WorldWideScience

Sample records for invasive estuarine snail

  1. Parasites reduce food web robustness because they are sensitive to secondary extinction as illustrated by an invasive estuarine snail

    Science.gov (United States)

    Lafferty, Kevin D.; Kuris, Armand M.

    2009-01-01

    A robust food web is one in which few secondary extinctions occur after removing species. We investigated how parasites affected the robustness of the Carpinteria Salt Marsh food web by conducting random species removals and a hypothetical, but plausible, species invasion. Parasites were much more likely than free-living species to suffer secondary extinctions following the removal of a free-living species from the food web. For this reason, the food web was less robust with the inclusion of parasites. Removal of the horn snail, Cerithidea californica, resulted in a disproportionate number of secondary parasite extinctions. The exotic Japanese mud snail, Batillaria attramentaria, is the ecological analogue of the native California horn snail and can completely replace it following invasion. Owing to the similarities between the two snail species, the invasion had no effect on predator–prey interactions. However, because the native snail is host for 17 host-specific parasites, and the invader is host to only one, comparison of a food web that includes parasites showed significant effects of invasion on the native community. The hypothetical invasion also significantly reduced the connectance of the web because the loss of 17 native trematode species eliminated many links.

  2. Effects of an invasive ant on land snails in the Ogasawara Islands.

    Science.gov (United States)

    Uchida, Shota; Mori, Hideaki; Kojima, Tsubasa; Hayama, Kayo; Sakairi, Yuko; Chiba, Satoshi

    2016-12-01

    We investigated how Pheidole megacephala has affected endemic achatinellid snails because these snails are excellent indicators of the impact of ants and they have high conservation value in Ogasawara. In 2015 we surveyed the Minamizaki area of Hahajima Island of Ogasawara, designated a core zone of the World Heritage Site, for P. megacephala. In Minamizaki, we determined the distribution and density of achatinellid snails in 2015 and compared these data with their distribution and density in 2005. Land cover in the survey area was entirely forest. We also tested whether P. megacephala preyed on achatinellid snails in the laboratory. P. megacephala was present in the forested areas of Minamizaki. Achatinellid snails were absent in 19 of 39 sites where P. megacephala was present, whereas in other areas densities of the snails ranged from 2 to 228 individuals/site. In the laboratory, P. megacephala carried 6 of 7 achatinellid snails and a broken shell was found. Snail distribution and density comparisons and results of the feeding experiments suggest that the presence of P. megacephala has contributed to the decline of achatinellid snails in forests in the survey area. Yet, P. megacephala is not on the official list of invasive non-native species. Stakeholders using the list of invasive species to develop conservation programs should recognize that invasiveness of non-native species differs depending on the ecosystem and that official lists may not be complete. © 2016 Society for Conservation Biology.

  3. Invasiveness does not predict impact: response of native land snail communities to plant invasions in riparian habitats

    Czech Academy of Sciences Publication Activity Database

    Horáčková, J.; Juřičková, L.; Šizling, A. L.; Jarošík, Vojtěch; Pyšek, Petr

    2014-01-01

    Roč. 9, č. 9 (2014), s. 1-10, e108296 E-ISSN 1932-6203 Institutional support: RVO:67985939 Keywords : plant invasions * land snails * impact Subject RIV: EF - Botanics Impact factor: 3.234, year: 2014

  4. Mesenchymal cells reactivate Snail1 expression to drive three-dimensional invasion programs

    DEFF Research Database (Denmark)

    Rowe, R.G.; Li, X.Y.; Hu, Y.

    2009-01-01

    Epithelial-mesenchymal transition (EMT) is required for mesodermal differentiation during development. The zinc-finger transcription factor, Snail1, can trigger EMT and is sufficient to transcriptionally reprogram epithelial cells toward a mesenchymal phenotype during neoplasia and fibrosis....... Whether Snail1 also regulates the behavior of terminally differentiated mesenchymal cells remains unexplored. Using a Snai1 conditional knockout model, we now identify Snail1 as a regulator of normal mesenchymal cell function. Snail1 expression in normal fibroblasts can be induced by agonists known...... to promote proliferation and invasion in vivo. When challenged within a tissue-like, three-dimensional extracellular matrix, Snail1-deficient fibroblasts exhibit global alterations in gene expression, which include defects in membrane type-1 matrix metalloproteinase (MT1-MMP)-dependent invasive activity...

  5. Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails.

    Directory of Open Access Journals (Sweden)

    Meng Xu

    Full Text Available Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in "100 of the World's Worst Invasive Alien Species"; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest "attack rates" a, shortest "handling times" h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.

  6. Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails

    Science.gov (United States)

    Xu, Meng; Mu, Xidong; Dick, Jaimie T. A.; Fang, Miao; Gu, Dangen; Luo, Du; Zhang, Jiaen; Luo, Jianren; Hu, Yinchang

    2016-01-01

    Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in “100 of the World's Worst Invasive Alien Species”; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest “attack rates” a, shortest “handling times” h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach. PMID:26771658

  7. Large-scale facilitation of a sessile community by an invasive habitat-forming snail

    Science.gov (United States)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Wernberg, Thomas

    2013-12-01

    We provide an example of extensive facilitation of a sessile community throughout an invaded estuary by the invasive snail Batillaria australis. We show that B. australis greatly increases a limiting resource (attachment space) to a community of sessile organisms and estimate that a large part of the invaded estuary now contain ca. 50 times more sessile individuals associated with the invader than all native snails combined. We argue that native snails are unlikely to have been dramatically reduced by the invader, and we therefore suggest that the shell-attached sessile community, as a functional group, has benefitted significantly from this invasion. These results expand the current understanding of how invaded marine systems respond to habitat-forming invaders.

  8. Plant selection and grazing activity of the invasive snail Theba ...

    African Journals Online (AJOL)

    The land snail Theba pisana is a coastal species native to the Mediterranean but has been introduced to regions all over the world, including South Africa and Australia, where it is considered a pest. This study examines the diet of T. pisana and its preference for certain dune plants in the Cape Recife Nature Reserve of ...

  9. Impact of invasive apple snails on the functioning and services of natural and managed wetlands

    Science.gov (United States)

    Horgan, Finbarr G.; Stuart, Alexander M.; Kudavidanage, Enoka P.

    2014-01-01

    At least 14 species of apple snail (Ampullariidae) have been released to water bodies outside their native ranges; however, less than half of these species have become widespread or caused appreciable impacts. We review evidence for the impact of apple snails on natural and managed wetlands focusing on those studies that have elucidated impact mechanisms. Significant changes in wetland ecosystems have been noted in regions where the snails are established: Two species in particular (Pomacea canaliculata and Pomacea maculata) have become major pests of aquatic crops, including rice, and caused enormous increases in molluscicide use. Invasive apple snails have also altered macrophyte community structure in natural and managed wetlands through selective herbivory and certain apple snail species can potentially shift the balance of freshwater ecosystems from clear water (macrophyte dominated) to turbid (plankton dominated) states by depleting densities of native aquatic plants. Furthermore, the introductions of some apple snail species have altered benthic community structure either directly, through predation, or indirectly, through exploitation competition or as a result of management actions. To date much of the evidence for these impacts has been based on correlations, with few manipulative field or mesocosm experiments. Greater attention to impact monitoring is required, and, for Asia in particular, a landscape approach to impact management that includes both natural and managed-rice wetlands is recommended.

  10. Large-scale facilitation of a sessile community by an invasive habitat-forming snail

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Wernberg, Thomas

    2013-01-01

    Abstract We provide an example of extensive facilitation of a sessile community throughout an invaded estuary by the invasive snail Batillaria australis. We show that B. australis greatly increases a limiting resource (attachment space) to a community of sessile organisms and estimate that a large......, as a functional group, has benefitted significantly from this invasion. These results expand the current understanding of how invaded marine systems respond to habitat-forming invaders....

  11. Life table estimates of the invasive snail Physa acuta Draparnaud, 1805, occurring in India

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    Saha Chilka

    2017-03-01

    Full Text Available The life table characteristics of the invasive snail Physa acuta were assessed in the laboratory using the individuals occurring in a newly colonised area in Burdwan, West Bengal, India. Using the changes in the shell length and the body weight of the snails as surrogate, the population growth of the snails was estimated along with longevity and the fecundity schedule. The cohort of P. acuta lived for a maximum of 22 weeks with a life expectancy (ex of 7.27 weeks and the age-specific survivorship being 0.825. Increment of the shell length of the snails complied with the von Bertalanffy growth equation, lt = 11.75(1 − exp−0.17(t−0.06, and the observed and the expected data of the length at time t (lt did not vary significantly (z score = 0.230; P = 0.818; n=20 pairs. Following attainment of sexual maturity between 28 and 42 days, oviposition continued till 20 weeks time, with 0.1-10 eggs laid by each individual. The eggs present per capsule remained between 01 and 11, whilst the net reproductive rate (R0, intrinsic rate of increase (rm and the finite rate of increase (λ were 116.07, 0.1 and 1.11, respectively. The observations are similar to those made earlier on the same species but from African and South American continents. The results of the present observation are pioneer in providing the initial studies about the life history of the invasive snail P. acuta in Indian context. Using the present information as a basis, further studies including long-term population monitoring should be initiated to understand the effects of the invasive snail P. acuta in the freshwater ecosystem of West Bengal, India.

  12. Effects of glyphosate-based herbicides on survival, development and growth of invasive snail (Pomacea canaliculata).

    Science.gov (United States)

    Xu, Yanggui; Li, Adela Jing; Li, Kaibin; Qin, Junhao; Li, Huashou

    2017-12-01

    This study tests the hypotheses that whether environmental relevance of glyphosate would help control spread of the invasive snail Pomacea canaliculata, or benefit its population growth worldwide. Our results showed that glyphosate induced acute toxicity to the snail only at high concentrations (96h LC50 at 175mg/L) unlikely to occur in the environment. Long-term exposures to glyphosate at sublethal levels (20 and 120mg/L) caused inhibition of food intake, limitation of growth performance and alterations in metabolic profiles of the snail. It is worth noting that glyphosate at 2mg/L benefited growth performance in P. canaliculata. Chronic exposures of glyphosate significantly enhanced overall metabolic rate and altered catabolism from protein to carbohydrate/lipid mode. Cellular responses in enzyme activities showed that the exposed snails could increase tolerance by their defense system against glyphosate-induced oxidative stress, and adjustment of metabolism to mitigate energy crisis. Our study displayed that sublethal concentrations of glyphosate might be helpful in control of the invasive species by food intake, growth performance and metabolic interruption; whether environmental relevance of glyphosate (≤2mg/L) benefits population growth of P. canaliculata is still inconclusive, which requires further field study. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Invasive Marine and Estuarine Animals of Hawai’i and other Pacific Islands

    Science.gov (United States)

    2005-09-01

    Polychaete 23 1 Bivalve 38 5 DISCUSSION: Marine and estuarine animals Gastropod 32 3 generally considered to be invasive in the state of Nudibranch 2...jellyfish, Phylloriza punctata sidered a nuisance because its nematocysts (image courtesy of Dauphin Island Sea can deliver a painful sting resulting in...Tridacna squamosa Bivalve ST HI GU Venerupis (=Tapes) philippanarum Bivalve ST HI B Amphithalamus inclusus Gastropod ST Boonea cincta Gastropod ST

  14. Drift algae, an invasive snail and elevated temperature reduce ecological performance of a warm-temperate seagrass, through additive effects

    DEFF Research Database (Denmark)

    Hoffle, H.; Wernberg, T.; Thomsen, M. S.

    2012-01-01

    Seagrasses are under pressure from multiple concurrent threats, including rising temperatures, invasive species and nutrient-driven algal accumulations. We quantified the abundance of drift algae and the invasive snail Batillaria australis in 3 Halophila ovalis seagrass beds in the Swan River....... The survey showed that drift algae varied considerably between sites and sampling times, and sites experienced average loads of 0.4 to 0.8 kg fresh wt m(-2) and extreme loads up to 2.5 kg fresh wt m(-2). In contrast, invasive snails were constantly abundant at all sites at all collection times (mean......, suggesting increased risk of hypoxia. Invasive snails reduced the biomass of H. ovalis leaves and roots, increased leaf plastochrone interval and decreased the depth of the sulphide horizon. Finally, elevated temperature increased leaf loss and reduced leaf biomass, and, in the presence of drift algae, also...

  15. Environmental risk assessment for invasive alien species : A case study of apple snails affecting ecosystem services in Europe

    NARCIS (Netherlands)

    Gilioli, Gianni; Schrader, Gritta; Carlsson, Nils; van Donk, Ellen; van Leeuwen, Casper H.A.; Martín, Pablo R.; Pasquali, Sara; Vilà, Montserrat; Vos, Sybren

    2017-01-01

    The assessment of the risk posed by invasive alien species (IAS) to the environment is a component of increasing importance for Pest Risk Analysis. Standardized and comprehensive procedures to assess their impacts on ecosystem services have been developed only recently. The invasive apple snails

  16. Effect of Climate Change on Invasion Risk of Giant African Snail (Achatina fulica Férussac, 1821: Achatinidae) in India.

    Science.gov (United States)

    Sarma, Roshmi Rekha; Munsi, Madhushree; Ananthram, Aravind Neelavara

    2015-01-01

    The Giant African Snail (Achatina fulica) is considered to be one the world's 100 worst invasive alien species. The snail has an impact on native biodiversity, and on agricultural and horticultural crops. In India, it is known to feed on more than fifty species of native plants and agricultural crops and also outcompetes the native snails. It was introduced into India in 1847 and since then it has spread all across the country. In this paper, we use ecological niche modeling (ENM) to assess the distribution pattern of Giant African Snail (GAS) under different climate change scenarios. The niche modeling results indicate that under the current climate scenario, Eastern India, peninsular India and the Andaman and Nicobar Islands are at high risk of invasion. The three different future climate scenarios show that there is no significant change in the geographical distribution of invasion prone areas. However, certain currently invaded areas will be more prone to invasion in the future. These regions include parts of Bihar, Southern Karnataka, parts of Gujarat and Assam. The Andaman and Nicobar and Lakshadweep Islands are highly vulnerable to invasion under changed climate. The Central Indian region is at low risk due to high temperature and low rainfall. An understanding of the invasion pattern can help in better management of this invasive species and also in formulating policies for its control.

