, Joseph A.; Hightower, Joseph E.; Flowers, H. Jared

    2015-01-01

    In 2012, the National Oceanic and Atmospheric Administration (NOAA) declared Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus to be threatened or endangered throughout its range in U.S. waters. Restoration of the subspecies will require much new information, particularly on the location and timing of spawning. We used a combination of acoustic telemetry and sampling with anchored artificial substrates (spawning pads) to detect fall (September–November) spawning in the Roanoke River in North Carolina. This population is included in the Carolina Distinct Population Segment, which was classified by NOAA as endangered. Sampling was done immediately below the first shoals encountered by anadromous fishes, near Weldon. Our collection of 38 eggs during the 21 d that spawning pads were deployed appears to be the first such collection (spring or fall) for wild-spawned Atlantic Sturgeon eggs. Based on egg development stages, estimated spawning dates were September 17–18 and 18–19 at water temperatures from 25.3°C to 24.3°C and river discharge from 55 to 297 m3/s. These observations about fall spawning and habitat use should aid in protecting critical habitats and planning research on Atlantic Sturgeon spawning in other rivers.

  19. Genetic diversity, kinship analysis, and broodstock management of captive Atlantic sturgeon for population restoration

    Science.gov (United States)

    Henderson, A.P.; Spidle, A.P.; King, T.L.

    2005-01-01

    Captive Atlantic sturgeon Acipenser oxyrinchus considered for use as broodstock in a restoration program were genotyped using nuclear DNA microsatellites and compared to wild collections from the Hudson River, New York (source of parents of the captive sturgeon) and from Albemarle Sound, North Carolina. Because the potential broodfish were the progeny of a small number of parents, maintaining genetic diversity and minimizing inbreeding is essential to a successful breeding and supplementation program. The microsatellite loci used in this analysis generated unique multilocus genotypes for each of 136 Atlantic sturgeon. Analyses indicated significant genetic separation between the New York and North Carolina collections and correctly identified the potential broodstock as a subset of the Hudson River population. Pairwise genetic distance (-In proportion of shared alleles) between half and full siblings in the potential broodfish was as great as 1.386, a value exceeded by only 36% of the sampled broodfish pairs available for mating. Because the current broodstock population does not seem to have deviated far from their ancestral population in the Hudson River, progeny from that broodstock, or the parents themselves, would seem to be genetically suitable for release back into the Hudson River.

  20. Sturgeon in the Sacramento–San Joaquin Watershed: New Insights to Support Conservation and Management

    Directory of Open Access Journals (Sweden)

    A. Peter Klimley

    2015-12-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2015v13iss4art1The goal of a day-long symposium on March 3, 2015, Sturgeon in the Sacramento–San Joaquin Watershed: New Insights to Support Conservation and Management, was to present new information about the physiology, behavior, and ecology of the green (Acipenser medirostris and white sturgeon (Acipenser transmontanus to help guide enhanced management and conservation efforts within the Sacramento–San Joaquin watershed. This symposium identified current unknowns and highlighted new electronic tracking technologies and physiological techniques to address these knowledge gaps. A number of presentations, each reviewing ongoing research on the two species, was followed by a round-table discussion, in which each of the participants was asked to share recom-mendations for future research on sturgeon in the watershed. This article presents an in-depth review of the scientific information presented at the sympo-sium with a summary of recommendations for future research.

  1. Life history and status of Shortnose Sturgeon (Acipenser brevirostrum LeSueur, 1818)

    Science.gov (United States)

    Kynard, Boyd; Bolden, Stephania; Kieffer, Micah; Collins, Mark; Brundage, Hal; Hilton, Eric; Litvak, Mark; Kinnison, Michael T.; King, Timothy L.; Peterson, Douglas C.

    2016-01-01

    Shortnose Sturgeon = SNS (Acipenser brevirostrum) is a small diadromous species with most populations living in large Atlantic coast rivers and estuaries of North America from New Brunswick, Canada, to GA, USA. There are no naturally landlocked populations, so all populations require access to fresh water and salt water to complete a natural life cycle. The species is amphidromous with use of fresh water and salt water (the estuary) varied across the species range, a pattern that may reflect whether freshwater or saltwater habitats provide optimal foraging and growth conditions. Migration is a dominant behavior during life history, beginning when fish are hatchling free embryos (southern SNS) or larvae (northeastern and far northern SNS). Migration continues by juveniles and nonspawning adult life stages on an individual time schedule with fish moving between natal river and estuary to forage or seek refuge, and by spawning adults migrating to and from riverine spawning grounds. Coastal movements by adults throughout the range (but particularly in the Gulf of Maine = GOM and among southern rivers) suggest widespread foraging, refuge use, and widespread colonization of new rivers. Colonization may also be occurring in the Potomac River, MD–VA–DC (midAtlantic region). Genetic studies (mtDNA and nDNA) identified distinct individual river populations of SNS, and recent rangewide nDNA studies identified five distinct evolutionary lineages of SNS in the USA: a northern metapopulation in GOM rivers; the Connecticut River; the Hudson River; a Delaware River–Chesapeake Bay metapopulation; and a large southern metapopulation (SC rivers to Altamaha River, GA). The Saint John River, NB, Canada, in the Bay of Fundy (north of the GOM), is the sixth distinct genetic lineage within SNS. Life history information from telemetry tracking supports the genetic information documenting extensive movement of adults among rivers within the three metapopulations. However

  2. Assessing water quality suitability for shortnose sturgeon in the Roanoke River, North Carolina, USA with an in situ bioassay approach

    Science.gov (United States)

    Cope, W.G.; Holliman, F.M.; Kwak, T.J.; Oakley, N.C.; Lazaro, P.R.; Shea, D.; Augspurger, T.; Law, J.M.; Henne, J.P.; Ware, K.M.

    2011-01-01

    The aim of this study was to determine the suitability of water quality in the Roanoke River of North Carolina for supporting shortnose sturgeon Acipenser brevirostrum, an endangered species in the United States. Fathead minnows Pimephales promelas were also evaluated alongside the sturgeon as a comparative species to measure potential differences in fish survival, growth, contaminant accumulation, and histopathology in a 28-day in situ toxicity test. Captively propagated juvenile shortnose sturgeon (total length 49??8mm, mean??SD) and fathead minnows (total length 39??3mm, mean??SD) were used in the test and their outcomes were compared to simultaneous measurements of water quality (temperature, dissolved oxygen, pH, conductivity, total ammonia nitrogen, hardness, alkalinity, turbidity) and contaminant chemistry (metals, polycyclic aromatic hydrocarbons, organochlorine pesticides, current use pesticides, polychlorinated biphenyls) in river water and sediment. In the in situ test, there were three non-riverine control sites and eight riverine test sites with three replicate cages (25??15-cm (OD) clear plexiglass with 200-??m tear-resistant Nitex?? screen over each end) of 20 shortnose sturgeon per cage at each site. There was a single cage of fathead minnows also deployed at each site alongside the sturgeon cages. Survival of caged shortnose sturgeon among the riverine sites averaged 9% (range 1.7-25%) on day 22 of the 28-day study, whereas sturgeon survival at the non-riverine control sites averaged 64% (range 33-98%). In contrast to sturgeon, only one riverine deployed fathead minnow died (average 99.4% survival) over the 28-day test period and none of the control fathead minnows died. Although chemical analyses revealed the presence of retene (7-isopropyl-1-methylphenanthrene), a pulp and paper mill derived compound with known dioxin-like toxicity to early life stages of fish, in significant quantities in the water (251-603ngL-1) and sediment (up to 5000ngg-1

  3. Cyclin D-Cdk4 is regulated by GATA-1 and required for megakaryocyte growth and polyploidization.

    Science.gov (United States)

    Muntean, Andrew G; Pang, Liyan; Poncz, Mortimer; Dowdy, Steven F; Blobel, Gerd A; Crispino, John D

    2007-06-15

    Endomitosis is a unique form of cell cycle used by megakaryocytes, in which the latter stages of mitosis are bypassed so that the cell can increase its DNA content and size. Although several transcription factors, including GATA-1 and RUNX-1, have been implicated in this process, the link between transcription factors and polyploidization remains undefined. Here we show that GATA-1-deficient megakaryocytes, which display reduced size and polyploidization, express nearly 10-fold less cyclin D1 and 10-fold increased levels of p16 compared with their wild-type counterparts. We further demonstrate that cyclin D1 is a direct GATA-1 target in megakaryocytes, but not erythroid cells. Restoration of cyclin D1 expression, when accompanied by ectopic overexpression of its partner Cdk4, resulted in a dramatic increase in megakaryocyte size and DNA content. However, terminal differentiation was not rescued. Of note, polyploidization was only modestly reduced in cyclin D1-deficient mice, likely due to compensation by elevated cyclin D3 expression. Finally, consistent with an additional defect conferred by increased levels of p16, inhibition of cyclin D-Cdk4 complexes with a TAT-p16 fusion peptide significantly blocked polyploidization of wild-type megakaryocytes. Together, these data show that GATA-1 controls growth and polyploidization by regulating cyclin D-Cdk4 kinase activity.

  4. Cyclin D–Cdk4 is regulated by GATA-1 and required for megakaryocyte growth and polyploidization

    Science.gov (United States)

    Muntean, Andrew G.; Pang, Liyan; Poncz, Mortimer; Dowdy, Steven F.; Blobel, Gerd A.

    2007-01-01

    Endomitosis is a unique form of cell cycle used by megakaryocytes, in which the latter stages of mitosis are bypassed so that the cell can increase its DNA content and size. Although several transcription factors, including GATA-1 and RUNX-1, have been implicated in this process, the link between transcription factors and polyploidization remains undefined. Here we show that GATA-1–deficient megakaryocytes, which display reduced size and polyploidization, express nearly 10-fold less cyclin D1 and 10-fold increased levels of p16 compared with their wild-type counterparts. We further demonstrate that cyclin D1 is a direct GATA-1 target in megakaryocytes, but not erythroid cells. Restoration of cyclin D1 expression, when accompanied by ectopic overexpression of its partner Cdk4, resulted in a dramatic increase in megakaryocyte size and DNA content. However, terminal differentiation was not rescued. Of note, polyploidization was only modestly reduced in cyclin D1–deficient mice, likely due to compensation by elevated cyclin D3 expression. Finally, consistent with an additional defect conferred by increased levels of p16, inhibition of cyclin D-Cdk4 complexes with a TAT-p16 fusion peptide significantly blocked polyploidization of wild-type megakaryocytes. Together, these data show that GATA-1 controls growth and polyploidization by regulating cyclin D-Cdk4 kinase activity. PMID:17317855

  5. Ontogenetic behavior and dispersal of Sacramento River white sturgeon, Acipenser transmontanus, with a note on body color

    Science.gov (United States)

    Kynard, B.; Parker, E.

    2005-01-01

    We studied Sacramento River white sturgeon, Acipenser transmontanus, in the laboratory to develop a conceptual model of ontogenetic behavior and provide insight into probable behavior of wild sturgeon. After hatching, free embryos initiated a low intensity, brief downstream dispersal during which fish swam near the bottom and were photonegative. The weak, short dispersal style and behavior of white sturgeon free embryos contrasts greatly with the intense, long dispersal style and behavior (photopositive and swimming far above the bottom) of dispersing free embryos of other sturgeon species. If spawned eggs are concentrated within a few kilometers downstream of a spawning site, the adaptive significance of the free embryo dispersal is likely to move fish away from the egg deposition site to avoid predation and reduce fish density prior to feeding. Larvae foraged on the open bottom, swam innate fish dispersal and post-dispersal rearing habitat, which is now highly altered by damming and reservoirs. Sacramento River white sturgeon has a two-step downstream dispersal by the free embryo and juvenile life intervals. Diel activity of all life intervals peaked at night, whether fish were dispersing or foraging. Nocturnal behavior is likely a response to predation, which occurs during both activities. An intense black-tail body color was present on foraging larvae, but was weak or absent on the two life intervals that disperse. Black-tail color may be an adaptation for avoiding predation, signaling among aggregated larvae, or both, but not for dispersal. ?? Springer 2005.

  6. Involvement of Receptor Activator of Nuclear Factor-κB Ligand (RANKL)-induced Incomplete Cytokinesis in the Polyploidization of Osteoclasts*

    Science.gov (United States)

    Takegahara, Noriko; Kim, Hyunsoo; Mizuno, Hiroki; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Tomura, Michio; Kanagawa, Osami; Ishii, Masaru; Choi, Yongwon

    2016-01-01

    Osteoclasts are specialized polyploid cells that resorb bone. Upon stimulation with receptor activator of nuclear factor-κB ligand (RANKL), myeloid precursors commit to becoming polyploid, largely via cell fusion. Polyploidization of osteoclasts is necessary for their bone-resorbing activity, but the mechanisms by which polyploidization is controlled remain to be determined. Here, we demonstrated that in addition to cell fusion, incomplete cytokinesis also plays a role in osteoclast polyploidization. In in vitro cultured osteoclasts derived from mice expressing the fluorescent ubiquitin-based cell cycle indicator (Fucci), RANKL induced polyploidy by incomplete cytokinesis as well as cell fusion. Polyploid cells generated by incomplete cytokinesis had the potential to subsequently undergo cell fusion. Nuclear polyploidy was also observed in osteoclasts in vivo, suggesting the involvement of incomplete cytokinesis in physiological polyploidization. Furthermore, RANKL-induced incomplete cytokinesis was reduced by inhibition of Akt, resulting in impaired multinucleated osteoclast formation. Taken together, these results reveal that RANKL-induced incomplete cytokinesis contributes to polyploidization of osteoclasts via Akt activation. PMID:26670608

  7. Involvement of Receptor Activator of Nuclear Factor-κB Ligand (RANKL)-induced Incomplete Cytokinesis in the Polyploidization of Osteoclasts.

    Science.gov (United States)

    Takegahara, Noriko; Kim, Hyunsoo; Mizuno, Hiroki; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Tomura, Michio; Kanagawa, Osami; Ishii, Masaru; Choi, Yongwon

    2016-02-12

    Osteoclasts are specialized polyploid cells that resorb bone. Upon stimulation with receptor activator of nuclear factor-κB ligand (RANKL), myeloid precursors commit to becoming polyploid, largely via cell fusion. Polyploidization of osteoclasts is necessary for their bone-resorbing activity, but the mechanisms by which polyploidization is controlled remain to be determined. Here, we demonstrated that in addition to cell fusion, incomplete cytokinesis also plays a role in osteoclast polyploidization. In in vitro cultured osteoclasts derived from mice expressing the fluorescent ubiquitin-based cell cycle indicator (Fucci), RANKL induced polyploidy by incomplete cytokinesis as well as cell fusion. Polyploid cells generated by incomplete cytokinesis had the potential to subsequently undergo cell fusion. Nuclear polyploidy was also observed in osteoclasts in vivo, suggesting the involvement of incomplete cytokinesis in physiological polyploidization. Furthermore, RANKL-induced incomplete cytokinesis was reduced by inhibition of Akt, resulting in impaired multinucleated osteoclast formation. Taken together, these results reveal that RANKL-induced incomplete cytokinesis contributes to polyploidization of osteoclasts via Akt activation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. A short-term look at potential changes in Lake Michigan slimy sculpin diets

    Science.gov (United States)

    French, John R. P.; Stickel, Richard G.; Stockdale, Beth A.; Black, M. Glen

    2010-01-01

    Diporeia hoyi and Mysis relicta are the most important prey items of slimy sculpins (Cottus cognatus) in the Great Lakes. Slimy sculpins were collected from dreissenid-infested bottoms off seven Lake Michigan ports at depths of 27–73 m in fall 2003 to study their lake-wide diets. Relatively large dreissenid biomass occurred at depths of 37- and 46-m. Quagga mussels (Dreissena bugnesis) composed at least 50% of dreissenid biomass at Manistique, Saugatuck, and Sturgeon Bay. Mysis accounted for 82% of the sculpin diet by dry weight at eastern Lake Michigan while Diporeia composed 54–69% of the diet at western Lake Michigan and dominated the diets of slimy sculpins at all sites deeper than 46 m. In northern Lake Michigan, this diet study in new sites showed that slimy sculpin consumed more prey with low energy contents, especially chironomids, than Mysis and Diporeia in shallow sites (depth diet studies on sedentary benthic fishes to be conducted along perimeters of the Great Lakes to observe changes in their diets that may be impacted by changing benthic macroinvertebrate communities.

  9. Analysis of piscicultural-biological results of works with Russian sturgeon brood fish at the sturgeon hatchery “Lebyazhy” (Astrakhan region, Russia

    Directory of Open Access Journals (Sweden)

    R. V. Kononenko

    2013-04-01

    Full Text Available The state of world stocks of sturgeons is on the edge of catastrophe. These species are either extinct or under threat of extinction under human impacts. At the same time, there are enterprises, fish hatcheries, which deal with restoration and replenishment of natural stocks with of endangered fish species. One of such hatcheries is the sturgeon hatchery “Lebyazhy” (Astrakhan region, Russian Federation. The aim of the study was an analysis of piscicultural-biological features of the Russian sturgeon brood fish. During the study, which was conducted in April–May 2011, 34 Russian sturgeon females were used in two rounds, 17 individuals each. For stimulating gametes maturation, the Derzhavin’s physiological method was used. Caviar was obtained by stripping the eggs under strict hygienic and sanitary norms. Eggs fertilization with the semi-dry method used the male milt that bought at the “Raskat” LLC. Egg stickiness elimination was performed with the aid of talc and apparatuses for the egg stickiness elimination. Eggs incubation was performed in the “Osetr” apparatuses until yolk-sac larvae hatching. The domesticated fish were subjected to bonitation for determining their readiness for spawning. As a result of this bonitation, the brood fish were separated into two groups: first round of rearing works: females with mean weight of 34.8 kg and age of 9 years; second round: females with mean weight of 32.3 kg and the same age. Among injected females of the first round, 100% positive reaction for the stimulating injection was observed, but 95% – among females of the second round. Maturation time of females of both rounds varied from 25 to 30 hours. The maturation state of gametes of sturgeon females or males was determined based on samples obtained. 90.2 kg of eggs were obtained from females of the first round. At the same time, the maximum quantity was observed in the female of 50.5 kg – 9.2 kg of caviar, and the least quantity

  10. HANDS: a tool for genome-wide discovery of subgenome-specific base-identity in polyploids.

    KAUST Repository

    Mithani, Aziz

    2013-09-24

    The analysis of polyploid genomes is problematic because homeologous subgenome sequences are closely related. This relatedness makes it difficult to assign individual sequences to the specific subgenome from which they are derived, and hinders the development of polyploid whole genome assemblies.We here present a next-generation sequencing (NGS)-based approach for assignment of subgenome-specific base-identity at sites containing homeolog-specific polymorphisms (HSPs): \\'HSP base Assignment using NGS data through Diploid Similarity\\' (HANDS). We show that HANDS correctly predicts subgenome-specific base-identity at >90% of assayed HSPs in the hexaploid bread wheat (Triticum aestivum) transcriptome, thus providing a substantial increase in accuracy versus previous methods for homeolog-specific base assignment.We conclude that HANDS enables rapid and accurate genome-wide discovery of homeolog-specific base-identity, a capability having multiple applications in polyploid genomics.

  11. HANDS: a tool for genome-wide discovery of subgenome-specific base-identity in polyploids.

    KAUST Repository

    Mithani, Aziz; Belfield, Eric J; Brown, Carly; Jiang, Caifu; Leach, Lindsey J; Harberd, Nicholas P

    2013-01-01

    The analysis of polyploid genomes is problematic because homeologous subgenome sequences are closely related. This relatedness makes it difficult to assign individual sequences to the specific subgenome from which they are derived, and hinders the development of polyploid whole genome assemblies.We here present a next-generation sequencing (NGS)-based approach for assignment of subgenome-specific base-identity at sites containing homeolog-specific polymorphisms (HSPs): 'HSP base Assignment using NGS data through Diploid Similarity' (HANDS). We show that HANDS correctly predicts subgenome-specific base-identity at >90% of assayed HSPs in the hexaploid bread wheat (Triticum aestivum) transcriptome, thus providing a substantial increase in accuracy versus previous methods for homeolog-specific base assignment.We conclude that HANDS enables rapid and accurate genome-wide discovery of homeolog-specific base-identity, a capability having multiple applications in polyploid genomics.

  12. Effect of starvation and refeeding on digestive enzyme activities in sturgeon (Acipenser naccarii) and trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Furné, Miriam; García-Gallego, Manuel; Hidalgo, M Carmen; Morales, Amalia E; Domezain, Alberto; Domezain, Julio; Sanz, Ana

    2008-04-01

    The digestive enzyme activities were determined in Adriatic sturgeon and rainbow trout during starvation and refeeding period. Overall, the digestive enzyme activities are affected in the same sense in both species. The protease and lipase activities were decreased later than amylase activity. Even after 1 month of starvation, both species would be prepared to digest protein and lipids in an effective way. After 72 days of starvation, the digestive machinery of the sturgeon and of the trout shows an altered capacity to digest macronutrients. The capacity to digest proteins and lipids, after 60 days of refeeding, begins to become re-established in sturgeon and trout. In contrast, in this period, the capacity to digest carbohydrates remains depressed in both species.

  13. H-PoP and H-PoPG: heuristic partitioning algorithms for single individual haplotyping of polyploids.

    Science.gov (United States)

    Xie, Minzhu; Wu, Qiong; Wang, Jianxin; Jiang, Tao

    2016-12-15

    Some economically important plants including wheat and cotton have more than two copies of each chromosome. With the decreasing cost and increasing read length of next-generation sequencing technologies, reconstructing the multiple haplotypes of a polyploid genome from its sequence reads becomes practical. However, the computational challenge in polyploid haplotyping is much greater than that in diploid haplotyping, and there are few related methods. This article models the polyploid haplotyping problem as an optimal poly-partition problem of the reads, called the Polyploid Balanced Optimal Partition model. For the reads sequenced from a k-ploid genome, the model tries to divide the reads into k groups such that the difference between the reads of the same group is minimized while the difference between the reads of different groups is maximized. When the genotype information is available, the model is extended to the Polyploid Balanced Optimal Partition with Genotype constraint problem. These models are all NP-hard. We propose two heuristic algorithms, H-PoP and H-PoPG, based on dynamic programming and a strategy of limiting the number of intermediate solutions at each iteration, to solve the two models, respectively. Extensive experimental results on simulated and real data show that our algorithms can solve the models effectively, and are much faster and more accurate than the recent state-of-the-art polyploid haplotyping algorithms. The experiments also show that our algorithms can deal with long reads and deep read coverage effectively and accurately. Furthermore, H-PoP might be applied to help determine the ploidy of an organism. https://github.com/MinzhuXie/H-PoPG CONTACT: xieminzhu@hotmail.comSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    Lake Cadagno (26 ha) is a crenogenic meromictic lake located in the Swiss Alps at 1921 m asl with a maximum depth of 21 m. The presence of crystalline rocks and a dolomite vein rich in gypsum in the catchment area makes the lake a typical “sulphuretum ” dominated by coupled carbon and sulphur...... cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

  15. Playa Lakes

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the spatial distribution of soil units associated with playa lakes. Specific soil types have been designated by the...

  16. Migrations and swimming capabilities of endangered pallid sturgeon (Scaphirhynchus albus) to guide passage designs in the fragmented Yellowstone River

    Science.gov (United States)

    Braaten, P. J.; Elliott, Caroline M.; Rhoten, Jason C.; Fuller, D. B.; McElroy, Brandon J.

    2015-01-01

    Fragmentation of the Yellowstone River is hypothesized to preclude recruitment of endangered Scaphirhynchus albus (pallid sturgeon) by impeding upstream spawning migrations and access to upstream spawning areas, thereby limiting the length of free-flowing river required for survival of early life stages. Building on this hypothesis, the reach of the Yellowstone River affected by Intake Diversion Dam (IDD) is targeted for modification. Structures including a rock ramp and by-pass channel have been proposed as restoration alternatives to facilitate passage. Limited information on migrations and swimming capabilities of pallid sturgeon is available to guide engineering design specifications for the proposed structures. Migration behavior, pathways (channel routes used during migrations), and swimming capabilities of free-ranging wild adult pallid sturgeon were examined using radiotelemetry, and complemented with hydraulic data obtained along the migration pathways. Migrations of 12–26% of the telemetered pallid sturgeon population persisted to IDD, but upstream passage over the dam was not detected. Observed migration pathways occurred primarily through main channel habitats; however, migrations through side channels up to 3.9 km in length were documented. The majority of pallid sturgeon used depths of 2.2–3.4 m and mean water velocities of 0.89–1.83 m/s while migrating. Results provide inferences on depths, velocities, and habitat heterogeneity of reaches successfully negotiated by pallid sturgeon that may be used to guide designs for structures facilitating passage at IDD. Passage will provide connectivity to potential upstream spawning areas on the Yellowstone River, thereby increasing the likelihood of recruitment for this endangered species.

  17. Inference of haplotypic phase and missing genotypes in polyploid organisms and variable copy number genomic regions

    Directory of Open Access Journals (Sweden)

    Balding David J

    2008-12-01

    Full Text Available Abstract Background The power of haplotype-based methods for association studies, identification of regions under selection, and ancestral inference, is well-established for diploid organisms. For polyploids, however, the difficulty of determining phase has limited such approaches. Polyploidy is common in plants and is also observed in animals. Partial polyploidy is sometimes observed in humans (e.g. trisomy 21; Down's syndrome, and it arises more frequently in some human tissues. Local changes in ploidy, known as copy number variations (CNV, arise throughout the genome. Here we present a method, implemented in the software polyHap, for the inference of haplotype phase and missing observations from polyploid genotypes. PolyHap allows each individual to have a different ploidy, but ploidy cannot vary over the genomic region analysed. It employs a hidden Markov model (HMM and a sampling algorithm to infer haplotypes jointly in multiple individuals and to obtain a measure of uncertainty in its inferences. Results In the simulation study, we combine real haplotype data to create artificial diploid, triploid, and tetraploid genotypes, and use these to demonstrate that polyHap performs well, in terms of both switch error rate in recovering phase and imputation error rate for missing genotypes. To our knowledge, there is no comparable software for phasing a large, densely genotyped region of chromosome from triploids and tetraploids, while for diploids we found polyHap to be more accurate than fastPhase. We also compare the results of polyHap to SATlotyper on an experimentally haplotyped tetraploid dataset of 12 SNPs, and show that polyHap is more accurate. Conclusion With the availability of large SNP data in polyploids and CNV regions, we believe that polyHap, our proposed method for inferring haplotypic phase from genotype data, will be useful in enabling researchers analysing such data to exploit the power of haplotype-based analyses.

  18. Haplotype assembly in polyploid genomes and identical by descent shared tracts.

    Science.gov (United States)

    Aguiar, Derek; Istrail, Sorin

    2013-07-01

    Genome-wide haplotype reconstruction from sequence data, or haplotype assembly, is at the center of major challenges in molecular biology and life sciences. For complex eukaryotic organisms like humans, the genome is vast and the population samples are growing so rapidly that algorithms processing high-throughput sequencing data must scale favorably in terms of both accuracy and computational efficiency. Furthermore, current models and methodologies for haplotype assembly (i) do not consider individuals sharing haplotypes jointly, which reduces the size and accuracy of assembled haplotypes, and (ii) are unable to model genomes having more than two sets of homologous chromosomes (polyploidy). Polyploid organisms are increasingly becoming the target of many research groups interested in the genomics of disease, phylogenetics, botany and evolution but there is an absence of theory and methods for polyploid haplotype reconstruction. In this work, we present a number of results, extensions and generalizations of compass graphs and our HapCompass framework. We prove the theoretical complexity of two haplotype assembly optimizations, thereby motivating the use of heuristics. Furthermore, we present graph theory-based algorithms for the problem of haplotype assembly using our previously developed HapCompass framework for (i) novel implementations of haplotype assembly optimizations (minimum error correction), (ii) assembly of a pair of individuals sharing a haplotype tract identical by descent and (iii) assembly of polyploid genomes. We evaluate our methods on 1000 Genomes Project, Pacific Biosciences and simulated sequence data. HapCompass is available for download at http://www.brown.edu/Research/Istrail_Lab/. Supplementary data are available at Bioinformatics online.

  19. Five nuclear loci resolve the polyploid history of switchgrass (Panicum virgatum L. and relatives.

    Directory of Open Access Journals (Sweden)

    Jimmy K Triplett

    Full Text Available Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum and common or Proso millet (P. miliaceum. Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have generated sequence data from five low copy nuclear loci and two chloroplast loci and have clarified the origin of P. virgatum. We find that all members of sects. Virgata and Urvilleana are the result of diversification after a single allopolyploidy event. The closest diploid relatives of switchgrass are in sect. Rudgeana, native to Central and South America. Within sections Virgata and Urvilleana, P. tricholaenoides is sister to the remaining species. Panicum racemosum and P. urvilleanum form a clade, which may be sister to P. chloroleucum. Panicum amarum, P. amarulum, and the lowland and upland ecotypes of P. virgatum together form a clade, within which relationships are complex. Hexaploid and octoploid plants are likely allopolyploids, with P. amarum and P. amarulum sharing genomes with P. virgatum. Octoploid P. virgatum plants are formed via hybridization between disparate tetraploids. We show that polyploidy precedes diversification in a complex set of polyploids; our data thus suggest that polyploidy could provide the raw material for diversification. In addition, we show two rounds of allopolyploidization in the ancestry of switchgrass, and identify additional species that may be part of its broader gene pool. This may be relevant for development of the crop for biofuels.

  20. Intraspecific ecological niche divergence and reproductive shifts foster cytotype displacement and provide ecological opportunity to polyploids.

    Science.gov (United States)

    Karunarathne, Piyal; Schedler, Mara; Martínez, Eric J; Honfi, Ana I; Novichkova, Anastasiia; Hojsgaard, Diego

    2018-05-11

    Niche divergence between polyploids and their lower ploidy progenitors is one of the primary mechanisms fostering polyploid establishment and adaptive divergence. However, within-species chromosomal and reproductive variability have usually been neglected in community ecology and biodiversity analyses even though they have been recognized to play a role in the adaptive diversification of lineages. We used Paspalum intermedium, a grass species with diverging genetic systems (diploidy vs. autopolyploidy, allogamy vs. autogamy and sexuality vs. apomixis), to recognize the causality of biogeographic patterns, adaptation and ecological flexibility of cytotypes. Chromosome counts and flow cytometry were used to characterize within-species genetic systems diversity. Environmental niche modelling was used to evaluate intraspecific ecological attributes associated with environmental and climatic factors and to assess correlations among ploidy, reproductive modes and ecological conditions ruling species' population dynamics, range expansion, adaptation and evolutionary history. Two dominant cytotypes non-randomly distributed along local and regional geographical scales displayed niche differentiation, a directional shift in niche optima and signs of disruptive selection on ploidy-related ecological aptitudes for the exploitation of environmental resources. Ecologically specialized allogamous sexual diploids were found in northern areas associated with higher temperature, humidity and productivity, while generalist autogamous apomictic tetraploids occurred in southern areas, occupying colder and less productive environments. Four localities with a documented shift in ploidy and four mixed populations in a zone of ecological transition revealed an uneven replacement between cytotypes. Polyploidy and contrasting reproductive traits between cytotypes have promoted shifts in niche optima, and increased ecological tolerance and niche divergence. Ecologically specialized diploids

  1. Basic chromosome numbers and polyploid levels in some South African and Australian grasses (Poaceae

    Directory of Open Access Journals (Sweden)

    J. J. Spies

    1991-10-01

    Full Text Available Chromosome numbers of 46 specimens of grasses, involving 24 taxa from South Africa and Australia, have been determined during the present study. For the first time chromosome numbers are given for Eragrostis sarmentosa (Thunb. Trin. (n = 20. Panicum aequinerve Nees (n = 18,  Digitaria argyrograpta (Nees Stapf (n = 9 and D. maitlandii Stapf & C.E. Hubb. (n = 9. Additional polyploid levels are described for Diplachne fusca (L. Beauv. ex Roem. & Schult. (n = 10 and Digitaria diagonalis (Nees Stapf var.  diagonalis (n = 9. B-chromosomes were observed in several different specimens. The presence of B-chromosomes often results in abnormal chromosomal behaviour during meiosis.

  2. The influence of dietary fatty acid composition on the respiratory and cardiovascular physiology of Adriatic sturgeon (Acipenser naccarii): a review

    DEFF Research Database (Denmark)

    McKenzie, DJ; Piraccini, G; Agnisola, C

    1999-01-01

    as 15% of dry feed weight), with an elevated content of highly unsaturated fatty acids of the co3 series (¿3 HUFA), had a significantly lower standard metabolic rate (SMR) and routine oxygen consumption (Mo2) than those fed a diet enriched with the same quantity of hydrogenated coconut oil......This paper reviews evidence that the fatty acid composition of dietary lipids influences the respiratory and cardiovascular physiology of Adriatic sturgeon {Acipenser naccarii) and, thereby, their tolerance of the stress of hypoxia. Sturgeon fed a commercial diet enriched in fish oil (menhaden oil...