  17. Invasive snails and an emerging infectious disease: results from the first national survey on Angiostrongylus cantonensis in China.

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    Shan Lv

    Full Text Available BACKGROUND: Eosinophilic meningitis (angiostrongyliasis caused by Angiostrongylus cantonensis is emerging in mainland China. However, the distribution of A. cantonensis and its intermediate host snails, and the role of two invasive snail species in the emergence of angiostrongyliasis, are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: A national survey pertaining to A. cantonensis was carried out using a grid sampling approach (spatial resolution: 40x40 km. One village per grid cell was randomly selected from a 5% random sample of grid cells located in areas where the presence of the intermediate host snail Pomacea canaliculata had been predicted based on a degree-day model. Potential intermediate hosts of A. cantonensis were collected in the field, restaurants, markets and snail farms, and examined for infection. The infection prevalence among intermediate host snails was estimated, and the prevalence of A. cantonensis within P. canaliculata was displayed on a map, and predicted for non-sampled locations. It was confirmed that P. canaliculata and Achatina fulica were the predominant intermediate hosts of A. cantonensis in China, and these snails were found to be well established in 11 and six provinces, respectively. Infected snails of either species were found in seven provinces, closely matching the endemic area of A. cantonensis. Infected snails were also found in markets and restaurants. Two clusters of A. cantonensis-infected P. canaliculata were predicted in Fujian and Guangxi provinces. CONCLUSIONS/SIGNIFICANCE: The first national survey in China revealed a wide distribution of A. cantonensis and two invasive snail species, indicating that a considerable number of people are at risk of angiostrongyliasis. Health education, rigorous food inspection and surveillance are all needed to prevent recurrent angiostrongyliasis outbreaks.

  18. Invasive Snails and an Emerging Infectious Disease: Results from the First National Survey on Angiostrongylus cantonensis in China

    Science.gov (United States)

    Lv, Shan; Zhang, Yi; Liu, He-Xiang; Hu, Ling; Yang, Kun; Steinmann, Peter; Chen, Zhao; Wang, Li-Ying; Utzinger, Jürg; Zhou, Xiao-Nong

    2009-01-01

    Background Eosinophilic meningitis (angiostrongyliasis) caused by Angiostrongylus cantonensis is emerging in mainland China. However, the distribution of A. cantonensis and its intermediate host snails, and the role of two invasive snail species in the emergence of angiostrongyliasis, are not well understood. Methodology/Principal Findings A national survey pertaining to A. cantonensis was carried out using a grid sampling approach (spatial resolution: 40×40 km). One village per grid cell was randomly selected from a 5% random sample of grid cells located in areas where the presence of the intermediate host snail Pomacea canaliculata had been predicted based on a degree-day model. Potential intermediate hosts of A. cantonensis were collected in the field, restaurants, markets and snail farms, and examined for infection. The infection prevalence among intermediate host snails was estimated, and the prevalence of A. cantonensis within P. canaliculata was displayed on a map, and predicted for non-sampled locations. It was confirmed that P. canaliculata and Achatina fulica were the predominant intermediate hosts of A. cantonensis in China, and these snails were found to be well established in 11 and six provinces, respectively. Infected snails of either species were found in seven provinces, closely matching the endemic area of A. cantonensis. Infected snails were also found in markets and restaurants. Two clusters of A. cantonensis–infected P. canaliculata were predicted in Fujian and Guangxi provinces. Conclusions/Significance The first national survey in China revealed a wide distribution of A. cantonensis and two invasive snail species, indicating that a considerable number of people are at risk of angiostrongyliasis. Health education, rigorous food inspection and surveillance are all needed to prevent recurrent angiostrongyliasis outbreaks. PMID:19190771

  19. Snail immunohistochemical overexpression correlates to recurrence risk in non-muscle invasive bladder cancer: results from a longitudinal cohort study.

    Science.gov (United States)

    Santi, Raffaella; Cai, Tommaso; Nobili, Stefania; Galli, Ilaria Camilla; Amorosi, Andrea; Comperat, Eva; Nesi, Gabriella

    2018-03-10

    The current WHO/ISUP classification and grading system subdivides urothelial tumours into prognostically distinct categories. Understanding the molecular pathways involved in bladder cancer development can improve patient stratification and management. This study aims to investigate the relationship between Snail, Slug and E-cadherin expressions and clinico-pathological features of non-muscle invasive bladder carcinoma (NMIBC). All patients attending the same urological centre from January to May 2002, who were pathologically diagnosed with NMIBC, were enrolled in this longitudinal cohort study. E-cadherin, Snail and Slug protein expressions were assessed by immunohistochemical analysis and compared with follow-up data. The main outcome measures were recurrence and progression rates. The cohort under investigation included 43 patients (38 men and 5 women, mean age 67.7 ± 10.6 years). High-grade (HG) carcinomas were 20/43, with 10 invasive cases (pT1). Low-grade (LG) carcinomas were 23/43, with no invasive cases (pTa). Among the eight HGpTa cases with recurrence, strong Snail expression was detected in six (75%). Out of the 17 LGpTa patients who experienced recurrence, 12 (70.6%) showed strong positivity for Snail. Among the 10 HGpT1 cases, recurrence was observed in 4, of which, 3 (75%) stained intensely for Snail. The Kaplan-Meier curves showed significantly different recurrence rates for patients with strong or weak Snail reactivity (p = 0.027). E-cadherin and Slug expression did not correlate with any of the parameters considered. On multivariate analysis, Snail expression was recognised as an independent prognostic factor for tumour recurrence (p = 0.003). In our study population, Snail immunohistochemical overexpression proved to be related to tumour recurrence in patients affected by NMIBC.

  20. Using ensemble forecasting to examine how climate change promotes worldwide invasion of the golden apple snail (Pomacea canaliculata).

    Science.gov (United States)

    Lei, Juncheng; Chen, Lian; Li, Hong

    2017-08-01

    The golden apple snail, Pomacea canaliculata, is one of the world's 100 most notorious invasive alien species. Knowledge about the critical climate variables that limit the global distribution range of the snail, as well as predictions of future species distributions under climate change, is very helpful for management of snail. In this study, the climatically suitable habitats for this kind of snail under current climate conditions were modeled by biomod2 and projected to eight future climate scenarios (2 time periods [2050s, 2080s] × 2 Representative Concentration Pathways [RCPs; RCP2.6, RCP8.5] × 2 atmospheric General Circulation Models [GCMs; Canadian Centre for Climate Modelling and Analysis (CCCMA), Commonwealth Scientific and Industrial Research Organisation (CSIRO)]). The results suggest that the lowest temperature of coldest month is the critical climate variable to restrict the global distribution range of P. canaliculata. It is predicted that the climatically suitable habitats for P. canaliculata will increase by an average of 3.3% in 2050s and 3.8% in 2080s for the RCP2.6 scenario, while they increase by an average of 8.7% in 2050s and 10.3% in 2080s for the RCP8.5 scenario. In general, climate change in the future may promote the global invasion of the invasive species. Therefore, it is necessary to take proactive measures to monitor and preclude the invasion of this species.

  1. Elevated native terrestrial snail abundance and diversity in association with an invasive understory shrub, Berberis thunbergii, in a North American deciduous forest

    Science.gov (United States)

    Utz, Ryan M.; Pearce, Timothy A.; Lewis, Danielle L.; Mannino, Joseph C.

    2018-01-01

    Invasive terrestrial plants often substantially reshape environments, yet how such invasions affect terrestrial snail assemblages remains understudied. We investigated how snail assemblages in deciduous forest soils with dense Berberis thunbergii (Japanese barberry), an invasive shrub in eastern North America, differ from forest areas lacking the shrub. Leaf litter and soil samples were collected from forest patches with dense B. thunbergii understories and adjacent control areas within two exurban forest tracts in western Pennsylvania, U.S.A. Snails were identified to species and quantified by standard diversity metrics. Contrary to our expectations, snails were significantly more abundant and diverse in B. thunbergii-invaded areas. Despite differences in abundance, the snail community composition did not differ between invaded and control habitats. The terrestrial snail assemblage we observed, which was composed entirely of native species, appears to respond favorably to B. thunbergii invasion and therefore may not be negatively impacted by physicochemical changes to soils typically observed in association with the plant. Such findings could reflect the fact that B. thunbergii likely creates more favorable habitat for snails by creating cooler, more humid, and more alkaline soil environments. However, the snail assemblages we retrieved may consist mostly of species with high tolerance to environmental degradation due to a legacy of land use change and acid deposition in the region.

  2. Development of ten microsatellite loci in the invasive giant African land snail, Achatina (=Lissachatina) fulica Bowdich, 1822

    Science.gov (United States)

    Morrison, Cheryl L.; Springmann, Marcus J.; Iwanowicz, Deborah D.; Wade, Christopher M.

    2015-01-01

    A suite of tetra-nucleotide microsatellite loci were developed for the invasive giant African land snail, Achatina (=Lissachatina) fulica Bowdich, 1822, from Ion Torrent next-generation sequencing data. Ten of the 96 primer sets tested amplified consistently in 30 snails from Miami, Florida, plus 12 individuals representative of their native East Africa, Indian and Pacific Ocean regions. The loci displayed moderate levels of allelic diversity (average 5.6 alleles/locus) and heterozygosity (average 42 %). Levels of genetic diversity were sufficient to produce unique multi-locus genotypes and detect phylogeographic structuring among regional samples. The invasive A. fulica can cause extensive damage to important food crops and natural resources, including native flora and fauna. The loci characterized here will be useful for determining the origins and tracking the spread of invasions, detecting fine-scale spatial structuring and estimating demographic parameters.

  3. Impacts of an invasive snail (Tarebia granifera) on nutrient cycling in tropical streams: the role of riparian deforestation in Trinidad, West Indies.

    Science.gov (United States)

    Moslemi, Jennifer M; Snider, Sunny B; Macneill, Keeley; Gilliam, James F; Flecker, Alexander S

    2012-01-01

    Non-native species and habitat degradation are two major catalysts of environmental change and often occur simultaneously. In freshwater systems, degradation of adjacent terrestrial vegetation may facilitate introduced species by altering resource availability. Here we examine how the presence of intact riparian cover influences the impact of an invasive herbivorous snail, Tarebia granifera, on nitrogen (N) cycling in aquatic systems on the island of Trinidad. We quantified snail biomass, growth, and N excretion in locations where riparian vegetation was present or removed to determine how snail demographics and excretion were related to the condition of the riparian zone. In three Neotropical streams, we measured snail biomass and N excretion in open and closed canopy habitats to generate estimates of mass- and area-specific N excretion rates. Snail biomass was 2 to 8 times greater and areal N excretion rates ranged from 3 to 9 times greater in open canopy habitats. Snails foraging in open canopy habitat also had access to more abundant food resources and exhibited greater growth and mass-specific N excretion rates. Estimates of ecosystem N demand indicated that snail N excretion in fully closed, partially closed, and open canopy habitats supplied 2%, 11%, and 16% of integrated ecosystem N demand, respectively. We conclude that human-mediated riparian canopy loss can generate hotspots of snail biomass, growth, and N excretion along tropical stream networks, altering the impacts of an invasive snail on the biogeochemical cycling of N.

  4. Impacts of an invasive snail (Tarebia granifera on nutrient cycling in tropical streams: the role of riparian deforestation in Trinidad, West Indies.

    Directory of Open Access Journals (Sweden)

    Jennifer M Moslemi

    Full Text Available Non-native species and habitat degradation are two major catalysts of environmental change and often occur simultaneously. In freshwater systems, degradation of adjacent terrestrial vegetation may facilitate introduced species by altering resource availability. Here we examine how the presence of intact riparian cover influences the impact of an invasive herbivorous snail, Tarebia granifera, on nitrogen (N cycling in aquatic systems on the island of Trinidad. We quantified snail biomass, growth, and N excretion in locations where riparian vegetation was present or removed to determine how snail demographics and excretion were related to the condition of the riparian zone. In three Neotropical streams, we measured snail biomass and N excretion in open and closed canopy habitats to generate estimates of mass- and area-specific N excretion rates. Snail biomass was 2 to 8 times greater and areal N excretion rates ranged from 3 to 9 times greater in open canopy habitats. Snails foraging in open canopy habitat also had access to more abundant food resources and exhibited greater growth and mass-specific N excretion rates. Estimates of ecosystem N demand indicated that snail N excretion in fully closed, partially closed, and open canopy habitats supplied 2%, 11%, and 16% of integrated ecosystem N demand, respectively. We conclude that human-mediated riparian canopy loss can generate hotspots of snail biomass, growth, and N excretion along tropical stream networks, altering the impacts of an invasive snail on the biogeochemical cycling of N.

  5. Invasion biology meets parasitology: a case study of parasite spill-back with Egyptian Fasciola gigantica in the invasive snail Pseudosuccinea columella.