  3. White Sturgeon Mitigation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam; 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Rien, Thomas A.; Hughes, Michele L.; Kern, J. Chris (Oregon Department of Fish and Wildlife, Clackamas, OR)

    2006-03-01

    We report on our progress from April 2004 through March 2005 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam. This is a multi-year study with many objectives requiring more than one year to complete; therefore, findings from a given year may be part of more significant findings yet to be reported.

  4. White Sturgeon Mitgation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam; 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Rein, Thomas A.; Hughes, Michele L.; Kern, J. Chris (Oregon Department of Fish and Wildlife, Clackamas, OR)

    2005-08-01

    We report on our progress from April 2003 through March 2004 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam. This is a multi-year study with many objectives requiring more than one year to complete; therefore, findings from a given year may be part of more significant findings yet to be reported.

  5. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Scott R.; Tuell, Michael A. (Nez Perce Tribe, Department of Fishereis Resource Management, Lapwai, ID)

    2003-03-01

    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 2000 annual report covers the fourth year of sampling of this multi-year study. In 2000 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon rivers. The Snake River was sampled between Lower Granite Dam (rkm 174) and the mouth of the Salmon River (rkm 303), and the Salmon River was sampled from its mouth upstream to Hammer Creek (rkm 84). A total of 53,277 hours of setline effort and 630 hours of hook-and-line effort was employed in 2000. A total of 538 white sturgeon were captured and tagged in the Snake River and 25 in the Salmon River. Since 1997, 32.8 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 48 cm to 271 cm and averaged 107 cm. In the Salmon River, white sturgeon ranged in total length from 103 cm to 227 cm and averaged 163 cm. Using the Jolly-Seber open population estimator, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,725 fish, with a 95% confidence interval of 1,668-5,783. A total of 10 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 54.7 km (34 miles) downstream to 78.8 km (49 miles) upstream; however, 43.6 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of

  6. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1999 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Tuell, Michael A.; Everett, Scott R. (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)

    2003-03-01

    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 1999 annual report covers the third year of sampling of this multi-year study. In 1999 white sturgeon were captured, marked and population data were collected in the Snake and Salmon rivers. A total of 33,943 hours of setline effort and 2,112 hours of hook-and-line effort was employed in 1999. A total of 289 white sturgeon were captured and tagged in the Snake River and 29 in the Salmon River. Since 1997, 11.1 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 27 cm to 261 cm and averaged 110 cm. In the Salmon River, white sturgeon ranged in total length from 98 cm to 244 cm and averaged 183.5 cm. Using the Jolly-Seber model, the abundance of white sturgeon < 60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 1,823 fish, with a 95% confidence interval of 1,052-4,221. A total of 15 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 6.4 km (4 miles) downstream to 13.7 km (8.5 miles) upstream; however, 83.6 percent of the detected movement was less than 0.8 kilometers (0.5 miles). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P < 0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River

  7. Effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and determine status and habitat requirements of white sturgeon populations in the Columbia and Snake Rivers upstream from the McNary Dam. Annual progress report, April 1994--March 1995

    International Nuclear Information System (INIS)

    Beiningen, K.T.

    1996-03-01

    The author reports on progress from April 1994 through March 1994 of research on white sturgeon in the lower Columbia River. The study began in July 1986 and is a cooperative effort of federal, state and tribal fisheries entities to determine the (1) the status and habitat requirements, and (2) the effects of mitigative measures on productivity of white sturgeon populations in the lower Columbia River. This report describes activities conducted during the third year of this contract's second phase. Information was collected, analyzed, and evaluated on subadult and adult life histories, population dynamics, quantity and quality of habitat, and production enhancement strategies. The report is divided into sections that evaluate success of developing and implementing a management plan for white sturgeon; evaluate growth, mortality, and contributions to fisheries of juvenile white sturgeon transplanted from areas downstream; describe the life history and population dynamics of subadult and adult white sturgeon; define habitat requirements for spawning and rearing of white sturgeon and quantify the extent of habitat available; describe reproductive and early life history characteristics of white sturgeon; and quantify physical habitat used by spawning and rearing white sturgeon in the free-flowing portion of the Columbia River

  8. Effects of Mitigative Measures on Productivity of White Sturgeon Populations in the Columbia River Downstream from McNary Dam; Determine Status and Habitat Requirements of White Sturgeon Populations in the Columbia and Snake Rivers Upstream from the McNary Dam, 1994-1995 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Beiningen, Kirk T. [Oregon Dept. of Fish and Wildlife, Portland, OR (US)

    1996-03-01

    The author reports on progress from April 1994 through March 1995 of research on white sturgeon in the lower Columbia River. The study began in July 1986 and is a cooperative effort of federal, state and tribal fisheries entities to determine the (1) the status and habitat requirements, and (2) the effects of mitigative measures on productivity of white sturgeon populations in the lower Columbia River. This report describes activities conducted during the third year of this contract's second phase. Information was collected, analyzed, and evaluated on sub-adult and adult life histories, population dynamics, quantity and quality of habitat, and production enhancement strategies. The report is divided into sections that evaluate success of developing and implementing a management plan for white sturgeon; evaluate growth, mortality, and contributions to fisheries of juvenile white sturgeon transplanted from areas downstream; describe the life history and population dynamics of sub-adult a nd adult white sturgeon; define habitat requirements for spawning and rearing of white sturgeon and quantify the extent of habitat available; describe reproductive and early life history characteristics of white sturgeon; and quantify physical habitat used by spawning and rearing white sturgeon in the free-flowing portion of the Columbia River.

  9. White sturgeon mitigation and restoration in the Columbia and Snake rivers upstream from Bonneville Dam Report C, Annual Progress Report April 2003 - March 2004

    Science.gov (United States)

    Parsley, Michael J.; Gadomski, Dena M.; Kofoot, Pete

    2005-01-01

    River discharge and water temperatures that occurred during April through July 2003 provided conditions suitable for spawning by white sturgeon downstream from Bonneville, The Dalles, John Day, and McNary dams. Although optimal spawning temperatures in the four tailraces occurred for less than two weeks, they coincided with a period of relatively high river discharge. Bottom-trawl sampling in Bonneville and The Dalles Reservoirs revealed the presence of young-of-the-year (YOY) white sturgeon in Bonneville Reservoir, but none were captured in The Dalles Reservoir. A comparison of five years of indices of abundance of YOY sturgeon from sampling done by ODFW with gillnets and the USGS with bottom trawls was completed. Despite obvious differences in gear sampling characteristics (e.g. one gear is actively fished, one passively fished), it appears that either gear can be used to assess relative trends in YOY white sturgeon abundance. The analyses suffered due to poor catches of YOY fish, as YOY were only captured in The Dalles Reservoir during three of the five years of comparison sampling, and during only one of four years in John Day Reservoir. However, both gears detected the presence or absence of YOY white sturgeon within a reservoir equally. That is, if any YOY white sturgeon were captured in any year in a reservoir, both gears captured at least one fish, and if one gear failed to collect any YOY white sturgeon, both gears failed. Concerns have been raised that the Wang et al. (1985) egg development relationships for Sacramento River white sturgeon may not be applicable to Columbia Basin stocks. However, using laboratory experiments with white sturgeon eggs incubated at 10, 12, 15, and 18o C, we found no significant differences in development rates of eggs of Columbia, Kootenai, Snake, and Sacramento river fish.

  10. Principles of lake sedimentology

    International Nuclear Information System (INIS)

    Janasson, L.

    1983-01-01

    This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index

  11. Physical characteristics of the lower San Joaquin River, California, in relation to white sturgeon spawning habitat, 2011–14

    Science.gov (United States)

    Marineau, Mathieu D.; Wright, Scott A.; Whealdon-Haught, Daniel R.; Kinzel, Paul J.

    2017-07-19

    The U.S. Fish and Wildlife Service confirmed that white sturgeon (Acipenser transmontanus) recently spawned in the lower San Joaquin River, California. Decreases in the San Francisco Bay estuary white sturgeon population have led to an increased effort to understand their migration behavior and habitat preferences. The preferred spawning habitat of other white sturgeon (for example, those in the Columbia and Klamath Rivers) is thought to be areas that have high water velocity, deep pools, and coarse bed material. Coarse bed material (pebbles and cobbles), in particular, is important for the survival of white sturgeon eggs and larvae. Knowledge of the physical characteristics of the lower San Joaquin River can be used to preserve sturgeon spawning habitat and lead to management decisions that could help increase the San Francisco Bay estuary white sturgeon population.Between 2011 and 2014, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, assessed selected reaches and tributaries of the lower river in relation to sturgeon spawning habitat by (1) describing selected spawning reaches in terms of habitat-related physical characteristics (such as water depth and velocity, channel slope, and bed material) of the lower San Joaquin River between its confluences with the Stanislaus and Merced Rivers, (2) describing variations in these physical characteristics during wet and dry years, and (3) identifying potential reasons for these variations.The lower San Joaquin River was divided into five study reaches. Although data were collected from all study reaches, three subreaches where the USFWS collected viable eggs at multiple sites in 2011–12 from Orestimba Creek to Sturgeon Bend were of special interest. Water depth and velocity were measured using two different approaches—channel cross sections and longitudinal profiles—and data were collected using an acoustic Doppler current profiler.During the first year of data collection (water

  12. Acoustic tag detections of green sturgeon in the Columbia River and Coos Bay estuaries, Washington and Oregon, 2010–11

    Science.gov (United States)

    Hansel, Hal C.; Romine, Jason G.; Perry, Russell W.

    2017-11-08

    The Columbia River, in Washington and Oregon, and Coos Bay, in Oregon, are economically important shipping channels that are inhabited by several fishes protected under the Endangered Species Act (ESA). Maintenance of shipping channels involves dredge operations to maintain sufficient in-channel depths to allow large ships to navigate the waterways safely. Fishes entrained by dredge equipment often die or experience delayed mortality. Other potential negative effects of dredging include increased turbidity, reductions in prey resources, and the release of harmful contaminants from the dredged sediments. One species of concern is the ESA-listed green sturgeon (Acipenser medirostris; Southern Distinct Population Segment). In this study, we used acoustic telemetry to identify habitat use, arrival and departure timing, and the extent of upstream migration of green sturgeon in the Columbia River and Coos Bay to help inform dredge operations to minimize potential take of green sturgeon. Autonomous acoustic receivers were deployed in Coos Bay from the mouth to river kilometer (rkm) 21.6 from October 2009 through October 2010. In the Columbia River Estuary, receivers were deployed between the mouth and rkm 37.8 from April to November in 2010 and 2011. A total of 29 subadult and adult green sturgeon were tagged with temperature and pressure sensor tags and released during the study, primarily in Willapa Bay and Grays Harbor, Washington, and the Klamath River, Oregon. Green sturgeon detected during the study but released by other researchers also were included in the study.The number of tagged green sturgeon detected in the two estuaries differed markedly. In Coos Bay, only one green sturgeon was detected for about 2 hours near the estuary mouth. In the Columbia River Estuary, 9 green sturgeon were detected in 2010 and 10 fish were detected in 2011. Green sturgeon entered the Columbia River from May through October during both years, with the greatest numbers of fish being

  13. Hematocrit and plasma osmolality values of young-of-year shortnose sturgeon following acute exposures to combinations of salinity and temperature

    Science.gov (United States)

    Ziegeweid, J.R.; Black, M.C.

    2010-01-01

    Little is known about the physiological capabilities of young-of-year (YOY) shortnose sturgeon. In this study, plasma osmolality and hematocrit values were measured for YOY shortnose sturgeon following 48-h exposures to 12 different combinations of salinity and temperature. Hematocrit levels varied significantly with temperature and age, and plasma osmolalities varied significantly with salinity and age. Plasma osmolality and hematocrit values were similar to previously published values for other sturgeons of similar age and size in similar treatment conditions. ?? 2010 Springer Science+Business Media B.V.

  14. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1997 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hoefs, Nancy (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)

    2004-02-01

    During 1997 the first phase of the Nez Perce Tribe White Sturgeon Project was completed and the second phase was initiated. During Phase I the ''Upper Snake River White Sturgeon Biological Assessment'' was completed, successfully: (1) compiling regional white sturgeon management objectives, and (2) identifying potential mitigation actions needed to rebuild the white sturgeon population in the Snake River between Hells Canyon and Lower Granite dams. Risks and uncertainties associated with implementation of these potential mitigative actions could not be fully assessed because critical information concerning the status of the population and their habitat requirements were unknown. The biological risk assessment identified the fundamental information concerning the white sturgeon population that is needed to fully evaluate the effectiveness of alternative mitigative strategies. Accordingly, a multi-year research plan was developed to collect specific biological and environmental data needed to assess the health and status of the population and characterize habitat used for spawning and rearing. In addition, in 1997 Phase II of the project was initiated. White sturgeon were captured, marked, and population data were collected between Lower Granite Dam and the mouth of the Salmon River. During 1997, 316 white sturgeon were captured in the Snake River. Of these, 298 were marked. Differences in the fork length frequency distributions of the white sturgeon were not affected by collection method. No significant differences in length frequency distributions of sturgeon captured in Lower Granite Reservoir and the mid- and upper free-flowing reaches of the Snake River were detected. The length frequency distribution indicated that white sturgeon between 92 and 183 cm are prevalent in the reaches of the Snake River that were sampled. However, white sturgeon >183 have not changed markedly since 1970. I would speculate that some factor other than past over

  15. Sex in the Suwannee, the secretive love life of Gulf Sturgeons

    Science.gov (United States)

    Sulak, Kenneth J.

    2014-01-01

    Mid-February in the Gulf of Mexico and a timeless ritual is about to repeat itself for perhaps the millionth time. Some mysterious signal, possibly increasing day length, flips an internal switch, feeding stops, and the homeward migration begins for the Gulf Sturgeon (Acipenser oxyrinchus desotoi). From far flung places along the Gulf Coast, Gulf Sturgeons start heading back to their natal rivers – they know the way instinctively. Maybe they seek out the special chemical taste of their home river, imprinted at hatching. Or perhaps the ultrasensitive electric organs decorating the underside of the snout can follow the map of the earth’s magnetic field. Either way, time to make a beeline for the welcoming waters of the Suwannee River, or maybe the Apalachicola, Choctawhatchee, or one of four other spawning rivers. Some of the adults are on a special mission – time to spawn, time to perpetuate the species. Mature males form the first wave in this homebound marathon, eager to get to the spawning grounds, eager to be the first to greet ready females with a series of sharp clicking sounds. Only spawning once each three years, females laden with large black eggs demure, taking their time, arriving in mid to late March, a month behind the early males. But most sturgeons, juveniles and immature adults not ready to spawn, are simply heading home. Not prompted by the spawning urge, they are just following the ancient annual cycle of intense winter feeding in the Gulf, followed by several months of fasting and R&R in the river.

  16. Assessing dorsal scute microchemistry for reconstruction of shortnose sturgeon life histories

    Science.gov (United States)

    Altenritter, Matthew E.; Kinnison, Michael T.; Zydlewski, Gayle B.; Secor, David H.; Zydlewski, Joseph D.

    2015-01-01

    The imperiled status of sturgeons worldwide places priority on the identification and protection of critical habitats. We assessed the micro-structural and micro-chemical scope for a novel calcified structure, dorsal scutes, to be used for reconstruction of past habitat use and group separation in shortnose sturgeon (Acipenser brevirostrum). Dorsal scutes contained a dual-layered structure composed of a thin multi-layered translucent zone lying dorsally above a thicker multi-layered zone. Banding in the thick multi-layered zone correlated strongly with pectoral fin spine annuli supporting the presence of chronological structuring that could contain a chemical record of past environmental exposure. Trace element profiles (Sr:Ca), collected using both wavelength dispersive electron microprobe analysis and laser ablation inductively coupled mass spectrometry, suggest scutes record elemental information useful for tracing transitions between freshwater and marine environments. Moreover, mirror-image like Sr:Ca profiles were observed across the dual-zone structuring of the scute that may indicate duplication of the microchemical profile in a single structure. Additional element:calcium ratios measured in natal regions of dorsal scutes (Ba:Ca, Mg:Ca) suggest the potential for further refinement of techniques for identification of river systems of natal origin. In combination, our results provide proof of concept that dorsal scutes possess the necessary properties to be used as structures for reconstructions of past habitat use in sturgeons. Importantly, scutes may be collected non-lethally and with less injury than current structures, like otoliths and fin spines, affording an opportunity for broader application of microchemical techniques.

  17. Estimating abundance without recaptures of marked pallid sturgeon in the Mississippi River.

    Science.gov (United States)

    Friedenberg, Nicholas A; Hoover, Jan Jeffrey; Boysen, Krista; Killgore, K Jack

    2018-04-01

    Abundance estimates are essential for assessing the viability of populations and the risks posed by alternative management actions. An effort to estimate abundance via a repeated mark-recapture experiment may fail to recapture marked individuals. We devised a method for obtaining lower bounds on abundance in the absence of recaptures for both panmictic and spatially structured populations. The method assumes few enough recaptures were expected to be missed by random chance. The upper Bayesian credible limit on expected recaptures allows probabilistic statements about the minimum number of individuals present in the population. We applied this method to data from a 12-year survey of pallid sturgeon (Scaphirhynchus albus) in the lower and middle Mississippi River (U.S.A.). None of the 241 individuals marked was recaptured in the survey. After accounting for survival and movement, our model-averaged estimate of the total abundance of pallid sturgeon ≥3 years old in the study area had a 1%, 5%, or 25% chance of being <4,600, 7,000, or 15,000, respectively. When we assumed fish were distributed in proportion to survey catch per unit effort, the farthest downstream reach in the survey hosted at least 4.5-15 fish per river kilometer (rkm), whereas the remainder of the reaches in the lower and middle Mississippi River hosted at least 2.6-8.5 fish/rkm for all model variations examined. The lower Mississippi River had an average density of pallid sturgeon ≥3 years old of at least 3.0-9.8 fish/rkm. The choice of Bayesian prior was the largest source of uncertainty we considered but did not alter the order of magnitude of lower bounds. Nil-recapture estimates of abundance are highly uncertain and require careful communication but can deliver insights from experiments that might otherwise be considered a failure. © 2017 Society for Conservation Biology.

  18. Movement and habitat studies of chinook salmon and white sturgeon. [Oncorhynchus tshawytscha, Acipenser transmontanus

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, J.M.

    1978-09-01

    Swimming depths of adult chinook salmon (Oncorhynchus tshawytscha), in relation to hydroelectric dam created gas supersaturation levels in the Snake River, were evaluated using pressure-sensitive radiofrequency transmitters. Gas saturation levels in spring 1976 ranged from 120 to 130% and chinook salmon depth of travel averaged 6.4 m. In fall 1976 and spring 1977, when gas saturation levels were below 108%, average salmon depths of travel were 3.0 and 4.0 m, respectively. In all cases, average depth of travel was below the critical zone (110% effective saturation), but spring 1976 chinook salmon traveled significantly deeper than fall 1976 and spring 1977 salmon. Internal and external radio transmitter attachment techniques were compared and results indicated the methods are equally reliable given proper insertion and attachment procedures. Percent returning and travel times to upstream dams were compared between equal numbers of radiotagged and spaghetti-anchor tagged control salmon. There were no significant differences in percent return or travel times between control and externally tagged salmon, but procedural difficulties involving internally tagged salmon altered their behavior to preclude such comparisons. Presence and operation of hydroelectric dams delayed salmon passage through the river and appeared to alter upstream migratory behavior. Movements of radiotagged white sturgeon (Acipenser transmontanus) from 1975 through 1977 were highly seasonal, beginning in June and ending in October. River temperatures apparently influenced both seasonal and diurnal movement activities. Movements began in June after water temperatures passed 13/sup 0/C and ceased when temperatures reached 13/sup 0/C (again) in autumn each year. Information derived from sturgeon carrying temperature sensing transmitters, combined with position determinations, indicated apparent diurnal movement cycles for sturgeon.

  19. Polyploid tumour cells elicit paradiploid progeny through depolyploidizing divisions and regulated autophagic degradation.

    Science.gov (United States)

    Erenpreisa, Jekaterina; Salmina, Kristine; Huna, Anda; Kosmacek, Elizabeth A; Cragg, Mark S; Ianzini, Fiorenza; Anisimov, Alim P

    2011-07-01

    'Neosis' describes the process whereby p53 function-deficient tumour cells undergo self-renewal after genotoxic damage apparently via senescing ETCs (endopolyploid tumour cells). We previously reported that autophagic digestion and extrusion of DNA occurs in ETC and subsequently revealed that self-renewal transcription factors are also activated under these conditions. Here, we further studied this phenomenon in a range of cell lines after genotoxic damage induced by gamma irradiation, ETO (etoposide) or PXT (paclitaxel) treatment. These experiments revealed that chromatin degradation by autophagy was compatible with continuing mitotic activity in ETC. While the actively polyploidizing primary ETC produced early after genotoxic insult activated self-renewal factors throughout the polygenome, the secondary ETC restored after failed multipolar mitosis underwent subnuclei differentiation. As such, only a subset of subnuclei continued to express OCT4 and NANOG, while those lacking these factors stopped DNA replication and underwent degradation and elimination through autophagy. The surviving subnuclei sequestered nascent cytoplasm to form subcells, while being retained within the confines of the old ETC. Finally, the preformed paradiploid subcells became released from their linking chromosome bridges through autophagy and subsequently began cell divisions. These data show that 'neotic' ETC resulting from genotoxically damaged p53 function-deficient tumour cells develop through a heteronuclear system differentiating the polyploid genome into rejuvenated 'viable' subcells (which provide mitotically propagating paradiploid descendents) and subnuclei, which become degraded and eliminated by autophagy. The whole process reduces aneuploidy in descendants of ETC.

  20. Halophilic archaea cultivated from surface sterilized middle-late eocene rock salt are polyploid.

    Directory of Open Access Journals (Sweden)

    Salla T Jaakkola

    Full Text Available Live bacteria and archaea have been isolated from several rock salt deposits of up to hundreds of millions of years of age from all around the world. A key factor affecting their longevity is the ability to keep their genomic DNA intact, for which efficient repair mechanisms are needed. Polyploid microbes are known to have an increased resistance towards mutations and DNA damage, and it has been suggested that microbes from deeply buried rock salt would carry several copies of their genomes. Here, cultivable halophilic microbes were isolated from a surface sterilized middle-late Eocene (38-41 million years ago rock salt sample, drilled from the depth of 800 m at Yunying salt mine, China. Eight unique isolates were obtained, which represented two haloarchaeal genera, Halobacterium and Halolamina. We used real-time PCR to show that our isolates are polyploid, with genome copy numbers of 11-14 genomes per cell in exponential growth phase. The ploidy level was slightly downregulated in stationary growth phase, but the cells still had an average genome copy number of 6-8. The polyploidy of halophilic archaea living in ancient rock salt might be a factor explaining how these organisms are able to overcome the challenge of prolonged survival during their entombment.

  1. TaGW2, a Good Reflection of Wheat Polyploidization and Evolution.

    Science.gov (United States)

    Qin, Lin; Zhao, Junjie; Li, Tian; Hou, Jian; Zhang, Xueyong; Hao, Chenyang

    2017-01-01

    Hexaploid wheat consists of three subgenomes, namely, A, B, and D. These well-characterized ancestral genomes also exist at the diploid and tetraploid levels, thereby rendering wheat as a good model species for studying polyploidization. Here, we performed intra- and inter-species comparative analyses of wheat and its relatives to dissect polymorphism and differentiation of the TaGW2 genes. Our results showed that genetic diversity of TaGW2 decreased with progression from the diploids to tetraploids and hexaploids. The strongest selection occurred in the promoter regions of TaGW2-6A and TaGW2-6B . Phylogenetic trees clearly indicated that Triticum urartu and Ae. speltoides were the donors of the A and B genomes in tetraploid and hexaploid wheats. Haplotypes detected among hexaploid genotypes traced back to the tetraploid level. Fst and π values revealed that the strongest selection on TaGW2 occurred at the tetraploid level rather than in hexaploid wheat. This infers that grain size enlargement, especially increased kernel width, mainly occurred in tetraploid genotypes. In addition, relative expression levels of TaGW2s significantly declined from the diploid level to tetraploids and hexaploids, further indicating that these genes negatively regulate kernel size. Our results also revealed that the polyploidization events possibly caused much stronger differentiation than domestication and breeding.

  2. Carboxyl-terminal-dependent recruitment of nonmuscle myosin II to megakaryocyte contractile ring during polyploidization.

    Science.gov (United States)

    Badirou, Idinath; Pan, Jiajia; Legrand, Céline; Wang, Aibing; Lordier, Larissa; Boukour, Siham; Roy, Anita; Vainchenker, William; Chang, Yunhua

    2014-10-16

    Endomitosis is a unique megakaryocyte (MK) differentiation process that is the consequence of a late cytokinesis failure associated with a contractile ring defect. Evidence from in vitro studies has revealed the distinct roles of 2 nonmuscle myosin IIs (NMIIs) on MK endomitosis: only NMII-B (MYH10), but not NMII-A (MYH9), is localized in the MK contractile ring and implicated in mitosis/endomitosis transition. Here, we studied 2 transgenic mouse models in which nonmuscle myosin heavy chain (NMHC) II-A was genetically replaced either by II-B or by a chimeric NMHCII that combined the head domain of II-A with the rod and tail domains of II-B. This study provides in vivo evidence on the specific role of NMII-B on MK polyploidization. It demonstrates that the carboxyl-terminal domain of the heavy chains determines myosin II localization to the MK contractile ring and is responsible for the specific role of NMII-B in MK polyploidization.

  3. Cholesterol is essential for mitosis progression and its deficiency induces polyploid cell formation

    International Nuclear Information System (INIS)

    Fernandez, Carlos; Lobo, Maria del Val T.; Gomez-Coronado, Diego; Lasuncion, Miguel A.

    2004-01-01

    As an essential component of mammalian cell membranes, cells require cholesterol for proliferation, which is either obtained from plasma lipoproteins or synthesized intracellularly from acetyl-CoA. In addition to cholesterol, other non-sterol mevalonate derivatives are necessary for DNA synthesis, such as the phosphorylated forms of isopentane, farnesol, geranylgeraniol, and dolichol. The aim of the present study was to elucidate the role of cholesterol in mitosis. For this, human leukemia cells (HL-60) were incubated in a cholesterol-free medium and treated with SKF 104976, which inhibits cholesterol biosynthesis by blocking sterol 14α-demethylase, and the expression of relevant cyclins in the different phases of the cell cycle was analyzed by flow cytometry. Prolonged cholesterol starvation induced the inhibition of cytokinesis and the formation of polyploid cells, which were multinucleated and had mitotic aberrations. Supplementing the medium with cholesterol completely abolished these effects, demonstrating they were specifically due to cholesterol deficiency. This is the first evidence that cholesterol is essential for mitosis completion and that, in the absence of cholesterol, the cells fail to undergo cytokinesis, entered G1 phase at higher DNA ploidy (tetraploidy), and then progressed through S (rereplication) into G2, generating polyploid cells

  4. Dataset of the HOX1 gene sequences of the wheat polyploids and their diploid relatives

    Directory of Open Access Journals (Sweden)

    Andrey B. Shcherban

    2018-02-01

    Full Text Available The TaHOX-1 gene of common wheat Triticum aestivum L. (BAD-genome encodes transcription factor (HD-Zip I which is characterized by the presence of a DNA-binding homeodomain (HD with an adjacent Leucine zipper (LZ motif. This gene can play a role in adapting plant to a variety of abiotic stresses, such as drought, cold, salinity etc., which strongly affect wheat production. However, it's both functional role in stress resistance and divergence during wheat evolution has not yet been elucidated. This data in brief article is associated with the research paper “Structural and functional divergence of homoeologous copies of the TaHOX-1 gene in polyploid wheats and their diploid ancestors”. The data set represents a recent survey of the primary HOX-1 gene sequences isolated from the first wheat allotetraploids (BA-genome and their corresponding Triticum and Aegilops diploid relatives. Specifically, we provide detailed information about the HOX-1 nucleotide sequences of the promoter region and both nucleotide and amino acid sequences of the gene. The sequencing data used here is available at DDBJ/EMBL/GenBank under the accession numbers MG000630-MG000698. Keywords: Wheat, Polyploid, HOX-1 gene, Homeodomain, Transcription factor, Promoter, Triticum, Aegilops

  5. Elucidating polyploidization of bermudagrasses as assessed by organelle and nuclear DNA markers.

    Science.gov (United States)

    Gulsen, Osman; Ceylan, Ahmet

    2011-12-01

    Clarification of relationships among ploidy series of Cynodon accessions could be beneficial to bermudagrass breeding programs, and would enhance our understanding of the evolutionary biology of this warm season grass species. This study was initiated to elucidate polyploidization among Cynodon accessions with different ploidy series collected from Turkey based on chloroplast and nuclear DNA. Forty Cynodon accessions including 7 diploids, 3 triploids, 10 tetraploids, 11 pentaploids, and 9 hexaploids were analyzed using chloroplast DNA restriction fragment-length polymorphism (cpDNA RFLP), chloroplast DNA simple sequence repeat (cpDNA SSR), and nuclear DNA markers based on neighbor-joining (NJ) and principle component analyses (PCA). All three-marker systems with two statistical algorithms clustered the diploids apart from the other ploidy levels. Assuming autopolyploidy, spontaneous polyploidization followed by rapid diversification among the higher ploidy levels than the diploids is likely in Cynodon's evolution. Few tetraploid and hexaploid accessions were clustered with or closely to the group of diploids, supporting the hypothesis above. Eleven haplotypes as estimated by cpDNA RFLP and SSR markers were detected. This study indicated that the diploids had different organelle genome from the rest of the ploidy series and provided valuable insight into relationships among ploidy series of Cynodon accessions based on cp and nuclear DNAs.

  6. Karyotypic changes through dysploidy persist longer over evolutionary time than polyploid changes.

    Directory of Open Access Journals (Sweden)

    Marcial Escudero

    Full Text Available Chromosome evolution has been demonstrated to have profound effects on diversification rates and speciation in angiosperms. While polyploidy has predated some major radiations in plants, it has also been related to decreased diversification rates. There has been comparatively little attention to the evolutionary role of gains and losses of single chromosomes, which may or not entail changes in the DNA content (then called aneuploidy or dysploidy, respectively. In this study we investigate the role of chromosome number transitions and of possible associated genome size changes in angiosperm evolution. We model the tempo and mode of chromosome number evolution and its possible correlation with patterns of cladogenesis in 15 angiosperm clades. Inferred polyploid transitions are distributed more frequently towards recent times than single chromosome gains and losses. This is likely because the latter events do not entail changes in DNA content and are probably due to fission or fusion events (dysploidy, as revealed by an analysis of the relationship between genome size and chromosome number. Our results support the general pattern that recently originated polyploids fail to persist, and suggest that dysploidy may have comparatively longer-term persistence than polyploidy. Changes in chromosome number associated with dysploidy were typically observed across the phylogenies based on a chi-square analysis, consistent with these changes being neutral with respect to diversification.

  7. Sturgeon and paddlefish (Acipenseridae) sagittal otoliths are composed of the calcium carbonate polymorphs vaterite and calcite.

    Science.gov (United States)

    Pracheil, B M; Chakoumakos, B C; Feygenson, M; Whitledge, G W; Koenigs, R P; Bruch, R M

    2017-02-01

    This study sought to resolve whether sturgeon (Acipenseridae) sagittae (otoliths) contain a non-vaterite fraction and to quantify how large a non-vaterite fraction is using neutron diffraction analysis. This study found that all otoliths examined had a calcite fraction that ranged from 18 ± 6 to 36 ± 3% by mass. This calcite fraction is most probably due to biological variation during otolith formation rather than an artefact of polymorph transformation during preparation. © 2016 The Fisheries Society of the British Isles.

  8. Progenitor-derivative relationships of Hordeum polyploids (Poaceae, Triticeae inferred from sequences of TOPO6, a nuclear low-copy gene region.

    Directory of Open Access Journals (Sweden)

    Jonathan Brassac

    Full Text Available Polyploidization is a major mechanism of speciation in plants. Within the barley genus Hordeum, approximately half of the taxa are polyploids. While for diploid species a good hypothesis of phylogenetic relationships exists, there is little information available for the polyploids (4×, 6× of Hordeum. Relationships among all 33 diploid and polyploid Hordeum species were analyzed with the low-copy nuclear marker region TOPO6 for 341 Hordeum individuals and eight outgroup species. PCR products were either directly sequenced or cloned and on average 12 clones per individual were included in phylogenetic analyses. In most diploid Hordeum species TOPO6 is probably a single-copy locus. Most sequences found in polyploid individuals phylogenetically cluster together with sequences derived from diploid species and thus allow the identification of parental taxa of polyploids. Four groups of sequences occurring only in polyploid taxa are interpreted as footprints of extinct diploid taxa, which contributed to allopolyploid evolution. Our analysis identifies three key species involved in the evolution of the American polyploids of the genus. (i All but one of the American tetraploids have a TOPO6 copy originating from the Central Asian diploid H. roshevitzii, the second copy clustering with different American diploid species. (ii All hexaploid species from the New World have a copy of an extinct close relative of H. californicum and (iii possess the TOPO6 sequence pattern of tetraploid H. jubatum, each with an additional copy derived from different American diploids. Tetraploid H. bulbosum is an autopolyploid, while the assumed autopolyploid H. brevisubulatum (4×, 6× was identified as allopolyploid throughout most of its distribution area. The use of a proof-reading DNA polymerase in PCR reduced the proportion of chimerical sequences in polyploids in comparison to Taq polymerase.

  9. Differential contributions to the transcriptome of duplicated genes in response to abiotic stresses in natural and synthetic polyploids.

    Science.gov (United States)

    Dong, Shaowei; Adams, Keith L

    2011-06-01

    Polyploidy has occurred throughout plant evolution and can result in considerable changes to gene expression when it takes place and over evolutionary time. Little is known about the effects of abiotic stress conditions on duplicate gene expression patterns in polyploid plants. We examined the expression patterns of 60 duplicated genes in leaves, roots and cotyledons of allotetraploid Gossypium hirsutum in response to five abiotic stress treatments (heat, cold, drought, high salt and water submersion) using single-strand conformation polymorphism assays, and 20 genes in a synthetic allotetraploid. Over 70% of the genes showed stress-induced changes in the relative expression levels of the duplicates under one or more stress treatments with frequent variability among treatments. Twelve pairs showed opposite changes in expression levels in response to different abiotic stress treatments. Stress-induced expression changes occurred in the synthetic allopolyploid, but there was little correspondence in patterns between the natural and synthetic polyploids. Our results indicate that abiotic stress conditions can have considerable effects on duplicate gene expression in a polyploid, with the effects varying by gene, stress and organ type. Differential expression in response to environmental stresses may be a factor in the preservation of some duplicated genes in polyploids. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  10. Construction of a plant-transformation-competent BIBAC library and genome sequence analysis of polyploid Upland cotton (Gossypium hirsutum L.)

    Science.gov (United States)

    Cotton is a world’s leading crop important to the world’s textile and energy industries, and a model species for studies of plant polyploidization, cellulose biosynthesis and cell wall biogenesis. Here, we report the construction and extensive analysis of a binary bacterial artificial chromosome (BI...

  11. The Evolutionary History Of The White-Rayed Species Of Melampodium (Asteraceae) Involved Multiple Cycles Of Hybridization And Polyploidization1

    Science.gov (United States)

    Rebernig, Carolin A.; Weiss-Schneeweiss, Hanna; Blöch, Cordula; Turner, Barbara; Stuessy, Tod F.; Obermayer, Renate; Villaseñor, Jose L.; Schneeweiss, Gerald M.

    2014-01-01

    Premise of the study Polyploidy plays an important role in race differentiation and eventually speciation. Underlying mechanisms include chromosomal and genomic changes facilitating reproductive isolation and/or stabilization of hybrids. A prerequisite for studying these processes is a sound knowledge on the origin of polyploids. A well-suited group for studying polyploid evolution consists of the three species of Melampodium ser. Leucantha (Asteraceae): M. argophyllum, M. cinereum, and M. leucanthum. Methods The origin of polyploids was inferred using network and tree-based phylogenetic analyses of several plastid and nuclear DNA sequences and of fingerprint data (AFLP). Genome evolution was assessed via genome size measurements, karyotype analysis, and in situ hybridization of ribosomal DNA. Key results Tetraploid cytotypes of the phylogenetically distinct M. cinereum and M. leucanthum had, compared to the diploid cytotypes, doubled genome sizes and no evidence of gross chromosomal rearrangements. Hexaploid M. argophyllum constituted a separate lineage with limited intermixing with the other species, except in analyses from nuclear ITS. Its genome size was lower than expected if M. cinereum and/or M. leucanthum were involved in its origin, and no chromosomal rearrangements were evident. Conclusions Polyploids in M. cinereum and M. leucanthum are of recent autopolyploid origin in line with the lack of significant genomic changes. Hexaploid M. argophyllum also appears to be of autopolyploid origin against the previous hypothesis of an allopolyploid origin involving the other two species, but some gene flow with the other species in early phases of differentiation cannot be excluded. PMID:22645096

  12. Genetic similarity of polyploids - A new version of the computer program POPDIST (ver. 1.2.0) considers intraspecific genetic differentiation

    DEFF Research Database (Denmark)

    Tomiuk, Jürgen; Guldbrandtsen, Bernt; Loeschcke, Volker

    2009-01-01

    For evolutionary studies of polyploid species estimates of the genetic identity between species with different degrees of ploidy are particularly required because gene counting in samples of polyploid individuals often cannot be done, e.g., in triploids the phenotype AB can be genotypically either...... ABB or AAB. We recently suggested a genetic distance measure that is based on phenotype counting and made available the computer program POPDIST. The program provides maximum-likelihood estimates of the genetic identities and distances between polyploid populations, but this approach...

  13. Fine-scale habitat preference of green sturgeon (Acipenser medirostris) within three spawning locations in the Sacramento River, California

    Science.gov (United States)

    Wyman, Megan T.; Thomas, Michael J.; McDonald, Richard R.; Hearn, Alexander R.; Battleson, Ryan D.; Chapman, Eric D.; Kinzel, Paul J.; Minear, J. Tobey; Mora, Ethan A.; Nelson, Jonathan M.; Pagel, Matthew D.; Klimley, A. Peter

    2018-01-01

    Vast sections of the Sacramento River have been listed as critical habitat by the National Marine Fisheries Service for green sturgeon spawning (Acipenser medirostris), yet spawning is known to occur at only a few specific locations. This study reveals the range of physical habitat variables selected by adult green sturgeon during their spawning period. We integrated fine-scale fish positions, physical habitat characteristics, discharge, bathymetry, and simulated velocity and depth using a 2-dimensional hydraulic model (FaSTMECH). The objective was to create habitat suitability curves for depth, velocity, and substrate type within three known spawning locations over two years. An overall cumulative habitat suitability score was calculated that averaged the depth, velocity, and substrate scores over all fish, sites, and years. A weighted usable area (WUA) index was calculated throughout the sampling periods for each of the three sites. Cumulative results indicate that the microhabitat characteristics most preferred by green sturgeon in these three spawning locations were velocities between 1.0-1.1 m/s, depths of 8-9 m, and gravel and sand substrate. This study provides guidance for those who may in the future want to increase spawning habitat for green sturgeon within the Sacramento River.

  14. Broadening the regulated-river management paradigm: A case study of the forgotten dead zone hindering Pallid Sturgeon recovery

    Science.gov (United States)

    Guy, Christopher S.; Treanor, Hilary B.; Kappenman, Kevin M.; Scholl, Eric A.; Ilgen, Jason E.; Webb, Molly A. H.

    2015-01-01

    The global proliferation of dams within the last half century has prompted ecologists to understand the effects of regulated rivers on large-river fishes. Currently, much of the effort to mitigate the influence of dams on large-river fishes has been focused on downriver effects, and little attention has been given to upriver effects. Through a combination of field observations and laboratory experiments, we tested the hypothesis that abiotic conditions upriver of the dam are the mechanism for the lack of recruitment in Pallid Sturgeon (Scaphirhynchus albus), an iconic large-river endangered species. Here we show for the first time that anoxic upriver habitat in reservoirs (i.e., the transition zone between the river and reservoir) is responsible for the lack of recruitment in Pallid Sturgeon. The anoxic condition in the transition zone is a function of reduced river velocities and the concentration of fine particulate organic material with high microbial respiration. As predicted, the river upstream of the transition zone was oxic at all sampling locations. Our results indicate that transition zones are an ecological sink for Pallid Sturgeon. We argue that ecologists, engineers, and policy makers need to broaden the regulated-river paradigm to consider upriver and downriver effects of dams equally to comprehensively mitigate altered ecosystems for the benefit of large-river fishes, especially for the Pallid Sturgeon.

  15. 75 FR 2102 - Endangered and Threatened Wildlife and Plants; Proposed Rule To List the Shovelnose Sturgeon as...

    Science.gov (United States)

    2010-01-14

    ... receive public comments on the proposal. If you have previously submitted comments, please do not resubmit... on the length of written comments submitted to us. If you have any questions concerning the [[Page...; Proposed Rule To List the Shovelnose Sturgeon as Threatened Due to Similarity of Appearance AGENCY: Fish...

  16. The second highest chromosome count among vertebrates is observed in cultured sturgeon and is associated with genome plasticity

    Czech Academy of Sciences Publication Activity Database

    Havelka, M.; Bytyutskyy, D.; Symonová, R.; Ráb, Petr; Flajšhans, M.

    2016-01-01

    Roč. 48, č. 12 (2016) ISSN 0999-193X R&D Projects: GA ČR GA14-02940S Institutional support: RVO:67985904 Keywords : sturgeon * spontaneous autopolyploidy * image-analysis densitometry Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.964, year: 2016

  17. The effect of thermal shock on morphological characteristics of blood cells in Siberian sturgeon (Acipenser baerii triploids

    Directory of Open Access Journals (Sweden)

    Teresa Wlasow

    2011-01-01

    Full Text Available The aim of the study was to evaluate the effect of thermal shock on morphotic blood elements in Siberian sturgeon Acipenser baerii triploids. The thermal shock (37 °C for 2 min was applied in the 18th min after fertilization. Blood was sampled from parallel cultured ten triploids and ten diploids on day 70 after hatching. Ploidy was assessed with the cytogenetic method and measurements of cellular nuclei. In the blood of triploids, significant dominance of immature red blood cells, erythrocytes with a displaced nucleus, microcytes and erythroplastids were observed. The blood of triploids was also characterized by a reduced number of lymphocytes. The percentage of neutrophil and eosinophil granulocytes was elevated; increased share of neutrophil granulocytes with a 4-, 5- or 6-segmented nucleus and eosinophil granulocytes with a nucleus consisting of three and more segments was observed. Disturbances in the picture of red blood cells can be considered as an expression of intensification of end-stage changes in triploids. The response to these changes in the blood of triploid Siberian sturgeon is an increase in the share of polymorphonuclear PMN, cells counted as microphages. Frequent presence of immature red blood cells in triploid Siberian sturgeon is a process that aims at counterbalancing the loss among these blood cells. It is the first report on morphological changes and proportions among blood cells in triploid Siberian sturgeon.

  18. Effects of poly-β-hydroxybutyrate (PHB) on Siberian sturgeon (Acipenser baerii) fingerlings performance and its gastrointestinal tract microbial community.

    Science.gov (United States)

    Najdegerami, Ebrahim H; Tran, Tiet Ngoc; Defoirdt, Tom; Marzorati, Massimo; Sorgeloos, Patrick; Boon, Nico; Bossier, Peter

    2012-01-01

    Poly-β-hydroxybutyrate (PHB) is a natural polymer that can be depolymerized into water-soluble short-chain fatty acid monomers. These monomers can act as microbial control agents. In this study, the effects of partially replacing the diet of Siberian sturgeon fingerlings with 2% and 5% PHB were investigated. Replacing 2% of the diet with PHB improved weight gain, specific growth rate (SGR) and survival in the sturgeon fingerlings during the 10-week experimental period. Community-level physiological profiling and PCR-denaturing gradient gel electrophoresis (PCR-DGGE) were used to analyze the microbial community diversity and community organization in the sturgeon gastrointestinal tract. DGGE analysis revealed that PHB affected the intestinal microbial species richness and diversity. The highest species richness was observed with 2% PHB. DNA sequencing of the dominant bands in 2% and 5% PHB treatments revealed that PHB stimulated bacteria belonging to the genera Bacillus and Ruminococcaceae. Principal component analysis, Lorenz curves and the Shannon index of Biolog Ecoplate data revealed that aerobic metabolic potential of the bacterial community was different in the PHB-treated fishes as compared with the control situation. Overall, our results indicate that PHB act as microbial control agents and replacement of 2% of Siberian sturgeon fingerling diet with PHB has beneficial effects.

  19. Investigation of some characteristics of enzymes that ensure the process of membrane digestion in paddlefish and Russian sturgeon

    Directory of Open Access Journals (Sweden)

    A. N. Nevalennyy

    2010-01-01

    Full Text Available Complex research of characteristics of some enzymes which are carrying out membrane hydrolysis of food at a spoonbilled cat and Russian sturgeon is carried out. High thermostability enzymes the squirrel of all investigated enzymes is marked.

  20. Great Lakes

    Science.gov (United States)

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

  1. Status of scientific knowledge, recovery progress, and future research directions for the Gulf Sturgeon, Acipenser oxyrinchus desotoi Vladykov, 1955

    Science.gov (United States)

    Sulak, Kenneth J.; Parauka, F; Slack, W. Todd; Ruth, T; Randall, Michael T.; Luke, K; Mette, M. F; Price, M. E

    2016-01-01

    The Gulf Sturgeon, Acipenser oxyrinchus desotoi, is an anadromous species of Acipenseridae and native to North America. It currently inhabits and spawns in the upper reaches of seven natal rivers along the northern coast of the Gulf of Mexico from the Suwannee River, Florida, to the Pearl River, Louisiana, during spring to autumn. Next to the Alligator Gar (Atractosteus spatula), the Gulf Sturgeon is currently the largest fish species occurring in U.S. Gulf Coast rivers, attaining a length of 2.35 m and weights exceeding 135 kg, but historically attained a substantially larger size. Historically, the spawning populations existed in additional rivers from which the species has been wholly or nearly extirpated, such as the Mobile and Ochlockonee rivers, and possibly the Rio Grande River. Most Gulf Sturgeon populations were decimated by unrestricted commercial fishing between 1895–1910. Subsequently most populations remained unrecovered or extirpated due to continued harvest until the 1970s–1980s, and the construction of dams blocking access to ancestral upriver spawning grounds. Late 20th Century harvest bans and net bans enacted by the several Gulf Coast states have stabilized several populations and enabled the Suwannee River population to rebound substantially and naturally. Hatchery supplementation has not been necessary in this regard to date. Sturgeon are resilient and adaptable fishes with a geological history of 150 million years. Research undertaken since the 1970s has addressed many aspects of Gulf Sturgeon life history, reproduction, migration, population biology, habitat requirements, and other aspects of species biology. However, many knowledge gaps remain, prominently including the life history of early developmental stages in the first year of life. Natural population recovery is evident for the Suwannee River population, but seems promising as well for at least four other populations. The Pascagoula and Pearl River populations face a challenging

  2. Synergistic effect of hydrogen peroxide on polyploidization during the megakaryocytic differentiation of K562 leukemia cells by PMA.

    Science.gov (United States)

    Ojima, Yoshihiro; Duncan, Mark Thompson; Nurhayati, Retno Wahyu; Taya, Masahito; Miller, William Martin

    2013-08-15

    The human myelogenous cell line, K562 has been extensively used as a model for the study of megakaryocytic (MK) differentiation, which could be achieved by exposure to phorbol 12-myristate 13-acetate (PMA). In this study, real-time PCR analysis revealed that the expression of catalase (cat) was significantly repressed during MK differentiation of K562 cells induced by PMA. In addition, PMA increased the intracellular reactive oxygen species (ROS) concentration, suggesting that ROS was a key factor for PMA-induced differentiation. PMA-differentiated K562 cells were exposed to hydrogen peroxide (H2O2) to clarify the function of ROS during MK differentiation. Interestingly, the percentage of high-ploidy (DNA content >4N) cells with H2O2 was 34.8±2.3% at day 9, and was 70% larger than that without H2O2 (21.5±0.8%). Further, H2O2 addition during the first 3 days of PMA-induced MK differentiation had the greatest effect on polyploidization. In an effort to elucidate the mechanisms of enhanced polyploidization by H2O2, the BrdU assay clearly indicated that H2O2 suppressed the division of 4N cells into 2N cells, followed by the increased polyploidization of K562 cells. These findings suggest that the enhancement in polyploidization mediated by H2O2 is due to synergistic inhibition of cytokinesis with PMA. Although H2O2 did not increase ploidy during the MK differentiation of primary cells, we clearly observed that cat expression was repressed in both immature and mature primary MK cells, and that treatment with the antioxidant N-acetylcysteine effectively blocked and/or delayed the polyploidization of immature MK cells. Together, these findings suggest that MK cells are more sensitive to ROS levels during earlier stages of maturation. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Status and Habitat Requirements of White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1988-1989 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Nigro, Anthony A. (Oregon Dept. of Fish and Wildlife, Portland, OR (USA))

    1989-09-01

    We report on our progress from April 1988 through March 1989 on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam. Highlights of results of our work in the Dalles and Bonneville reservoirs are: using setlines, we caught 1,586 sturgeon in The Dalles Reservoir and 484 sturgeon in Bonneville Reservoir in 1988. Fork length of fish caught ranged from 34 cm to 274 cm. Of the fish caught we marked 1,248 in The Dalles Reservoir and 341 in Bonneville Reservoir. Of the fish marked in 1988, we recaptured 82 in The Dalles Reservoir and none in Bonneville Reservoir. We recaptured 89 fish marked in 1987 in The Dalles Reservoir. Anglers recaptured 35 fish marked in 1988 and 16 fish marked in 1987 in The Dalles Reservoir. Anglers recaptured 2 sturgeon marked in 1988 in Bonneville Reservoir. Individual papers were processed separately for the data base.

  4. Evaluate Potenial Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Scott R.; Tuell, Michael A.; Hesse, Jay A. (Nez Perce Tribe, Department of Fisheries Management, Lapwai, ID)

    2004-02-01

    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This report presents a summary of results from the 1997-2002 Phase II data collection and represents the end of phase II. From 1997 to 2001 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon. A total of 1,785 white sturgeon were captured and tagged in the Snake River and 77 in the Salmon River. Since 1997, 25.8 percent of the tagged white sturgeon have been recaptured. Relative density of white sturgeon was highest in the free-flowing segment of the Snake River, with reduced densities of fish in Lower Granite Reservoir, and low densities the Salmon River. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir, the free-flowing Snake River and the Salmon River (Chi-Square test, P<0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 30 percent since the 1970's. Using the Jolly-Seber model, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,483 fish, with a 95% confidence interval of 1,208-7,477. Total annual mortality rate was estimated to be 0.14 (95% confidence interval of 0.12 to 0.17). A total of 35 white sturgeon were fitted with radio-tags during 1999-2002. The movement of these fish ranged from 53 km (33 miles) downstream to 77 km (48 miles) upstream; however, 38.8 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No

  5. Gender and gonadal maturity stage identification of captive Chinese sturgeon, Acipenser sinensis, using ultrasound imagery and sex steroids.

    Science.gov (United States)

    Du, Hao; Zhang, Xiaoyan; Leng, Xiaoqian; Zhang, Shuhuan; Luo, Jiang; Liu, Zhigang; Qiao, Xingmei; Kynard, Boyd; Wei, Qiwei

    2017-05-01

    Long lifespan and late maturation make it difficult to establish gamete maturity and breeding age of captive endangered Chinese sturgeon, Acipenser sinensis. This greatly handicaps timely breeding and future conservation stocking efforts. We used ultrasound imagery and sex steroids to determine the gender and gonadal maturity stage of captive Chinese sturgeon (age, 10-17years old). The echogenicity of the reproductive organs and the respective morphology of the gonads were described and two quantitative parameters p o (proportion of the ovary to the entire reproductive organs) and d (thickness of the reproductive organs) were measured to characterize sex and maturity stage of Chinese sturgeon. Females were accordingly placed fish into several categories: F II (F II - , F II , F II + ), F III (F III , F III + ) and F IV (F IV , F IV + ) and F VI and males as M II , M III , M IV , M V and M VI . The accuracy of gender and maturity stage determination provided by ultrasonographic methods was 72.7% for F II - ovary (n=11) and 76.2% for M II testis (n=42). Accuracy of sex and maturity determination using only serum sex steroid of testosterone (T) and estradiol-17β (E 2 ) was low (58-73%, depending on maturity stage). However, when the two methods were used together, accuracy increased sharply, especially for immature (II stage) females. In summary, of 151 Chinese sturgeon, whose sex and maturity stage were independently confirmed, 88.1% (n=133), 62.9% (n=95), and 96.7% (n=146) were successfully sexed and staged using ultrasound, sex steroids, or both methods, respectively. The results provide reliable non-invasive techniques for determining sex and gonadal maturation of captive Chinese sturgeon. These methods can track individual gonad characteristics over multi-year reproductive cycles, which will assist captive broodstock management, artificial reproduction, and future conservation stocking. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Hierarchical Bayesian Markov switching models with application to predicting spawning success of shovelnose sturgeon

    Science.gov (United States)

    Holan, S.H.; Davis, G.M.; Wildhaber, M.L.; DeLonay, A.J.; Papoulias, D.M.

    2009-01-01

    The timing of spawning in fish is tightly linked to environmental factors; however, these factors are not very well understood for many species. Specifically, little information is available to guide recruitment efforts for endangered species such as the sturgeon. Therefore, we propose a Bayesian hierarchical model for predicting the success of spawning of the shovelnose sturgeon which uses both biological and behavioural (longitudinal) data. In particular, we use data that were produced from a tracking study that was conducted in the Lower Missouri River. The data that were produced from this study consist of biological variables associated with readiness to spawn along with longitudinal behavioural data collected by using telemetry and archival data storage tags. These high frequency data are complex both biologically and in the underlying behavioural process. To accommodate such complexity we developed a hierarchical linear regression model that uses an eigenvalue predictor, derived from the transition probability matrix of a two-state Markov switching model with generalized auto-regressive conditional heteroscedastic dynamics. Finally, to minimize the computational burden that is associated with estimation of this model, a parallel computing approach is proposed. ?? Journal compilation 2009 Royal Statistical Society.

  7. Penicillin improves the milt quality of Persian sturgeon, Acipenser persicus during short-term storage

    Directory of Open Access Journals (Sweden)

    Mostafa Halimi

    2014-04-01

    Full Text Available This study was conducted to examine the effects of antibiotic (5000 units of penicillin on sperm quality of Persian sturgeon, Acipenser persicus during 9 days in vitro storage of milt. For this purpose, the milt samples were stored in the presence and absence of 5000 units of penicillin. Freshwater was used as sperm activator. The milt samples were stored at 4°C and the motility indices were measured 0, 3, 6 and 9 days after storage. The sperm duration and percentage of sperm motility decreased after 6 days of storage both in the presence and absence of antibiotic, although this decrease was more significant in the absence of antibiotic. After 9 days of storage, the lowest values of sperm motility indices was recorded for antibiotic receiving milt samples while no motile spermatozoa observed for antibiotic-free milt samples. In conclusion, our results demonstrated that 5000 units of penicillin improve the Persian sturgeon milt quality during short-term storage.

  8. Vegetable Production in an Integrated Aquaponic System with Stellate Sturgeon and Spinach – Matador variety

    Directory of Open Access Journals (Sweden)

    Stefan Mihai Petrea

    2014-05-01

    Full Text Available This study aims to reveal the performances parameters, both in terms of quantity and quality, for spinach (Spinacia oleracea - Matador variety, growth in an aquaponic integrated system, along with stellate sturgeons (A. stellatus under three crops densities (V1 - 59 crops/m2, V2 – 48 crops/m2 and V3 – 39 crops/m2, by using hydroton as growing substrate, under a continuous flow hydraulic regime. The experiment was run in triplicate for each one of the three variants. The water quality was monitored and a series of growth parameters were determined, as follows: leaf area index (LAI, relative growth rate (RGR, average net assimilation rate (NAR, mean leaf area ratio (LAR and crop growth rate (CGR. Also the concentration of chlorophyll a, b, carotenoids, ash and dry matter for spinach leaf, from each of the three experimental variants was determined and compared with the one of marketable spinach, growth conventional, in soil. It can be concluded that statistical significant differences (p<0.05 were recorded in terms of growth performance and crops quality, between the experimental variants. Also the quality of spinach grown in aquaponic conditions, by using effluent derived from stellate sturgeon intensive aquaculture is similar to that of the marketable spinach, growth conventional.

  9. Natural growth and diet of known-age pallid sturgeon (Scaphirhynchus albus) early life stages in the upper Missouri River basin, Montana and North Dakota

    Science.gov (United States)

    Braaten, P.J.; Fuller, D.B.; Lott, R.D.; Haddix, T.M.; Holte, L.D.; Wilson, R.H.; Bartron, M.L.; Kalie, J.A.; DeHaan, P.W.; Ardren, W.R.; Holm, R.J.; Jaeger, M.E.

    2012-01-01

    Prior to anthropogenic modifications, the historic Missouri River provided ecological conditions suitable for reproduction, growth, and survival of pallid sturgeon Scaphirhynchus albus. However, little information is available to discern whether altered conditions in the contemporary Missouri River are suitable for feeding, growth and survival of endangered pallid sturgeon during the early life stages. In 2004 and 2007, nearly 600 000 pallid sturgeon free embryos and larvae were released in the upper Missouri River and survivors from these releases were collected during 2004–2010 to quantify natural growth rates and diet composition. Based on genetic analysis and known-age at release (1–17 days post-hatch, dph), age at capture (dph, years) could be determined for each survivor. Totals of 23 and 28 survivors from the 2004 and 2007 releases, respectively, were sampled. Growth of pallid sturgeon was rapid (1.91 mm day−1) during the initial 13–48 dph, then slowed as fish approached maximum length (120–140 mm) towards the end of the first growing season. The diet of young-of-year pallid sturgeon was comprised of Diptera larvae, Diptera pupae, and Ephemeroptera nymphs. Growth of pallid sturgeon from ages 1–6 years was about 48.0 mm year−1. This study provides the first assessment of natural growth and diet of young pallid sturgeon in the wild. Results depict pallid sturgeon growth trajectories that may be expected for naturally produced wild stocks under contemporary habitat conditions in the Missouri River and Yellowstone River.

  10. Commercial fishing gear modifications to reduce interactions between Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the southern flounder (Paralichthys lethostigma) fishery in North Carolina (USA).

    Science.gov (United States)

    Levesque, Juan C; Hager, Christian; Diaddorio, Eric; Dickey, R Jason

    2016-01-01

    Bycatch of protected species in commercial fishing operations is a primary concern to fishery managers because it threatens the conservation, protection, and recovery of fragile species, such as the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus). One potential solution to reduce the risk associated with commercial fishing operations is to design commercial fishing gear that is more selective in terms of interactions between Atlantic sturgeon and commercial fisheries. Given this conservation and management need, the overarching goal was to reduce Atlantic sturgeon fishery interactions and maintain southern flounder (Paralichthys lethostigma) catch in North Carolina. The specific objectives of this study were to design and evaluate the effectiveness of a modified gillnet. Overall, the results proved that lowering the profile and amount of webbing had a beneficial impact at reducing Atlantic sturgeon incidental encounters and bycatch. The modified gillnet reduced bycatch and Atlantic sturgeon encounters by 39.6% and 60.9%, respectively. Our design entangled 51.6% fewer southern flounder, which corresponded to a 48.9% reduction in total weight; the modified gear entangled slightly larger southern flounder than the control gear. Our findings showed the number of Atlantic sturgeon encounters was positively associated with mean water depth, with more Atlantic sturgeon encountered in deeper (5.1-6.3 m) than shallower waters; 75% were encountered at depths between 4.6 and 6.1 m. Most southern flounder (n = 518, 39.7%) were taken at a water depth between 3.76 and 5.0 m. This observation suggests that southern flounder prefer slightly shallower waters than Atlantic sturgeon.

  11. Isolation and characterization of an atypical Siberian sturgeon herpesvirus strain in Russia: novel North American Acipenserid herpesvirus 2 strain in Europe?

    Science.gov (United States)

    Doszpoly, A; Kalabekov, I M; Breyta, R; Shchelkunov, I S

    2017-10-01

    Siberian sturgeon herpesvirus (SbSHV) was isolated in Russia for the first time in 2006. Nine SbSHV isolates were recovered from different fish hatcheries producing the same cytopathic effect in cell cultures, the same clinical signs and mortality kinetics in virus-infected fish and the same virus neutralization pattern and shared identical nucleotide sequences. In 2011, a new isolate was recovered from juvenile sturgeon, which caused completely different cytopathic effect. That isolate was not readily neutralized by Siberian sturgeon hyperimmune antisera, and its DNA was not recognized by the routine PCR developed for SbSHV detection. Molecular study of the novel isolate revealed that it was more closely related to North American Acipenserid herpesvirus 2 (AciHV-2) isolates from white sturgeon, while the genome sequences of the former SbSHV isolates showed high similarity to the AciHV-2 isolated from shortnose sturgeon. While clinical signs and mortality caused by the novel isolate in infected Siberian sturgeon were similar to those of the formerly described SbSHV isolates, the incubation period and mean time to death produced by the novel isolate were twice as long. The differences between the former isolates and the recent one suggest that a novel SbSHV strain emerged in Europe and the molecular findings imply its North American origin. © 2017 John Wiley & Sons Ltd.

  12. Preliminary evaluation of the effectiveness of visible implant elastomer and coded wire tags for tagging young-of-the-year Atlantic sturgeon, Acipenser oxyrinchus

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    Kapusta Andrzej

    2015-12-01

    Full Text Available The aim of the study was to determine the retention rates of visible implant elastomer (VIE and coded wire tags (CWT and the impact tagging had on the growth of Atlantic sturgeon, Acipenser oxyrinchus Mitchill, during an eight-week rearing period under laboratory conditions. Two size groups of young-of-the-year (YOY sturgeon were used in the study. The tagging was not found to have a significant impact on the final total length or body weight or the condition coefficient of the sturgeon from either size group. Sturgeon survival in the different groups ranged from 90.6 to 100%. Mortality was not noted until two (CWT and four (VIE weeks following tagging and was probably not linked to tagging. The retention rate for VIE tags implanted in the rostrum in both size groups was 100%, while for tags implanted at the base of the pectoral fin was 93.5%. The retention of CWT in the smaller fish was 90%, and in the larger sturgeon it was 100%. Tagging small sturgeon with CWT and VIE is minimally invasive, and it did not impact the growth or condition of the tagged fish.

  13. Phosphorylation of ribosomal protein S6 kinase 1 at Thr421/Ser424 and dephosphorylation at Thr389 regulates SP600125-induced polyploidization of megakaryocytic cell lines.

    Science.gov (United States)

    Li, Chang-Ling; Yang, Jin-Gang; Lin, Di; Zhao, Yong-Shan; Liu, Shuo; Xing, Si-Ning; Zhao, Song; Chen, Cong-Qin; Jiang, Zhi-Ming; Pu, Fei-Fei; Cao, Jian-Ping; Ma, Dong-Chu

    2014-01-01

    Megakaryocytes (MKs) are one of the few cell types that become polyploid; however, the mechanisms by which these cells are designated to become polyploid are not fully understood. In this investigation, we successfully established two relatively synchronous polyploid cell models by inducing Dami and CMK cells with SP600125. We found that SP600125 induced the polyploidization of Dami and CMK cells, concomitant with the phosphorylation of ribosomal protein S6 kinase 1 (S6K1) at Thr421/Ser424 and dephosphorylation at Thr389. The polyploidization was partially blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor, through direct binding to S6K1, leading to dephosphorylation at Thr421/Ser424 and phosphorylation at Thr389, independent of PKA. Overexpression of a rapamycin-resistant mutant of S6K1 further enhanced the inhibitory effect of LY294002 on the SP600125-induced polyploidization of Dami and CMK cells. SP600125 also induced the polyploidization of Meg-01 cells, which are derived from a patient with chronic myelogenous leukemia, without causing a significant change in S6K1 phosphorylation. Additionally, SP600125 induced the polyploidization of HEL cells, which are derived from a patient with erythroleukemia, and phosphorylation at Thr389 of S6K1 was detected. However, the polyploidization of both Meg-01 cells and HEL cells as a result of SP600125 treatment was lower than that of SP600125-induced Dami and CMK cells, and it was not blocked by H-89 despite the increased phosphorylation of S6K1 at Thr389 in both cell lines in response to H-89. Given that the Dami and CMK cell lines were derived from patients with acute megakaryocytic leukemia (AMKL) and expressed high levels of platelet-specific antigens, our data suggested that SP600125-induced polyploidization is cell-type specific, that these cell lines were more differentiated, and that phosphorylation at Thr421/Ser424 and dephosphorylation at Thr389 of S6K1 may play an important role in the SP600125

  14. Phosphorylation of ribosomal protein S6 kinase 1 at Thr421/Ser424 and dephosphorylation at Thr389 regulates SP600125-induced polyploidization of megakaryocytic cell lines.