    Directory of Open Access Journals (Sweden)

    Daniel S Grabner

    Full Text Available The liver fluke Fasciola gigantica is a trematode parasite of ruminants and humans that occurs naturally in Africa and Asia. Cases of human fascioliasis, attributable at least in part to F. gigantica, are significantly increasing in the last decades. The introduced snail species Galba truncatula was already identified to be an important intermediate host for this parasite and the efficient invader Pseudosuccinea columella is another suspect in this case. Therefore, we investigated snails collected in irrigation canals in Fayoum governorate in Egypt for prevalence of trematodes with focus on P. columella and its role for the transmission of F. gigantica. Species were identified morphologically and by partial sequencing of the cytochrome oxidase subunit I gene (COI. Among all 689 snails found at the 21 sampling sites, P. columella was the most abundant snail with 296 individuals (42.96% and it was also the most dominant species at 10 sites. It was not found at 8 sites. Molecular detection by PCR and sequencing of the ITS1-5.8S-ITS2 region of the ribosomal DNA (rDNA revealed infections with F. gigantica (3.38%, Echinostoma caproni (2.36% and another echinostome (7.09% that could not be identified further according to its sequence. No dependency of snail size and trematode infection was found. Both high abundance of P. columella in the Fayoum irrigation system and common infection with F. gigantica might be a case of parasite spill-back (increased prevalence in local final hosts due to highly susceptible introduced intermediate host species from the introduced P. columella to the human population, explaining at least partly the observed increase of reported fascioliasis-cases in Egypt. Eichhornia crassipes, the invasive water hyacinth, which covers huge areas of the irrigation canals, offers safe refuges for the amphibious P. columella during molluscicide application. As a consequence, this snail dominates snail communities and efficiently transmits

  6. Predation risk affects growth and reproduction of an invasive snail and its lethal effect depends on prey size

    Science.gov (United States)

    Guo, Jing; Martín, Pablo R.; Zhang, Chunxia

    2017-01-01

    The behavior of invasive species under predation risk has been studied extensively, but their growth and reproductive responses have rarely been investigated. We conducted experiments with juveniles and adults of the invasive freshwater snail Pomacea canaliculata, and we observed changes in growth and reproduction in response to predation risk from a caged predator (Trachemys scripta elegans). P. canaliculata produced eggs earlier in the presence of predators and injured conspecifics compared with the control group (no risk), although the total number of egg masses laid by per female was exceeded by that of the controls after 15 days. Egg hatching success noticeably decreased under predation risk, and the incubation period was significantly prolonged; however, the oviposition height of the snails was not affected. A lethal effect of predation risk was detected in juvenile snails but not in adults. The growth of juvenile P. canaliculata was inhibited under predation risk, probably due to a reduction in food intake. Adult females exhibited a greater reduction in growth under predation risk than males, which likely resulted in part from the high reproductive investment of females in egg laying. These results indicate that P. canaliculata snails under predation risk face a trade-off between predator avoidance and growth and reproduction, where the lethal effect of predation risk is linked to the size of the prey. PMID:29136660

  7. Predation risk affects growth and reproduction of an invasive snail and its lethal effect depends on prey size.

    Directory of Open Access Journals (Sweden)

    Jing Guo

    Full Text Available The behavior of invasive species under predation risk has been studied extensively, but their growth and reproductive responses have rarely been investigated. We conducted experiments with juveniles and adults of the invasive freshwater snail Pomacea canaliculata, and we observed changes in growth and reproduction in response to predation risk from a caged predator (Trachemys scripta elegans. P. canaliculata produced eggs earlier in the presence of predators and injured conspecifics compared with the control group (no risk, although the total number of egg masses laid by per female was exceeded by that of the controls after 15 days. Egg hatching success noticeably decreased under predation risk, and the incubation period was significantly prolonged; however, the oviposition height of the snails was not affected. A lethal effect of predation risk was detected in juvenile snails but not in adults. The growth of juvenile P. canaliculata was inhibited under predation risk, probably due to a reduction in food intake. Adult females exhibited a greater reduction in growth under predation risk than males, which likely resulted in part from the high reproductive investment of females in egg laying. These results indicate that P. canaliculata snails under predation risk face a trade-off between predator avoidance and growth and reproduction, where the lethal effect of predation risk is linked to the size of the prey.

  8. A temperature-dependent physiologically based model for the invasive apple snail Pomacea canaliculata

    Science.gov (United States)

    Gilioli, Gianni; Pasquali, Sara; Martín, Pablo R.; Carlsson, Nils; Mariani, Luigi

    2017-11-01

    In order to set priorities in management of costly and ecosystem-damaging species, policymakers and managers need accurate predictions not only about where a specific invader may establish but also about its potential abundance at different geographical scales. This is because density or biomass per unit area of an invasive species is a key predictor of the magnitude of environmental and economic impact in the invaded habitat. Here, we present a physiologically based demographic model describing and explaining the population dynamics of a widespread freshwater invader, the golden apple snail Pomacea canaliculata, which is causing severe environmental and economic impacts in invaded wetlands and rice fields in Southeastern Asia and has also been introduced to North America and Europe . The model is based on bio-demographic functions for mortality, development and fecundity rates that are driven by water temperature for the aquatic stages (juveniles and adults) and by air temperature for the aerial egg masses. Our model has been validated against data on the current distribution in South America and Japan, and produced consistent and realistic patterns of reproduction, growth, maturation and mortality under different scenarios in accordance to what is known from real P. canaliculata populations in different regions and climates. The model further shows that P. canaliculata will use two different reproductive strategies (semelparity and iteroparity) within the potential area of establishment, a plasticity that may explain the high invasiveness of this species across a wide range of habitats with different climates. Our results also suggest that densities, and thus the magnitude of environmental and agricultural damage, will be largely different in locations with distinct climatic regimes within the potential area of establishment. We suggest that physiologically based demographic modelling of invasive species will become a valuable tool for invasive species managers.

  9. Rac1/β-Catenin Signalling Pathway Contributes to Trophoblast Cell Invasion by Targeting Snail and MMP9

    Directory of Open Access Journals (Sweden)

    Minghua Fan

    2016-03-01

    Full Text Available Background/Aims: Preeclampsia is an idiopathic and serious complication during gestation in which placental trophoblast cells differentiate into several functional subtypes, including highly invasive extravillous trophoblasts (EVTs. Although the cause and pathogenesis of preeclampsia have remained unclear, numerous studies have suggested that the inadequacy of EVT invasion leads to imperfect uterine spiral artery remodelling, which plays a crucial role in the development of preeclampsia. Rac1, or Ras-related C3 botulinum toxin substrate 1, was found to be a key regulator of the migration, invasion uand apoptosis of various tumour cells. Because EVTs share similar invasive and migratory biological behaviours with malignant cells, this study aimed to determine whether the Rac1 signalling pathway affects trophoblast invasion and is thus involved in the pathogenesis of preeclampsia. Methods: We measured the activity of Rac1 and its downstream targets, β-catenin, Snail and MMP9 in placental tissues from patients experiencing a normal pregnancy and those with preeclampsia. Furthermore, we treated HTR-8/SVneo cells with a shRNA Rac1 vector and the β-catenin inhibitor IWP-2 and explored Rac1 signalling pathway activation as well as the effects of Snail and β-catenin on trophoblast invasion. Results: In placental samples from patients experiencing a normal pregnancy and those with preeclampsia, active Rac1 levels and MMP9 protein and mRNA levels were significantly decreased in term pregnancy samples compared to early pregnancy samples. Lower levels were found in preeclampsia samples than in normal term pregnancy samples, and these levels significantly declined in severe preeclampsia samples compared with mild preeclampsia samples. Further analyses demonstrated that both Rac1 shRNA and the β-catenin inhibitor significantly suppressed MMP9 and Snail activation in trophoblasts, thus impairing trophoblast invasion. Notably, silencing Rac1 down

  10. Profound Effects of Population Density on Fitness-Related Traits in an Invasive Freshwater Snail

    Science.gov (United States)

    Zachar, Nicholas; Neiman, Maurine

    2013-01-01

    Population density can profoundly influence fitness-related traits and population dynamics, and density dependence plays a key role in many prominent ecological and evolutionary hypotheses. Here, we evaluated how individual-level changes in population density affect growth rate and embryo production early in reproductive maturity in two different asexual lineages of Potamopyrgus antipodarum, a New Zealand freshwater snail that is an important model system for ecotoxicology and the evolution of sexual reproduction as well as a potentially destructive worldwide invader. We showed that population density had a major influence on individual growth rate and early-maturity embryo production, effects that were often apparent even when comparing treatments that differed in population density by only one individual. While individual growth rate generally decreased as population density increased, we detected a hump-shaped relationship between embryo production and density, with females from intermediate-density treatments producing the most embryos and females from low- and high-density treatments producing the fewest embryos. The two lineages responded similarly to the treatments, indicating that these effects of population density might apply more broadly across P. antipodarum. These results indicate that there are profound and complex relationships between population density, growth rate, and early-maturity embryo production in at least two lineages of this important model system, with potential implications for the study of invasive populations, research on the maintenance of sex, and approaches used in ecotoxicology. PMID:24278240

  11. Profound effects of population density on fitness-related traits in an invasive freshwater snail.

    Directory of Open Access Journals (Sweden)

    Nicholas Zachar

    Full Text Available Population density can profoundly influence fitness-related traits and population dynamics, and density dependence plays a key role in many prominent ecological and evolutionary hypotheses. Here, we evaluated how individual-level changes in population density affect growth rate and embryo production early in reproductive maturity in two different asexual lineages of Potamopyrgus antipodarum, a New Zealand freshwater snail that is an important model system for ecotoxicology and the evolution of sexual reproduction as well as a potentially destructive worldwide invader. We showed that population density had a major influence on individual growth rate and early-maturity embryo production, effects that were often apparent even when comparing treatments that differed in population density by only one individual. While individual growth rate generally decreased as population density increased, we detected a hump-shaped relationship between embryo production and density, with females from intermediate-density treatments producing the most embryos and females from low- and high-density treatments producing the fewest embryos. The two lineages responded similarly to the treatments, indicating that these effects of population density might apply more broadly across P. antipodarum. These results indicate that there are profound and complex relationships between population density, growth rate, and early-maturity embryo production in at least two lineages of this important model system, with potential implications for the study of invasive populations, research on the maintenance of sex, and approaches used in ecotoxicology.

  12. Profound effects of population density on fitness-related traits in an invasive freshwater snail.

    Science.gov (United States)

    Zachar, Nicholas; Neiman, Maurine

    2013-01-01

    Population density can profoundly influence fitness-related traits and population dynamics, and density dependence plays a key role in many prominent ecological and evolutionary hypotheses. Here, we evaluated how individual-level changes in population density affect growth rate and embryo production early in reproductive maturity in two different asexual lineages of Potamopyrgus antipodarum, a New Zealand freshwater snail that is an important model system for ecotoxicology and the evolution of sexual reproduction as well as a potentially destructive worldwide invader. We showed that population density had a major influence on individual growth rate and early-maturity embryo production, effects that were often apparent even when comparing treatments that differed in population density by only one individual. While individual growth rate generally decreased as population density increased, we detected a hump-shaped relationship between embryo production and density, with females from intermediate-density treatments producing the most embryos and females from low- and high-density treatments producing the fewest embryos. The two lineages responded similarly to the treatments, indicating that these effects of population density might apply more broadly across P. antipodarum. These results indicate that there are profound and complex relationships between population density, growth rate, and early-maturity embryo production in at least two lineages of this important model system, with potential implications for the study of invasive populations, research on the maintenance of sex, and approaches used in ecotoxicology.

  13. Uric acid deposits and estivation in the invasive apple-snail, Pomacea canaliculata.

    Science.gov (United States)

    Giraud-Billoud, Maximiliano; Abud, María A; Cueto, Juan A; Vega, Israel A; Castro-Vazquez, Alfredo

    2011-04-01

    The physiological ability to estivate is relevant for the maintenance of population size in the invasive Pomacea canaliculata. However, tissue reoxygenation during arousal from estivation poses the problem of acute oxidative stress. Uric acid is a potent antioxidant in several systems and it is stored in specialized tissues of P. canaliculata. Changes in tissue concentration of thiobarbituric acid reactive substances (TBARS), uric acid and allantoin were measured during estivation and arousal in P. canaliculata. Both TBARS and uric acid increased two-fold during 45 days estivation, probably as a consequence of concomitant oxyradical production during uric acid synthesis by xanthine oxidase. However, after arousal was induced, uric acid and TBARS dropped to or near baseline levels within 20 min and remained low up to 24h after arousal induction, while the urate oxidation product allantoin continuously rose to a maximum at 24h after induction, indicating the participation of uric acid as an antioxidant during reoxygenation. Neither uric acid nor allantoin was detected in the excreta during this 24h period. Urate oxidase activity was also found in organs of active snails, but activity shut down during estivation and only a partial and sustained recovery was observed in the midgut gland. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Snail promotes Cyr61 secretion to prime collective cell migration and form invasive tumor nests in squamous cell carcinoma.