    Directory of Open Access Journals (Sweden)

    Chang-Ling Li

    Full Text Available Megakaryocytes (MKs are one of the few cell types that become polyploid; however, the mechanisms by which these cells are designated to become polyploid are not fully understood. In this investigation, we successfully established two relatively synchronous polyploid cell models by inducing Dami and CMK cells with SP600125. We found that SP600125 induced the polyploidization of Dami and CMK cells, concomitant with the phosphorylation of ribosomal protein S6 kinase 1 (S6K1 at Thr421/Ser424 and dephosphorylation at Thr389. The polyploidization was partially blocked by H-89, a cAMP-dependent protein kinase (PKA inhibitor, through direct binding to S6K1, leading to dephosphorylation at Thr421/Ser424 and phosphorylation at Thr389, independent of PKA. Overexpression of a rapamycin-resistant mutant of S6K1 further enhanced the inhibitory effect of LY294002 on the SP600125-induced polyploidization of Dami and CMK cells. SP600125 also induced the polyploidization of Meg-01 cells, which are derived from a patient with chronic myelogenous leukemia, without causing a significant change in S6K1 phosphorylation. Additionally, SP600125 induced the polyploidization of HEL cells, which are derived from a patient with erythroleukemia, and phosphorylation at Thr389 of S6K1 was detected. However, the polyploidization of both Meg-01 cells and HEL cells as a result of SP600125 treatment was lower than that of SP600125-induced Dami and CMK cells, and it was not blocked by H-89 despite the increased phosphorylation of S6K1 at Thr389 in both cell lines in response to H-89. Given that the Dami and CMK cell lines were derived from patients with acute megakaryocytic leukemia (AMKL and expressed high levels of platelet-specific antigens, our data suggested that SP600125-induced polyploidization is cell-type specific, that these cell lines were more differentiated, and that phosphorylation at Thr421/Ser424 and dephosphorylation at Thr389 of S6K1 may play an important role in

  15. Meiotic behavior of two polyploid species of genus Pleurodema (Anura: Leiuperidae from central Argentina

    Directory of Open Access Journals (Sweden)

    Nancy E. Salas

    2014-06-01

    Full Text Available Polyploidy is an important evolutionary force but rare in vertebrates. However, in anurans, the genus Pleurodema has polyploid species, two of them tetraploid and one octoploid. The manner in which the chromosomes join in diakinesis can vary among species and, crucially, if they differ in their ploidy levels. In this work, we describe the meiotic configurations in two cryptic species from central Argentina, with different ploidy levels, Pleurodema kriegi (tetraploid and P. cordobae (octoploid. A total of 306 diakineses from 19 individuals were analyzed. In meiosis, P. kriegi form 22 bivalents, whereas P. cordobae exhibits variation in meiotic figures. We discuss the possible allo- and autopolyploid origin of these species, and we consider that the autopolyploid origin of P. cordobae from P. kriegi might be the most feasible.

  16. Comparative inference of duplicated genes produced by polyploidization in soybean genome.

    Science.gov (United States)

    Yang, Yanmei; Wang, Jinpeng; Di, Jianyong

    2013-01-01

    Soybean (Glycine max) is one of the most important crop plants for providing protein and oil. It is important to investigate soybean genome for its economic and scientific value. Polyploidy is a widespread and recursive phenomenon during plant evolution, and it could generate massive duplicated genes which is an important resource for genetic innovation. Improved sequence alignment criteria and statistical analysis are used to identify and characterize duplicated genes produced by polyploidization in soybean. Based on the collinearity method, duplicated genes by whole genome duplication account for 70.3% in soybean. From the statistical analysis of the molecular distances between duplicated genes, our study indicates that the whole genome duplication event occurred more than once in the genome evolution of soybean, which is often distributed near the ends of chromosomes.

  17. Gene Conversion in Angiosperm Genomes with an Emphasis on Genes Duplicated by Polyploidization

    Directory of Open Access Journals (Sweden)

    Xi-Yin Wang

    2011-01-01

    Full Text Available Angiosperm genomes differ from those of mammals by extensive and recursive polyploidizations. The resulting gene duplication provides opportunities both for genetic innovation, and for concerted evolution. Though most genes may escape conversion by their homologs, concerted evolution of duplicated genes can last for millions of years or longer after their origin. Indeed, paralogous genes on two rice chromosomes duplicated an estimated 60–70 million years ago have experienced gene conversion in the past 400,000 years. Gene conversion preserves similarity of paralogous genes, but appears to accelerate their divergence from orthologous genes in other species. The mutagenic nature of recombination coupled with the buffering effect provided by gene redundancy, may facilitate the evolution of novel alleles that confer functional innovations while insulating biological fitness of affected plants. A mixed evolutionary model, characterized by a primary birth-and-death process and occasional homoeologous recombination and gene conversion, may best explain the evolution of multigene families.

  18. Extensive and biased intergenomic nonreciprocal DNA exchanges shaped a nascent polyploid genome, Gossypium (cotton).

    Science.gov (United States)

    Guo, Hui; Wang, Xiyin; Gundlach, Heidrun; Mayer, Klaus F X; Peterson, Daniel G; Scheffler, Brian E; Chee, Peng W; Paterson, Andrew H

    2014-08-01

    Genome duplication is thought to be central to the evolution of morphological complexity, and some polyploids enjoy a variety of capabilities that transgress those of their diploid progenitors. Comparison of genomic sequences from several tetraploid (AtDt) Gossypium species and genotypes with putative diploid A- and D-genome progenitor species revealed that unidirectional DNA exchanges between homeologous chromosomes were the predominant mechanism responsible for allelic differences between the Gossypium tetraploids and their diploid progenitors. Homeologous gene conversion events (HeGCEs) gradually subsided, declining to rates similar to random mutation during radiation of the polyploid into multiple clades and species. Despite occurring in a common nucleus, preservation of HeGCE is asymmetric in the two tetraploid subgenomes. At-to-Dt conversion is far more abundant than the reciprocal, is enriched in heterochromatin, is highly correlated with GC content and transposon distribution, and may silence abundant A-genome-derived retrotransposons. Dt-to-At conversion is abundant in euchromatin and genes, frequently reversing losses of gene function. The long-standing observation that the nonspinnable-fibered D-genome contributes to the superior yield and quality of tetraploid cotton fibers may be explained by accelerated Dt to At conversion during cotton domestication and improvement, increasing dosage of alleles from the spinnable-fibered A-genome. HeGCE may provide an alternative to (rare) reciprocal DNA exchanges between chromosomes in heterochromatin, where genes have approximately five times greater abundance of Dt-to-At conversion than does adjacent intergenic DNA. Spanning exon-to-gene-sized regions, HeGCE is a natural noninvasive means of gene transfer with the precision of transformation, potentially important in genetic improvement of many crop plants. Copyright © 2014 by the Genetics Society of America.

  19. Hybridization among distantly related species: Examples from the polyploid genus Curcuma (Zingiberaceae).

    Science.gov (United States)

    Záveská, Eliška; Fér, Tomáš; Šída, Otakar; Marhold, Karol; Leong-Škorničková, Jana

    2016-07-01

    Discerning relationships among species evolved by reticulate and/or polyploid evolution is not an easy task, although it is widely discussed. The economically important genus Curcuma (ca. 120 spp.; Zingiberaceae), broadly distributed in tropical SE Asia, is a particularly interesting example of a group of palaeopolyploid origin whose evolution is driven mainly by hybridization and polyploidization. Although a phylogeny and a new infrageneric classification of Curcuma, based on commonly used molecular markers (ITS and cpDNA), have recently been proposed, significant evolutionary questions remain unresolved. We applied a multilocus approach and a combination of modern analytical methods to this genus to distinguish causes of gene tree incongruence and to identify hybrids and their parental species. Five independent regions of nuclear DNA (DCS, GAPDH, GLOBOSA3, LEAFY, ITS) and four non-coding cpDNA regions (trnL-trnF, trnT-trnL, psbA-trnH and matK), analysed as a single locus, were employed to construct a species tree and hybrid species trees using (*)BEAST and STEM-hy. Detection of hybridogenous species in the dataset was also conducted using the posterior predictive checking approach as implemented in JML. The resulting species tree outlines the relationships among major evolutionary lineages within Curcuma, which were previously unresolved or which conflicted depending upon whether they were based on ITS or cpDNA markers. Moreover, by using the additional markers in tests of plausible topologies of hybrid species trees for C. vamana, C. candida, C. roscoeana and C. myanmarensis suggested by previous molecular and morphological evidence, we found strong evidence that all the species except C. candida are of subgeneric hybrid origin. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Quantification of ploidy in proteobacteria revealed the existence of monoploid, (mero-oligoploid and polyploid species.

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    Vito Pecoraro

    Full Text Available Bacteria are generally assumed to be monoploid (haploid. This assumption is mainly based on generalization of the results obtained with the most intensely studied model bacterium, Escherichia coli (a gamma-proteobacterium, which is monoploid during very slow growth. However, several species of proteobacteria are oligo- or polyploid, respectively. To get a better overview of the distribution of ploidy levels, genome copy numbers were quantified in four species of three different groups of proteobacteria. A recently developed Real Time PCR approach, which had been used to determine the ploidy levels of halophilic archaea, was optimized for the quantification of genome copy numbers of bacteria. Slow-growing (doubling time 103 minutes and fast-growing (doubling time 25 minutes E. coli cultures were used as a positive control. The copy numbers of the origin and terminus region of the chromosome were determined and the results were in excellent agreement with published data. The approach was also used to determine the ploidy levels of Caulobacter crescentus (an alpha-proteobacterium and Wolinella succinogenes (an epsilon-proteobacterium, both of which are monoploid. In contrast, Pseudomonas putida (a gamma-proteobacterium contains 20 genome copies and is thus polyploid. A survey of the proteobacteria with experimentally-determined genome copy numbers revealed that only three to four of 11 species are monoploid and thus monoploidy is not typical for proteobacteria. The ploidy level is not conserved within the groups of proteobacteria, and there are no obvious correlations between the ploidy levels with other parameters like genome size, optimal growth temperature or mode of life.

  1. Identification of a potent small molecule capable of regulating polyploidization, megakaryocyte maturation, and platelet production.

    Science.gov (United States)

    Huang, Nick; Lou, Mabel; Liu, Hua; Avila, Cecilia; Ma, Yupo

    2016-12-08

    Megakaryocytic cell maturation involves polyploidization, and megakaryocyte (MK) ploidy correlates with their maturation and platelet production. Retardation of MK maturation is closely associated with poor MK engraftment after cord blood transplantation and neonatal thrombocytopenia. Despite the high prevalence of thrombocytopenia in a range of setting that affect infants to adults, there are still very limited modalities of treatment. Human CD34 + cells were isolated from cord blood or bone marrow samples acquired from consenting patients. Cells were cultured and induced using 616452 and compared to current drugs on the market such as rominplostim or TPO. Ploidy analysis was completed using propidium iodide staining and flow cytometry analysis. Animal studies consisted of transplanting human CD34 + cells into NOD.Cg-Prkdc scid Il2rg tm1Wjl /SzJ mice followed by daily injections of 15 mg/kg of 616452. Within one week of culture, the chemical was able to induce polyploidization, the process required for megakaryocyte maturation with the accumulation of DNA content, to 64 N or greater to achieve a relative adult size. We observed fold increases as high as 200-fold in cells of 16 N or greater compared to un-induced cells with a dose-dependent manner. In addition, MK differentiated in the presence of 616452 demonstrated a more robust capacity of MK differentiation than that of MKs cultured with rominplostim used for adult idiopathic thrombocytopenic purpura (ITP) patients. In mice transplanted with human cord blood, 616452 strikingly enhanced MK reconstitution in the marrow and human peripheral platelet production. The molecular therapeutic actions for this chemical may be through TPO-independent pathways. Our studies may have an important impact on our fundamental understanding of fetal MK biology, the clinical management of thrombocytopenic neonates and leukemic differentiation therapy.

  2. Bone marrow niche-inspired, multi-phase expansion of megakaryocytic progenitors with high polyploidization potential

    Science.gov (United States)

    Panuganti, Swapna; Papoutsakis, Eleftherios T.; Miller, William M.

    2010-01-01

    Background Megakaryopoiesis encompasses hematopoietic stem and progenitor cell (HSPC) commitment to the megakaryocytic cell (Mk) lineage, expansion of Mk progenitors and mature Mks, polyploidization, and platelet release. pH and pO2 increase from the endosteum to sinuses, and different cytokines are important for various stages of differentiation. We hypothesized that mimicking the changing conditions during Mk differentiation in the bone marrow would facilitate expansion of progenitors that could generate many high-ploidy Mks. Methods CD34+ HSPCs were cultured at pH 7.2 and 5% O2 with stem cell factor (SCF), thrombopoietin (Tpo), and all combinations of Interleukin (IL)-3, IL-6, IL-11, and Flt-3 ligand to promote Mk progenitor expansion. Cells cultured with selected cytokines were shifted to pH 7.4 and 20% O2 to generate mature Mks, and treated with nicotinamide to enhance polyploidization. Results Using Tpo+SCF+IL-3+IL-11, we obtained 3.5 CD34+CD41+ Mk progenitors per input HSPC, while increasing purity from 1% to 17%. Cytokine cocktails with IL-3 yielded more progenitors and mature Mks, although the purities were lower. Mk production was much greater at higher pH and pO2. Although fewer progenitors were present, shifting to 20% O2/pH 7.4 at day 5 (versus days 7 or 9) yielded the greatest mature Mk production, 14 per input HSPC. Nicotinamide more than doubled the percentage of high-ploidy Mks to 40%. Discussion We obtained extensive Mk progenitor expansion, while ensuring that the progenitors could produce high-ploidy Mks. We anticipate that subsequent optimization of cytokines for mature Mk production and delayed nicotinamide addition will greatly increase high-ploidy Mk production. PMID:20482285

  3. [Rat cardiomyocyte remodeling after neonatal cryptosporidiosis. II. Elongation, excessive polyploidization and HIF-1alpha overexpression].

    Science.gov (United States)

    Anatskaia, O V; Sidorenko, N V; Matveev, I V; Kropotov, A V; Vinogradov, A E

    2012-01-01

    Retrospective epidemyological studies evidence that infant diseases leave survivors with an increased susceptibility to cardiovascular diseases in later life. At the same time, the mechanisms of this link remain poorly understood. Based on medical statistics reporting that infectious gastroenteritis is the most common cause of maladies in babies, infants and children, we analysed the effects of moderate cryptosporidial gastroenteritis on the heart and ventricular cardiomyocyte remodelling in rats of the first month of life. The disease was challenged by a worldwide human protozoic pathogen Cryptosporidium parvum (Apicomplexa, Sporozoa). The main symptoms manifested in the growth retardation moderate diarrhea. Using real-time PCR, cytophotometry, confocal microscopy and image analysis, we indicated that cryptosporidiosis was associated, with the atrophy heart and the elongation, narrowing, protein content decrease and hyperpolyploidization of cardiomyocytes and the moderate overexpression of hypoxia inducible factor 1alpha (HIF-1alpha) mRNA. Cardiomyocyte shape remodeling and heart atrophy presented in all age groups. The severity of these changes, hovewer, declined gradually from younger to older groups. In contrast, hyperpolyploidization and HIF-1alpha mRNA overexpression were registered mainly among animals aged between 6 and 13 days, and were barely detected and non-significant in older age groups. In the rat the time period covering 6-13 days after birth is known to coincide with the intensive cardiomyocyte polyploidization and the switch from proliferation to hypertrophy. Thus, our data indicate that neonatal cryptosporidiosis may be potential cardiovascular diseases risk factor and that one of the critical time windows for the growing heart covers the time period when cardiomyocyte undergo polyploidization.

  4. Bone marrow niche-inspired, multiphase expansion of megakaryocytic progenitors with high polyploidization potential.

    Science.gov (United States)

    Panuganti, Swapna; Papoutsakis, Eleftherios T; Miller, William M

    2010-10-01

    Megakaryopoiesis encompasses hematopoietic stem and progenitor cell (HSPC) commitment to the megakaryocytic cell (Mk) lineage, expansion of Mk progenitors and mature Mks, polyploidization and platelet release. pH and pO2 increase from the endosteum to sinuses, and different cytokines are important for various stages of differentiation. We hypothesized that mimicking the changing conditions during Mk differentiation in the bone marrow would facilitate expansion of progenitors that could generate many high-ploidy Mks. CD34+ HSPCs were cultured at pH 7.2 and 5% O2 with stem cell factor (SCF), thrombopoietin (Tpo) and all combinations of Interleukin (IL)-3, IL-6, IL-11 and Flt-3 ligand to promote Mk progenitor expansion. Cells cultured with selected cytokines were shifted to pH 7.4 and 20% O2 to generate mature Mks, and treated with nicotinamide (NIC) to enhance polyploidization. Using Tpo + SCF + IL-3 + IL-11, we obtained 3.5 CD34+ CD41+ Mk progenitors per input HSPC, while increasing purity from 1% to 17%. Cytokine cocktails with IL-3 yielded more progenitors and mature Mks, although the purities were lower. Mk production was much greater at higher pH and pO2. Although fewer progenitors were present, shifting to 20% O2 /pH 7.4 at day 5 (versus days 7 or 9) yielded the greatest mature Mk production, 14 per input HSPC. NIC more than doubled the percentage of high-ploidy Mks to 40%. We obtained extensive Mk progenitor expansion, while ensuring that the progenitors could produce high-ploidy Mks. We anticipate that subsequent optimization of cytokines for mature Mk production and delayed NIC addition will greatly increase high-ploidy Mk production.

  5. The pachytene checkpoint and its relationship to evolutionary patterns of polyploidization and hybrid sterility.

    Science.gov (United States)

    Li, X C; Barringer, B C; Barbash, D A

    2009-01-01

    Sterility is a commonly observed phenotype in interspecific hybrids. Sterility may result from chromosomal or genic incompatibilities, and much progress has been made toward understanding the genetic basis of hybrid sterility in various taxa. The underlying mechanisms causing hybrid sterility, however, are less well known. The pachytene checkpoint is a meiotic surveillance system that many organisms use to detect aberrant meiotic products, in order to prevent the production of defective gametes. We suggest that activation of the pachytene checkpoint may be an important mechanism contributing to two types of hybrid sterility. First, the pachytene checkpoint may form the mechanistic basis of some gene-based hybrid sterility phenotypes. Second, the pachytene checkpoint may be an important mechanism that mediates chromosomal-based hybrid sterility phenotypes involving gametes with non-haploid (either non-reduced or aneuploid) chromosome sets. Studies in several species suggest that the strength of the pachytene checkpoint is sexually dimorphic, observations that warrant future investigation into whether such variation may contribute to differences in patterns of sterility between male and female interspecific hybrids. In addition, plants seem to lack the pachytene checkpoint, which correlates with increased production of unreduced gametes and a higher incidence of polyploid species in plants versus animals. Although the pachytene checkpoint occurs in many animals and in fungi, at least some of the genes that execute the pachytene checkpoint are different among organisms. This finding suggests that the penetrance of the pachytene checkpoint, and even its presence or absence can evolve rapidly. The surprising degree of evolutionary flexibility in this meiotic surveillance system may contribute to the observed variation in patterns of hybrid sterility and in rates of polyploidization.

  6. Bathymetry of Lake Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  7. Bathymetry of Lake Ontario

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  8. Bathymetry of Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  9. Great Lakes Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and...

  10. Bathymetry of Lake Huron

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  11. Geographic relatedness and predictability of Escherichia coli along a peninsular beach complex of Lake Michigan

    Science.gov (United States)

    Nevers, M.B.; Shively, D.A.; Kleinheinz, G.T.; McDermott, C.M.; Schuster, W.; Chomeau, V.; Whitman, R.L.

    2009-01-01

    To determine more accurately the real-time concentration of fecal indicator bacteria (FIB) in beach water, predictive modeling has been applied in several locations around the Great Lakes to individual or small groups of similar beaches. Using 24 beaches in Door County, Wisconsin, we attempted to expand predictive models to multiple beaches of complex geography. We examined the importance of geographic location and independent variables and the consequential limitations for potential beach or beach group models. An analysis of Escherichia coli populations over 4 yr revealed a geographic gradient to the beaches, with mean E. coli concentrations decreasing with increasing distance from the city of Sturgeon Bay. Beaches grouped strongly by water type (lake, bay, Sturgeon Bay) and proximity to one another, followed by presence of a storm or creek outfall or amount of shoreline enclosure. Predictive models developed for beach groups commonly included wave height and cumulative 48-h rainfall but generally explained little E. coli variation (adj. R2 = 0.19-0.36). Generally low concentrations of E. coli at the beaches influenced the effectiveness of model results presumably because of low signal-to-noise ratios and the rarity of elevated concentrations. Our results highlight the importance of the sensitivity of regressors and the need for careful methods evaluation. Despite the attractiveness of predictive models as an alternative beach monitoring approach, it is likely that FIB fluctuations at some beaches defy simple prediction approaches. Regional, multi-beach, and individual beach predictive models should be explored alongside other techniques for improving monitoring reliability at Great Lakes beaches. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  12. Great Lakes Science Center

    Data.gov (United States)

    Federal Laboratory Consortium — Since 1927, Great Lakes Science Center (GLSC) research has provided critical information for the sound management of Great Lakes fish populations and other important...

  13. Acute and chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

    Science.gov (United States)

    Ingersoll, Christopher G.; Contributions by Wang, Ning; Calfee, Robin D.; Beahan, Erinn; Brumbaugh, William G.; Dorman, Rebecca A.; Hardesty, Doug K.; Kunz, James L.; Little, Edward E.; Mebane, Christopher A.; Puglis, Holly J.

    2014-01-01

    White sturgeon (Acipenser transmontanus) are experiencing poor recruitment in the trans boundary reach of the upper Columbia River in eastern Washington State. Limited toxicity data indicated that early life stages of white sturgeon are sensitive to metals. In acute 4-day (d) exposures with larval white sturgeon, previous studies have reported that the 4-day median lethal concentrations (LC50) based on biotic ligand model (BLM) normalization for copper were below the U.S. Environmental Protection Agency national recommended acute water-quality criterion. In previously published chronic 66-d exposures starting with newly fertilized eggs of white sturgeon, 20-percent lethal effect concentrations (LC20s) for copper, cadmium, or zinc generally were within a factor of two of the chronic values of the most sensitive fish species in the databases of the U.S. Environmental Protection Agency water-quality criteria (WQC) for the three metals. However, there were some uncertainties in the chronic exposures previously performed with white sturgeon, including (1) low control survival (37 percent), (2) more control fish tested in each replicate compared to other treatments, (3) limited replication of treatments (n=2), (4) lack of reported growth data (such as dry weight), and (5) wide dilution factors for exposure concentrations (6- to 8-fold dilutions). The U.S. Environmental Protection Agency concluded that additional studies are needed to generate more toxicity data to better define lethal and sublethal toxicity thresholds for metals for white sturgeon. The objective of the study was to further evaluate the acute and chronic toxicity of cadmium, copper, lead, or zinc to early life stages of white sturgeon in water-only exposures. Toxicity tests also were performed with commonly tested rainbow trout (Oncorhynchus mykiss) under similar test conditions to determine the relative sensitivity between white sturgeon and rainbow trout to these metals. Toxicity data generated from

  14. A New Perspective on Polyploid Fragaria (Strawberry) Genome Composition Based on Large-Scale, Multi-Locus Phylogenetic Analysis

    OpenAIRE

    Yang, Yilong; Davis, Thomas M

    2017-01-01

    Abstract The subgenomic compositions of the octoploid (2n = 8× = 56) strawberry (Fragaria) species, including the economically important cultivated species Fragaria x ananassa, have been a topic of long-standing interest. Phylogenomic approaches utilizing next-generation sequencing technologies offer a new window into species relationships and the subgenomic compositions of polyploids. We have conducted a large-scale phylogenetic analysis of Fragaria (strawberry) species using the Fluidigm Ac...

  15. Multiple Polyploidization Events across Asteraceae with Two Nested Events in the Early History Revealed by Nuclear Phylogenomics.

    Science.gov (United States)

    Huang, Chien-Hsun; Zhang, Caifei; Liu, Mian; Hu, Yi; Gao, Tiangang; Qi, Ji; Ma, Hong

    2016-11-01

    Biodiversity results from multiple evolutionary mechanisms, including genetic variation and natural selection. Whole-genome duplications (WGDs), or polyploidizations, provide opportunities for large-scale genetic modifications. Many evolutionarily successful lineages, including angiosperms and vertebrates, are ancient polyploids, suggesting that WGDs are a driving force in evolution. However, this hypothesis is challenged by the observed lower speciation and higher extinction rates of recently formed polyploids than diploids. Asteraceae includes about 10% of angiosperm species, is thus undoubtedly one of the most successful lineages and paleopolyploidization was suggested early in this family using a small number of datasets. Here, we used genes from 64 new transcriptome datasets and others to reconstruct a robust Asteraceae phylogeny, covering 73 species from 18 tribes in six subfamilies. We estimated their divergence times and further identified multiple potential ancient WGDs within several tribes and shared by the Heliantheae alliance, core Asteraceae (Asteroideae-Mutisioideae), and also with the sister family Calyceraceae. For two of the WGD events, there were subsequent great increases in biodiversity; the older one proceeded the divergence of at least 10 subfamilies within 10 My, with great variation in morphology and physiology, whereas the other was followed by extremely high species richness in the Heliantheae alliance clade. Our results provide different evidence for several WGDs in Asteraceae and reveal distinct association among WGD events, dramatic changes in environment and species radiations, providing a possible scenario for polyploids to overcome the disadvantages of WGDs and to evolve into lineages with high biodiversity. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  16. Evaluating interception of larval pallid sturgeon on the Lower Missouri River- data acquisition, interpolation, and visualization

    Science.gov (United States)

    Bulliner, E. A., IV; Erwin, S. O.; Anderson, B. J.; Wilson, H.; Jacobson, R. B.

    2016-12-01

    The transition from endogenous to exogenous feeding is an important life-stage transition for many riverine fish larvae. On the Missouri River, U.S., riverine alteration has decreased connectivity between the navigation channel and complex, food-producing and foraging areas on the channel margins, namely shallow side channels and sandbar complexes. A favored hypothesis, the interception hypothesis, for recruitment failure of pallid sturgeon is that drifting larvae are not able to exit the highly engineered navigation channel, and therefore starve. We present work exploring measures of hydraulic connectivity between the navigation channel and channel margins using multiple data-collection protocols with acoustic Doppler current profilers (ADCPs). As ADCP datasets alone often do not have high enough spatial resolution to characterize interception and connectivity sufficiently at the scale of drifting sturgeon larvae, they are often supplemented with physical and empirical models. Using boat-mounted ADCPs, we collected 3-dimensional current velocities with a variety of driving techniques (specifically, regularly spaced transects, reciprocal transects, and irregular patterns) around areas of potential larval interception. We then used toolkits based in Python to interpolate 3-dimensional velocity fields at spatial scales finer than the original measurements, and visualized resultant velocity vectors and flowlines in the software package Paraview. Using these visualizations, we investigated the necessary resolution of field measurements required to model connectivity with channel margin areas on large, highly engineered river ecosystems such as the Missouri River. We anticipate that results from this work will be used to help inform models of larval interception under current conditions. Furthermore, results from this work will be useful in developing monitoring strategies to evaluate the restoration of channel complexity to support ecological functions.

  17. Characteristics and Significance of Magma Emplacement Horizons, Black Sturgeon Sill, Nipigon, Ontario

    Science.gov (United States)

    Zieg, M. J.; Hone, S. V.

    2017-12-01

    Spatial scales strongly control the timescales of processes in igneous intrusions, particularly through the thermal evolution of the magma, which in turn governs the evolution of crystallinity, viscosity, and other important physical and chemical properties of the system. In this study, we have collected a highly detailed data set comprising geochemical (bulk rock composition), textural (size and alignment of plagioclase crystals), and mineralogical (modal abundance) profiles through the central portion of the 250 m thick Black Sturgeon diabase sill. In this data, we have identified characteristic signals in texture (soft and somewhat diffuse chills), composition (reversals in differentiation trends), and mineralogy (olivine accumulations), all coinciding and recurring at roughly 10 meter intervals. Based on these signatures, we are able to map out multiple zones representing discrete pulses of magma that were emplaced sequentially as the intrusion was inflated. Simple thermal calculations suggest that each 10 meters of new crystallization would require repose times on the order of 10-100 years. To build up 250 meters of magma at this rate would only require approximately 250-2500 years, significantly less than the thermal lifetime of the entire sill. The soft chills we observe in the Black Sturgeon sill are therefore consistent with a system that remained warm throughout the emplacement process. Successive pulses were injected into partially crystalline mush, rather than pure liquid (which would result in hybridization) or solid (which would produce sharp hard chills). Episodic emplacement is by now widely recognized as a fundamental process in the formation of large felsic magma chambers; our results suggest that this also may be an important consideration in understanding the evolution of smaller mafic intrusions.

  18. Chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

    Science.gov (United States)

    Wang, Ning; Ingersoll, Christopher G.; Dorman, Rebecca A.; Brumbaugh, William G.; Mebane, Christopher A.; Kunz, James L.; Hardesty, Douglas K.

    2014-01-01

    Chronic toxicity of cadmium, copper, lead, or zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) was evaluated in water-only exposures started with newly hatched larvae or approximately 1-mo-old juveniles. The 20% effect concentration (EC20) for cadmium from the sturgeon tests was higher than the EC20 from the trout tests, whereas the EC20 for copper, lead, or zinc for the sturgeon were lower than those EC20s for the trout. When the EC20s from the present study were included in compiled toxicity databases for all freshwater species, species mean chronic value for white sturgeon was in a relatively low percentile of the species sensitivity distribution for copper (9th percentile) and in the middle percentile for cadmium (55th percentile), zinc (40th percentile), or lead (50th percentile). However, the species mean chronic value for rainbow trout was in a high percentile for copper, lead, and zinc (∼68th–82nd percentile), but in a low percentile for cadmium (23rd percentile). The trout EC20s for each of the 4 metals and the sturgeon EC20s for cadmium or lead were above US Environmental Protection Agency chronic ambient water quality criteria (AWQC) or Washington State chronic water quality standards (WQS), whereas the sturgeon EC20s for copper or zinc were approximately equal to or below the chronic AWQC and WQS. In addition, acute 50% effect concentrations (EC50s) for copper obtained in the first 4 d of the chronic sturgeon test were below the final acute value used to derive acute AWQC and below acute WQS for copper.

  19. Shifting distributions of adult Atlantic sturgeon amidst post-industrialization and future impacts in the Delaware River: a maximum entropy approach.

    Directory of Open Access Journals (Sweden)

    Matthew W Breece

    Full Text Available Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus experienced severe declines due to habitat destruction and overfishing beginning in the late 19(th century. Subsequent to the boom and bust period of exploitation, there has been minimal fishing pressure and improving habitats. However, lack of recovery led to the 2012 listing of Atlantic sturgeon under the Endangered Species Act. Although habitats may be improving, the availability of high quality spawning habitat, essential for the survival and development of eggs and larvae may still be a limiting factor in the recovery of Atlantic sturgeon. To estimate adult Atlantic sturgeon spatial distributions during riverine occupancy in the Delaware River, we utilized a maximum entropy (MaxEnt approach along with passive biotelemetry during the likely spawning season. We found that substrate composition and distance from the salt front significantly influenced the locations of adult Atlantic sturgeon in the Delaware River. To broaden the scope of this study we projected our model onto four scenarios depicting varying locations of the salt front in the Delaware River: the contemporary location of the salt front during the likely spawning season, the location of the salt front during the historic fishery in the late 19(th century, an estimated shift in the salt front by the year 2100 due to climate change, and an extreme drought scenario, similar to that which occurred in the 1960's. The movement of the salt front upstream as a result of dredging and climate change likely eliminated historic spawning habitats and currently threatens areas where Atlantic sturgeon spawning may be taking place. Identifying where suitable spawning substrate and water chemistry intersect with the likely occurrence of adult Atlantic sturgeon in the Delaware River highlights essential spawning habitats, enhancing recovery prospects for this imperiled species.

  20. Epigenetic contribution to successful polyploidizations: variation in global cytosine methylation along an extensive ploidy series in Dianthus broteri (Caryophyllaceae).

    Science.gov (United States)

    Alonso, Conchita; Balao, Francisco; Bazaga, Pilar; Pérez, Ricardo

    2016-11-01

    Polyploidization is a significant evolutionary force in plants which involves major genomic and genetic changes, frequently regulated by epigenetic factors. We explored whether natural polyploidization in Dianthus broteri complex resulted in substantial changes in global DNA cytosine methylation associated to ploidy. Global cytosine methylation was estimated by high-performance liquid chromatography (HPLC) in 12 monocytotypic populations with different ploidies (2×, 4×, 6×, 12×) broadly distributed within D. broteri distribution range. The effects of ploidy level and local variation on methylation were assessed by generalized linear mixed models (GLMMs). Dianthus broteri exhibited a higher methylation percent (˜33%) than expected by its monoploid genome size and a large variation among study populations (range: 29.3-35.3%). Global methylation tended to increase with ploidy but did not significantly differ across levels due to increased variation within the highest-order polyploidy categories. Methylation varied more among hexaploid and dodecaploid populations, despite such cytotypes showing more restricted geographic location and increased genetic relatedness than diploids and tetraploids. In this study, we demonstrate the usefulness of an HPLC method in providing precise and genome reference-free global measure of DNA cytosine methylation, suitable to advance current knowledge of the roles of this epigenetic mechanism in polyploidization processes. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  1. Transcriptome-derived evidence supports recent polyploidization and a major phylogeographic division in Trithuria submersa (Hydatellaceae, Nymphaeales).