    Science.gov (United States)

    Tanaka, Fumi; Rizqiawan, Andra; Higashikawa, Koichiro; Tobiume, Kei; Okui, Gaku; Shigeishi, Hideo; Ono, Shigehiro; Shimasue, Hiroshi; Kamata, Nobuyuki

    2013-02-28

    We previously identified genes associated with Snail-mediated squamous cell carcinoma (SCC) invasiveness, in which we observed significant elevation of Cyr61 expression. In this study, SCC cell lines overexpressing Cyr61 exhibited constitutive activation of Rho A and upregulated invasiveness without the disruption of homophilic cell attachment. Humoral Cyr61 enhanced further production of endogenous Cyr61 by SCC cells, which stimulated collective cell migration and the development of an invasive tumor nest. We propose a Cyr61-dependent model for the development of invasive SCC nest, whereby a subset of tumor cells that highly produce Cyr61 may direct other tumor cells to undergo collective cell migration, resulting in a formation of primary SCC mass. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  15. Salinity adaptation of the invasive New Zealand mud snail (Potamopyrgus antipodarum) in the Columbia River estuary (Pacific Northwest, USA): Physiological and molecular studies

    Science.gov (United States)

    Hoy, Marshal; Boese, Bruce L.; Taylor, Louise; Reusser, Deborah; Rodriguez, Rusty

    2012-01-01

    In this study, we examine salinity stress tolerances of two populations of the invasive species New Zealand mud snail Potamopyrgus antipodarum, one population from a high salinity environment in the Columbia River estuary and the other from a fresh water lake. In 1996, New Zealand mud snails were discovered in the tidal reaches of the Columbia River estuary that is routinely exposed to salinity at near full seawater concentrations. In contrast, in their native habitat and throughout its spread in the western US, New Zealand mud snails are found only in fresh water ecosystems. Our aim was to determine whether the Columbia River snails have become salt water adapted. Using a modification of the standard amphipod sediment toxicity test, salinity tolerance was tested using a range of concentrations up to undiluted seawater, and the snails were sampled for mortality at daily time points. Our results show that the Columbia River snails were more tolerant of acute salinity stress with the LC50 values averaging 38 and 22 Practical Salinity Units for the Columbia River and freshwater snails, respectively. DNA sequence analysis and morphological comparisons of individuals representing each population indicate that they were all P. antipodarum. These results suggest that this species is salt water adaptable and in addition, this investigation helps elucidate the potential of this aquatic invasive organism to adapt to adverse environmental conditions.

  16. Count your eggs before they invade: identifying and quantifying egg clutches of two invasive apple snail species (Pomacea).

    Science.gov (United States)

    Kyle, Colin H; Plantz, Allyson L; Shelton, Therese; Burks, Romi L

    2013-01-01

    Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea) provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number) of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and managers can quickly

  17. Count your eggs before they invade: identifying and quantifying egg clutches of two invasive apple snail species (Pomacea.

    Directory of Open Access Journals (Sweden)

    Colin H Kyle

    Full Text Available Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and

  18. Influence of the invasive Asian clam Corbicula fluminea (Bivalvia: Corbiculidae) on estuarine epibenthic assemblages

    Science.gov (United States)

    Ilarri, M. I.; Souza, A. T.; Antunes, C.; Guilhermino, L.; Sousa, R.

    2014-04-01

    One of the most widespread invasive alien species (IAS) in aquatic ecosystems is the Asian clam Corbicula fluminea. Several studies have shown that C. fluminea can cause large-scale changes in macrozoobenthic assemblages; however, very few attempted to investigate the effects of this IAS on mobile epibenthic species, such as fishes and crustaceans. In this context, the influence of C. fluminea on epibenthic species was investigated during one year by comparing the associated epibenthic fauna in three nearby sites of the Minho estuary (NW of the Iberian Peninsula), wherein the abiotic conditions are similar but the density of the Asian clam is highly different. From a total of 13 species, six were significantly influenced by C. fluminea; five responded positively, namely the brown shrimp Crangon crangon, the European eel Anguilla anguilla, the common goby Pomatoschistus microps, the brown trout Salmo trutta fario and the great pipefish Syngnathus acus, whereas the shore crab Carcinus maenas was negatively influenced. However, stomach contents analysis revealed that fish and crustacean species do not feed on C. fluminea, suggesting that this IAS is still not a large component of the diet of higher trophic levels in this estuarine ecosystem. Our results suggest that the structure provided by C. fluminea shells is likely to be one of the main factors responsible for the differences observed. C. fluminea physical structure seems to influence the epibenthic associated fauna, when found in densities higher than 1000 ind./m2, with sedentary small-bodied crustaceans and fishes being mainly attracted by the increasing in habitat complexity and consequent enhancement of heterogeneity and shelter availability.

  19. Hybridization and invasiveness in the freshwater snail Melanoides tuberculata: hybrid vigour is more important than increase in genetic variance.

    Science.gov (United States)

    Facon, B; Jarne, P; Pointier, J P; David, P

    2005-05-01

    Many invasive taxa are hybrids, but how hybridization boosts the invasive process remains poorly known. We address this question in the clonal freshwater snail Melanoides tuberculata from Martinique, using three parental and two hybrid lines. We combine an extensive field survey (1990-2003) and a quantitative genetic experiment to show that hybrid lines have outcompeted their parents in natural habitats, and that this increased invasiveness co-occurred with pronounced shifts in life-history traits, such as growth, fecundity and juvenile size. Given the little time between hybrid creation and sampling, and the moderate standing genetic variance for life-history traits in hybrids, we show that some of the observed trait changes between parents and hybrids were unlikely to arise only by continuous selection. We therefore suggest that a large part of hybrid advantage stems from immediate heterosis upon hybridization.

  20. Mesenchymal cells reactivate Snail1 expression to drive three-dimensional invasion programs

    DEFF Research Database (Denmark)

    Rowe, R.G.; Li, X.Y.; Hu, Y.

    2009-01-01

    Epithelial-mesenchymal transition (EMT) is required for mesodermal differentiation during development. The zinc-finger transcription factor, Snail1, can trigger EMT and is sufficient to transcriptionally reprogram epithelial cells toward a mesenchymal phenotype during neoplasia and fibrosis. Whet...

  1. Rab25 augments cancer cell invasiveness through a β1 integrin/EGFR/VEGF-A/Snail signaling axis and expression of fascin.

    Science.gov (United States)

    Jeong, Bo Young; Cho, Kyung Hwa; Jeong, Kang Jin; Park, Yun-Yong; Kim, Jin Man; Rha, Sun Young; Park, Chang Gyo; Mills, Gordon B; Cheong, Jae-Ho; Lee, Hoi Young

    2018-01-26

    The small GTP-binding protein Rab25 is associated with tumor formation and progression. However, recent studies have shown discordant effects of Rab25 on cancer cell progression depending on cell lineage. In the present study, we elucidate the underlying mechanisms by which Rab25 induces cellular invasion. We demonstrate that Rab25 increases β1 integrin levels and subsequent activation of EGFR and upregulation of VEGF-A expression, leading to increased Snail expression, epithelial-to-mesenchymal transition and cancer cell invasiveness. Strikingly, we identify that Snail mediates Rab25-induced cancer cell invasiveness through fascin expression and that ectopic expression of Rab25 aggravates metastasis of ovarian cancer cells to the lung. We thus demonstrate a novel role of a β1 integrin/EGFR/VEGF-A/Snail signaling cascade in Rab25-induced cancer cell aggressiveness through induction of fascin expression, thus providing novel biomarkers and potential therapeutic targets for Rab25-expressing cancer cells.

  2. Metagenomic Analysis of the Microbiota from the Crop of an Invasive Snail Reveals a Rich Reservoir of Novel Genes

    Science.gov (United States)

    Cardoso, Alexander M.; Cavalcante, Janaína J. V.; Cantão, Maurício E.; Thompson, Claudia E.; Flatschart, Roberto B.; Glogauer, Arnaldo; Scapin, Sandra M. N.; Sade, Youssef B.; Beltrão, Paulo J. M. S. I.; Gerber, Alexandra L.; Martins, Orlando B.; Garcia, Eloi S.; de Souza, Wanderley; Vasconcelos, Ana Tereza R.

    2012-01-01

    The shortage of petroleum reserves and the increase in CO2 emissions have raised global concerns and highlighted the importance of adopting sustainable energy sources. Second-generation ethanol made from lignocellulosic materials is considered to be one of the most promising fuels for vehicles. The giant snail Achatina fulica is an agricultural pest whose biotechnological potential has been largely untested. Here, the composition of the microbial population within the crop of this invasive land snail, as well as key genes involved in various biochemical pathways, have been explored for the first time. In a high-throughput approach, 318 Mbp of 454-Titanium shotgun metagenomic sequencing data were obtained. The predominant bacterial phylum found was Proteobacteria, followed by Bacteroidetes and Firmicutes. Viruses, Fungi, and Archaea were present to lesser extents. The functional analysis reveals a variety of microbial genes that could assist the host in the degradation of recalcitrant lignocellulose, detoxification of xenobiotics, and synthesis of essential amino acids and vitamins, contributing to the adaptability and wide-ranging diet of this snail. More than 2,700 genes encoding glycoside hydrolase (GH) domains and carbohydrate-binding modules were detected. When we compared GH profiles, we found an abundance of sequences coding for oligosaccharide-degrading enzymes (36%), very similar to those from wallabies and giant pandas, as well as many novel cellulase and hemicellulase coding sequences, which points to this model as a remarkable potential source of enzymes for the biofuel industry. Furthermore, this work is a major step toward the understanding of the unique genetic profile of the land snail holobiont. PMID:23133637

  3. Metagenomic analysis of the microbiota from the crop of an invasive snail reveals a rich reservoir of novel genes.

    Directory of Open Access Journals (Sweden)

    Alexander M Cardoso

    Full Text Available The shortage of petroleum reserves and the increase in CO(2 emissions have raised global concerns and highlighted the importance of adopting sustainable energy sources. Second-generation ethanol made from lignocellulosic materials is considered to be one of the most promising fuels for vehicles. The giant snail Achatina fulica is an agricultural pest whose biotechnological potential has been largely untested. Here, the composition of the microbial population within the crop of this invasive land snail, as well as key genes involved in various biochemical pathways, have been explored for the first time. In a high-throughput approach, 318 Mbp of 454-Titanium shotgun metagenomic sequencing data were obtained. The predominant bacterial phylum found was Proteobacteria, followed by Bacteroidetes and Firmicutes. Viruses, Fungi, and Archaea were present to lesser extents. The functional analysis reveals a variety of microbial genes that could assist the host in the degradation of recalcitrant lignocellulose, detoxification of xenobiotics, and synthesis of essential amino acids and vitamins, contributing to the adaptability and wide-ranging diet of this snail. More than 2,700 genes encoding glycoside hydrolase (GH domains and carbohydrate-binding modules were detected. When we compared GH profiles, we found an abundance of sequences coding for oligosaccharide-degrading enzymes (36%, very similar to those from wallabies and giant pandas, as well as many novel cellulase and hemicellulase coding sequences, which points to this model as a remarkable potential source of enzymes for the biofuel industry. Furthermore, this work is a major step toward the understanding of the unique genetic profile of the land snail holobiont.

  4. Expression of e-cadherin, n-cadherin and snail and their correlation with clinicopathological variants: an immunohistochemical study of 132 invasive ductal breast carcinomas in Egypt

    Directory of Open Access Journals (Sweden)

    Hanan Mohamed Abd ElMoneim

    2011-01-01

    Full Text Available OBJECTIVE: To evaluate the expression of the cell adhesion molecules E-cadherin and N-cadherin and the transcription factor Snail in invasive ductal breast carcinomas and to determine their relationships with clinicopathological features. METHODS: Immunohistochemistry was used to examine E-cadherin, N-cadherin, and Snail protein expression in 132 invasive breast carcinomas. RESULTS: The expression of E-cadherin was decreased (negative or weak in 37.1% of invasive carcinomas, while N-cadherin and Snail overexpression were detected in 51.9% and 40.9% of carcinomas, respectively. Low E-cadherin expression was significantly correlated with poorly differentiated carcinoma (53.1%, positive node status (80.9%, poor Nottingham Prognostic Index (64.7%, and the presence of estrogen and progesterone receptors. Overexpression of N-cadherin and Snail were also significantly correlated with poorly differentiated carcinoma, positive node status, and poor Nottingham Prognostic Index but were correlated with the absence of hormone receptors. Loss of E-cadherin immunoexpression was strongly associated with the presence of membranous N-cadherin (87.8% and nuclear Snail (69.4%. CONCLUSION: Loss of E-cadherin and overexpression of N-cadherin and Snail in breast carcinomas may play a central role in the development of invasive ductal breast carcinoma. These biomarkers may provide a valuable reference for the study of invasive ductal carcinoma progression and to characterize the biological behavior of the tumor. In the future, increased N-cadherin and decreased E-cadherin expression may be used as indicators of the progression and prognosis of invasive ductal carcinoma.

  5. Effect of Twist, Snail and YB-1 gene expression in cervical cancer tissue on cell invasion and epithelial-mesenchymal transition

    Directory of Open Access Journals (Sweden)

    Xin-Qin Kang1

    2017-05-01

    Full Text Available Objective: To study the effect of Twist, Snail and YB-1 gene expression in cervical cancer tissue on cell invasion and epithelial-mesenchymal transition. Methods: Cervical cancer tissue samples and tissue samples adjacent to carcinoma were collected from 138 patients with radical operation for cervical cancer, fluorescence quantitative PCR method was used to detect the mRNA expression of Twist, Snail and YB-1 genes, cell invasion-related genes and epithelial-mesenchymal transition marker genes, the Pearson test was used to analyze the correlation of Twist, Snail and YB-1 gene mRNA expression in cervical cancer tissue with cell invasion and epithelial-mesenchymal transition. Results: Twist, Snail and YB-1 gene mRNA expression in cervical cancer tissue were higher than those in tissue adjacent to carcinoma, the invasion genes STAT3, YAP1, TUG1, FoxM1 and Rab11 mRNA expression were higher than those in tissue adjacent to carcinoma, and the epithelial-mesenchymal transition markers E-cadherin and β-catenin gene mRNA expression were lower than those in tissue adjacent to carcinoma while vimentin gene mRNA expression was higher than that in tissue adjacent to carcinoma. Pearson test showed that Twist, Snail and YB-1 gene mRNA expression in cervical cancer tissue were directly correlated with cell invasion and epithelial-mesenchymal transition. Conclusion: Twist, Snail and YB-1 genes are highly expressed in cervical cancer tissue, and their abnormal expression directly leads to the increased tumor cell invasion activity and the aggravated epithelial-mesenchymal transition.