    Science.gov (United States)

    Marques, Isabel; Montgomery, Sean A; Barker, Michael S; Macfarlane, Terry D; Conran, John G; Catalán, Pilar; Rieseberg, Loren H; Rudall, Paula J; Graham, Sean W

    2016-04-01

    Relatively little is known about species-level genetic diversity in flowering plants outside the eudicots and monocots, and it is often unclear how to interpret genetic patterns in lineages with whole-genome duplications. We addressed these issues in a polyploid representative of Hydatellaceae, part of the water-lily order Nymphaeales. We examined a transcriptome of Trithuria submersa for evidence of recent whole-genome duplication, and applied transcriptome-derived microsatellite (expressed-sequence tag simple-sequence repeat (EST-SSR)) primers to survey genetic variation in populations across its range in mainland Australia. A transcriptome-based Ks plot revealed at least one recent polyploidization event, consistent with fixed heterozygous genotypes representing underlying sets of homeologous loci. A strong genetic division coincides with a trans-Nullarbor biogeographic boundary. Patterns of 'allelic' variation (no more than two variants per EST-SSR genotype) and recently published chromosomal evidence are consistent with the predicted polyploidization event and substantial homozygosity underlying fixed heterozygote SSR genotypes, which in turn reflect a selfing mating system. The Nullarbor Plain is a barrier to gene flow between two deep lineages of T. submersa that may represent cryptic species. The markers developed here should also be useful for further disentangling species relationships, and provide a first step towards future genomic studies in Trithuria. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  2. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

  3. The interactive effects of selenomethionine and methylmercury on their absorption, disposition, and elimination in juvenile white sturgeon

    DEFF Research Database (Denmark)

    Huang, Susie Shih-Yin; Strathe, Anders Bjerring; Fadel, James G.

    2013-01-01

    in juvenile white sturgeon, a benthic fish species at high risk to exposures of both contaminants. Selenium and Hg were provided as L-selenomethionine (SeMet) and methylmercury (MeHg), respectively. Groups of 10 sturgeon were orally intubated with a single dose of either 0 (control), SeMet (500 µg Se/kg body...... weight; BW), MeHg (850 µg Hg/kg BW), or their combination (Se/Hg; 500 µg Se/kg and 850 µg Hg/kg BW). The blood was repeatedly sampled and urine collected from the fish, over a 48 h post intubation period. At 48 h, the fish were sacrificed for Se and Hg tissue concentration and distribution. The co...

  4. Optimizing the co-feeding strategy of Persian sturgeon (Acipenser persicus larvae using Artemia nauplii and formulated diet

    Directory of Open Access Journals (Sweden)

    Naser Agh

    2013-07-01

    Full Text Available High mortality and labor costs are associated with first-feeding sturgeon culture, particularly during the period of dietary transition from live to formulated feed. Therefore we investigated the effects of various feeding treatments on the survival and growth of the Persian sturgeon (Acipenser persicus larvae during a 20-day culture period. Three replicate groups (250 fish/replicate of first-feeding larvae were fed according to four main feeding regimes: (1 live food (live nauplii of brine shrimp Artemia urmiana; (2 indirect transition (5 days live food followed by gradual transition to formulated diet; (3 direct transition (using different combinations of live and formulated diet from the start feeding onwards; (4 formulated feed (FD from the start feeding. Results indicated that growth and survival were higher in the indirect transition feeding regime than in other regimes. Based on our study, co-feeding of A. persicus should start five days after prior feeding with live food.

  5. Ontogeny of salinity tolerance and evidence for seawater-entry preparation in juvenile green sturgeon, Acipenser medirostris.

    Science.gov (United States)

    Allen, Peter J; McEnroe, Maryann; Forostyan, Tetyana; Cole, Stephanie; Nicholl, Mary M; Hodge, Brian; Cech, Joseph J

    2011-12-01

    We measured the ontogeny of salinity tolerance and the preparatory hypo-osmoregulatory physiological changes for seawater entry in green sturgeon (Acipenser medirostris), an anadromous species occurring along the Pacific Coast of North America. Salinity tolerance was measured every 2 weeks starting in 40-day post-hatch (dph) juveniles and was repeated until 100% survival at 34‰ was achieved. Fish were subjected to step increases in salinity (5‰ 12 h(-1)) that culminated in a 72-h exposure to a target salinity, and treatment groups (0, 15, 20, 25, 30, 34‰; and abrupt exposure to 34‰) were adjusted as fish developed. After 100% survival was achieved (134 dph), a second experiment tested two sizes of fish for 28-day seawater (33‰) tolerance, and gill and gastrointestinal tract tissues were sampled. Their salinity tolerance increased and plasma osmolality decreased with increasing size and age, and electron microscopy revealed three types of mitochondria-rich cells: one in fresh water and two in seawater. In addition, fish held on a natural photoperiod in fresh water at 19°C showed peaks in cortisol, thyroid hormones and gill and pyloric ceca Na(+), K(+)-ATPase activities at body sizes associated with seawater tolerance. Therefore, salinity tolerance in green sturgeon increases during ontogeny (e.g., as these juveniles may move down estuaries to the ocean) with increases in body size. Also, physiological and morphological changes associated with seawater readiness increased in freshwater-reared juveniles and peaked at their seawater-tolerant ages and body sizes. Their seawater-ready body size also matched that described for swimming performance decreases, presumably associated with downstream movements. Therefore, juvenile green sturgeon develop structures and physiological changes appropriate for seawater entry while growing in fresh water, indicating that hypo-osmoregulatory changes may proceed by multiple routes in sturgeons.

  6. Assessment of the impacts of the Salem and Hope Creek Stations on shortnose sturgeon, 'Acipenser brevirostrum' lesueur. Technical report

    International Nuclear Information System (INIS)

    Masnik, M.T.; Wilson, J.H.

    1980-04-01

    Acipenser brevirostrum, a federally recognized endangered species, is known from the Delaware River in the vicinity of the Salem and Hope Creek Nuclear Stations. The potential for adverse impact to this species due to the completion of construction and the operation of these stations is assessed. A review of the literature pertaining to the distribution, life history, and tolerance of this species is presented. Both historical records and current status of the shortnose sturgeon population in the Delaware River are discussed

  7. Effects of stocking density on lipid deposition and expression of lipid-related genes in Amur sturgeon (Acipenser schrenckii).

    Science.gov (United States)

    Ren, Yuanyuan; Wen, Haishen; Li, Yun; Li, Jifang; He, Feng; Ni, Meng

    2017-12-01

    To investigate the correlation between lipid deposition variation and stocking density in Amur sturgeon (Acipenser schrenckii) and the possible physiological mechanism, fish were conducted in different stocking densities (LSD 5.5 kg/m 3 , MSD 8.0 kg/m 3 , and HSD 11.0 kg/m 3 ) for 70 days and then the growth index, lipid content, lipase activities, and the mRNA expressions of lipid-related genes were examined. Results showed that fish subjected to higher stocking density presented lower final body weights (FBW), specific growth ratio (SGR), and gonad adipose tissue index (GAI) (P density lipoprotein cholesterol (HDL-C) decreased significantly with increasing stocking density, while no significant change was observed for low-density lipoprotein cholesterol (LDL-C). Furthermore, the cDNAs encoding lipoprotein lipase (LPL) and hepatic lipase (HL) were isolated in Amur sturgeon, respectively. The full-length LPL cDNA was composed of 1757 bp with an open reading frame of 501 amino acids, while the complete nucleotide sequences of HL covered 1747 bp encoding 499 amino acids. In the liver, the activities and mRNA levels of LPL were markedly lower in HSD group, which were consistent with the variation tendency of HL. Fish reared in HSD group also presented lower levels of activities and mRNA expression of LPL in the muscle and gonad. Moreover, the expressions of peroxisome proliferator-activated receptor α (PPARα) in both the liver and skeletal muscle were significantly upregulated in HSD group. Overall, the results indicated that high stocking density negatively affects growth performance and lipid deposition of Amur sturgeon to a certain extent. The downregulation of LPL and HL and the upregulation of PPARα may be responsible for the lower lipid distribution of Amur sturgeon in higher stocking density.

  8. Environmental calcium and variation in yolk sac size influence swimming performance in larval lake sturgeon (Acipenser fulvescens)

    DEFF Research Database (Denmark)

    Deslauriers, David; Svendsen, Jon Christian; Genz, Janet

    2018-01-01

    , because the yolk sac is likely to affect drag forces during swimming. Testing swimming performance of larval A. fulvescens reared in four different calcium treatments spanning the range of 4-132 mg l-1 [Ca2+], this study found no treatment effects on the sprint swimming speed. A novel test of volitional...... reduced swimming performance and could be more susceptible to predation or premature downstream drift. Our study reveals how environmental factors and phenotypic variation influence locomotor performance in a larval fish....

  9. The relationship between morphological and sexual indices in suitable brood Russian sturgeon Acipenser gueldenstaedtii (Brandt and Ratzeburg, 1833

    Directory of Open Access Journals (Sweden)

    Bahram Falahatkar

    2014-09-01

    Full Text Available Owing to reduction of sturgeon stocks in various water bodies, artificial propagation has become significantly important for stock restoration and appropriate broodstock selection is vital in this process. Selection of suitable broodstocks may influence the quality and quantity of obtained eggs and larva. The present study aimed to examine correlation between some morphometric and reproductive parameters to find suitable brood fish for artificial reproduction in Russian sturgeon, Acipenser gueldenstaedtii. Forty fish free of any external disease symptom and abnormality were selected for the study. Following biometric measurements including weight, total length, abdominal girth, PV (distance between pectoral and pelvic fins, LX (distance between anal and caudal fins, polarization index (PI, gonadosomatic index, absolute fecundity, and fertilization rate, correlations between these morphometric and biological characteristics with emphasis on breeding were calculated. There was higher correlation between weight-absolute fecundity and length-PV in fish responded to artificial breeding, while correlation between age-PV, length-PV and weight-abdominal girth were higher in those fish not responded to artificial breeding. The results suggests that it is quite possible to select suitable Russian sturgeon spawners for artificial propagation based on combination of body weight, LX, PV, age, abdominal girth and total length, however the most useful criteria for the selection seems to be precise measurement of the polarization index.

  10. 2005 Annual Synthesis Report, Pallid Sturgeon Population Assessment Program and Associated Fish Community Monitoring for the Missouri River

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Eric W.; Hanrahan, Timothy P.; Harnish, Ryan A.; Bellgraph, Brian J.; Duncan, Joanne P.; Allwardt, Craig H.

    2008-08-12

    Pallid sturgeon, Scaphirhynchus albus, have declined throughout the Missouri River since dam construction and inception of the Bank Stabilization and Navigation Project in 1912. Their decline likely is due to the loss and degradation of their natural habitat as a result of changes in the river’s structure and function, as well as the pallid sturgeon’s inability to adapt to these changes. The U. S. Army Corps of Engineers has been working with state and federal agencies to develop and conduct a Pallid Sturgeon Monitoring and Assessment Program (Program), with the goal of recovering pallid sturgeon populations. The Program has organized the monitoring and assessment efforts into distinct geographic segments, with state and federal resource management agencies possessing primary responsibility for one or more segment. To date, the results from annual monitoring have been reported for individual Program segments. However, monitoring results have not been summarized or evaluated for larger spatial scales, encompassing more than one Program segment. This report describes a summary conducted by the Pacific Northwest National Laboratory (PNNL) that synthesizes the 2005 sampling year monitoring results from individual segments.

  11. 2006 Annual Synthesis Report, Pallid Sturgeon Population Assessment Program and Associated Fish Community Monitoring for the Missouri River

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Eric W.; Hanrahan, Timothy P.; Harnish, Ryan A.; Bellgraph, Brian J.; Duncan, Joanne P.; Allwardt, Craig H.

    2008-08-12

    Pallid sturgeon, Scaphirhynchus albus, have declined throughout the Missouri River since dam construction and inception of the Bank Stabilization and Navigation Project in 1912. Their decline likely is due to the loss and degradation of their natural habitat as a result of changes in the river’s structure and function, as well as the pallid sturgeon’s inability to adapt to these changes. The U. S. Army Corps of Engineers has been working with state and federal agencies to develop and conduct a Pallid Sturgeon Monitoring and Assessment Program (Program), with the goal of recovering pallid sturgeon populations. The Program has organized the monitoring and assessment efforts into distinct geographic segments, with state and federal resource management agencies possessing primary responsibility for one or more segment. To date, the results from annual monitoring have been reported for individual Program segments. However, monitoring results have not been summarized or evaluated for larger spatial scales, encompassing more than one Program segment. This report describes a summary conducted by the Pacific Northwest National Laboratory (PNNL) that synthesizes the 2006 sampling year monitoring results from individual segments.

  12. Co-infection of Acipenserid herpesvirus 2 (AciHV-2) and Streptococcus iniae in cultured white sturgeon Acipenser transmontanus.

    Science.gov (United States)

    Soto, Esteban; Richey, Christine; Stevens, Brittany; Yun, Susan; Kenelty, Kirsten; Reichley, Stephen; Griffin, Matt; Kurobe, Tomofumi; Camus, Al

    2017-03-30

    A mortality event in cultured white sturgeon Acipenser transmontanus (Richardson, 1836) sub-adults was investigated. After transfer between farms, high mortality was observed in fish, associated with back arching, abnormal swimming, and ulcerative skin lesions. Necropsy of moribund individuals revealed hemorrhagic ascites and petechial hemorrhages in the coelomic peritoneum and serosa of internal organs. Acipenserid herpesvirus 2 (AciHV-2) was isolated from external tissue samples, then identified and genotyped by sequencing of the terminase and polymerase genes. In addition, Streptococcus iniae was recovered from internal organs of affected fish. Histologic changes were limited to interstitial hematopoietic areas of the kidney and consisted of small foci of necrosis accompanied by fibrin deposition, minimal inflammatory response, and small numbers of bacterial cocci compatible with streptococci. Identity was confirmed by partial sequencing of the 16S rRNA, rpoB, and gyrB genes. Genetic fingerprinting demonstrated a genetic profile distinct from S. iniae isolates recovered from previous outbreaks in wild and cultured fish in North America, South America, and the Caribbean. Although the isolates were resistant to white sturgeon complement in serum killing assays, in vivo challenges failed to fulfill Koch's postulates. However, the clinical presentation, coupled with consistent recovery of S. iniae and AciHV-2 from moribund fish, suggests viral and bacterial co-infection were the proximate cause of death. To our knowledge, this represents the first report of AciHV-2 and S. iniae co-infection in cultured white sturgeon.

  13. Long-term ecosystem monitoring and assessment of the Detroit River and Western Lake Erie.

    Science.gov (United States)

    Hartig, J H; Zarull, M A; Ciborowski, J J H; Gannon, J E; Wilke, E; Norwood, G; Vincent, A N

    2009-11-01

    Over 35 years of US and Canadian pollution prevention and control efforts have led to substantial improvements in environmental quality of the Detroit River and western Lake Erie. However, the available information also shows that much remains to be done. Improvements in environmental quality have resulted in significant ecological recovery, including increasing populations of bald eagles (Haliaeetus leucocephalus), peregrine falcons (Falco columbarius), lake sturgeon (Acipenser fulvescens), lake whitefish (Coregonus clupeaformis), walleye (Sander vitreus), and burrowing mayflies (Hexagenia spp.). Although this recovery is remarkable, many challenges remain, including population growth, transportation expansion, and land use changes; nonpoint source pollution; toxic substances contamination; habitat loss and degradation; introduction of exotic species; and greenhouse gases and global warming. Research/monitoring must be sustained for effective management. Priority research and monitoring needs include: demonstrating and quantifying cause-effect relationships; establishing quantitative endpoints and desired future states; determining cumulative impacts and how indicators relate; improving modeling and prediction; prioritizing geographic areas for protection and restoration; and fostering long-term monitoring for adaptive management. Key management agencies, universities, and environmental and conservation organizations should pool resources and undertake comprehensive and integrative assessments of the health of the Detroit River and western Lake Erie at least every 5 years to practice adaptive management for long-term sustainability.

  14. Increase of genetic variation in 'Blue Daisy' (Brachycome multifida) by in-vitro mutagenesis and polyploidization

    International Nuclear Information System (INIS)

    Walther, F.; Sauer, A.

    1989-01-01

    'Blue Daisy' was recently introduced from Australia and became a popular ornamental in Europe, but it lacks genetic variation and does not produce seeds under European environment conditions. Thus, the development of new cultivars is handicapped. 'Blue Daisy' is vegetatively propagated by cuttings. Techniques were developed to increase genetic variation by in-vitro mutation induction and polyploidization. For in-vitro propagation nodal segments with one pinnate leaf were placed on MS-medium containing 0.1 mg/l NAA and 2 mg/l BAP (medium 'a') or 2 mg/l IAA and 0.2 mg/l BAP (medium 'b') solidified by 0.6% Oxoid agar. 25 deg C and 16 h illumination (800 lux) resulted in highest propagation rates. After 4 weeks on medium 'b' large numbers of axillary shoots could be cut off and placed for rooting on 1/3 strength MS-medium supplemented with 2 mg/l IAA. Another 3 weeks later plantlets could be transferred into the greenhouse for further cultivation. The chromosome number of B. multifida is 2n=14. Polyploidy was obtained by placing in-vitro derived explants for about 3 weeks on solid MS-medium 'a' containing 0.1% colchicine. The resulting axillary buds were transferred for 3-5 months to medium 'b' for shoot development. After rooting and transfer into the greenhouse polyploidy was first determined by comparison of pollen grains from treated and untreated plants. For confirmation, the number of chromosomes was counted using the orcein-acetic squash method. Two different polyploid types were obtained: one more erect and one more hanging phenotype, both having enlarged leaves and flowers. X-ray doses of 10-50 Gy were applied to freshly cut nodal segments. The explants were placed on solid medium 'b' in petri dishes. Inhibition of shoot development was used as criterium of radiosensitivity. The described procedure of in-vitro propagation of Brachycome during 3 years did not give any somaclonal variant. The shoots developing after application of X-rays were rooted and all

  15. Relating river discharge and water temperature to the recruitment of age‐0 White Sturgeon (Acipenser transmontanus Richardson, 1836) in the Columbia River using over‐dispersed catch data

    Science.gov (United States)

    Counihan, Timothy D.; Chapman, Colin G.

    2018-01-01

    The goals were to (i) determine if river discharge and water temperature during various early life history stages were predictors of age‐0 White Sturgeon, Acipenser transmontanus, recruitment, and (ii) provide an example of how over‐dispersed catch data, including data with many zero observations, can be used to better understand the effects of regulated rivers on the productivity of depressed sturgeon populations. An information theoretic approach was used to develop and select negative binomial and zero‐inflated negative binomial models that model the relation of age‐0 White Sturgeon survey data from three contiguous Columbia River reservoirs to river discharge and water temperature during spawning, egg incubation, larval, and post‐larval phases. Age‐0 White Sturgeon were collected with small mesh gill nets in The Dalles and John Day reservoirs from 1997 to 2014 and a bottom trawl in Bonneville Reservoir from 1989 to 2006. Results suggest that seasonal river discharge was positively correlated with age‐0 recruitment; notably that discharge, 16 June–31 July was positively correlated to age‐0 recruitment in all three reservoirs. The best approximating models for two of the three reservoirs also suggest that seasonal water temperature may be a determinant of age‐0 recruitment. Our research demonstrates how over‐dispersed catch data can be used to better understand the effects of environmental conditions on sturgeon populations caused by the construction and operation of dams.

  16. Responses of heat shock protein 70 and caspase-3/7 to dietary selenomethionine in juvenile white sturgeon

    Directory of Open Access Journals (Sweden)

    Weifang Wang

    2016-03-01

    Full Text Available An 8-week feeding trial was conducted to investigate the responses of juvenile white sturgeon (Acipenser transmontanus to elevated dietary selenium (Se based on the determination of the RNA/DNA ratio in muscle, heat shock protein 70 (Hsp70, and caspase-3/7 in muscle and/or liver tissues. Four semi-purified test diets were prepared by adding different levels of L-selenomethionine (0, 50, 100, and 200 mg/kg diet. The analytical determinations of total Se were 2.2, 19.7, 40.1, and 77.7 mg/kg diet. The sturgeon (initial body weight: 30 ± 2 g; mean ± SEM were raised in indoor tanks provided with flow through freshwater (18–19 °C. There were three replicates for each dietary treatment with 25 fish per replicate. The liver and muscle tissues were collected at 4 and 8 weeks after feeding the test diets. A significant interaction between duration and levels of dietary Se exposures on RNA/DNA ratio in the muscle tissue was detected (P < 0.05. Although there was no significant main effect due to the duration of dietary Se exposures (i.e., 4 weeks versus 8 weeks on muscle RNA/DNA ratio (P ≥ 0.05, the ratio was significantly decreased with increasing dietary Se levels. Significant main effects were caused by the duration and levels of dietary Se exposures on Hsp70 in both the muscle and liver tissues, with significant increases in Hsp70 due to a longer exposure (8 weeks and higher levels (40.1 and 77.7 mg Se/kg diet of dietary Se. The caspase-3/7 activity in the liver were significantly higher in fish fed the diets containing 40.1 and 77.7 mg Se/kg diet than those fed the other diets. The toxic thresholds of Se in the muscle were estimated to be 32.2 and 26.6 mg Se/kg for the depressed specific growth rate and the induced Hsp70 response in muscle, respectively. This result indicated that the Hsp70 response in muscle is a more sensitive biomarker than the SGR of sturgeon for evaluating Se toxicity in white sturgeon. Results of the

  17. Limnology of Eifel maar lakes

    National Research Council Canada - National Science Library

    Scharf, Burkhard W; Björk, Sven

    1992-01-01

    ... & morphometry - Physical & chemical characteristics - Calcite precipitation & solution in Lake Laacher See - Investigations using sediment traps in Lake Gemundener Maar - Phytoplankton of Lake Weinfelder Maar...

  18. Target innervation is necessary for neuronal polyploidization in the terrestrial slug Limax.

    Science.gov (United States)

    Matsuo, Ryota; Yamagishi, Miki; Wakiya, Kyoko; Tanaka, Yoko; Ito, Etsuro

    2013-08-01

    The brain of gastropod mollusks contains many giant neurons with polyploid genomic DNAs. Such DNAs are generated through repeated DNA endoreplication during body growth. However, it is not known what triggers DNA endoreplication in neurons. There are two possibilities: (1) DNAs are replicated in response to some unknown molecules in the hemolymph that reflect the nutritive status of the animal; or (2) DNAs are replicated in response to some unknown factors that are retrogradely transported through axons from the innervated target organs. We first tested whether hemolymph with rich nutrition could induce DNA endoreplication. We tested whether the transplanted brain exhibits enhanced DNA endoreplication like an endogenous brain does when transplanted into the homocoel of the body of a slug whose body growth is promoted by an increased food supply. However, no enhancement was observed in the frequency of DNA endoreplication when we compared the transplanted brains in the growth-promoted and growth-suppressed host slugs, suggesting that the humoral environment is irrelevant to triggering the body growth-dependent DNA endoreplication. Next, we tested the requirement of target innervation by surgically dissecting a unilateral posterior pedal nerve of an endogenous brain. Substantially lower number of neurons exhibited DNA endoreplication in the pedal ganglion ipsilateral to the dissected nerve. These results support the view that enhanced DNA endoreplication is mediated by target innervation and is not brought about through the direct effect of humoral factors in the hemolymph during body growth. Copyright © 2013 Wiley Periodicals, Inc.

  19. Asymmetric Evolution and Expansion of the NAC Transcription Factor in Polyploidized Cotton

    Directory of Open Access Journals (Sweden)

    Kai Fan

    2018-01-01

    Full Text Available Polyploidy in Gossypium hirsutum conferred different properties from its diploid ancestors under the regulation of transcription factors. The NAC transcription factor is a plant-specific family that can be related to plant growth and development. So far, little is known about the NAC family in cotton. This study identified 495 NAC genes in three cotton species and investigated the evolution and expansion of different genome-derived NAC genes in cotton. We revealed 15 distinct NAC subfamilies in cotton. Different subfamilies had different gene proportions, expansion rate, gene loss rate, and orthologous exchange rate. Paleohexaploidization (35% and cotton-specific decaploidy (32% might have primarily led to the expansion of the NAC family in cotton. Half of duplication events in G. hirsutum were inherited from its diploid ancestor, and others might have occurred after interspecific hybridization. In addition, NAC genes in the At and Dt subgenomes displayed asymmetric molecular evolution, as evidenced by their different gene loss rates, orthologous exchange, evolutionary rates, and expression levels. The dominant duplication event was different during the cotton evolutionary history. Different genome-derived NACs might have interacted with each other, which ultimately resulted in morphogenetic evolution. This study delineated the expansion and evolutionary history of the NAC family in cotton and illustrated the different fates of NAC genes during polyploidization.

  20. Asymmetric epigenetic modification and elimination of rDNA sequences by polyploidization in wheat.

    Science.gov (United States)

    Guo, Xiang; Han, Fangpu

    2014-11-01

    rRNA genes consist of long tandem repeats clustered on chromosomes, and their products are important functional components of the ribosome. In common wheat (Triticum aestivum), rDNA loci from the A and D genomes were largely lost during the evolutionary process. This biased DNA elimination may be related to asymmetric transcription and epigenetic modifications caused by the polyploid formation. Here, we observed both sets of parental nucleolus organizing regions (NORs) were expressed after hybridization, but asymmetric silencing of one parental NOR was immediately induced by chromosome doubling, and reversing the ploidy status could not reactivate silenced NORs. Furthermore, increased CHG and CHH DNA methylation on promoters was accompanied by asymmetric silencing of NORs. Enrichment of H3K27me3 and H3K9me2 modifications was also observed to be a direct response to increased DNA methylation and transcriptional inactivation of NOR loci. Both A and D genome NOR loci with these modifications started to disappear in the S4 generation and were completely eliminated by the S7 generation in synthetic tetraploid wheat. Our results indicated that asymmetric epigenetic modification and elimination of rDNA sequences between different donor genomes may lead to stable allopolyploid wheat with increased differentiation and diversity. © 2014 American Society of Plant Biologists. All rights reserved.

  1. Polyploidization without mitosis improves in vivo liver transduction with lentiviral vectors.

    Science.gov (United States)

    Pichard, Virginie; Couton, Dominique; Desdouets, Chantal; Ferry, Nicolas

    2013-02-01

    Lentiviral vectors are efficient gene delivery vehicles for therapeutic and research applications. In contrast to oncoretroviral vectors, they are able to infect most nonproliferating cells. In the liver, induction of cell proliferation dramatically improved hepatocyte transduction using all types of retroviral vectors. However, the precise relationship between hepatocyte division and transduction efficiency has not been determined yet. Here we compared gene transfer efficiency in the liver after in vivo injection of recombinant lentiviral or Moloney murine leukemia viral (MoMuLV) vectors in hepatectomized rats treated or not with retrorsine, an alkaloid that blocks hepatocyte division and induces megalocytosis. Partial hepatectomy alone resulted in a similar increase in hepatocyte transduction using either vector. In retrorsine-treated and partially hepatectomized rats, transduction with MoMuLV vectors dropped dramatically. In contrast, we observed that retrorsine treatment combined with partial hepatectomy increased lentiviral transduction to higher levels than hepatectomy alone. Analysis of nuclear ploidy in single cells showed that a high level of transduction was associated with polyploidization. In conclusion, endoreplication could be exploited to improve the efficiency of liver-directed lentiviral gene therapy.

  2. Mediterranean species of Caulerpa are polyploid with smaller genomes in the invasive ones.

    Directory of Open Access Journals (Sweden)

    Elena Varela-Álvarez

    Full Text Available Caulerpa species are marine green algae, which often act as invasive species with rapid clonal proliferation when growing outside their native biogeographical borders. Despite many publications on the genetics and ecology of Caulerpa species, their life history and ploidy levels are still to be resolved and are the subject of large controversy. While some authors claimed that the thallus found in nature has a haplodiplobiontic life cycle with heteromorphic alternation of generations, other authors claimed a diploid or haploid life cycle with only one generation involved. DAPI-staining with image analysis and microspectrophotometry were used to estimate relative nuclear DNA contents in three species of Caulerpa from the Mediterranean, at individual, population and species levels. Results show that ploidy levels and genome size vary in these three Caulerpa species, with a reduction in genome size for the invasive ones. Caulerpa species in the Mediterranean are polyploids in different life history phases; all sampled C. taxifolia and C. racemosa var. cylindracea were in haplophasic phase, but in C. prolifera, the native species, individuals were found in both diplophasic and haplophasic phases. Different levels of endopolyploidy were found in both C. prolifera and C. racemosa var. cylindracea. Life history is elucidated for the Mediterranean C. prolifera and it is hypothesized that haplophasic dominance in C. racemosa var. cylindracea and C. taxifolia is a beneficial trait for their invasive strategies.

  3. Kootenai River White Sturgeon Recovery Implementation Plan and Schedule; 2005-2010, Technical Report 2004-2005.

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Paul

    2007-03-01

    Kootenai River white sturgeon have been declining for at least 50 years and extinction of the wild population is now imminent (Paragamian et al. 2005). Only 630 adults were estimated to remain in 2002 from a population ten times that size just 20 years ago. Significant recruitment of young sturgeon has not been observed since the early 1970s and consistent annual recruitment has not been seen since the 1950s. The remaining wild population consists of a cohort of large, old fish that is declining by about 9% per year as fish die naturally and are not replaced. At this rate, the wild population will disappear around the year 2040. Numbers have already reached critical low levels where genetic and demographic risks are acute. The Kootenai River White Sturgeon Recovery Team was convened in 1994, provided a draft Recovery Plan in 1996 and the first complete Recovery Plan for Kootenai River white sturgeon in 1999 (USFWS 1996, 1999). The Plan outlined a four part strategy for recovery, including: (1) measures to restore natural recruitment, (2) use of conservation aquaculture to prevent extinction, (3) monitoring survival and recovery, and (4) updating and revising recovery plan criteria and objectives as new information becomes available. Sturgeon recovery efforts are occurring against a backdrop of a broader ecosystem protection and restoration program for the Kootenai River ecosystem. With abundance halving time of approximately 8 years, the Kootenai River white sturgeon population is rapidly dwindling, leaving managers little time to act. Decades of study consistently indicate that recruitment failure occurs between embryo and larval stages. This assertion is based on four key observations. First, almost no recruitment has occurred during the last 30 years. Second, thousands of naturally produced white sturgeon embryos, most viable, have been collected over the past decade, resulting from an estimated 9 to 20 spawning events each year. Third, Kootenai River white

  4. Bathymetry of Lake Erie and Lake Saint Clair

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

  5. REARING OF PELED (COREGONUS PELED Gmelin IN POLYCULTURE WITH CYPRINIDS (CYPRINIDAE AND STURGEONS (ACIPENSERIDAE

    Directory of Open Access Journals (Sweden)

    G. Kurinenko

    2016-03-01

    Full Text Available Purpose. To analyze the results of rearing and provide aquaculture-biological characteristic of peled reared in polyculture with sturgeons and cyprinids based on pond technology. Methodology. The material for the studies were fry, young-of-the-year, yearlings and age-1+ peled produced from eggs exported in March 2009 from Russian Federation. Rearing of peled was carried out based on the technology developed by the All-Union Scientific and Research Institute of Pond Fish Culture for coregonids with the use of methodical recommendations on the biotechnology of industrial rearing of seed coregonids. Studies were carried out at the pond fish farm “Korop” of Lviv region. Water supply of rearing ponds was done by self-flow. The investigation of fish diet and hydrobiological studies were carried out using conventional methods. Findings. We performed a study of fish egg incubation and produced larvae with their further rearing in floating cages to the fingerling stage. Rearing of peled in polyculture allows increasing the fish productivity parameters at the first year of rearing by 1.3%, at the second year by 0.9%. Average weights of age-1 and age-1+ peled were 185.3 g and 450 g, respectively. In these rearing conditions, daily growth of the young-of-the-year was within 0.1-1.5 g, age-1+ – 1.1-3.3 g. As a positive result of rearing, we should note high weight gain during winter period that was more than 50%. We also investigated qualitative and quantitative composition of zooplankton and peled juvenile diet. Originality. The works of peled rearing based on pond technology in polyculture with sturgeons and cyprinids were carried out in the conditions of Ukraine for the first time. Practical value. The results of the performed works along with similar previous works on peled rearing in ponds will be used for the creation of methodical recommendations on rearing of peled seeds, which will be used by Ukrainian fish farms in future.