  6. Invasive Pomacea snails as important intermediate hosts of Angiostrongylus cantonensis in Laos, Cambodia and Vietnam: implications for outbreaks of eosinophilic meningitis.

    Science.gov (United States)

    Lv, Shan; Guo, Yun-Hai; Nguyen, Hung Manh; Sinuon, Muth; Sayasone, Somphou; Lo, Nathan C; Zhou, Xiao-Nong; Andrews, Jason R

    2018-03-21

    The rat lungworm Angiostrongylus cantonensis causes human eosinophilic meningitis and it is endemic in Southeast Asia, but little is known about its distribution in Laos, Cambodia and Vietnam. We conducted a multi-country survey for A. cantonensis in these countries to estimate its prevalence in snails along the Mekong River and the east coast of Vietnam. We identified Angiostrongylus species by morphological and molecular analysis. We found A. cantonensis in the invasive snail, Pomacea spp. The wide accessibility of Pomacea snails, along with their infection by A. cantonensis, indicates that this snail species could be used in surveillance for preventing outbreaks of eosinophilic meningitis. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Climate and pH predict the potential range of the invasive apple snail (Pomacea insularum) in the southeastern United States.

    Science.gov (United States)

    Byers, James E; McDowell, William G; Dodd, Shelley R; Haynie, Rebecca S; Pintor, Lauren M; Wilde, Susan B

    2013-01-01

    Predicting the potential range of invasive species is essential for risk assessment, monitoring, and management, and it can also inform us about a species' overall potential invasiveness. However, modeling the distribution of invasive species that have not reached their equilibrium distribution can be problematic for many predictive approaches. We apply the modeling approach of maximum entropy (MaxEnt) that is effective with incomplete, presence-only datasets to predict the distribution of the invasive island apple snail, Pomacea insularum. This freshwater snail is native to South America and has been spreading in the USA over the last decade from its initial introductions in Texas and Florida. It has now been documented throughout eight southeastern states. The snail's extensive consumption of aquatic vegetation and ability to accumulate and transmit algal toxins through the food web heighten concerns about its spread. Our model shows that under current climate conditions the snail should remain mostly confined to the coastal plain of the southeastern USA where it is limited by minimum temperature in the coldest month and precipitation in the warmest quarter. Furthermore, low pH waters (pH <5.5) are detrimental to the snail's survival and persistence. Of particular note are low-pH blackwater swamps, especially Okefenokee Swamp in southern Georgia (with a pH below 4 in many areas), which are predicted to preclude the snail's establishment even though many of these areas are well matched climatically. Our results elucidate the factors that affect the regional distribution of P. insularum, while simultaneously presenting a spatial basis for the prediction of its future spread. Furthermore, the model for this species exemplifies that combining climatic and habitat variables is a powerful way to model distributions of invasive species.

  8. Climate and pH predict the potential range of the invasive apple snail (Pomacea insularum in the southeastern United States.

    Directory of Open Access Journals (Sweden)

    James E Byers

    Full Text Available Predicting the potential range of invasive species is essential for risk assessment, monitoring, and management, and it can also inform us about a species' overall potential invasiveness. However, modeling the distribution of invasive species that have not reached their equilibrium distribution can be problematic for many predictive approaches. We apply the modeling approach of maximum entropy (MaxEnt that is effective with incomplete, presence-only datasets to predict the distribution of the invasive island apple snail, Pomacea insularum. This freshwater snail is native to South America and has been spreading in the USA over the last decade from its initial introductions in Texas and Florida. It has now been documented throughout eight southeastern states. The snail's extensive consumption of aquatic vegetation and ability to accumulate and transmit algal toxins through the food web heighten concerns about its spread. Our model shows that under current climate conditions the snail should remain mostly confined to the coastal plain of the southeastern USA where it is limited by minimum temperature in the coldest month and precipitation in the warmest quarter. Furthermore, low pH waters (pH <5.5 are detrimental to the snail's survival and persistence. Of particular note are low-pH blackwater swamps, especially Okefenokee Swamp in southern Georgia (with a pH below 4 in many areas, which are predicted to preclude the snail's establishment even though many of these areas are well matched climatically. Our results elucidate the factors that affect the regional distribution of P. insularum, while simultaneously presenting a spatial basis for the prediction of its future spread. Furthermore, the model for this species exemplifies that combining climatic and habitat variables is a powerful way to model distributions of invasive species.

  9. Physiology of the invasive apple snail Pomacea maculata: tolerance to low temperatures

    Science.gov (United States)

    Deaton, Lewis E.; Schmidt, William; Leblanc, Brody; Carter, Jacoby; Mueck, Kristy; Merino, Sergio

    2016-01-01

    Apple snails of the genus Pomacea native to South America have invaded and become established in Europe, Asia, and the United States. Both the channeled apple snail Pomacea canaliculata and the island apple snail Pomacea maculata have been reported in the United States. The two species are difficult to distinguish using morphological characters, leading to uncertainty about the identity of the animals from populations in the United States. Because the snails are subtropical, their tolerance of low temperatures is a critical factor in limiting the spread of the animals from present localities along the coast of the Gulf of Mexico to more northern areas. The tolerance of P. maculata collected in Louisiana to temperatures as low as 0°C was examined. There was no mortality among animals maintained in water at temperatures of 20°C or 15°C for 10 days. Survival of animals during a 10-day exposure to water at temperatures 10°C and 5°C was 50%. The LD50 for a 10-day exposure was 7°C. Snails did not survive more than 5 days in liquid water at 0°C. Ammonia excretion by animals in temperatures of 20°C and 15°C was comparable to values reported for freshwater gastropods; at very low temperatures, excretion of ammonia was decreased. There was no difference in the mean values of the osmolality of the hemolymph of animals exposed to 20°C, 15°C and 10°C for 10 days. Sequencing of mitochondrial cytochrome oxidase 1 identified the animals in the Louisiana population used in this study as P. maculata.

  10. Spatial variation in adult sex ratio across multiple scales in the invasive golden apple snail, Pomacea canaliculata.

    Science.gov (United States)

    Xu, Meng; Fang, Miao; Yang, Yexin; Dick, Jaimie T A; Song, Hongmei; Luo, Du; Mu, Xidong; Gu, Dangen; Luo, Jianren; Hu, Yinchang

    2016-04-01

    Adult sex ratio (ASR) has critical effects on behavior and life history and has implications for population demography, including the invasiveness of introduced species. ASR exhibits immense variation in nature, yet the scale dependence of this variation is rarely analyzed. In this study, using the generalized multilevel models, we investigated the variation in ASR across multiple nested spatial scales and analyzed the underlying causes for an invasive species, the golden apple snail Pomacea canaliculata. We partitioned the variance in ASR to describe the variations at different scales and then included the explanatory variables at the individual and group levels to analyze the potential causes driving the variation in ASR. We firstly determined there is a significant female-biased ASR for this species when accounting for the spatial and temporal autocorrelations of sampling. We found that, counter to nearly equal distributed variation at plot, habitat and region levels, ASR showed little variation at the town level. Temperature and precipitation at the region level were significantly positively associated with ASR, whereas the individual weight, the density characteristic, and sampling time were not significant factors influencing ASR. Our study suggests that offspring sex ratio of this species may shape the general pattern of ASR in the population level while the environmental variables at the region level translate the unbiased offspring sex ratio to the female-biased ASR. Future research should consider the implications of climate warming on the female-biased ASR of this invasive species and thus on invasion pattern.

  11. Life history traits of the invasive estuarine shrimp Palaemon macrodactylus (Caridea: Palaemonidae in a marine environment (Mar del Plata, Argentina

    Directory of Open Access Journals (Sweden)

    María Guadalupe Vázquez

    2012-08-01

    Full Text Available The invasive oriental shrimp Palaemon macrodactylus has been extensively recorded around the world, mainly in estuarine zones. In this study, the life history of this species was studied in Mar del Plata harbour (Argentina, a fully marine area where a stable and dense population has been established. Growth, sex proportion, morphological relationships, size at maturity and reproductive cycle were analysed between March 2007 and March 2009. A total of 9 and 7 modal classes (M1-M9 were detected in the size frequency distributions of females and males, respectively. The modes of both sexes were the same until M4 but from M5 to M7 females were larger than males. The life span was about one year with a clear seasonal growth. Recruitment and reproductive periods were recorded from December to March and October to March, respectively. The total sex ratio was biased to females. Nevertheless, a clear predominance of males was observed in classes smaller than 5.25 mm carapace length (CL. Females reached maturity at a larger size in spring to early summer (October–January than in late summer (February–March; the estimated sizes for 50% sexual maturity were 6.79 mm and 5.91 mm CL, respectively. The results showed great differences from a presumably native estuarine population (Japan, such as shorter life span, smaller maximum size and smaller size at maturity.

  12. Diversity and abundance of epibiota on invasive and native estuarine gastropods depend on substratum and salinity

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Brunbjerg, Ane Kirstine

    2015-01-01

    for the concurrent influence of many environmental factors on epibiota communities. This study aimed to determine the importance of salinity, depth, wave exposure, habitat and shell type for community structure of sessile epibiota in the Swan River Estuary, Western Australia. We quantified the epibiota on 3...... factors. The five factors accounted for 3-34% of the total deviance explained of the models, with shell type and salinity levels being the only significant factors in nine of 14 models. These results highlight an overwhelming importance of shell type and salinity in explaining estuarine epibiota...

  13. KPNA2 promotes migration and invasion in epithelial ovarian cancer cells by inducing epithelial-mesenchymal transition via Akt/GSK-3β/Snail activation.

    Science.gov (United States)

    Huang, Long; Zhou, Yun; Cao, Xin-Ping; Lin, Jia-Xin; Zhang, Lan; Huang, Shu-Ting; Zheng, Min

    2018-01-01

    Background : Increased karyopherin alpha 2 (KPNA2) expression has been demonstrated in epithelial ovarian carcinoma (EOC) tissue. However, its role in the disease is not clear. Here, we investigate the mechanism of involvement of KPNA2 in EOC. Methods : Stable cell lines expressing KPNA2, or KPNA2 shRNAs, were constructed. The effects of KPNA2 overexpression and knockdown on EOC cell migration, invasion, and epithelial-to-mesenchymal transition (EMT) were evaluated using relevant assays and western blot analysis. Key components of the Akt/GSK-3β/Snail signaling pathway were detected using western blotting and immunofluorescence. Results: KPNA2 overexpression increased the migration and invasion of EOC cells (EFO-21 and SK-OV3); these cells also exhibited characteristics of EMT. Key proteins in the Akt/GSK-3β/Snail signaling pathway were also upregulated in cells overexpressing KPNA2. In contrast, knockdown of KPNA2 effectively suppressed migration and invasion of these EOC cells. Conclusions: KPNA2 may reduce the migration and invasion of EOC by inhibiting the Akt/GSK-3β/Snail signaling pathway and suppressing EMT.

  14. P2Y2 receptor promotes the migration and invasion of breast cancer cells via EMT-related genes Snail and E-cadherin.

    Science.gov (United States)

    Qiu, Ying; Liu, Yan; Li, Wei-Hua; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

    2018-01-01

    Adenosine 5'-triphosphate (ATP) is one of the most abundant biochemical constituents within the tumor microenvironment and is postulated to play critical roles in the progression of a number of types of tumors via interaction with the P2Y2 receptor. In the present study, we demonstrated that the P2Y2 receptor was highly expressed in MCF7 and Hs578T breast cancer cells. Downregulation of the P2Y2 receptor by small interfering RNA (siRNA) significantly attenuated ATP- or UTP-driven migration and invasion of the breast cancer cells as well as expression of EMT-related genes Snail and E-cadherin. Consistent with the observations in vitro, the P2Y2 receptor was found to be abundantly expressed at the invasive edge of the tumor, in infiltrating tumor cells in breast adipose tissues and/or the cancer embolus in the lymphatic sinuses compared with the tumor core areas. Furthermore, high Snail expression and weak or negative expression of E-cadherin were observed at the invasive edge of tumors. Taken together, these data indicate that the P2Y2 receptor promoted cell migration and invasion in breast cancer cells via EMT-related genes Snail and E-cadherin.

  15. Insights into embryo defenses of the invasive apple snail Pomacea canaliculata: egg mass ingestion affects rat intestine morphology and growth.

    Science.gov (United States)

    Dreon, Marcos S; Fernández, Patricia E; Gimeno, Eduardo J; Heras, Horacio

    2014-06-01

    The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF) ingestion on the rat small intestine morphology and physiology. Through a combination of biochemical, histochemical, histopathological, scanning electron microscopy, cell culture and feeding experiments, we analyzed intestinal morphology, growth rate, hemaglutinating activity, cytotoxicity and cell proliferation after oral administration of PVF to rats. PVF adversely affects small intestine metabolism and morphology and consequently the standard growth rate, presumably by lectin-like proteins, as suggested by PVF hemaglutinating activity and its cytotoxic effect on Caco-2 cell culture. Short-term effects of ingested PVF were studied in growing rats. PVF-supplemented diet induced the appearance of shorter and wider villi as well as fused villi. This was associated with changes in glycoconjugate expression, increased cell proliferation at crypt base, and hypertrophic mucosal growth. This resulted in a decreased absorptive surface after 3 days of treatment and a diminished rat growth rate that reverted to normal after the fourth day of treatment. Longer exposure to PVF induced a time-dependent lengthening of the small intestine while switching to a control diet restored intestine length and morphology after 4 days. Ingestion of PVF rapidly limits the ability of potential predators to absorb nutrients by inducing large, reversible changes in intestinal morphology and growth rate. The occurrence of toxins that affect intestinal morphology and absorption is a strategy against predation not recognized among animals before. Remarkably, this defense is rather similar to the toxic effect of plant antipredator strategies. This defense

  16. Insights into embryo defenses of the invasive apple snail Pomacea canaliculata: egg mass ingestion affects rat intestine morphology and growth.

    Directory of Open Access Journals (Sweden)

    Marcos S Dreon

    2014-06-01

    Full Text Available The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF ingestion on the rat small intestine morphology and physiology.Through a combination of biochemical, histochemical, histopathological, scanning electron microscopy, cell culture and feeding experiments, we analyzed intestinal morphology, growth rate, hemaglutinating activity, cytotoxicity and cell proliferation after oral administration of PVF to rats. PVF adversely affects small intestine metabolism and morphology and consequently the standard growth rate, presumably by lectin-like proteins, as suggested by PVF hemaglutinating activity and its cytotoxic effect on Caco-2 cell culture. Short-term effects of ingested PVF were studied in growing rats. PVF-supplemented diet induced the appearance of shorter and wider villi as well as fused villi. This was associated with changes in glycoconjugate expression, increased cell proliferation at crypt base, and hypertrophic mucosal growth. This resulted in a decreased absorptive surface after 3 days of treatment and a diminished rat growth rate that reverted to normal after the fourth day of treatment. Longer exposure to PVF induced a time-dependent lengthening of the small intestine while switching to a control diet restored intestine length and morphology after 4 days.Ingestion of PVF rapidly limits the ability of potential predators to absorb nutrients by inducing large, reversible changes in intestinal morphology and growth rate. The occurrence of toxins that affect intestinal morphology and absorption is a strategy against predation not recognized among animals before. Remarkably, this defense is rather similar to the toxic effect of plant antipredator strategies

  17. Movement ecology: size-specific behavioral response of an invasive snail to food availability.

    Science.gov (United States)

    Snider, Sunny B; Gilliam, James F

    2008-07-01

    Immigration, emigration, migration, and redistribution describe processes that involve movement of individuals. These movements are an essential part of contemporary ecological models, and understanding how movement is affected by biotic and abiotic factors is important for effectively modeling ecological processes that depend on movement. We asked how phenotypic heterogeneity (body size) and environmental heterogeneity (food resource level) affect the movement behavior of an aquatic snail (Tarebia granifera), and whether including these phenotypic and environmental effects improves advection-diffusion models of movement. We postulated various elaborations of the basic advection diffusion model as a priori working hypotheses. To test our hypotheses we measured individual snail movements in experimental streams at high- and low-food resource treatments. Using these experimental movement data, we examined the dependency of model selection on resource level and body size using Akaike's Information Criterion (AIC). At low resources, large individuals moved faster than small individuals, producing a platykurtic movement distribution; including size dependency in the model improved model performance. In stark contrast, at high resources, individuals moved upstream together as a wave, and body size differences largely disappeared. The model selection exercise indicated that population heterogeneity is best described by the advection component of movement for this species, because the top-ranked model included size dependency in advection, but not diffusion. Also, all probable models included resource dependency. Thus population and environmental heterogeneities both influence individual movement behaviors and the population-level distribution kernels, and their interaction may drive variation in movement behaviors in terms of both advection rates and diffusion rates. A behaviorally informed modeling framework will integrate the sentient response of individuals in terms of

  18. Anatomy of predator snail Huttonella bicolor, an invasive species in Amazon rainforest, Brazil (Pulmonata, Streptaxidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2013-01-01

    Full Text Available The morpho-anatomy of the micro-predator Huttonella bicolor (Hutton, 1838 is investigated in detail. The species is a micro-predator snail, which is splaying in tropical and subtropical areas all over the world, the first report being from the Amazon Rainforest region of northern Brazil. The shell is very long, with complex peristome teeth. The radula bears sharp pointed teeth. The head lacks tentacles, bearing only ommatophores. The pallial cavity lacks well-developed vessels (except for pulmonary vessel; the anus and urinary aperture are on pneumostome. The kidney is solid, with ureter totally closed (tubular; the primary ureter is straight, resembling orthurethran fashion. The buccal mass has an elongated and massive odontophore, of which muscles are described; the odontophore cartilages are totally fused with each other. The salivary ducts start as one single duct, bifurcating only prior to insertion. The mid and hindguts are relatively simple and with smooth inner surfaces; there is practically no intestinal loop. The genital system has a zigzag-fashioned fertilization complex, narrow prostate, no bursa copulatrix, short and broad vas deferens, and simple penis with gland at distal tip. The nerve ring bears three ganglionic masses, and an additional pair of ventral ganglia connected to pedal ganglia, interpreted as odontophore ganglia. These features are discussed in light of the knowledge of other streptaxids and adaptations to carnivory.

  19. Snail Snooping.

    Science.gov (United States)

    Miller, Dorothy

    1993-01-01

    Presents an activity in which students in grades 5-8 learn about snail reproduction by observing and charting the activities of land snails, freshwater snails, and slugs. Instructions to implement and extend the activity are provided. (MDH)

  20. How did this snail get here? Several dispersal vectors inferred for an aquatic invasive species

    NARCIS (Netherlands)

    Van Leeuwen, C.H.A.; Huig, N.; Van der Velde, G.; Van Alen, T.; Wagemaker, C.A.M.; Sherman, C.D.H.; Klaassen, M.R.J.; Figuerola, J.

    2013-01-01

    How species reach and persist in isolated habitats remains an open question in many cases, especially for rapidly spreading invasive species. This is particularly true for temporary freshwater ponds, which can be remote and may dry out annually, but may still harbour high biodiversity. Persistence

  1. Invasive Marine and Estuarine Animals of Hawaii and Other Pacific Islands

    Science.gov (United States)

    2005-08-01

    Oligochaetes 1 1 Polychaetes 2 1 2 5 7 Bivalves 2 8 1 1 3 2 5 8 12 Gastropods 1 2 1 1 1 3 8 9 Nudibranchs 1 4 2 4 Copepods 1 1 2 2 3 Barnacles 3 1 1...favorite aquarium fish because of its colorful appearance. It bears poisonous dorsal, anal, and pelvic spines. The toxin is painful , but is generally...predatory gastropod on the North American Atlantic coast," Biological Bulletin 204, 96-103. Massachusetts Aquatic Invasive Species Working Group. (2002

  2. Zinc finger protein 668 suppresses non-small cell lung cancer invasion and migration by downregulating Snail and upregulating E-cadherin and zonula occludens-1.

    Science.gov (United States)

    Zhang, Xiupeng; Jiang, Guiyang; Wu, Jingjing; Zhou, Haijing; Zhang, Yong; Miao, Yuan; Feng, Yangyang; Yu, Juanhan

    2018-03-01

    Zinc finger protein 668 (ZNF668) is a recently discovered protein and its expression levels, as well as its involvement in the invasion and metastasis of non-small cell lung cancer (NSCLC), are largely unknown. In the present study, immunohistochemical analysis demonstrated that ZNF668 protein expression was decreased in lung tumors (51/167, 30.5%) compared with adjacent normal lung tissues (43/62, 69.4%; P<0.001). Subsequent statistical analysis revealed that ZNF668 expression was negatively associated with increased tumor-node-metastasis stage (P=0.019) and lymph node metastasis (P=0.002). Following ZNF668 downregulation by transfection of a ZNF668 -expressing plasmid or small interfering RNA, it was demonstrated that ZNF668 inhibited the invasion and migration of NSCLC cells. Furthermore, restoration of ZNF668 expression downregulated the expression of Snail and increased the protein levels of epithelial (E-)cadherin and zonula occludens-1 (ZO-1). The results of the present study suggest that ZNF668 is downregulated in human NSCLC. Furthermore, restoration of ZNF668 expression was demonstrated to decrease the expression of Snail and increase the expression of E-cadherin and ZO-1, suppressing the invasion and migration of NSCLC cells.

  3. [6]-Gingerol Prevents Disassembly of Cell Junctions and Activities of MMPs in Invasive Human Pancreas Cancer Cells through ERK/NF-κB/Snail Signal Transduction Pathway

    Directory of Open Access Journals (Sweden)

    Sung Ok Kim

    2013-01-01

    Full Text Available To study the effects of [6]-gingerol, a ginger phytochemical, on tight junction (TJ molecules, we investigated TJ tightening and signal transduction pathways in human pancreatic duct cell-derived cancer cell line PANC-1. The following methods were utilized: MTT assay to determine cytotoxicity; zymography to examine matrix metalloproteinase (MMP activities; transepithelial electrical resistance (TER and paracellular flux for TJ measurement; RT-PCR and immunoblotting for proteins related to TJ and invasion; and EMSA for NF-κB activity in PANC-1 cells. Results revealed that TER significantly increased and claudin 4 and MMP-9 decreased compared to those of the control. TJ protein levels, including zonula occludens (ZO- 1, occludin, and E-cadherin, increased in [6]-gingerol-treated cells, which correlated with a decrease in paracellular flux and MMP activity. Furthermore, NF-κB/Snail nuclear translocation was suppressed via downregulation of the extracellular signal-regulated kinase (ERK pathway in response to [6]-gingerol treatment. Moreover, treatment with U0126, an ERK inhibitor, completely blocked NF-κB activity. In conclusion, these findings demonstrate that [6]-gingerol regulates TJ-related proteins and suppresses invasion and metastasis through NF-κB/Snail inhibition via inhibition of the ERK pathway. Therefore, [6]-gingerol may suppress the invasive activity of PANC-1 cells.

  4. Utilization of the invasive plant Impatiens parviflora DC. by the snail Columella edentula Draparnaud in oak-hornbeam forests

    Directory of Open Access Journals (Sweden)

    Renata Piskorz

    2011-01-01

    Full Text Available This study investigated the extend to which the snail Columella edentula is more strongly associated with the small balsam Impatiens parviflora than with other plants in the herb layer of an oak-hornbeam forest, and to interpret the character of the interaction Impatiens parviflora - Columella edentula. Numbers of C. edentula and rates of colonization were compared on various plant species under natural and laboratory conditions. Seasonal variation in snail abundance on I. parviflora was observed on permanent plots. The leaf injuries caused by C. edentula were localized in respect of the morphological and anatomical structure of leaves. The results show that I. parviflora is one of the plant species of the herb layer that are most abundantly colonized by this snail in oak-hornbeam forest. Snail finds a plant particularly suitable as a place for resting. The most favoured attachment site is on the underside of the leaf, along the midrib, which provides the highest and relatively stable humidity, as well as protection from direct sunlight and predators. I. parviflora is also a food for the snails, but they do not eat these fragments of leaves where calcium carbonate is accumulated.

  5. Observations of raccoon (Procyon lotor) predation on the invasive Maculata apple snail (Pomacea maculata) in southern Louisiana

    Science.gov (United States)

    Carter, Jacoby; Merino, Sergio; Prejean, Drew; LaFleur, Gary Jr.

    2017-01-01

    We used camera traps to determine which predators were responsible for depredated Pomacea maculata (Maculata Apple Snail) shells at 2 different study sites. Evidence of predation at these sites included operculums near the shells with a small amount of flesh attached and shells accumulating a meter or more from the water’s edge with no evidence of recent flooding. In both locations, the most frequently observed potential predators were Procyon lotor (Raccoon), which was the only species directly observed capturing and eating Apple Snails.

  6. Tracing the invasion of the mediterranean land snail Cornu aspersum aspersum becoming an agricultural and garden pest in areas recently introduced.

    Science.gov (United States)

    Guiller, Annie; Martin, Marie-Claire; Hiraux, Céline; Madec, Luc

    2012-01-01

    This study is the first on the genetics of invasive populations of one of the most widely spread land mollusc species known in the world, the "Brown Snail" Cornu aspersum aspersum. Deliberately or accidentally imported, the species has become recently a notorious pest outside its native Mediterranean range. We compared the spatial structure and genetic variability of invasive (America, Oceania, South Africa) versus native populations using five microsatellite loci and mitochondrial (Cyt b and 16S rRNA) genes as a first step towards (i) the detection of potential source populations, and (ii) a better understanding of mechanisms governing evolutionary changes involved in the invasion process. Results based on multivariate analysis (Discriminant Analysis of Principal Components), Bayesian statistical inference (Clustering, Approximate Bayesian Computation) and demographic tests allowed a construction of the introduction pathways of the species over recent centuries. While emigrants originated from only one of the two native lineages, the West one, the most likely scenario involved several introduction events and "source switching" comprising (i) an early stage (around 1660) of simultaneous introductions from Europe (France, Spain) towards Oceania (New Zealand) and California, (ii) from the early 18(th) century, a second colonization wave from bridgehead populations successfully established in California, (iii) genetic admixture in invasive areas where highly divergent populations came into contact as in New Zealand. Although these man-made pathways are consistent with historical data, introduction time estimates suggest that the two putative waves of invasion would have occurred long before the first field observations recorded, both in America and in Oceania. A prolonged lag period as the use of an incorrect generation time could explain such 100-150 years discrepancy. Lastly, the contrasting patterns of neutral genetic signal left in invasive populations are

  7. A pilot study testing a natural and a synthetic Molluscicide for controlling invasive apple snails (Pomacea maculata)

    Science.gov (United States)

    Olivier, Heather M.; Jenkins, Jill A.; Berhow, Mark; Carter, Jacoby

    2016-01-01

    Pomacea maculata (formerly P. insularum), an apple snail native to South America, was discovered in Louisiana in 2008. These snails strip vegetation, reproduce at tremendous rates, and have reduced rice production and caused ecosystem changes in Asia. In this pilot study snails were exposed to two molluscicides, a tea (Camellia sinensis) seed derivative (TSD) or niclosamide monohydrate (Pestanal®, 2′,5-dichloro-4′-nitrosalicylanilide, CAS #73360-56-2). Mortality was recorded after exposure to high or low concentrations (0.03 and 0.015 g/L for TSD, 1.3 and 0.13 mg/L for niclosamide). The TSD induced 100 % mortality at both concentrations. Niclosamide caused 100 % and 17 % mortality at high and low concentrations respectively. These molluscicides were also tested on potential biocontrol agents, the red swamp crayfish (Procambarus clarkii) and redear sunfish (Lepomis microlophus). No crayfish mortalities occurred at either concentration for either chemical, but sunfish experienced 100 % mortality with TSD (0.03 g/L), and 21 % mortality with niclosamide (0.13 mg/L).