  6. Evidence of natural reproduction of Atlantic sturgeon in the Connecticut River from unlikely sources.

    Directory of Open Access Journals (Sweden)

    Tom Savoy

    Full Text Available Atlantic Sturgeon is listed under the U.S. Endangered Species Act as five Distinct Population Segments (DPS. The "endangered" New York Bight (NYB DPS is thought to only harbor two populations; one in the Hudson River and a second smaller one in the Delaware River. Historically, the Connecticut River probably supported a spawning population of Atlantic Sturgeon that was believed extirpated many decades ago. In 2014, we successfully collected pre-migratory juvenile specimens from the lower Connecticut River which were subjected to mitochondrial DNA (mtDNA control region sequence and microsatellite analyses to determine their genetic relatedness to other populations coastwide. Haplotype and allelic frequencies differed significantly between the Connecticut River collection and all other populations coastwide. Sibship analyses of the microsatellite data indicated that the Connecticut River collection was comprised of a small number of families that were likely the offspring of a limited number of breeders. This was supported by analysis of effective population size (Ne and number of breeders (Nb. STRUCTURE analysis suggested that there were 11 genetic clusters among the coastwide collections and that from the Connecticut River was distinct from those in all other rivers. This was supported by UPGMA analyses of the microsatellite data. In AMOVA analyses, among region variation was maximized, and among population within regions variation minimized when the Connecticut River collection was separate from the other two populations in the NYB DPS indicating the dissimilarity between the Connecticut River collection and the other two populations in the NYB DPS. Use of mixed stock analysis indicated that the Connecticut River juvenile collection was comprised of specimens primarily of South Atlantic and Chesapeake Bay DPS origins. The most parsimonious explanation for these results is that the Connecticut River hosted successful natural reproduction in 2013

  7. Comparative proteomic study on Brassica hexaploid and its parents provides new insights into the effects of polyploidization.

    Science.gov (United States)

    Shen, Yanyue; Zhang, Yu; Zou, Jun; Meng, Jinling; Wang, Jianbo

    2015-01-01

    Polyploidy has played an important role in promoting plant evolution through genomic merging and doubling. Although genomic and transcriptomic changes have been observed in polyploids, the effects of polyploidization on proteomic divergence are poorly understood. In this study, we reported quantitative analysis of proteomic changes in leaves of Brassica hexaploid and its parents using isobaric tags for relative and absolute quantitation (iTRAQ) coupled with mass spectrometry. A total of 2044 reproducible proteins were quantified by at least two unique peptides. We detected 452 proteins differentially expressed between Brassica hexaploid and its parents, and 100 proteins were non-additively expressed in Brassica hexaploid, which suggested a trend of non-additive protein regulation following genomic merger and doubling. Functional categories of cellular component biogenesis, immune system process, and response to stimulus, were significantly enriched in non-additive proteins, probably providing a driving force for variation and adaptation in allopolyploids. In particular, majority of the total 452 differentially expressed proteins showed expression level dominance of one parental expression, and there was an expression level dominance bias toward the tetraploid progenitor. In addition, the percentage of differentially expressed proteins that matched previously reported differentially genes were relatively low. This study aimed to get new insights into the effects of polyploidization on proteomic divergence. Using iTRAQ LC-MS/MS technology, we identified 452 differentially expressed proteins between allopolyploid and its parents which involved in response to stimulus, multi-organism process, and immune system process, much more than previous studies using 2-DE coupled with mass spectrometry technology. Therefore, our manuscript represents the most comprehensive analysis of protein profiles in allopolyploid and its parents, which will lead to a better understanding of

  8. Re-annotation of the physical map of Glycine max for polyploid-like regions by BAC end sequence driven whole genome shotgun read assembly

    Directory of Open Access Journals (Sweden)

    Shultz Jeffry

    2008-07-01

    Full Text Available Abstract Background Many of the world's most important food crops have either polyploid genomes or homeologous regions derived from segmental shuffling following polyploid formation. The soybean (Glycine max genome has been shown to be composed of approximately four thousand short interspersed homeologous regions with 1, 2 or 4 copies per haploid genome by RFLP analysis, microsatellite anchors to BACs and by contigs formed from BAC fingerprints. Despite these similar regions,, the genome has been sequenced by whole genome shotgun sequence (WGS. Here the aim was to use BAC end sequences (BES derived from three minimum tile paths (MTP to examine the extent and homogeneity of polyploid-like regions within contigs and the extent of correlation between the polyploid-like regions inferred from fingerprinting and the polyploid-like sequences inferred from WGS matches. Results Results show that when sequence divergence was 1–10%, the copy number of homeologous regions could be identified from sequence variation in WGS reads overlapping BES. Homeolog sequence variants (HSVs were single nucleotide polymorphisms (SNPs; 89% and single nucleotide indels (SNIs 10%. Larger indels were rare but present (1%. Simulations that had predicted fingerprints of homeologous regions could be separated when divergence exceeded 2% were shown to be false. We show that a 5–10% sequence divergence is necessary to separate homeologs by fingerprinting. BES compared to WGS traces showed polyploid-like regions with less than 1% sequence divergence exist at 2.3% of the locations assayed. Conclusion The use of HSVs like SNPs and SNIs to characterize BACs wil improve contig building methods. The implications for bioinformatic and functional annotation of polyploid and paleopolyploid genomes show that a combined approach of BAC fingerprint based physical maps, WGS sequence and HSV-based partitioning of BAC clones from homeologous regions to separate contigs will allow reliable de

  9. Sexual polyploidization in red clover Poliploidização sexual em trevo vermelho

    Directory of Open Access Journals (Sweden)

    Carine Simioni

    2006-02-01

    Full Text Available Because sexual polyploidization broadens genetic basis and supply plant breeders with more variability for the selection process, it can be useful in red clover breeding. This paper reports results of three crossing cycles, starting from a parental generation of tetraploid red clover plants (female parent, and diploids from the Quiñiqueli cultivar, selected for production of more than 1% of giant pollen grains (male parent aiming to obtain tetraploid plants to be used in red clover breeding programs. Crosses in the next generations were performed by mutual cross-pollinations. Chromosome number chimerism and high pollen sterility were detected in F1, F2 and F3, but there was a trend towards increasing seed production and seed viability along the generations, probably due to successful competition between fertile and sterile gametes. The identification of fertile triploids, as well as their recurrent formation along the generations, indicates that triploid block is not complete in red clover, and that triploids may be successfully used as a bridge for the production of sexual polyploids.Porque a poliploidização sexual amplia a base genética e proporciona aos melhoristas maior variabilidade para o processo de seleção, ela pode ser uma ferramenta útil ao melhoramento de trevo vermelho. Com o objetivo de obter plantas tetraplóides que possam ser utilizadas em programas de melhoramento de trevo vermelho, este trabalho relata resultados de três ciclos de cruzamentos, partindo de uma população parental de plantas tetraplóides de trevo vermelho, como genitores femininos, e de diplóides da cultivar Quiñiqueli, selecionados para produção de mais de 1% de grãos de pólen gigantes, como genitores masculinos. Nas outras gerações, os cruzamentos foram realizados por polinizações cruzadas mútuas. Quimerismo para número cromossômico e alta esterilidade de pólen foram detectados em F1 , F2 e F3, mas houve uma tendência para aumento da

  10. Ecological range shift in the polyploid members of the South American genus Fosterella (Bromeliaceae).

    Science.gov (United States)

    Paule, Juraj; Wagner, Natascha D; Weising, Kurt; Zizka, Georg

    2017-08-01

    The distribution of polyploidy along a relatively steep Andean elevation and climatic gradient is studied using the genus Fosterella L.B. Sm. (Bromeliaceae) as a model system. Ecological differentiation of cytotypes and the link of polyploidy with historical biogeographic processes such as dispersal events and range shift are assessed. 4',6-Diamidino-2-phenylindole (DAPI) staining of nuclei and flow cytometry were used to estimate the ploidy levels of 159 plants from 22 species sampled throughout the distribution range of the genus. Ecological differentiation among ploidy levels was tested by comparing the sets of climatic variables. Ancestral chromosome number reconstruction was carried out on the basis of a previously generated phylogeographic framework. This study represents the first assessment of intrageneric, intraspecific and partially intrapopulational cytotype diversity in a genus of the Bromeliaceae family. In Fosterella , the occurrence of polyploidy was limited to the phylogenetically isolated penduliflora and rusbyi groups. Cytotypes were found to be ecologically differentiated, showing that polyploids preferentially occupy colder habitats with high annual temperature variability (seasonality). The combined effects of biogeographic history and adaptive processes are presumed to have shaped the current cytotype distribution in the genus. The results provide indirect evidence for both adaptive ecological and non-adaptive historical processes that jointly influenced the cytotype distribution in the predominantly Andean genus Fosterella (Bromeliaceae). The results also exemplify the role of polyploidy as an important driver of speciation in a topographically highly structured and thus climatically diverse landscape. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  11. Alike but different: the evolution of the Tubifex tubifex species complex (Annelida, Clitellata) through polyploidization.

    Science.gov (United States)

    Marotta, Roberto; Crottini, Angelica; Raimondi, Elena; Fondello, Cristina; Ferraguti, Marco

    2014-04-02

    Tubifex tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. tubifex species complex.

  12. Genetic Diversity and Population Structure of Varronia curassavica: A Medicinal Polyploid Species in a Threatened Ecosystem.

    Science.gov (United States)

    Hoeltgebaum, Marcia Patricia; Dos Reis, Maurício Sedrez

    2017-06-01

    Varronia curassavica is an important medicinal species associated with the restinga, one of the most threatened coastal ecosystems of the Atlantic Forest. These circumstances call for studies aimed at estimating effective population size and gene flow to improve conservation efforts. Hence, the present study aimed to characterize the genetic diversity, ploidy level, and population structure of this species in different areas of restinga using microsatellites. Varronia curassavica was characterized as an autotetraploid, with high genetic variability, low divergence, and no significant fixation indices, indicating the absence of, or reduced, inbreeding and genetic drift in the study area. About 44% of the alleles occurred at low frequency in adults of all populations and 41% in the progenies evaluated. Gene flow was high, consistent with outcrossing species with high dispersal capacity (Nm = 4.87). The results showed no tendency toward isolation by distance. The estimated effective size indicates that the populations studied have the potential to ensure conservation of the species in the long term. The genetic variability and population structure of V. curassavica, as determined in this study, could form the foundation for activities directed toward the sustainable use of this resource and its conservation. Even though the restinga ecosystem has suffered dramatic reductions in area, this study provides evidence that this species is resilient to anthropogenic threats to its genetic integrity, since it is a polyploid with self-incompatibility mechanisms that contribute to maintaining high genetic diversity in an panmictic meta-population along the coast of Santa Catarina. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Characterisation of ALS genes in the polyploid species Schoenoplectus mucronatus and implications for resistance management.

    Science.gov (United States)

    Scarabel, Laura; Locascio, Antonella; Furini, Antonella; Sattin, Maurizio; Varotto, Serena

    2010-03-01

    The polyploid weed Schoenoplectus mucronatus (L.) Palla has evolved target-site resistance to ALS-inhibiting herbicides in Italian rice crops. Molecular and genetic characterisation of the resistance mechanism is relevant to the evolution and management of herbicide resistance. The authors aimed (a) to study the organisation of the target-site loci in two field-selected S. mucronatus populations with different cross-resistance patterns, (b) to identify the mutations endowing resistance to ALS inhibitors and determine the role of these mutations by using transgenesis and (c) to analyse the implications for the management of the S. mucronatus populations. Two complete ALS genes (ALS1 and ALS2) having an intron and a third partial intronless ALS gene (ALS3) were identified. The presence of multiple ALS genes was confirmed by Southern blot analyses, and ALS loci were characterised by examining cytosine methylation. In S. mucronatus leaves, the transcripts of ALS1, ALS2 and ALS3 were detected. Two mutations endowing resistance (Pro(197) to His and Trp(574) to Leu) were found in both resistant populations, but at different frequencies. Tobacco plants transformed with the two resistant alleles indicated that the Pro(197)-to-His substitution conferred resistance to SU and TP herbicides, while the allele with the Trp(574)-to-Leu substitution conferred cross-resistance to SU, TP, IMI and PTB herbicides. Schoenoplectus mucronatus has multiple ALS genes characterised by methylated sites that can influence the expression profile. The two mutated alleles proved to be responsible for ALS resistance. At population level, the resistance pattern depends on the frequency of various resistant genotypes, and this influences the efficacy of various ALS-inhibiting herbicides.

  14. Generation of erythroid cells from polyploid giant cancer cells: re-thinking about tumor blood supply.

    Science.gov (United States)

    Yang, Zhigang; Yao, Hong; Fei, Fei; Li, Yuwei; Qu, Jie; Li, Chunyuan; Zhang, Shiwu

    2018-04-01

    During development and tumor progression, cells need a sufficient blood supply to maintain development and rapid growth. It is reported that there are three patterns of blood supply for tumor growth: endothelium-dependent vessels, mosaic vessels, and vasculogenic mimicry (VM). VM was first reported in highly aggressive uveal melanomas, with tumor cells mimicking the presence and function of endothelial cells forming the walls of VM vessels. The walls of mosaic vessels are randomly lined with both endothelial cells and tumor cells. We previously proposed a three-stage process, beginning with VM, progressing to mosaic vessels, and eventually leading to endothelium-dependent vessels. However, many phenomena unique to VM channel formation remain to be elucidated, such as the origin of erythrocytes before VM vessels connect with endothelium-dependent vessels. In adults, erythroid cells are generally believed to be generated from hematopoietic stem cells in the bone marrow. In contrast, embryonic tissue obtains oxygen through formation of blood islands, which are largely composed of embryonic hemoglobin with a higher affinity with oxygen, in the absence of mature erythrocytes. Recent data from our laboratory suggest that embryonic blood-forming mechanisms also exist in cancer tissue, particularly when these tissues are under environmental stress such as hypoxia. We review the evidence from induced pluripotent stem cells in vitro and in vivo to support this previously underappreciated cell functionality in normal and cancer cells, including the ability to generate erythroid cells. We will also summarize the current understanding of tumor angiogenesis, VM, and our recent work on polyploid giant cancer cells, with emphasis on their ability to generate erythroid cells and their association with tumor growth under hypoxia. An alternative embryonic pathway to obtain oxygen in cancer cells exists, particularly when they are under hypoxic conditions.

  15. Lake or Pond WBID

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT DEC (Vermont Department of Environmental Conservation) manages an inventory of lake and pond information. The "Lakes and Ponds Inventory" stores the Water...

  16. National Lakes Assessment Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S. The U.S....

  17. DNR 24K Lakes

    Data.gov (United States)

    Minnesota Department of Natural Resources — Medium scale lake polygons derived from the National Wetlands Inventory (NWI) polygons and MnDOT Basemap lake delineations. Integrated with the DNR 24K Streams...

  18. Metallothionein as potential biomarker of cadmium exposure in Persian sturgeon (Acipenser persicus).

    Science.gov (United States)

    Shariati, Fatemeh; Esaili Sari, Abbas; Mashinchian, Ali; Pourkazemi, Mohammad

    2011-10-01

    Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l(-1)) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l(-1) Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills. Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination.

  19. Vulnerability of larval and juvenile white sturgeon to barotrauma: can they handle the pressure?

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard S.; Cook, Katrina V.; Pflugrath, Brett D.; Rozeboom, Latricia L.; Johnson, Rachelle C.; McLellan, Jason; Linley, Timothy J.; Gao, Yong; Baumgartner, Lee J.; Dowell, Frederick E.; Miller, Erin A.; White, Timothy A.

    2013-07-01

    Techniques were developed to determine which life stages of fish are vulnerable to barotrauma from expansion of internal gases during decompression. Eggs, larvae and juvenile hatchery-reared white sturgeon (Acipenser transmontanus; up to 91 days post hatch; dph), were decompressed to assess vulnerability to barotrauma and identify initial swim bladder inflation. Barotrauma related injury and mortality were first observed 9 dph, on the same day as initial exogenous feeding. However, barotrauma related injury did not occur again until swim bladder inflation 75 dph (visible from necropsy and x-ray radiographs). Swim bladder inflation was not consistent among individuals, with only 44% being inflated 91 dph. Additionally, swim bladder inflation did not appear to be size dependent among fish ranging in total length from 61-153 mm at 91 dph. The use of a combination of decompression tests and x-ray radiography was validated as a method to determine initial swim bladder inflation and vulnerability to barotrauma. Extending these techniques to other species and life history stages would help to determine fish susceptibility to hydroturbine passage and aid in fish conservation.

  20. Vulnerability of larval and juvenile white sturgeon to barotrauma: can they handle the pressure?

    Science.gov (United States)

    Brown, Richard S; Cook, Katrina V; Pflugrath, Brett D; Rozeboom, Latricia L; Johnson, Rachelle C; McLellan, Jason G; Linley, Timothy J; Gao, Yong; Baumgartner, Lee J; Dowell, Frederick E; Miller, Erin A; White, Timothy A

    2013-01-01

    Techniques were developed to determine which life stages of fish are vulnerable to barotrauma from expansion of internal gases during decompression. Eggs, larvae, and juvenile hatchery-reared white sturgeon (Acipenser transmontanus; up to 91 days post hatch; d.p.h.) were decompressed to assess vulnerability to barotrauma and identify initial swim bladder inflation. Barotrauma-related injury and mortality were first observed 9 d.p.h., on the same day as initial exogenous feeding. However, barotrauma-related injury did not occur again until swim bladder inflation 75 d.p.h. (visible at necropsy and on radiographs). Swim bladder inflation was not consistent among individuals, with only 44% being inflated 91 d.p.h. Additionally, swim bladder inflation did not appear to be size dependent among fish ranging in total length from 61 to 153 mm at 91 d.p.h. The use of a combination of decompression tests and radiography was validated as a method to determine initial swim bladder inflation and vulnerability to barotrauma. Extending these techniques to other species and life-history stages would help to determine the susceptibility of fish to hydro turbine passage and aid in fish conservation.

  1. Morphometric Characteristics and Length-Weight Relationship of Russian Sturgeon Juveniles Fed with Different Ratio

    Directory of Open Access Journals (Sweden)

    Raluca Cristina ANDREI(GURIENCU

    2017-11-01

    Full Text Available The aim of this paper was to analyze some morphometric characteristics and the correlation between them for Russian sturgeon juveniles (Acipenser gueldenstaedtii reared in a recirculating aquaculture system fed at different fed with different ratio: 1% body weight (BW, 1.5% BW, 2% BW and ad libitum feeding (which was around 2.8% BW.Fish, with an average body mass around 248.194 ± 1.59 g. Following biometric measurements were made for each fish, including weight (W, total length (TL, standard length (SL, fork length (FL, maximum body depth (last depth of caudal peduncle, H; preanal distance (AD, predorsal distance (PD, length of head (C, preorbital distance (PO, length of pectoral fin (LPF, interorbital distance (ID, maximum width of head (MH, width of mouth (WM, width of the head at the level of the mouth (WHM. The obtained results showed significant differences between all morphometric measurements (p<0.05 for all the experimental variants, emphasizing that in the ad libitum feeding all morphometric measurements were significantly higher than in the other experimental variants. In order to highlight more eloquent these differences, were developed some linear regressions between the morphometric measurements and significant positive correlation (p<0.05 between dependent and independent variables were found.

  2. Understanding the basis of shortnose sturgeon (Acipenser brevirostrum) partial migration in the Gulf of Maine

    Science.gov (United States)

    Altenritter, Matthew E.; Zydlewski, Gayle B.; Kinnison, Michael T.; Zydlewski, Joseph D.; Wippelhauser, Gail S.

    2018-01-01

    Movement of shortnose sturgeon (Acipenser brevirostrum) among major river systems in the Gulf of Maine is common and has implications for the management of this endangered species. Directed movements of 61 telemetered individuals monitored between 2010 and 2013 were associated with the river of tagging and individual characteristics. While a small proportion of fish tagged in the Kennebec River moved to the Penobscot River (5%), a much higher proportion of fish tagged in the Penobscot River moved to the Kennebec River (66%), during probable spawning windows. This suggests that Penobscot River fish derive from a migratory contingent within a larger Kennebec River population. Despite this connectivity, fish captured in the Penobscot River were larger (∼100 mm fork length) and had higher condition factors (median Fulton’s K: 0.76) than those captured in the Kennebec River (median Fulton’s K: 0.61). Increased abundance and resource limitation in the Kennebec River may be constraining growth and promoting migration to the Penobscot River by individuals with sufficient initial size and condition. Migrants could experience an adaptive reproductive advantage relative to nonmigratory individuals.

  3. Identification of a new mineralized tissue in the notochord of reared Siberian sturgeon (Acipenser baerii).

    Science.gov (United States)

    Leprévost, Amandine; Azaïs, Thierry; Trichet, Michael; Sire, Jean-Yves

    2017-11-01

    In a study aiming to improve knowledge on the mineralization of the axial skeleton in reared Siberian sturgeon (Acipenser baerii Brandt, 1869), we discovered a new mineralized tissue within the notochord. To our knowledge, such a structure has never been reported in any vertebrate species with the exception of the pathological mineralization of the notochord remains in degenerative intervertebral disks of mammals. Here, we describe this enigmatic tissue using X-ray microtomography, histological analyses and solid state NMR-spectroscopy. We also performed a 1-year monitoring of the mineral content (MC) of the notochord in relation with seasonal variations of temperature. In all specimens studied from 2-year-old juveniles onwards, this mineralized structure was found within a particular region of the notochord called funiculus. This feature first appears in the abdominal region then extends posteriorly with ageing, while the notochord MC also increases. The mineral phase is mainly composed of amorphous calcium phosphate, a small amount of which changes into hydroxyapatite with ageing. The putative role of this structure is discussed as either a store of minerals available for the phosphocalcic metabolism, or a mechanical support in a species with a poorly mineralized axial skeleton. A pathological feature putatively related to rearing conditions is also discussed. © 2017 Wiley Periodicals, Inc.

  4. A bibliography of all known publications & reports on the Gulf sturgeon, Acipenser oxyrinchus desotoi

    Science.gov (United States)

    Price, Melissa; Adler, Jennifer; Littles, Chanda; Randolph, April Norem; Nash, Ursula A.; Gillett, Bethan; Randall, Michael T.; Sulak, Kenneth J.; Walsh, Stephen J.; Brownell, Prescott

    2013-01-01

    This functional bibliography is meant to be a complete and comprehensive bibliography of all discoverable reports containing information on the Gulf Sturgeon (GS). This bibliography contains all known reports presenting, documenting, summarizing, listing, or interpreting information on the GS through 31 December 2013. Report citations are organized into four sections. Section I includes published scientific journal articles, books, dissertations and theses, published and unpublished technical reports, published harvest prohibitions, and online articles reporting substantive scientific information. Section II includes newspaper, newsletter, magazine, book, agency news releases, and online articles reporting on GS occurrences, mortalities, captures, jumping, boat collisions, aquaculture, historical photographs, and other largely non-scientific or anecdotal issues. Section III consists of books, theses, ecotour-guides, media articles, editorials, and blogs reporting a mix of anecdotal information, historical information, and opinion on GS conservation, habitat issues, exploitation, aquaculture, and human interaction - but presenting very limited or no substantive scientific information. Section IV includes videos, films and audio recordings documenting GS life history and behavior.

  5. Sediment cores and chemistry for the Kootenai River White Sturgeon Habitat Restoration Project, Boundary County, Idaho

    Science.gov (United States)

    Barton, Gary J.; Weakland, Rhonda J.; Fosness, Ryan L.; Cox, Stephen E.; Williams, Marshall L.

    2012-01-01

    The Kootenai Tribe of Idaho, in cooperation with local, State, Federal, and Canadian agency co-managers and scientists, is assessing the feasibility of a Kootenai River habitat restoration project in Boundary County, Idaho. This project is oriented toward recovery of the endangered Kootenai River white sturgeon (Acipenser transmontanus) population, and simultaneously targets habitat-based recovery of other native river biota. Projects currently (2010) under consideration include modifying the channel and flood plain, installing in-stream structures, and creating wetlands to improve the physical and biological functions of the ecosystem. River restoration is a complex undertaking that requires a thorough understanding of the river. To assist in evaluating the feasibility of this endeavor, the U.S. Geological Survey collected and analyzed the physical and chemical nature of sediment cores collected at 24 locations in the river. Core depths ranged from 4.6 to 15.2 meters; 21 cores reached a depth of 15.2 meters. The sediment was screened for the presence of chemical constituents that could have harmful effects if released during restoration activities. The analysis shows that concentrations of harmful chemical constituents do not exceed guideline limits that were published by the U.S. Army Corps of Engineers in 2006.

  6. Effects of thermal regime on ovarian maturation and plasma sex steroids in farmed white sturgeon, Acipenser transmontanus

    Science.gov (United States)

    Webb, M.A.H.; Van Eenennaam, J. P.; Feist, G.W.; Linares-Casenave, J.; Fitzpatrick, M.S.; Schreck, C.B.; Doroshov, S.I.

    2001-01-01

    Recently, commercial aquaculture farms in Northern California have exposed gravid, cultured white sturgeon females to cold water (12 ?? 1??C) throughout the late phase of vitellogenesis and ovarian follicle maturation resulting in improved ovulation rates and egg quality. However, the optimum timing for transfer of broodfish to the cold water and the capacity of transferred broodfish to maintain reproductive competence over an extended time in cold water had not been evaluated. Gravid white sturgeon females that have been raised at water temperatures of 16-20??C were transported to either cold water (12 ?? 1??C; Group 1) in November 1997 or maintained in ambient water temperatures (10-19??C; Group 2) until early spring. In March 1998, half of the fish in Group 2 had regressed ovaries, but the remaining females had intact ovarian follicles and were transported to the cold water. Ovarian follicles and blood were collected from females until they reached the stage of spawning readiness (determined by germinal vesicle position and an oocyte maturation assay) or underwent ovarian regression. Exposure of gravid sturgeon females to ambient water temperatures (14.5 ?? 2.3??C, mean ?? S.D.) from October to March led to a decrease in plasma sex steroids and a high incidence of ovarian regression in fish with a more advanced stage of oocyte development. Transfer of females with intact ovarian follicles to cold water (12 ?? 1??C) in the fall or early spring resulted in normal ovarian development in the majority of females. Holding females in cold water does not seem to override their endogenous reproductive rhythms but extends their capacity to maintain oocyte maturational competence over a longer period of time. A temperature-sensitive phase in ovarian development may occur during the transition from vitellogenic growth to oocyte maturation, and the degree and timing of sensitivity to environmental temperature are dependent on the female's endogenous reproductive rhythm

  7. Effects of Mitigation Measures on Productivity of the White Sturgeon Populations in the Columbia River Downstream from McNary Dam, and Status and Habitat Requirements of White Sturgeon Populations in the Columbia and Snake Rivers Upstream from McNary Dam, 1992-1993 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Beamesdorfer, Raymond C.; Nigro, Anthony A. (Oregon Department of Fish and Wildlife, Portland, OR)

    1993-12-01

    We report on our progress from April 1992-March 1993 in research on white sturgeon in the lower Columbia River. The study began in July 1986 and progress through 1992 was summarized in a comprehensive report in 2 volumes (Beamesderfer and Nigro 1993a, 1993b). This report details activities during the first year of Phase II of this sturgeon research. In Phase I, we assessed the status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam. Phase II will examine the effects on white sturgeon productivity of mitigative measures recommended in Phase I. The status and habitat requirements of white sturgeon populations upstream from McNary Dam will also be examined in Phase II. The study is a cooperative effort by the Oregon Department of Fish and Wildlife, Washington Department of Fisheries, U.S. Fish and Wildlife Service, and National Marine Fisheries Service. Work during the past year has focused on: (1) analysis of results of limited sampling conducted in 1992, (2) submission of Phase I results to the peer-review literature to ensure widespread dissemination, clarity of presentation, and credibility of findings, and (3) preparations for additional field work in 1993. In report sections A to D, each agency reports 1992 results if applicable and the current status of manuscripts. Results of field work conducted in 1993 will be reported in the 1994 annual report.

  8. Effects of lecithin on growth and hematological indices in juveniles of Siberian sturgeon (Acipenser baeri Brandet 1869)

    OpenAIRE

    Najafipour Moghadam, E.; Falahatkar, B.; Kalbassi, M.R.

    2011-01-01

    This study was carried out to evaluate the effects of dietary lecithin on growth performance and hematological indices in juveniles of Siberian sturgeon (Acipenser baeri). Fish with initial average weight of 32.9±0.3 grams were fed five isoproteic and isolipidic formulated diets with different soybean lecithin levels including 0, 2.5, 5, 7.5 and 10% in triplicate groups for 8 weeks. Results showed that lecithin supplementation to 7.5% significantly increased some growth indices such as body w...

  9. Polyploidization of murine mesenchymal cells is associated with suppression of the long noncoding RNA H19 and reduced tumorigenicity.

    Science.gov (United States)

    Shoshani, Ofer; Massalha, Hassan; Shani, Nir; Kagan, Sivan; Ravid, Orly; Madar, Shalom; Trakhtenbrot, Luba; Leshkowitz, Dena; Rechavi, Gideon; Zipori, Dov

    2012-12-15

    Mesenchymal stromal cells (MSC) are used extensively in clinical trials; however, the possibility that MSCs have a potential for malignant transformation was raised. We examined the genomic stability versus the tumor-forming capacity of multiple mouse MSCs. Murine MSCs have been shown to be less stable and more prone to malignant transformation than their human counterparts. A large series of independently isolated MSC populations exhibited low tumorigenic potential under syngeneic conditions, which increased in immunocompromised animals. Unexpectedly, higher ploidy correlated with reduced tumor-forming capacity. Furthermore, in both cultured MSCs and primary hepatocytes, polyploidization was associated with a dramatic decrease in the expression of the long noncoding RNA H19. Direct knockdown of H19 expression in diploid cells resulted in acquisition of polyploid cell traits. Moreover, artificial tetraploidization of diploid cancer cells led to a reduction of H19 levels, as well as to an attenuation of the tumorigenic potential. Polyploidy might therefore serve as a protective mechanism aimed at reducing malignant transformation through the involvement of the H19 regulatory long noncoding RNA.

  10. Status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam, annual progress report, July 1986 - March 1987.; ANNUAL

    International Nuclear Information System (INIS)

    Oregon Department of Fish and Wildlife; Washington Department of Fisheries

    1987-01-01

    Measure 804(e)(8) of the Northwest Power Planning Council (NPPC) Fish and Wildlife Program states that Bonneville Power Administration (BPA) ''shall fund research to determine the impacts of development and operation of the hydroelectric power system on sturgeon in the Columbia River Basin...'' In June 1985, BPA sponsored a workshop to define and list in priority order research needs in the basin (Fickeisen 1985a). In December 1985, BPA submitted a research program implementation plan (Fickeisen 1985b) to the NPPC. The purpose of the plan is to provide guidance for conducting research necessary to address four objectives identified by regional fishery interests for protecting, mitigating and enhancing white sturgeon populations in the Columbia River basin. The plan's objectives are: (1) Assess the current status of Columbia River basin white sturgeon stocks. (2) Provide the basis to evaluate the need for protection, mitigation and enhancement of white sturgeon in the Columbia River system. (3) Provide information that can be used to evaluate potential methods of protection, mitigation and enhancement of existing stocks. (4) Provide tools to assess the effectiveness of protection, mitigation and enhancement efforts

  11. Status and Habitat Requirements of the White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1990-1991 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Nigro, Anthony A. (Oregon Department of Fish and Wildlife, Portland, OR)

    1991-09-01

    We report on our effort from April 1990 to March 1991 to describe the life history and population dynamics of white sturgeon Acipenser transmontanus in.John Day Reservoir. We set 1188 set lines and 26 gill nets. We caught 623 white sturgeon with set lines and 236 with gill nets. Catch per unit effort was much higher in areas near the tailrace than in downstream sites. Our setlines were size selective. We recaptured 3 fish released in John Day Reservoir in 1989 and 28 fish released in 1990. Sport and commercial fishermen recovered 62 tags from fish we tagged in Bonneville, The Dalles and John Day reservoirs, 1987-1990. We observed extensive movements of marked sturgeon within the reservoirs. We completed aging of available samples from all three reservoirs from 1987-1990. We aged fish as old as 46 years. Bone marks were observed on 74 of 78 fish previously injected with oxytetracycline and annulus formation was generally complete after June. We estimated parameters in a length-weight equation. About 1.5% of the female white sturgeon we examined to date had early or late vitellogenic eggs and would be expected to spawn the following year.

  12. Status and Habitat Requirements of White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1986-1987 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, Jr., George T. (National Marine Fisheries Service, Environmental and Technical Services Division, Portland, OR); Beckman, Lance G. (US Fish and Wildlife Service, Portland, OR); Kreitman, Gayle (Washington Department of Fisheries, Olympia, WA)

    1987-06-01

    Measure 804(e)(8) of the Northwest Power Planning Council (NPPC) Fish and Wildlife Program states that Bonneville Power Administration (BPA) ''shall fund research to determine the impacts of development and operation of the hydroelectric power system on sturgeon in the Columbia River Basin...'' In June 1985, BPA sponsored a workshop to define and list in priority order research needs in the basin (Fickeisen 1985a). In December 1985, BPA submitted a research program implementation plan (Fickeisen 1985b) to the NPPC. The purpose of the plan is to provide guidance for conducting research necessary to address four objectives identified by regional fishery interests for protecting, mitigating and enhancing white sturgeon populations in the Columbia River basin. The plan's objectives are: (1) Assess the current status of Columbia River basin white sturgeon stocks. (2) Provide the basis to evaluate the need for protection, mitigation and enhancement of white sturgeon in the Columbia River system. (3) Provide information that can be used to evaluate potential methods of protection, mitigation and enhancement of existing stocks. (4) Provide tools to assess the effectiveness of protection, mitigation and enhancement efforts.