  8. A Pilot Study Testing a Natural and a Synthetic Molluscicide for Controlling Invasive Apple Snails (Pomacea maculata).

    Science.gov (United States)

    Olivier, Heather M; Jenkins, Jill A; Berhow, Mark; Carter, Jacoby

    2016-03-01

    Pomacea maculata (formerly P. insularum), an apple snail native to South America, was discovered in Louisiana in 2008. These snails strip vegetation, reproduce at tremendous rates, and have reduced rice production and caused ecosystem changes in Asia. In this pilot study snails were exposed to two molluscicides, a tea (Camellia sinensis) seed derivative (TSD) or niclosamide monohydrate (Pestanal(®), 2',5-dichloro-4'-nitrosalicylanilide, CAS #73360-56-2). Mortality was recorded after exposure to high or low concentrations (0.03 and 0.015 g/L for TSD, 1.3 and 0.13 mg/L for niclosamide). The TSD induced 100 % mortality at both concentrations. Niclosamide caused 100 % and 17 % mortality at high and low concentrations respectively. These molluscicides were also tested on potential biocontrol agents, the red swamp crayfish (Procambarus clarkii) and redear sunfish (Lepomis microlophus). No crayfish mortalities occurred at either concentration for either chemical, but sunfish experienced 100 % mortality with TSD (0.03 g/L), and 21 % mortality with niclosamide (0.13 mg/L).

  9. Distribution and the origin of invasive apple snails, Pomacea canaliculata and P. maculata (Gastropoda: Ampullariidae) in China.

    Science.gov (United States)

    Yang, Qian-Qian; Liu, Su-Wen; He, Chao; Yu, Xiao-Ping

    2018-01-19

    Species of Pomacea, commonly known as apple snails, are native to South America, and have become widely distributed agricultural and environmental pests in southern China since their introduction in the 1980s. However, only since 2010 have researchers recognized that at least two species, P. canaliculata and P. maculata, are present in China. Although impacts of apple snails have been extensively documented, confusion still persists regarding current distributions and origin of the species in China. To resolve this confusion, we used phylogenetic and phylogeographic methods to analyze 1464 mitochondrial COI sequences, including 349 new sequences from samples collected in southern China and 1115 publicly available sequences from snails collected in the native and introduced ranges. Pomacea canaliculata was found at all sampled localities, while P. maculata was found at only five sampled localities in the Sichuan basin and Zhejiang province. Our data indicate that Chinese populations of P. canaliculata share an Argentinian origin, consistent with multiple introductions of this species elsewhere in Asia. In addition, just a single lineage of P. maculata is established in China, which shares with populations in Brazil.

  10. Effects of absolute fasting on reproduction and survival of the invasive apple snailPomacea canaliculatain its native range.

    Science.gov (United States)

    Tamburi, Nicolás E; Martín, Pablo R

    2016-08-01

    A South American freshwater gastropod, the apple snail Pomacea canaliculata, has become a driver of ecosystemic changes in wetlands and an important rice pest after its introduction to various parts of the world, mainly Asia. The objective of this study was to study the effect of an abrupt interruption in food availability in the short term (up to 4 weeks) and long term (up to 8 months) on survival and reproductive activity. The main results indicate that short-term fasting mainly affects the survival of males, but only when they are raised together with females, probably due to a greater mate-searching activity that increases mortality in the individuals with lower reserves. The number of copulating snails or egg-laying females shows an abrupt drop when fasting and a rapid recovery after the food supply is restored. The strategy of discontinuing reproductive activity prioritizes energy conservation for the survival of the females. Interpopulation variation in resistance to starvation was observed in adults, which can be explained to some extent by the food availability that they experienced in their natural environment. No interpopulational differences in survival were seen in hatchlings. The mean maximum values of survival under starvation were 52.6 days in hatchlings and the 3.3% of adults survive over than 200 days, which may be a relevant trait in dispersal and establishment in new habitats.

  11. Effects of absolute fasting on reproduction and survival of the invasive apple snail Pomacea canaliculata in its native range

    Science.gov (United States)

    Tamburi, Nicolás E.

    2016-01-01

    Abstract A South American freshwater gastropod, the apple snail Pomacea canaliculata, has become a driver of ecosystemic changes in wetlands and an important rice pest after its introduction to various parts of the world, mainly Asia. The objective of this study was to study the effect of an abrupt interruption in food availability in the short term (up to 4 weeks) and long term (up to 8 months) on survival and reproductive activity. The main results indicate that short-term fasting mainly affects the survival of males, but only when they are raised together with females, probably due to a greater mate-searching activity that increases mortality in the individuals with lower reserves. The number of copulating snails or egg-laying females shows an abrupt drop when fasting and a rapid recovery after the food supply is restored. The strategy of discontinuing reproductive activity prioritizes energy conservation for the survival of the females. Interpopulation variation in resistance to starvation was observed in adults, which can be explained to some extent by the food availability that they experienced in their natural environment. No interpopulational differences in survival were seen in hatchlings. The mean maximum values of survival under starvation were 52.6 days in hatchlings and the 3.3% of adults survive over than 200 days, which may be a relevant trait in dispersal and establishment in new habitats. PMID:29491925

  12. Snail Trails

    Science.gov (United States)

    Galus, Pamela

    2002-01-01

    The slime trails of snails lead the author's students to a better understanding of science as inquiry and the processes of science. During this five-day activity, students get up close and personal with one of her favorite creatures, the land snail. Students begin by observing the organism and recording their observations. After making initial…

  13. Environmental risk assessment for invasive alien species: A case study of apple snails affecting ecosystem services in Europe

    NARCIS (Netherlands)

    Gilioli, Gianni; Schrader, Gritta; Carlsson, Nils; van Donk, Ellen; van Leeuwen, Casper H.A.; Martín, Pablo R.; Pasquali, Sara; Vilà, Montserrat; Vos, Sybren

    Abstract The assessment of the risk posed by invasive alien species (IAS) to the environment is a component of increasing importance for Pest Risk Analysis. Standardized and comprehensive procedures to assess their impacts on ecosystem services have been developed only recently. The invasive apple

  14. Reproductive ecology of the giant African snail in South Florida

    DEFF Research Database (Denmark)

    Roda, Amy; Nachman, Gøsta Støger; Weihman, Scott

    2016-01-01

    Giant African snail (Achatina fulica (Bowdich, 1822)), an important invasive snail, was recently found in South Florida, USA. An extensive eradication effort was initiated consisting of pesticide applications, debris removal and hand collections. We studied the reproduction capacity and population...... eggs, which were found year round. As the snails increased in size, they were more likely to include reproducing individuals. However, the percentage of gravid snails peaked when snails were approximately 90 mm. Although more prevalent, small (... of egg producing snails, eventually resulting in local extinctions of this important pest....

  15. TPD52L2 impacts proliferation, invasiveness and apoptosis of glioblastoma cells via modulation of wnt/β-catenin/snail signaling.

    Science.gov (United States)

    Qiang, Zhou; Jun-Jie, Li; Hai, Wang; Hong, Li; Bing-Xi, Lei; Lei, Chen; Wei, Xiang; Ya-Wei, Liu; Huang, Annie; Song-Tao, Qi; Yun-Tao, Lu

    2018-02-09

    Intratumoral heterogeneity greatly hinders efficiency of target therapy in glioblastoma (GBM). To decipher the underlying mechanisms of heterogeneity, patient-derived adult GBM cells were separately isolated from margins of T1 gadolinium enhancing tumor lesions (PNCs) and T1 gadolinium enhancing core lesions (ECs). Single clone culture was conducted in ECs and U87MG cell line to screen clones with distinct biological phenotypes. Single cell clones with diverse phenotypes were simultaneously separated from ECs and U87 cell line. PNCs, GCs(H) and U87(H) exhibited longer cellular protrusion than ECs, GCs(L) and U87(L), respectively. Cell strains with longer protrusion exhibited higher invasive ability and lower sensitivity to temozolomide (TMZ) and radiation. Subsequently, TPD52L2 was verified as the functional protein to regulate the cellular heterogeneity by the proteomics analysis. Downregulation of TPD52L2 enhanced cell invasion whereas inhibited cell proliferation rate and sensitivity to chemotherapy in vivo and in vitro, this condition was reversed when TPD52L2 was overexpressed. The invasiveness was facilitated by up-regulating CTNNB1/β-catenin and SNAI1/Snail mediated EMT process. In addition, the clinical data of 88 GBM cases in our neurosurgery center was analyzed to reveal the influence of TPD52L2 in the prognosis of GBM. Low expression of TPD52L2 exacerbated prognosis of GBM patients received standard radiotherapy plus concomitant and adjuvant TMZ (Stupp strategy). Taken together, TPD52L2 is an important biomarker influencing GBM prognosis. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Effects of Spartina alterniflora invasion on the communities of methanogens and sulfate-reducing bacteria in estuarine marsh sediments

    Directory of Open Access Journals (Sweden)

    Jemaneh eZeleke

    2013-08-01

    Full Text Available The effect of plant invasion on the microorganisms of soil sediments is very important for estuary ecology. The community structures of methanogens and sulfate-reducing bacteria (SRB as a function of Spartina alterniflora invasion in Phragmites australis-vegetated sediments of the Dongtan wetland in the Yangtze River estuary, China, were investigated using 454 pyrosequencing and quantitative real-time PCR (qPCR of the methyl coenzyme M reductase A (mcrA and dissimilatory sulfite-reductase (dsrB genes. Sediment samples were collected from two replicate locations, and each location included three sampling stands each covered by monocultures of P. australis, S. alterniflora and both plants (transition stands, respectively. qPCR analysis revealed higher copy numbers of mcrA genes in sediments from S. alterniflora stands than P. australis stands (5- and 7.5-fold more in the spring and summer, respectively, which is consistent with the higher methane flux rates measured in the S. alterniflora stands (up to 8.01 ± 5.61 mg m-2 h-1. Similar trends were observed for SRB, and they were up to two orders of magnitude higher than the methanogens. Diversity indices indicated a lower diversity of methanogens in the S. alterniflora stands than the P. australis stands. In contrast, insignificant variations were observed in the diversity of SRB with the invasion. Although Methanomicrobiales and Methanococcales, the hydrogenotrophic methanogens, dominated in the salt marsh, Methanomicrobiales displayed a slight increase with the invasion and growth of S. alterniflora, whereas the later responded differently. Methanosarcina, the metabolically diverse methanogens, did not vary with the invasion of, but Methanosaeta, the exclusive acetate utilizers, appeared to increase with S. alterniflora invasion. In SRB, sequences closely related to the families Desulfobacteraceae and Desulfobulbaceae dominated in the salt marsh, although they displayed minimal changes with the S

  17. Endosymbiotic and host proteases in the digestive tract of the invasive snail Pomacea canaliculata: diversity, origin and characterization.

    Directory of Open Access Journals (Sweden)

    Martín S Godoy

    Full Text Available Digestive proteases of the digestive tract of the apple snail Pomacea canaliculata were studied. Luminal protease activity was found in the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Several protease bands and their apparent molecular weights were identified in both tissue extracts and luminal contents by gel zymography: (1 a 125 kDa protease in salivary gland extracts and in the crop content; (2 a 30 kDa protease throughout all studied luminal contents and in extracts of the midgut gland and of the endosymbionts isolated from this gland; (3 two proteases of 145 and 198 kDa in the coiled gut content. All these proteases were inhibited by aprotinin, a serine-protease inhibitor, and showed maximum activity between 30°C and 35°C and pH between 8.5 and 9.5. Tissue L-alanine-N-aminopeptidase activity was determined in the wall of the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Our findings show that protein digestion in P. canaliculata is carried out through a battery of diverse proteases originated from the salivary glands and the endosymbionts lodged in the midgut gland and by proteases of uncertain origin that occur in the coiled gut lumen.

  18. Endosymbiotic and host proteases in the digestive tract of the invasive snail Pomacea canaliculata: diversity, origin and characterization.

    Science.gov (United States)

    Godoy, Martín S; Castro-Vazquez, Alfredo; Castro-Vasquez, Alfredo; Vega, Israel A

    2013-01-01

    Digestive proteases of the digestive tract of the apple snail Pomacea canaliculata were studied. Luminal protease activity was found in the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Several protease bands and their apparent molecular weights were identified in both tissue extracts and luminal contents by gel zymography: (1) a 125 kDa protease in salivary gland extracts and in the crop content; (2) a 30 kDa protease throughout all studied luminal contents and in extracts of the midgut gland and of the endosymbionts isolated from this gland; (3) two proteases of 145 and 198 kDa in the coiled gut content. All these proteases were inhibited by aprotinin, a serine-protease inhibitor, and showed maximum activity between 30°C and 35°C and pH between 8.5 and 9.5. Tissue L-alanine-N-aminopeptidase activity was determined in the wall of the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Our findings show that protein digestion in P. canaliculata is carried out through a battery of diverse proteases originated from the salivary glands and the endosymbionts lodged in the midgut gland and by proteases of uncertain origin that occur in the coiled gut lumen.

  19. Immune Defenses of the Invasive Apple Snail Pomacea canaliculata (Caenogastropoda, Ampullariidae): Phagocytic Hemocytes in the Circulation and the Kidney.