  13. Growth potential and habitat requirements of endangered age-0 pallid sturgeon (Scaphirhynchus albus) in the Missouri River, USA, determined using a individual-based model framework

    Science.gov (United States)

    Deslauriers, David; Heironimus, Laura B.; Rapp, Tobias; Graeb, Brian D. S.; Klumb, Robert A.; Chipps, Steven R.

    2018-01-01

    An individual-based model framework was used to evaluate growth potential of the federally endangered pallid sturgeon (Scaphirhynchus albus) in the Missouri River. The model, developed for age-0 sturgeon, combines information on functional feeding response, bioenergetics and swimming ability to regulate consumption and growth within a virtual foraging arena. Empirical data on water temperature, water velocity and prey density were obtained from three sites in the Missouri River and used as inputs in the model to evaluate hypotheses concerning factors affecting pallid sturgeon growth. The model was also used to evaluate the impacts of environmental heterogeneity and water velocity on individual growth variability, foraging success and dispersal ability. Growth was simulated for a period of 100 days using 100 individuals (first feeding; 19 mm and 0.035 g) per scenario. Higher growth was shown to occur at sites where high densities of Ephemeroptera and Chironomidae larvae occurred throughout the growing season. Highly heterogeneous habitats (i.e., wide range of environmental conditions) and moderate water velocities (0.3 m/s) were also found to positively affect growth rates. The model developed here provides an important management and conservation tool for evaluating growth hypotheses and(or) identifying habitats in the Missouri River that are favourable to age-0 pallid sturgeon growth.

  14. Novel functions for atypical E2Fs, E2F7 and E2F8, in polyploidization and liver cancer

    NARCIS (Netherlands)

    Pandit, Shusil Kumar

    2014-01-01

    Atypical E2F transcription factors, E2F7 and E2F8, function as transcriptional repressors of E2F target genes and are crucial for controlling the cell proliferation. In this thesis, we reveal that these two factors are crucial for liver cell polyploidization, embryonic development and prevention of

  15. White Sturgeon Management Plan in the Snake River between Lower Granite and Hells Canyon Dams; Nez Perce Tribe, 1997-2005 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Nez Perce Tribe Resources Management Staff, (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)

    2005-09-01

    White sturgeon in the Hells Canyon reach (HCR) of the Snake River are of cultural importance to the Nez Perce Tribe. However, subsistence and ceremonial fishing opportunities have been severely limited as a result of low numbers of white sturgeon in the HCR. Hydrosystem development in the Columbia River Basin has depressed numbers and productivity of white sturgeon in the HCR by isolating fish in impounded reaches of the basin, restricting access to optimal rearing habitats, reducing the anadromous forage base, and modifying early life-history habitats. Consequently, a proactive management plan is needed to mitigate for the loss of white sturgeon production in the HCR, and to identify and implement feasible measures that will restore and rebuild the white sturgeon population to a level that sustains viability and can support an annual harvest. This comprehensive and adaptive management plan describes the goals, objectives, strategies, actions, and expected evaluative timeframes for restoring the white sturgeon population in the HCR. The goal of this plan, which is to maintain a viable, persistent population that can support a sustainable fishery, is supported by the following objectives: (1) a natural, stable age structure comprising both juveniles and a broad spectrum of spawning age-classes; (2) stable or increasing numbers of both juveniles and adults; (3) consistent levels of average recruitment to ensure future contribution to reproductive potential; (4) stable genetic diversity comparable to current levels; (5) a minimum level of abundance of 2,500 adults to minimize extinction risk; and (6) provision of an annual sustainable harvest of 5 kg/ha. To achieve management objectives, potential mitigative actions were developed by a Biological Risk Assessment Team (BRAT). Identified strategies and actions included enhancing growth and survival rates by restoring anadromous fish runs and increasing passage opportunities for white sturgeon, reducing mortality rates

  16. A novel nucleo-cytoplasmic hybrid clone formed via androgenesis in polyploid gibel carp

    Directory of Open Access Journals (Sweden)

    Zhou Li

    2011-03-01

    Full Text Available Abstract Background Unisexual vertebrates have been demonstrated to reproduce by gynogenesis, hybridogenesis, parthenogenesis, or kleptogenesis, however, it is uncertain how the reproduction mode contributes to the clonal diversity. Recently, polyploid gibel carp has been revealed to possess coexisting dual modes of unisexual gynogenesis and sexual reproduction and to have numerous various clones. Using sexual reproduction mating between clone D female and clone A male and subsequent 7 generation multiplying of unisexual gynogenesis, we have created a novel clone strain with more than several hundred millions of individuals. Here, we attempt to identify genetic background of the novel clone and to explore the significant implication for clonal diversity contribution. Methods Several nuclear genome markers and one cytoplasmic marker, the mitochondrial genome sequence, were used to identify the genetic organization of the randomly sampled individuals from different generations of the novel clone. Results Chromosome number, Cot-1 repetitive DNA banded karyotype, microsatellite patterns, AFLP profiles and transferrin alleles uniformly indicated that nuclear genome of the novel clone is identical to that of clone A, and significantly different from that of clone D. However, the cytoplasmic marker, its complete mtDNA genome sequence, is same to that of clone D, and different from that of clone A. Conclusions The present data indicate that the novel clone is a nucleo-cytoplasmic hybrid between the known clones A and D, because it originates from the offspring of gonochoristic sexual reproduction mating between clone D female and clone A male, and contains an entire nuclear genome from the paternal clone A and a mtDNA genome (cytoplasm from the maternal clone D. It is suggested to arise via androgenesis by a mechanism of ploidy doubling of clone A sperm in clone D ooplasm through inhibiting the first mitotic division. Significantly, the selected nucleo

  17. Sibling Rivalry in Myxococcus xanthus Is Mediated by Kin Recognition and a Polyploid Prophage.

    Science.gov (United States)

    Dey, Arup; Vassallo, Christopher N; Conklin, Austin C; Pathak, Darshankumar T; Troselj, Vera; Wall, Daniel

    2016-01-19

    Myxobacteria form complex social communities that elicit multicellular behaviors. One such behavior is kin recognition, in which cells identify siblings via their polymorphic TraA cell surface receptor, to transiently fuse outer membranes and exchange their contents. In addition, outer membrane exchange (OME) regulates behaviors, such as inhibition of wild-type Myxococcus xanthus (DK1622) from swarming. Here we monitored the fate of motile cells and surprisingly found they were killed by nonmotile siblings. The kill phenotype required OME (i.e., was TraA dependent). The genetic basis of killing was traced to ancestral strains used to construct DK1622. Specifically, the kill phenotype mapped to a large "polyploid prophage," Mx alpha. Sensitive strains contained a 200-kb deletion that removed two of three Mx alpha units. To explain these results, we suggest that Mx alpha expresses a toxin-antitoxin cassette that uses the OME machinery of M. xanthus to transfer a toxin that makes the population "addicted" to Mx alpha. Thus, siblings that lost Mx alpha units (no immunity) are killed by cells that harbor the element. To test this, an Mx alpha-harboring laboratory strain was engineered (by traA allele swap) to recognize a closely related species, Myxococcus fulvus. As a result, M. fulvus, which lacks Mx alpha, was killed. These TraA-mediated antagonisms provide an explanation for how kin recognition specificity might have evolved in myxobacteria. That is, recognition specificity is determined by polymorphisms in traA, which we hypothesize were selected for because OME with non-kin leads to lethal outcomes. The transition from single cell to multicellular life is considered a major evolutionary event. Myxobacteria have successfully made this transition. For example, in response to starvation, individual cells aggregate into multicellular fruiting bodies wherein cells differentiate into spores. To build fruits, cells need to recognize their siblings, and in part, this is

  18. A novel nucleo-cytoplasmic hybrid clone formed via androgenesis in polyploid gibel carp

    Science.gov (United States)

    2011-01-01

    Background Unisexual vertebrates have been demonstrated to reproduce by gynogenesis, hybridogenesis, parthenogenesis, or kleptogenesis, however, it is uncertain how the reproduction mode contributes to the clonal diversity. Recently, polyploid gibel carp has been revealed to possess coexisting dual modes of unisexual gynogenesis and sexual reproduction and to have numerous various clones. Using sexual reproduction mating between clone D female and clone A male and subsequent 7 generation multiplying of unisexual gynogenesis, we have created a novel clone strain with more than several hundred millions of individuals. Here, we attempt to identify genetic background of the novel clone and to explore the significant implication for clonal diversity contribution. Methods Several nuclear genome markers and one cytoplasmic marker, the mitochondrial genome sequence, were used to identify the genetic organization of the randomly sampled individuals from different generations of the novel clone. Results Chromosome number, Cot-1 repetitive DNA banded karyotype, microsatellite patterns, AFLP profiles and transferrin alleles uniformly indicated that nuclear genome of the novel clone is identical to that of clone A, and significantly different from that of clone D. However, the cytoplasmic marker, its complete mtDNA genome sequence, is same to that of clone D, and different from that of clone A. Conclusions The present data indicate that the novel clone is a nucleo-cytoplasmic hybrid between the known clones A and D, because it originates from the offspring of gonochoristic sexual reproduction mating between clone D female and clone A male, and contains an entire nuclear genome from the paternal clone A and a mtDNA genome (cytoplasm) from the maternal clone D. It is suggested to arise via androgenesis by a mechanism of ploidy doubling of clone A sperm in clone D ooplasm through inhibiting the first mitotic division. Significantly, the selected nucleo-cytoplasmic hybrid female

  19. Phylogeography of the European sturgeon (Acipenser sturio): A critically endangered species.

    Science.gov (United States)

    Chassaing, Olivier; Desse-Berset, Nathalie; Hänni, Catherine; Hughes, Sandrine; Berrebi, Patrick

    2016-01-01

    The European sturgeon (Acipenser sturio) was once a common species throughout Europe, but the sole remaining natural population presently inhabits the Gironde Estuary in France (Atlantic coast). The species was classified as 'Critically Endangered' in 1996, and the Gironde population is now on the verge of extinction. In this setting, and for the first time, we present the past phylogeographical features of this species throughout Europe along with an assessment of its former genetic diversity. This study was based on a molecular analysis (mtDNA CR sequencing) of 10 living specimens from the Gironde Estuary, 55 museum specimens that had been caught along 19th and 20th centuries, and 59 archaeological remains dating back to 260-5000years BP, from which mitochondrial DNA was extracted and amplified. Although discontinuous, the produced data provided a realistic image of the former structure of A. sturio in Europe. Reconstruction of the phylogenetic trees and haplotypes network led to the identification of several clades. The mitochondrial genetic diversity of this species was found to be much greater at the core (Iberian Peninsula, Mediterranean and Adriatic regions) than along the margins (Atlantic-Northern Europe, Black Sea) of its range. A series of hypotheses on the dates and causes of changes in the species' major structures are put forward on the basis of these data. Finally, competition with A. oxyrinchus, a sibling species whose presence in Northern Europe was recently reconsidered, is presented as a major factor in the evolution of this species. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Effects of multiple collections on spermatozoa quality of Persian sturgeon, Acipenser persicus: motility, density and seminal plasma composition.

    Science.gov (United States)

    Aramli, M S; Kalbassi, M R; Gharibi, M R

    2015-02-01

    In this study, we investigated the effects of multiple collections of sperm on the endangered Persian sturgeon, Acipenser persicus, in terms of a number of sperm functional parameters (percentage of motile spermatozoa, total time period of motility and sperm concentration) as well as on the ionic composition, protein concentration and osmolality of seminal plasma. Semen samples were collected from 12 induced male fish in three experimental groups that had been injected intramuscularly with LHRH-A2, at dosages of 5 μg/kg body weight, at a number of time regimes: at 12 h, 17 h and 24 h after spawning induction (1); at 24, 29 and 34 h after spawning induction (2); and at 36, 41 and 46 h after spawning induction (3). The percentage of motile spermatozoa and the period of sperm motility decreased significantly (p collections. The concentration of spermatozoa decreased after the third collection, but this decline was not significant. No significant effect of multiple collections on protein concentration and ionic content (with exception of the Cl(-) ion) of seminal plasma was observed. In all experimental groups, a moderate impact of sequential collection on the osmolality (p collections on spermatological characteristics in the Persian sturgeon. Our results confirm that sequential stripping after the third collections has a negative effect on a number of functional parameters associated with sperm. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  1. White Sturgeon Mitigation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam; 2000-2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Kern, J. Chris; Ward, David L.; Farr, Ruth A. (Oregon Department of Fish and Wildlife)

    2002-02-01

    We report on our progress from April 2000 through March 2001 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW; Report A), Washington Department of Fish and Wildlife (WDFW; Report B), U.S. Geological Survey Biological Resources Division (USGS; Report C), Columbia River Inter-Tribal Fish Commission (CRITFC; Report D), the U.S. Fish and Wildlife Service (USFWS; Report E), and Oregon State University (OSU; Report F). This is a multi-year study with many objectives requiring more than one year to complete; therefore, findings from a given year may be part of more significant findings yet to be reported. Highlights of results of our work from April 2000 through March 2001 are listed.

  2. Determination of hematology and plasma chemistry reference intervals for 3 populations of captive Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus).

    Science.gov (United States)

    Matsche, Mark A; Arnold, Jill; Jenkins, Erin; Townsend, Howard; Rosemary, Kevin

    2014-09-01

    The imperiled status of Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus), a large, long-lived, anadromous fish found along the Atlantic coast of North America, has prompted efforts at captive propagation for research and stock enhancement. The purpose of this study was to establish hematology and plasma chemistry reference intervals of captive Atlantic sturgeon maintained under different culture conditions. Blood specimens were collected from a total of 119 fish at 3 hatcheries: Lamar, PA (n = 36, ages 10-14 years); Chalk Point, MD (n = 40, siblings of Lamar); and Horn Point, Cambridge, MD (n = 43, mixed population from Chesapeake Bay). Reference intervals (using robust techniques), median, mean, and standard deviations were determined for WBC, RBC, thrombocytes, PCV, HGB, MCV, MCH, MCHC, and absolute counts for lymphocytes (L), neutrophils (N), monocytes, and eosinophils. Chemistry analytes included concentrations of total proteins, albumin, glucose, urea, calcium, phosphate, sodium, potassium, chloride, and globulins, AST, CK, and LDH activities, and osmolality. Mean concentrations of total proteins, albumin, and glucose were at or below the analytic range. Statistical comparisons showed significant differences among hatcheries for each remaining plasma chemistry analyte and for PCV, RBC, MCHC, MCH, eosinophil and monocyte counts, and N:L ratio throughout all 3 groups. Therefore, reference intervals were calculated separately for each population. Reference intervals for fish maintained under differing conditions should be established per population. © 2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.

  3. White Sturgeon Mitigation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam, 1999-2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ward, David L. (Oregon Department of Fish and Wildlife, Portland, OR)

    2001-04-01

    We report on our progress from April 1999 through March 2000 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW; Report A), Washington Department of Fish and Wildlife (WDFW; Report B), U.S. Geological Survey Biological Resources Division (USGS; Report C), Columbia River Inter-Tribal Fish Commission (CRITFC; Report D), and the U.S. Fish and Wildlife Service (USFWS; Report E). This is a multi-year study with many objectives requiring more than one year to complete. Therefore, findings from a given year may be part of more significant findings yet to be reported. Highlights of results of our work from April 1999 through March 2000 are given.

  4. Defining winter trophic habitat of juvenile Gulf Sturgeon in the Suwannee and Apalachicola rivermouth estuaries, acoustic telemetry investigations

    Science.gov (United States)

    Sulak, K.J.; Randall, M.T.; Edwards, R.E.; Summers, T.M.; Luke, K.E.; Smith, W.T.; Norem, A.D.; Harden, William M.; Lukens, R.H.; Parauka, F.; Bolden, S.; Lehnert, R.

    2009-01-01

    Three automated listening post-telemetry studies were undertaken in the Suwannee and Apalachicola estuaries to gain knowledge of habitats use by juvenile Gulf Sturgeons (Acipenser oxyrinchus desotoi) on winter feeding grounds. A simple and reliable method for external attachment of small acoustic tags to the dorsal fin base was developed using shrink-tubing. Suspending receivers on masts below anchored buoys improved reception and facilitated downloading; a detection range of 500–2500 m was realized. In the Apalachicola estuary, juvenile GS stayed in shallow water (days at a time. For juvenile sturgeons, the stress and metabolic cost of enduring high salinity (Jarvis et al., 2001; McKenzie et al., 2001; Singer and Ballantyne, 2002) for short periods in deep offshore waters seems adaptively advantageous relative to the risk of cold-event mortality in shallow inshore waters of lower salinity. Thus, while juveniles can tolerate high salinities for days to weeks to escape cold events, they appear to make only infrequent use of open polyhaline waters. Throughout the winter foraging period, juvenile GS stayed primarily within the core area of Suwannee River mouth influence, extending about 12 km north and south of the river mouth, and somewhat seaward of Suwannee Reef (< 5 km offshore). None were detected departing the core area past either of the northern or southern acoustic gates, located 66 and 52 km distant from the river mouth, respectively.

  5. White Sturgeon Mitigation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam; 1998-1999 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ward, David L.

    2000-12-01

    The authors report on their progress from April 1998 through March 1999 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW; Report A), Washington Department of Fish and Wildlife (WDFW; Report B), U.S. Geological Survey Biological Resources Division (USGS; Report C), U.S. Fish and Wildlife Service (USFWS; Report D), Columbia River Inter-Tribal Fish Commission (CRITFC; Report E), and the University of Idaho (UI; Report F). This is a multi-year study with many objectives requiring more than one year to complete. Therefore, findings from a given year may be part of more significant findings yet to be reported. Highlights of results of our work from April 1998 through March 1999 are given.

  6. Fins improve the swimming performance of fish sperm: a hydrodynamic analysis of the Siberian sturgeon Acipenser baerii.

    Science.gov (United States)

    Gillies, Eric A; Bondarenko, Volodymyr; Cosson, Jacky; Pacey, Allan A

    2013-02-01

    The flagella of sturgeon sperm have an ultrastructure comprising paddle-like fins extending along most of their length. These fins are seen in several other marine and freshwater fish. The sperm of these fish are fast swimmers and are relatively short lived: it is therefore tempting to think of these fins as having evolved for hydrodynamic advantage, but the actual advantage they impart, at such a small length scale and slow speed, is unclear. The phrase "the fins improve hydrodynamic efficiency" is commonly found in biological literature, yet little hydrodynamic analysis has previously been used to support such conjectures. In this paper, we examine various hydrodynamic models of sturgeon sperm and investigate both swimming velocity and energy expenditure. All of the models indicate a modest hydrodynamic advantage of finned sperm, in both straight line swimming speed and a hydrodynamic efficiency measure. We find a hydrodynamic advantage for a flagellum with fins, over one without fins, of the order of 15-20% in straight line propulsive velocity and 10-15% in a hydrodynamic efficiency measure. Copyright © 2012 Wiley Periodicals, Inc.

  7. Age and Heat Stress as Determinants of Telomere Length in a Long-Lived Fish, the Siberian Sturgeon.

    Science.gov (United States)

    Simide, Rémy; Angelier, Frédéric; Gaillard, Sandrine; Stier, Antoine

    2016-01-01

    Telomeres shorten at each cell division due to the end-replication problem but also in response to oxidative stress. Consequently, telomeres shorten with age in many endotherms, and this shortening is accelerated under stressful environmental conditions. Data in ectotherm vertebrates remain scarce so far, so our goal was to review existing data for fish and to test the influence of age and stress on telomere length in a very long-lived fish, the Siberian sturgeon (Acipenser baerii). Our review of the literature revealed age-related telomere shortening in approximately half of the published studies. In the Siberian sturgeon, we found a significant telomere shortening with age, both at the intraindividual level using red blood cells (-12.5% in 16 mo) and at the interindividual level using cross-sectional samples of fin over an age range of 8 yr. We also found that heat stress (30°C) significantly reduced telomere length by 15.0% after only 1 mo of exposure. Our results highlight that both age and stressful environmental conditions might be important determinants of telomere length in fish.

  8. Western Alaska ESI: LAKES (Lake Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing lakes and land masses used in the creation of the Environmental Sensitivity Index (ESI) for Western Alaska. The...

  9. Construction of a plant-transformation-competent BIBAC library and genome sequence analysis of polyploid Upland cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    Lee, Mi-Kyung; Zhang, Yang; Zhang, Meiping; Goebel, Mark; Kim, Hee Jin; Triplett, Barbara A; Stelly, David M; Zhang, Hong-Bin

    2013-03-28

    Cotton, one of the world's leading crops, is important to the world's textile and energy industries, and is a model species for studies of plant polyploidization, cellulose biosynthesis and cell wall biogenesis. Here, we report the construction of a plant-transformation-competent binary bacterial artificial chromosome (BIBAC) library and comparative genome sequence analysis of polyploid Upland cotton (Gossypium hirsutum L.) with one of its diploid putative progenitor species, G. raimondii Ulbr. We constructed the cotton BIBAC library in a vector competent for high-molecular-weight DNA transformation in different plant species through either Agrobacterium or particle bombardment. The library contains 76,800 clones with an average insert size of 135 kb, providing an approximate 99% probability of obtaining at least one positive clone from the library using a single-copy probe. The quality and utility of the library were verified by identifying BIBACs containing genes important for fiber development, fiber cellulose biosynthesis, seed fatty acid metabolism, cotton-nematode interaction, and bacterial blight resistance. In order to gain an insight into the Upland cotton genome and its relationship with G. raimondii, we sequenced nearly 10,000 BIBAC ends (BESs) randomly selected from the library, generating approximately one BES for every 250 kb along the Upland cotton genome. The retroelement Gypsy/DIRS1 family predominates in the Upland cotton genome, accounting for over 77% of all transposable elements. From the BESs, we identified 1,269 simple sequence repeats (SSRs), of which 1,006 were new, thus providing additional markers for cotton genome research. Surprisingly, comparative sequence analysis showed that Upland cotton is much more diverged from G. raimondii at the genomic sequence level than expected. There seems to be no significant difference between the relationships of the Upland cotton D- and A-subgenomes with the G. raimondii genome, even though G

  10. Pollution at Lake Mariut

    International Nuclear Information System (INIS)

    Nour ElDin, H.; Halim, S. N.; Shalby, E.

    2004-01-01

    Lake Mariut, south Alexandria, Egypt suffered in the recent decades from intensive pollution as a result of a continuous discharge of huge amounts of agriculture wastewater that contains a large concentration of the washed pesticides and fertilizers in addition to domestic and industrial untreated wastewater. The over flow from the lake is discharged directly to the sea through El-Max pumping station via EI-Umum drain. Lake Mariout is surrounded by a huge number of different industrial activities and also the desert road is cutting the lake, this means that a huge number of various pollutants cycle through the air and settle down in the lake, by the time and during different seasons these pollutants after accumulation and different chemical interactions will release again from the lake to the surrounding area affecting the surrounding zone

  11. Great Lakes Literacy Principles

    Science.gov (United States)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

    Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

  12. The Key Lake project

    International Nuclear Information System (INIS)

    1991-01-01

    Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included

  13. Nuclear and plastid haplotypes suggest rapid diploid and polyploid speciation in the N Hemisphere Achillea millefolium complex (Asteraceae

    Directory of Open Access Journals (Sweden)

    Guo Yan-Ping

    2012-01-01

    Full Text Available Abstract Background Species complexes or aggregates consist of a set of closely related species often of different ploidy levels, whose relationships are difficult to reconstruct. The N Hemisphere Achillea millefolium aggregate exhibits complex morphological and genetic variation and a broad ecological amplitude. To understand its evolutionary history, we study sequence variation at two nuclear genes and three plastid loci across the natural distribution of this species complex and compare the patterns of such variations to the species tree inferred earlier from AFLP data. Results Among the diploid species of A. millefolium agg., gene trees of the two nuclear loci, ncpGS and SBP, and the combined plastid fragments are incongruent with each other and with the AFLP tree likely due to incomplete lineage sorting or secondary introgression. In spite of the large distributional range, no isolation by distance is found. Furthermore, there is evidence for intragenic recombination in the ncpGS gene. An analysis using a probabilistic model for population demographic history indicates large ancestral effective population sizes and short intervals between speciation events. Such a scenario explains the incongruence of the gene trees and species tree we observe. The relationships are particularly complex in the polyploid members of A. millefolium agg. Conclusions The present study indicates that the diploid members of A. millefolium agg. share a large part of their molecular genetic variation. The findings of little lineage sorting and lack of isolation by distance is likely due to short intervals between speciation events and close proximity of ancestral populations. While previous AFLP data provide species trees congruent with earlier morphological classification and phylogeographic considerations, the present sequence data are not suited to recover the relationships of diploid species in A. millefolium agg. For the polyploid taxa many hybrid links and

  14. Synergistic effects of polyploidization and elicitation on biomass and hyoscyamine content in hairy roots of Datura stramonium

    Directory of Open Access Journals (Sweden)

    Belabbassi, O.

    2016-01-01

    Full Text Available Description of the subject. The hyoscyamine, a tropane alkaloid, widely used in medicine, can be produced from Datura sp. (Solanaceae. However, its content in the spontaneous roots remains low; therefore, hairy roots (HRs were envisaged as a potential alternative to improve its biosynthesis. The hairy roots are characterized by a good genetic stability and a rapid growth. Indeed, Datura stramonium HRs have widely been studied in the perspective of improving the yield of hyoscyamine. This study is part of this same perspective. Objectives. This paper aims to study the effects of polyploidization of HRs induced by colchicine in synergy with elicitation (with acetylsalicylic [ASA] or salicylic acids [SA] on the hyoscyamine content in D. stramonium. Method. Colchicine was applied at different concentrations and periods, on a selected hairy root line (LDS of D. stramonium obtained by infection with Agrobactrium rhizogenes strain A4. The selection of tetraploid HR lines was performed by the cytogenetic analysis using light microscopy. The effect of polyploidization and elicitation was studied on the biomass (dry weight and hyoscyamine content of HRs. Results. The untreated HR line (control shows a diploid level with 2n = 24 chromosomes. However, the HR lines treated with colchicine show, in most cases, an endoreduplication of their genetic material. The survival rate of endoreduplicated lines varies between 30% and 93%, depending on concentration and exposure time to colchicine. Moreover, the tetraploid HR line shows an increase in its biomass and hyoscyamine content in comparison to the diploid HR line (LDS. Further, elicitation of HRs by ASA or AS at the 10-4 M concentration causes a low decrease or increase in dry weight, respectively. However, the same treatments show a significant increase in the yield of hyoscyamine in elicited HR lines. Consequently, our work indicates that the combination of polyploidy and elicitation can lead to significant

  15. Evolutionary dynamics of the Pgk1 gene in the polyploid genus Kengyilia (Triticeae: Poaceae and its diploid relatives.

    Directory of Open Access Journals (Sweden)

    Xing Fan

    Full Text Available The level and pattern of nucleotide variation in duplicate gene provide important information on the evolutionary history of polyploids and divergent process between homoeologous loci within lineages. Kengyilia is a group of allohexaploid species with the StYP genomic constitutions in the wheat tribe. To investigate the evolutionary dynamics of the Pgk1 gene in Kengyilia and its diploid relatives, three copies of Pgk1 homoeologues were isolated from all sampled hexaploid Kengyilia species and analyzed with the Pgk1 sequences from 47 diploid taxa representing 18 basic genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that (1 Kengyilia species from the Central Asia and the Qinghai-Tibetan plateau have independent origins with geographically differentiated P genome donors and diverged levels of nucleotide diversity at Pgk1 locus; (2 a relatively long-time sweep event has allowed the Pgk1 gene within Agropyron to adapt to cold climate triggered by the recent uplifts of the Qinghai-Tibetan Plateau; (3 sweep event and population expansion might result in the difference in the d(N/d(S value of the Pgk1 gene in allopatric Agropyron populations, and this difference may be genetically transmitted to Kengyilia lineages via independent polyploidization events; (4 an 83 bp MITE element insertion has shaped the Pgk1 loci in the P genome lineage with different geographical regions; (5 the St and P genomes in Kengyilia were donated by Pseudoroegneria and Agropyron, respectively, and the Y genome is closely related to the Xp genome of Peridictyon sanctum. The interplay of evolutionary forces involving diverged natural selection, population expansion, and transposable events in geographically differentiated P genome donors could attribute to geographical differentiation of Kengyilia species via independent origins.

  16. Limnology of Eifel maar lakes

    National Research Council Canada - National Science Library

    Scharf, Burkhard W; Björk, Sven

    1992-01-01

    ... : Species composition & seasonal periodicity - Qualitative & quantitative investigations on cladoceran zooplankton of oligotrophic maar lakes - Population dynamics of pelagic copepods in maar lakes - Population dynamics...

  17. [SP600125-induced polyploidization of megakaryocytic leukemia cell lines by ribosomal protein S6 kinase 1 depends on the degree of cell differentiation].

    Science.gov (United States)

    Wang, Lili; Yang, Jingang; Li, Changling; Xing, Sining; Yu, Ying; Liu, Shuo; Zhao, Song; Ma, Dongchu

    2016-10-01

    Objective To investigate regulatory role of ribosomal protein S6 kinase 1 (S6K1) in the polyploidization of different megakaryocytic leukemia cell lines at the different differentiation stages. Methods Megakaryocytic leukemia cell lines (Dami, Meg-01 and HEL cells) were induced towards polyploidization by SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. The SP600125-inducing process was blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor. The phenotype (CD41a, CD42a and CD42b) and DNA ploidy were detected by flow cytometry. The expression and phosphorylation of S6K1 and related proteins were detected by Western blotting. Results SP600125 induced polyploidization and increased the phosphorylation of eukaryotic initiation factor 4E binding protein 1 (4E-BP1) in Dami, Meg-01 and HEL cells. However, the effect of SP600125 on polyploidization of the three cell lines was different, with the strongest effect on Dami cells and the weakest on Meg-01 cells. Moreover, SP600125 increased the phosphorylation of S6K1 Thr421/Ser424 and decreased the phosphorylation of Thr389 in Dami cells. However, it only increased the phosphorylation of Thr389 in HEL cells and had no effect on the phosphorylation of S6K1 in Meg-01 cells. Interestingly, H-89 only partially blocked the polyploidization of Dami cells, although it decreased the phosphorylation of 4E-BP1 in all SP600125-induced three cell lines. Noticeably, H-89 decreased the phosphorylation of S6K1 Thr421/Ser424 and increased the phosphorylation of Thr389 in Dami cells. However, H-89 had no effect on the phosphorylation of Thr421/Ser424, although it increased the phosphorylation of Thr389 in Meg-01 and HEL cells. Phenotypic analysis showed that the three cell lines were at different levels of differentiation in megakaryocytic lineage, with the highest differentiation in Dami and the lowest in Meg-01 cells. Conclusion SP600125-induced polyploidization of megakaryocytic leukemia cell lines is dependent on the effect

  18. Lakes, Lagerstaetten, and Evolution

    Science.gov (United States)

    Kordesch, E. G.; Park, L. E.

    2001-12-01

    The diversity of terrestrial systems is estimated to be greater than in the marine realm. However no hard data yet exists to substantiate this claim. Ancient lacustrine deposits may preserve an exceptionally diverse fossil fauna and aid in determining continental faunal diversities. Fossils preserved in lake deposits, especially those with exceptional preservation (i.e. Konservat Lagerstaetten), may represent a dependable method for determining species diversity changes in the terrestrial environment because of their faunal completeness. Important Konservat Lagerstaetten, such as the Green River Formation (US) and Messel (Germany), both Eocene in age, are found in lake sediments and show a remarkable faunal diversity for both vertebrates and invertebrates. To date information from nearly 25 lake lagerstaetten derived from different types of lake basins from the Carboniferous to the Miocene have been collected and described. Carboniferous sites derive from the cyclothems of Midcontinent of the US while many Cenozoic sites have been described from North and South America as well as Europe and Australia. Asian sites contain fossils from the Mesozoic and Cenozoic. With this data, insight into the evolutionary processes associated with lake systems can be examined. Do lakes act as unique evolutionary crucibles in contrast to marine systems? The speciation of cichlid fishes in present-day African lakes appears to be very high and is attributed to the diversity of environments found in large rift lakes. Is this true of all ancient lakes or just large rift lakes? The longevity of a lake system may be an important factor in allowing speciation and evolutionary processes to occur; marine systems are limited only in the existence of environments as controlled by tectonics and sea level changes, on the order of tens of millions of years. Rift lakes are normally the longest lived in the millions of years. Perhaps there are only certain types of lakes in which speciation of

  19. Gluconeogenesis during starvation and refeeding phase is affected by previous dietary carbohydrates levels and a glucose stimuli during early life in Siberian sturgeon (Acipenser baerii

    Directory of Open Access Journals (Sweden)

    Xiaofang Liang

    2017-09-01

    Full Text Available Gluconeogenesis responses was assessed during a short starvation period and subsequent refeeding in Siberian sturgeon (Acipenser baerii previously fed different dietary carbohydrates levels and experienced to a glucose stimuli during early life. The sturgeon larvae were previously fed either a high glucose diet (G or a low glucose diet (F from the first feeding to yolk absorption (8 to 12 d post-hatching [dph]. Each group of fish was sub-divided into 2 treatments at 13 dph and was fed either a high-carbohydrate diet (H or a low carbohydrate diet (L until 20 wk. In the current study, the fish in 4 groups (GL, FL, GH and FH were experienced to starvation for 21 d following by re-feeding of their corresponding diets for 21 d. Fish were sampled at postprandial 6 and 24 h before starvation (P6h and P24h, starvation 7, 14 and 21 d (S7, S14 and S21 and 1, 7, 14 and 21 d during refeeding (R1, R7, R14 and R21. Plasma samples during refeeding were taken at P6h at each time point. Glycaemia levels, liver and muscle glycogen contents, activities and mRNA levels of hepatic gluconeogenic enzymes were examined. We found that both dietary carbohydrate levels and early glucose stimuli significantly affected the metabolic responses to starvation and refeeding in Siberian sturgeon (P < 0.05. During prolonged starvation, Siberian sturgeon firstly mobilized the liver glycogen and then improved gluconeogenesis when the dietary carbohydrates were abundant, whereas preserved the liver glycogen stores at a stable level and more effectively promoted gluconeogenesis when the dietary carbohydrates are absent to maintain glucose homoeostasis. During refeeding, as most teleostean, Siberian sturgeon failed controlling the activities and mRNA levels of phosphoenolpyruvate carboxykinase cytosolic forms (PEPCK-C, fructose-1,6-bisphosphatase (FBPase, but particularly controlled phosphoenolpyruvate carboxykinase mitochondrial forms (PEPCK-M activities and mRNA expression

  20. Visual Basic, Excel-based fish population modeling tool - The pallid sturgeon example

    Science.gov (United States)

    Moran, Edward H.; Wildhaber, Mark L.; Green, Nicholas S.; Albers, Janice L.

    2016-02-10

    The model presented in this report is a spreadsheet-based model using Visual Basic for Applications within Microsoft Excel (http://dx.doi.org/10.5066/F7057D0Z) prepared in cooperation with the U.S. Army Corps of Engineers and U.S. Fish and Wildlife Service. It uses the same model structure and, initially, parameters as used by Wildhaber and others (2015) for pallid sturgeon. The difference between the model structure used for this report and that used by Wildhaber and others (2015) is that variance is not partitioned. For the model of this report, all variance is applied at the iteration and time-step levels of the model. Wildhaber and others (2015) partition variance into parameter variance (uncertainty about the value of a parameter itself) applied at the iteration level and temporal variance (uncertainty caused by random environmental fluctuations with time) applied at the time-step level. They included implicit individual variance (uncertainty caused by differences between individuals) within the time-step level.The interface developed for the model of this report is designed to allow the user the flexibility to change population model structure and parameter values and uncertainty separately for every component of the model. This flexibility makes the modeling tool potentially applicable to any fish species; however, the flexibility inherent in this modeling tool makes it possible for the user to obtain spurious outputs. The value and reliability of the model outputs are only as good as the model inputs. Using this modeling tool with improper or inaccurate parameter values, or for species for which the structure of the model is inappropriate, could lead to untenable management decisions. By facilitating fish population modeling, this modeling tool allows the user to evaluate a range of management options and implications. The goal of this modeling tool is to be a user-friendly modeling tool for developing fish population models useful to natural resource

  1. Ecology of Meromictic Lakes

    NARCIS (Netherlands)

    Gulati, R.D.; Zadereev, E.S.; Degermendzhy, A.G.

    2017-01-01

    This volume presents recent advances in the research on meromictic lakes and a state-of-the art overview of this area. After an introduction to the terminology and geographic distribution of meromictic lakes, three concise chapters describe their physical, chemical and biological features. The

  2. Effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and status and habitat requirements of white sturgeon populations in the Columbia and Snake Rivers upstream from McNary Dam

    International Nuclear Information System (INIS)

    Beamesderfer, R.C.; Nigro, A.A.

    1993-12-01

    This report details activities during the first year of Phase II of this sturgeon research. In Phase I, the authors assessed the status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam. Phase II will examine the effects on white sturgeon productivity of mitigative measures recommended in Phase I. The status and habitat requirements of white sturgeon populations upstream from McNary Dam will also be examined in Phase II. The study is a cooperative effort by the Oregon Department of Fish and Wildlife, Washington Department of Fisheries, US Fish and Wildlife Service, and National Marine Fisheries Service. Work during the past year has focused on: (1) analysis of results of limited sampling conducted in 1992, (2) submission of Phase I results to the peer-review literature to ensure widespread dissemination, clarity of presentation, and credibility of findings, and (3) preparation for additional field work in 1993. In report sections A to D, each agency reports 1992 results if applicable and the current status of manuscripts. Results of field work conducted in 1993 will be reported in the 1994 annual report

  3. Effects of Mitigative Measures on Productivity of White Sturgeon Populations in the Columbia River Downstream from McNary Dam; Determine Status and Habitat Requirements of White Sturgeon Populations in the Columbia and Snake Rivers Upstream from McNary Dam, 1995-1996 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Rien, Thomas A.; Beiningen, Kirk T. (Oregon Department of Fish and Wildlife, Portland, OR)

    1997-07-01

    This project began in July 1986 and is a cooperative effort of federal, state, and tribal fisheries entities to determine (1) the status and habitat requirements, and (2) effects of mitigative measures on productivity of white sturgeon populations in the lower Colombia and Snake rivers.

  4. Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

    African Journals Online (AJOL)

    Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

  5. Lake trout in northern Lake Huron spawn on submerged drumlins

    Science.gov (United States)

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  6. Effect of morphological fin curl on the swimming performance and station-holding ability of juvenile shovelnose sturgeon

    Science.gov (United States)

    Deslauriers, David; Johnston, Ryan; Chipps, Steven R.

    2016-01-01

    We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index < 8%. Fin-curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.

  7. STUDIES REGARDING THE PRESENCE OF THE PATHOGENS BACTERIA INTO A RECIRCULATING SYSTEM OF BELUGA STURGEON INTENSIVE REARING

    Directory of Open Access Journals (Sweden)

    ANGELICA DOCAN

    2008-10-01

    Full Text Available Recirculating aquaculture offers good potential for successful fish farming since is often independent of environmental conditions. Maintaining healthy fish in a recirculating system involves establishing adequate dissolved oxygen levels, removal of solid wastes, and sufficient ammonia nitrification to assure optimal rearing conditions. Neglecting these, the fish immune system will depress, the facultative pathogen germs will be able to provoke important disease outbreaks into cultured biomass, as was happened in our recirculating pilot system. In this study are presented the pathological aspects registered to the beluga sturgeon of 1 year, reared into our recirculating pilot system, pathological aspects generated by a haemorrhagic bacterial septicaemia which was manifested in the conditions of low concentrations of DO. The disease was diagnosed to the affected fish through anatomopathological and clinical exam, haematological exam and microbiological exam.

  8. Biological effects in natural populations of small rodents in radiocontaminated areas. The frequency of bone marrow polyploid cells in bank voles in different years following the Chernobyl accident

    International Nuclear Information System (INIS)

    Ryabokon', N.I.

    1999-01-01

    On the basis of metaphase analysis results the peculiarities of dynamics of genome mutation frequency (polyploid cells) were studied in bone marrow of bank voles inhibiting the areas with different contamination level due to the Chernobyl accident (8-1526 kBq/m 2 for 137 Cs) in 1986-1991. Unexpectedly high frequencies of polyploid cells exceeding the pre-accidental level by factor of 10 1 -10 3 were recorded in all populations studied. Relationship between the frequency of parameter studied and the concentration of radionuclides incorporated in animal carcasses was proved. Statistically significant rise in the frequency of genome mutations with the time was revealed up to 1991, i.e. approximately to 12-th post-accidental animal generation [ru

  9. Using drift nets to capture early life stages and monitor spawning of the yangtze river chinese sturgeon (Acipenser sinensis)

    Science.gov (United States)

    Wei, Q.W.; Kynard, B.; Yang, D.G.; Chen, X.H.; Du, H.; Shen, L.; Zhang, H.

    2009-01-01

    A sampling system for capturing sturgeon eggs using a D-shaped bottom anchored drift net was used to capture early life stages (ELS) of Chinese sturgeon, Acipenser sinensis, and monitor annual spawning success at Yichang on the Yangtze River, 1996-2004, before and just after the Three Gorges Dam began operation. Captured were 96 875 ELS (early life stages: eggs, yolk-sac larvae = eleuthero embryos, and larvae); most were eggs and only 2477 were yolk-sac larvae. Most ELS were captured in the main river channel and inside the bend at the Yichang spawning reach. Yolk-sac larvae were captured for a maximum of 3 days after hatching began, indicating quick dispersal downstream. The back-calculated day of egg fertilization over the eight years indicated a maximum spawning window of 23 days (20 October-10 November). Spawning in all years was restricted temporally, occurred mostly at night and during one or two spawning periods, each lasting several days. The brief temporal spawning window may reduce egg predation by opportunistic predators by flooding the river bottom with millions of eggs. During 1996-2002, the percentage of fertilized eggs in an annual 20-egg sample was between 63.5 to 94.1%; however, in 2003 the percentage fertilized was only 23.8%. This sudden decline may be related to the altered environmental conditions at Yichang caused by operation of the Three Gorges Dam. Further studies are needed to monitor spawning and changes in egg fertilization in this threatened population. ?? 2009 Blackwell Verlag GmbH.

  10. Lactococcus lactis subsp. lactis infection in Bester sturgeon, a cultured hybrid of Huso huso × Acipenser ruthenus, in Taiwan.

    Science.gov (United States)

    Chen, Ming-Hui; Hung, Shao-Wen; Shyu, Ching-Lin; Lin, Cheng-Chung; Liu, Pan-Chen; Chang, Chen-Hsuan; Shia, Wei-Yau; Cheng, Ching-Fu; Lin, Shiun-Long; Tu, Ching-Yu; Lin, Yu-Hsing; Wang, Way-Shyan

    2012-10-01

    Approximately 5300 hybrid sturgeons with an average body weight of 600-800 g were farmed in 3 round tankers measuring 3m in diameter each containing 28,000 L of aerated groundwater. According to the owner's description, the diseased fish had anorexia, pale body color, and reddish spots on the abdomen. The morbidity and lethality rates in this outbreak were about 70% (3706/5300) and 100% (3706/3706), respectively. The clinical examination revealed enteritis, enlarged abdomen, and rapid respiration rate. The gross findings revealed a volume of about 4 mL of ascites. The histopathological examination showed multiple massive, hemorrhagic or coagulative necrotic foci in the liver and spleen. Furthermore, there was diffuse infiltration of glycogen in hepatic cells, and a few polymorphonuclear and mononuclear leucocytes were observed surrounding the spleen. Some bacterial clumps were noted around the necrotic foci. We also observed that there was moderate to severe, acute, multifocal, coagulative necrosis in the renal parenchyma, with some necrotic foci present beneath the margin of the kidney. Additionally, multifocal, coagulative necrosis was found in the pancreas. Results of microbiologic examinations, including biochemical characteristics, PCR amplification of 16S rRNA gene, sequencing and comparison, and phylogenetic analysis, revealed the pathogen of this infection was Lactococcus lactis subsp. lactis, and based on the results of an antimicrobial agent sensitivity test the bacterium was only sensitive to ampicillin and florfenicol. Additionally, results of in vivo experimental infections in hybrid tilapia showed that 1×10(8) and 1×10(9) CFU/mL of our isolate caused death in all fish and LD(50) values ranged from 10(2) to 10(5) CFU/mL. To the best of the authors' knowledge, this is the first reported case of Lactococcus lactis subsp. lactis infection in hybrid sturgeon. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam

    International Nuclear Information System (INIS)

    Nigro, A.A.

    1991-09-01

    We report on our progress from April 1990 through March 1991 on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW), Washington Department of Fisheries (WDF), US Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS). Study objectives addressed by each agency are to describe the life history and population dynamics of subadults and adults between Bonneville and McNary dams and evaluate the need and identify potential methods for protecting, mitigating and enhancing populations downstream from NcNary Dam; to describe the white sturgeon recreational fishery between Bonneville and McNary dams, describe reproductive and early life history characteristics downstream from Bonneville Dam and describe life history and population dynamics of subadults and adults downstream from Bonneville Dam; to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available between Bonneville and McNary dams; and to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available downstream from Bonneville Dam. Our approach is to work concurrently downstream and upstream from Bonneville Dam. Upstream from Bonneville Dam we began work in the Dalles Reservoir in 1987 and expanded efforts to Bonneville Reservoir in 1988 and John Day Reservoir in 1989. Highlights of results of this work in the Dalles, Bonneville and John Day reservoirs are included in the four pages included in this report

  12. White Sturgeon Mitigation and Restoration in the Columbia and Snake Rivers Upstream from Bonneville Dam; Annual Progress Report, April 2007 - March 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Mallette, Christine [Oregon Department of Fish and Wildlife

    2009-07-28

    We report on our progress from April 2007 through March 2008 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW; Report A), Washington Department of Fish and Wildlife (WDFW; Report B), Columbia River Inter-Tribal Fish Commission (CRITFC; Report C), and Montana State University (MSU; Report D). This is a multi-year study with many objectives requiring more than one year to complete; therefore, findings from a given year may be part of more significant findings yet to be reported.

  13. Genomic and transcriptomic alterations following intergeneric hybridization and polyploidization in the Chrysanthemum nankingense×Tanacetum vulgare hybrid and allopolyploid (Asteraceae).

    Science.gov (United States)

    Qi, Xiangyu; Wang, Haibin; Song, Aiping; Jiang, Jiafu; Chen, Sumei; Chen, Fadi

    2018-01-01

    Allopolyploid formation involves two major events: interspecific hybridization and polyploidization. A number of species in the Asteraceae family are polyploids because of frequent hybridization. The effects of hybridization on genomics and transcriptomics in Chrysanthemum nankingense×Tanacetum vulgare hybrids have been reported. In this study, we obtained allopolyploids by applying a colchicine treatment to a synthesized C. nankingense × T. vulgare hybrid. Sequence-related amplified polymorphism (SRAP), methylation-sensitive amplification polymorphism (MSAP), and high-throughput RNA sequencing (RNA-Seq) technologies were used to investigate the genomic, epigenetic, and transcriptomic alterations in both the hybrid and allopolyploids. The genomic alterations in the hybrid and allopolyploids mainly involved the loss of parental fragments and the gain of novel fragments. The DNA methylation level of the hybrid was reduced by hybridization but was restored somewhat after polyploidization. There were more significant differences in gene expression between the hybrid/allopolyploid and the paternal parent than between the hybrid/allopolyploid and the maternal parent. Most differentially expressed genes (DEGs) showed down-regulation in the hybrid/allopolyploid relative to the parents. Among the non-additive genes, transgressive patterns appeared to be dominant, especially repression patterns. Maternal expression dominance was observed specifically for down-regulated genes. Many methylase and methyltransferase genes showed differential expression between the hybrid and parents and between the allopolyploid and parents. Our data indicate that hybridization may be a major factor affecting genomic and transcriptomic changes in newly formed allopolyploids. The formation of allopolyploids may not simply be the sum of hybridization and polyploidization changes but also may be influenced by the interaction between these processes.

  14. Species-Level Phylogeny and Polyploid Relationships in Hordeum (Poaceae) Inferred by Next-Generation Sequencing and In Silico Cloning of Multiple Nuclear Loci.

    Science.gov (United States)

    Brassac, Jonathan; Blattner, Frank R

    2015-09-01

    Polyploidization is an important speciation mechanism in the barley genus Hordeum. To analyze evolutionary changes after allopolyploidization, knowledge of parental relationships is essential. One chloroplast and 12 nuclear single-copy loci were amplified by polymerase chain reaction (PCR) in all Hordeum plus six out-group species. Amplicons from each of 96 individuals were pooled, sheared, labeled with individual-specific barcodes and sequenced in a single run on a 454 platform. Reference sequences were obtained by cloning and Sanger sequencing of all loci for nine supplementary individuals. The 454 reads were assembled into contigs representing the 13 loci and, for polyploids, also homoeologues. Phylogenetic analyses were conducted for all loci separately and for a concatenated data matrix of all loci. For diploid taxa, a Bayesian concordance analysis and a coalescent-based dated species tree was inferred from all gene trees. Chloroplast matK was used to determine the maternal parent in allopolyploid taxa. The relative performance of different multilocus analyses in the presence of incomplete lineage sorting and hybridization was also assessed. The resulting multilocus phylogeny reveals for the first time species phylogeny and progenitor-derivative relationships of all di- and polyploid Hordeum taxa within a single analysis. Our study proves that it is possible to obtain a multilocus species-level phylogeny for di- and polyploid taxa by combining PCR with next-generation sequencing, without cloning and without creating a heavy load of sequence data. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

  15. Stocking density affects the growth performance and metabolism of Amur sturgeon by regulating expression of genes in the GH/IGF axis

    Science.gov (United States)

    Ren, Yuanyuan; Wen, Haishen; Li, Yun; Li, Jifang

    2017-07-01

    The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three different stocking densities (low stocking density, LSD: 5.5 kg/m3; medium stocking density, MSD: 8.0 kg/m3; and high stocking density, HSD: 11.0 kg/m3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower final body weight and specific growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2 (IGF-2), while the concentrations of serum growth hormone (GH) and insulin-like growth factor 1 (IGF-1) decreased in the HSD group. The full-length cDNAs of GH and IGF-2 genes (995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor (GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively affects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.

  16. The structure of the conus arteriosus of the sturgeon (Acipenser naccarii) heart: II. The myocardium, the subepicardium, and the conus-aorta transition.

    Science.gov (United States)

    Icardo, José M; Colvee, Elvira; Cerra, Maria C; Tota, Bruno

    2002-12-01

    Sturgeons constitute a family of living "fossil" fish whose heart is related to that of other ancient fish and the elasmobranches. We have undertaken a systematic study of the structure of the sturgeon heart aimed at unraveling the relationship between the heart structure and the adaptive evolutionary changes. In a related paper, data were presented on the conus valves and the subendocardium. Here, the structure of the conus myocardium, the subepicardial tissue, and the conus-aorta transition were studied by conventional light, transmission, and scanning electron microscopy. In addition, actin localization by fluorescent phalloidin was used. The conus myocardium is organized into bundles whose spatial organization changes along the conus length. The variable orientation of the myocardial cell bundles may be effective in emptying the conus lumen during contraction and in preventing reflux of blood. Myocardial cell bundles are separated by loose connective tissue that contains collagen and elastin fibers, vessels, and extremely flat cells separating the cell bundles and enclosing blood vessels and collagen fibers. The ultrastructure of the myocardial cells was found to be very similar to that of other fish groups, suggesting that it is largely conservative. The subepicardium is characterized by the presence of nodular structures that contain lympho-hemopoietic (thymus-like) tissue in the young sturgeons and a large number of lymphocytes after the sturgeons reach sexual maturity. This tissue is likely implicated in the establishment and maintenance of the immune responses. The intrapericardial ventral aorta shows a middle layer of circumferentially oriented cells and internal and external layers with cells oriented longitudinally. Elastin fibers completely surround each smooth muscle cell, and the spaces between the different layers are occupied by randomly arranged collagen bundles. The intrapericardial segment of the ventral aorta is a true transitional segment

  17. Yellowstone Lake Nanoarchaeota

    Directory of Open Access Journals (Sweden)

    Scott eClingenpeel

    2013-09-01

    Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

  18. Whiting in Lake Michigan

    Science.gov (United States)

    2002-01-01

    Satellites provide a view from space of changes on the Earth's surface. This series of images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the Orbview-2 satellite shows the dramatic change in the color of Lake Michigan during the summer. The bright color that appears in late summer is probably caused by calcium carbonate-chalk-in the water. Lake Michigan always has a lot of calcium carbonate in it because the floor of the lake is limestone. During most of the year the calcium carbonate remains dissolved in the cold water, but at the end of summer the lake warms up, lowering the solubility of calcium carbonate. As a result, the calcium carbonate precipitates out of the water, forming clouds of very small solid particles that appear as bright swirls from above. The phenomenon is appropriately called a whiting event. A similar event occured in 1999, but appears to have started later and subsided earlier. It is also possible that a bloom of the algae Microcystis is responsible for the color change, but unlikely because of Lake Michigan's depth and size. Microcystis blooms have occured in other lakes in the region, however. On the shore of the lake it is possible to see the cities of Chicago, Illinois, and Milwaukee, Wisconsin. Both appear as clusters of gray-brown pixels. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  19. Ecology of playa lakes

    Science.gov (United States)

    Haukos, David A.; Smith, Loren M.

    1992-01-01

    Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

  20. Status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam. Volume 2: Supplemental papers and data documentation; Final report

    International Nuclear Information System (INIS)

    Beamesderfer, R.C.; Nigro, A.A.

    1995-01-01

    This is the final report for research on white sturgeon Acipenser transmontanus from 1986--92 and conducted by the National Marine Fisheries Service (NMFS), Oregon Department of Fish and Wildlife (ODFW), US Fish and Wildlife Service (USFWS), and Washington Department of Fisheries (WDF). Findings are presented as a series of papers, each detailing objectives, methods, results, and conclusions for a portion of this research. This volume includes supplemental papers which provide background information needed to support results of the primary investigations addressed in Volume 1. This study addresses measure 903(e)(1) of the Northwest Power Planning Council's 1987 Fish and Wildlife Program that calls for ''research to determine the impact of development and operation of the hydropower system on sturgeon in the Columbia River Basin.'' Study objectives correspond to those of the ''White Sturgeon Research Program Implementation Plan'' developed by BPA and approved by the Northwest Power Planning Council in 1985. Work was conducted on the Columbia River from McNary Dam to the estuary

  1. Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington-Part I: exposure characterization.

    Science.gov (United States)

    Frew, John A; Sadilek, Martin; Grue, Christian E

    2015-11-01

    Willapa Bay and Grays Harbor (WA, USA) comprise the largest region of commercial oyster cultivation on the Pacific Coast. The activities of 2 species of burrowing shrimp impair growth and survival of oysters reared on the intertidal mudflats. To maintain viable harvests, the oyster growers have proposed controlling the shrimp by applying the insecticide imidacloprid onto harvested beds. Green sturgeon (listed in the Endangered Species Act) forage on burrowing shrimp and could be exposed to imidacloprid in the sediment porewater and through consumed prey. Studies were conducted to evaluate the likelihood that green sturgeon would be exposed to imidacloprid and to characterize the subsequent environmental exposure. Comparisons between treated and untreated control beds following test application of the insecticide suggested that green sturgeon fed opportunistically on imidacloprid-impaired shrimp. The highest interpolated imidacloprid residue concentrations in field samples following chemical application were 27.8 µg kg(-1) and 31.4 µg kg(-1) in porewater and shrimp, respectively. Results from modeled branchial and dietary uptake, based on conservative assumptions, indicated that the porewater exposure route had the greatest contribution to systemic absorption of imidacloprid. The highest average daily uptake from porewater (177.9 µg kg(-1) body wt) was 9.5-fold greater than total dietary uptake (18.8 µg kg(-1) body wt). Concentrations and durations of exposure would be lower than the levels expected to elicit direct acute or chronic toxic effects. © 2015 SETAC.

  2. Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington--Part II: controlled exposure studies.

    Science.gov (United States)

    Frew, John A; Grue, Christian E

    2015-11-01

    The activities of 2 species of burrowing shrimp have a negative impact on the growth and survival of oysters reared on intertidal mudflats in Willapa Bay and Grays Harbor, Washington (USA). To maintain viable harvests, oyster growers proposed the application of the neonicotinoid insecticide imidacloprid onto harvested beds for the control of burrowing shrimp. In test applications, water column concentrations of imidacloprid were relatively low and dissipated rapidly. The foraging activities of the green sturgeon (listed in the US Endangered Species Act) could result in exposure to higher, more sustained imidacloprid concentrations within sediment porewater and from the consumption of contaminated shrimp. Controlled experiments were conducted using surrogate white sturgeon to determine acute and chronic effect concentrations, to examine overt effects at more environmentally realistic concentrations and durations of exposure, and to assess chemical depuration. The 96-h median lethal concentration was 124 mg L(-1) , and the predicted 35-d no-observed-adverse-effect concentration was 0.7 mg L(-1) . No overt effects were observed following environmentally relevant exposures. Imidacloprid half-life in plasma was greater than 32 h. Measured concentrations of imidacloprid in porewater were significantly lower than the derived acute and chronic effect concentrations for white sturgeon. Exposure risk quotients were calculated using the effect concentrations and estimated environmental exposure. The resulting values were considerably below the level of concern for direct effects from either acute or chronic exposure to an endangered species. © 2015 SETAC.

  3. A fully-stochasticized, age-structured population model for population viability analysis of fish: Lower Missouri River endangered pallid sturgeon example

    Science.gov (United States)

    Wildhaber, Mark L.; Albers, Janice; Green, Nicholas; Moran, Edward H.

    2017-01-01

    We develop a fully-stochasticized, age-structured population model suitable for population viability analysis (PVA) of fish and demonstrate its use with the endangered pallid sturgeon (Scaphirhynchus albus) of the Lower Missouri River as an example. The model incorporates three levels of variance: parameter variance (uncertainty about the value of a parameter itself) applied at the iteration level, temporal variance (uncertainty caused by random environmental fluctuations over time) applied at the time-step level, and implicit individual variance (uncertainty caused by differences between individuals) applied within the time-step level. We found that population dynamics were most sensitive to survival rates, particularly age-2+ survival, and to fecundity-at-length. The inclusion of variance (unpartitioned or partitioned), stocking, or both generally decreased the influence of individual parameters on population growth rate. The partitioning of variance into parameter and temporal components had a strong influence on the importance of individual parameters, uncertainty of model predictions, and quasiextinction risk (i.e., pallid sturgeon population size falling below 50 age-1+ individuals). Our findings show that appropriately applying variance in PVA is important when evaluating the relative importance of parameters, and reinforce the need for better and more precise estimates of crucial life-history parameters for pallid sturgeon.

  4. [Protein kinase A inhibitor H-89 blocks polyploidization of SP600125-induced CMK cells by regulating phosphorylation of ribosomal protein S6 kinase 1].

    Science.gov (United States)

    Zhao, Song; Yang, Jingang; Li, Changling; Xing, Sining; Yu, Ying; Liu, Shuo; Pu, Feifei; Ma, Dongchu

    2016-10-01

    Objective To investigate the regulatory effect of post-translation modification of ribosomal protein S6 kinase 1 (S6K1) on the polyploidization of megakaryocytes. Methods SP600125, a c-Jun N-terminal kinase (JNK) inhibitor, and H-89, a cAMP-dependent protein kinase (PKA) inhibitor, were used to treat CMK cells separately or in combination. With propidium iodide (PI) to dye DNA in the treated cells, the relative DNA content was detected by flow cytometry, and then the DNA polyploidy was analyzed. The change of expression and phosphorylation of ribosomal protein S6 kinase 1 (S6K1), an important mammalian target of rapamycin (mTOR) downstream target molecule, was analyzed by Western blotting. Molecular docking study and kinase activity assay were performed to analyze the combination of H-89 with S6K1 and the effect of H-89 on the activity of S6K1 kinase. Results SP600125 induced CMK cell polyploidization in a time-dependent and dose-dependent manner. At the same time, it increased the phosphorylation of S6K1 at Thr421/Ser424 and decreased the phosphorylation of S6K1 at Thr389. H-89 not only blocked polyploidization, but also decreased the phosphorylation of S6K1 at Thr421/Ser424 and increased the phosphorylation of S6K1 at Thr389. Molecular docking and kinase activity assay showed that H-89 occupied the ATP binding sites of S6K1 and inhibited its activity. Noticeably, both H-89 and SP600125 inhibited the activity of PKA. Moreover, the two drugs further inhibited the activity of PKA when used together. Therefore, these data indicated that H-89 blocked the SP600125-induced polyploidization of CMK cells mainly by changing S6K1 phosphorylation state, rather than its inhibitory effect on PKA. Conclusion H-89 can block the polyploidization of SP600125-induced CMK cells by regulating S6K1 phosphorylation state.

  5. A next-generation sequencing method for overcoming the multiple gene copy problem in polyploid phylogenetics, applied to Poa grasses

    Directory of Open Access Journals (Sweden)

    Robin Charles

    2011-03-01

    Full Text Available Abstract Background Polyploidy is important from a phylogenetic perspective because of its immense past impact on evolution and its potential future impact on diversification, survival and adaptation, especially in plants. Molecular population genetics studies of polyploid organisms have been difficult because of problems in sequencing multiple-copy nuclear genes using Sanger sequencing. This paper describes a method for sequencing a barcoded mixture of targeted gene regions using next-generation sequencing methods to overcome these problems. Results Using 64 3-bp barcodes, we successfully sequenced three chloroplast and two nuclear gene regions (each of which contained two gene copies with up to two alleles per individual in a total of 60 individuals across 11 species of Australian Poa grasses. This method had high replicability, a low sequencing error rate (after appropriate quality control and a low rate of missing data. Eighty-eight percent of the 320 gene/individual combinations produced sequence reads, and >80% of individuals produced sufficient reads to detect all four possible nuclear alleles of the homeologous nuclear loci with 95% probability. We applied this method to a group of sympatric Australian alpine Poa species, which we discovered to share an allopolyploid ancestor with a group of American Poa species. All markers revealed extensive allele sharing among the Australian species and so we recommend that the current taxonomy be re-examined. We also detected hypermutation in the trnH-psbA marker, suggesting it should not be used as a land plant barcode region. Some markers indicated differentiation between Tasmanian and mainland samples. Significant positive spatial genetic structure was detected at Conclusions Our results demonstrate that 454 sequencing of barcoded amplicon mixtures can be used to reliably sample all alleles of homeologous loci in polyploid species and successfully investigate phylogenetic relationships among

  6. Halls Lake 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salt marsh habitats along the shoreline of Halls Lake are threatened by wave erosion, but the reconstruction of barrier islands to reduce this erosion will modify or...

  7. Lake Level Reconstructions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past lake levels, mostly related to changes in moisture balance (evaporation-precipitation). Parameter keywords describe what was measured in this data...

  8. The Key Lake project

    International Nuclear Information System (INIS)

    Glattes, G.

    1985-01-01

    Aspects of project financing for the share of the Canadian subsidiary of Uranerzbergbau-GmbH, Bonn, in the uranium mining and milling facility at Key Lake, Saskatchewan, by a Canadian bank syndicate. (orig.) [de

  9. Great Lakes Ice Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the 2001/2002...

  10. Foy Lake paleodiatom data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Percent abundance of 109 diatom species collected from a Foy Lake (Montana, USA) sediment core that was sampled every ∼5–20 years, yielding a ∼7 kyr record over 800...

  11. Dragon Lake, Siberia

    Science.gov (United States)

    2002-01-01

    Nicknamed 'Dragon Lake,' this body of water is formed by the Bratskove Reservoir, built along the Angara river in southern Siberia, near the city of Bratsk. This image was acquired in winter, when the lake is frozen. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on December 19, 1999. This is a natural color composite image made using blue, green, and red wavelengths. Image provided by the USGS EROS Data Center Satellite Systems Branch

  12. Lake Chad, Chad, Africa

    Science.gov (United States)

    1992-01-01

    Hydrologic and ecologic changes in the Lake Chad Basin are shown in this Oct 1992 photograph. In space photo documentation, Lake Chad was at its greatest area extent (25,000 sq. km.) during Gemini 9 in June 1966 (see S66-38444). Its reduction during the severe droughts from 1968 to 1974 was first noted during Skylab (1973-1974). After the drought began again in 1982, the lake reached its minimum extent (1,450 sq. km.) in Space Shuttle photographs taken in 1984 and 1985. In this STS-52 photograph, Lake Chad has begun to recover. The area of the open water and interdunal impoundments in the southern basin (the Chari River Basin) is estimated to be 1,900 to 2100 sq. km. Note the green vegetation in the valley of the K'Yobe flow has wetted the northern lake basin for the first time in several years. There is evidence of biomass burning south of the K'Yobe Delta and in the vegetated interdunal areas near the dike in the center of the lake. Also note the dark 'Green Line' of the Sahel (the g

  13. Resilience and Restoration of Lakes

    Directory of Open Access Journals (Sweden)

    Stephen R. Carpenter

    1997-06-01

    Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

  14. Is Lake Chabot Eutrophic?

    Science.gov (United States)

    Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

    2013-12-01

    Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

  15. Glacial lake inventory and lake outburst potential in Uzbekistan.

    Science.gov (United States)

    Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

    2017-08-15

    Climate change has been