    Science.gov (United States)

    Cueto, Juan A; Rodriguez, Cristian; Vega, Israel A; Castro-Vazquez, Alfredo

    2015-01-01

    participate in the storage and circulation of this compound. Injection of microorganisms in the foot results in phagocytosis by hemocytes in the islets, and the different phagosomes formed are similar to those in circulating hyalinocytes. Dispersed hemocytes were obtained after kidney collagenase digestion and cell sorting, and they were able to phagocytize fluorescent beads. A role for the kidney as an immune barrier is proposed for this snail.

  20. Immune Defenses of the Invasive Apple Snail Pomacea canaliculata (Caenogastropoda, Ampullariidae: Phagocytic Hemocytes in the Circulation and the Kidney.

    Directory of Open Access Journals (Sweden)

    Juan A Cueto

    hyalinocytes participate in the storage and circulation of this compound. Injection of microorganisms in the foot results in phagocytosis by hemocytes in the islets, and the different phagosomes formed are similar to those in circulating hyalinocytes. Dispersed hemocytes were obtained after kidney collagenase digestion and cell sorting, and they were able to phagocytize fluorescent beads. A role for the kidney as an immune barrier is proposed for this snail.

  1. Variation in thermal sensitivity and thermal tolerances in an invasive species across a climatic gradient: lessons from the land snail Cornu aspersum.

    Directory of Open Access Journals (Sweden)

    Juan Diego Gaitán-Espitia

    Full Text Available The ability of organisms to perform at different temperatures could be described by a continuous nonlinear reaction norm (i.e., thermal performance curve, TPC, in which the phenotypic trait value varies as a function of temperature. Almost any shift in the parameters of this performance curve could highlight the direct effect of temperature on organism fitness, providing a powerful framework for testing thermal adaptation hypotheses. Inter-and intraspecific differences in this performance curve are also reflected in thermal tolerances limits (e.g., critical and lethal limits, influencing the biogeographic patterns of species' distribution. Within this context, here we investigated the intraspecific variation in thermal sensitivities and thermal tolerances in three populations of the invasive snail Cornu aspersum across a geographical gradient, characterized by different climatic conditions. Thus, we examined population differentiation in the TPCs, thermal-coma recovery times, expression of heat-shock proteins and standard metabolic rate (i.e., energetic costs of physiological differentiation. We tested two competing hypotheses regarding thermal adaptation (the "hotter is better" and the generalist-specialist trade-offs. Our results show that the differences in thermal sensitivity among populations of C. aspersum follow a latitudinal pattern, which is likely the result of a combination of thermodynamic constraints ("hotter is better" and thermal adaptations to their local environments (generalist-specialist trade-offs. This finding is also consistent with some thermal tolerance indices such as the Heat-Shock Protein Response and the recovery time from chill-coma. However, mixed responses in the evaluated traits suggest that thermal adaptation in this species is not complete, as we were not able to detect any differences in neither energetic costs of physiological differentiation among populations, nor in the heat-coma recovery.

  2. Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands

    Science.gov (United States)

    Yam, Rita S. W.; Fan, Yen-Tzu; Wang, Tzu-Ting

    2016-01-01

    Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents. PMID:26927135

  3. Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands

    Directory of Open Access Journals (Sweden)

    Rita S. W. Yam

    2016-02-01

    Full Text Available Pomacea canaliculata (Ampullariidae has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents.

  4. Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands.

    Science.gov (United States)

    Yam, Rita S W; Fan, Yen-Tzu; Wang, Tzu-Ting

    2016-02-24

    Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents.

  5. The faucet snail (Bithynia tentaculata) invades the St. Louis River Estuary

    Science.gov (United States)

    The European-origin faucet snail (Bithynia tentaculata) now numbers among the aquatic invasive species present in the St. Louis River Estuary. This snail has been in the lower Great Lakes since the early 20th century but is new to the Lake Superior basin. We found faucet snails...

  6. Fecundity of the Chinese mystery snail in a Nebraska reservoir

    Science.gov (United States)

    Stephen, Bruce J.; Allen, Craig R.; Chaine, Noelle M.; Fricke, Kent A.; Haak, Danielle M.; Hellman, Michelle L.; Kill, Robert A.; Nemec, Kristine T.; Pope, Kevin L.; Smeenk, Nicholas A.; Uden, Daniel R.; Unstad, Kody M.; VanderHam, Ashley E.; Wong, Alec

    2013-01-01

    The Chinese mystery snail (Bellamya chinensis) is a non-indigenous, invasive species in freshwater ecosystems of North America. We provide fecundity estimates for a population of these snails in a Nebraska reservoir. We dissected 70 snails, of which 29 were females. Nearly all female snails contained developing young, with an average of 25 young per female. Annual fecundity was estimated at between 27.2 and 33.3 young per female per year. Based on an estimated adult population and the calculated fecundity, the annual production for this reservoir was between 2.2 and 3.7 million young.

  7. Prognostic significance of snail expression in hilar cholangiocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Dalu [Department of Hepatobiliary Surgery, Tianjin Medical University Cancer Institute and Hospital, Hexi District, Tianjin (China); Liang, Jun [Department of Oncology, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China); Li, Rong [Department of Hepatobiliary Surgery, Tianjin Medical University Cancer Institute and Hospital, Hexi District, Tianjin (China); Liu, Shihai [Department of Laboratory Center, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China); Wang, Jigang [Department of Oncology, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China); Zhang, Kejun; Chen, Dong [Department of General Surgery, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China)

    2012-05-11

    Many patients with hilar cholangiocarcinoma (HC) have a poor prognosis. Snail, a transcription factor and E-cadherin repressor, is a novel prognostic factor in many cancers. The aim of this study was to evaluate the relationship between snail and E-cadherin protein expression and the prognostic significance of snail expression in HC. We examined the protein expression of snail and E-cadherin in HC tissues from 47 patients (22 males and 25 females, mean age 61.2 years) using immunohistochemistry and RT-PCR. Proliferation rate was also evaluated in the same cases by the MIB1 index. High, low and negative snail protein expression was recorded in 18 (38%), 17 (36%), and 12 (26%) cases, respectively, and 40.4% (19/47) cases showed reduced E-cadherin protein expression in HC samples. No significant correlation was found between snail and E-cadherin protein expression levels (P = 0.056). No significant correlation was found between snail protein expression levels and gender, age, tumor grade, vascular or perineural invasion, nodal metastasis and invasion, or proliferative index. Cancer samples with positive snail protein expression were associated with poor survival compared with the negative expresser groups. Kaplan-Meier curves comparing different snail protein expression levels to survival showed highly significant separation (P < 0.0001, log-rank test). With multivariate analysis, only snail protein expression among all parameters was found to influence survival (P = 0.0003). We suggest that snail expression levels can predict poor survival regardless of pathological features and tumor proliferation. Immunohistochemical detection of snail protein expression levels in routine sections may provide the first biological prognostic marker.

  8. Ecology of Estuarine Macrobenthos

    NARCIS (Netherlands)

    Herman, P.M.J.; Middelburg, J.J.; Koppel, J. van de; Heip, C.H.R.

    1999-01-01

    Macrobenthos is an important component of estuarine ecosystems. Based on a cross-system comparison, we show that estuarine macrobenthos may directly process a significant portion of the system-wide primary production, and that estuarine macrobenthic biomass may be predicted from primary production

  9. MicroRNA-106b-25 cluster targets β-TRCP2, increases the expression of Snail and enhances cell migration and invasion in H1299 (non small cell lung cancer) cells

    Energy Technology Data Exchange (ETDEWEB)

    Savita, Udainiya; Karunagaran, Devarajan, E-mail: karuna@iitm.ac.in

    2013-05-17

    Highlights: •miR-106b-25 cluster directly targets the 3′UTR of the β-TRCP2 transcript. •β-TRCP2 mRNA was lower in H1299 cells stably expressing miR-106b-25 cluster. •miR-106b-25 cluster increased the expression of Snail. •miR-106b-25 cluster promoted the migration, colony formation and invasion. •miR-106b-25 cluster enhanced endothelial tube formation. -- Abstract: Lung cancer causes high mortality without a declining trend and non small cell lung cancer represents 85% of all pulmonary carcinomas. MicroRNAs (miRNAs) serve as fine regulators of proliferation, migration, invasion/metastasis and angiogenesis of normal and cancer cells. Using TargetScan6.2, we predicted that the ubiquitin ligase, β-TRCP2, could be a target for two of the constituent miRNAs of the miR-106b-25 cluster (miR-106b and miR-93). We generated a stable clone of miR-106b-25 cluster (CL) or the empty vector (EV) in H1299 (non small cell lung cancer) cells. The expression of β-TRCP2 mRNA was significantly lower in CL than that in EV cells. Transient expression of miR-93 but not antimiR-93 decreased the expression of β-TRCP2 mRNA in H1299 cells. β-TRCP2-3′UTR reporter assay revealed that its activity in CL cells was only 60% of that in EV cells. Snail protein expression was higher in CL than that in EV cells and H1299 cells exhibited an increase in the expression of Snail upon transient transfection with miR-93. miR-106b-25 cluster-induced migration of CL measured by scratch assay was more than that in EV cells and no significant difference in migration was observed between antimiR-93-transfected H1299 cells and the corresponding control-oligo-transfected cells. miR-106b-25 cluster-induced migration of CL cells was again confirmed in a Boyden chamber assay without the matrigel. CL cells were more invasive than EV cells when assessed using Boyden chambers with matrigel but there were no significant changes in the cell viabilities between EV and CL cells. Colony formation assay

  10. Reproductive Ecology of the Giant African Snail in South Florida: Implications for Eradication Programs

    Science.gov (United States)

    2016-01-01

    Giant African snail (Achatina fulica (Bowdich, 1822)), an important invasive snail, was recently found in South Florida, USA. An extensive eradication effort was initiated consisting of pesticide applications, debris removal and hand collections. We studied the reproduction capacity and population dynamics of snails collected from 22 populations for two years to help evaluate the likely success of the eradication program. A total of 23,890 snails, ranging from 25–131 mm, were measured, dissected and the number of eggs in each snail counted. Gravid snails ranged from 48–128 mm. Only 5% of snails had eggs, which were found year round. As the snails increased in size, they were more likely to include reproducing individuals. However, the percentage of gravid snails peaked when snails were approximately 90 mm. Although more prevalent, small (snails. We evaluated the effect of control measures on six populations having >1000 adult snails and used data from the two largest populations to investigate how environmental factors (temperature, humidity, and rainfall) interacted with population dynamics and control measures. More snails were collected in weeks with high humidity and more gravid snails were collected when the temperature was higher. The addition of metaldehyde pesticides had the greatest impact on population dynamics by reducing snail numbers. In populations with fewer snails, their numbers were already declining before the use of metaldehyde, although the new treatment accelerated the process. As a consequence of the eradication program, egg-producing snails were no longer collected from most populations by the end of the study. The aggressive and persistent control efforts apparently lead to reduced populations of egg producing snails, eventually resulting in local extinctions of this important pest. PMID:27861504

  11. The major egg reserve protein from the invasive apple snail Pomacea maculata is a complex carotenoprotein related to those of Pomacea canaliculata and Pomacea scalaris.

    Science.gov (United States)

    Pasquevich, M Y; Dreon, M S; Heras, H

    2014-03-01

    Snails from the genus Pomacea lay conspicuous masses of brightly colored eggs above the water. Coloration is given by carotenoproteins that also which play important roles in protection against sun radiation, stabilizing and transporting antioxidant molecules and helping to protect embryos from desiccation and predators. They seem a key acquisition, but have been little studied. Here we report the characteristics of the major carotenoprotein from Pomacea maculata and the first comparison among these egg proteins. This particle, hereafter PmPV1, represents ~52% of perivitellin fluid protein. It is a glyco-lipo-carotenoprotein responsible for the bright reddish egg coloration. With VHDL characteristics, PmPV1 apparent molecular mass is 294kDa, composed of five non-covalently bound subunits of pI 4.7-9.8 and masses between 26 and 36kDa whose N-terminal sequences were obtained. It is a glyco-lipo-carotenoprotein scarcely lipidated (Pomacea canaliculata. The characterization of PmPV1 allows the first comparisons among snail carotenoproteins and further highlights the importance of these perivitellins in the reproductive strategy of Pomacea. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Models of Snail Locomotion

    Science.gov (United States)

    Chan, Brian; Hosoi, Anette

    2003-11-01

    All snails move over a thin layer of mucus using periodic deformations of their muscular foot. This unusual mode of locomotion can be modeled as a thin film of viscous fluid sandwiched between a flexible membrane and a rigid substrate. We present theoretical, numerical and experimental studies of locomotion via viscous stresses generated in thin films. Study of snail locomotion led us to design and construct several mechanical models: RoboSnail 1 which mimics snail locomotion incorrectly, but still proves to be a valid propulsion device over a thin viscous fluid layer and RoboSnail 2 which mimics land snails and uses forward-propagating compression waves on the base of the foot. Experimental results from the prototype machines are compared with long wavelength numerical and theoretical models.

  13. The snail lemma

    OpenAIRE

    Vitale, Enrico

    2016-01-01

    The classical snake lemma produces a six terms exact sequence starting from a commutative square with one of the edge being a regular epimorphism. We establish a new diagram lemma, that we call snail lemma, removing such a condition. We also show that the snail lemma subsumes the snake lemma and we give an interpretation of the snail lemma in terms of strong homotopy kernels. Our results hold in any pointed regular protomodular category.

  14. Snail: More than EMT

    OpenAIRE

    Wu, Yadi; Zhou, Binhua P.

    2010-01-01

    Snail has moved into the fast lane of development and cancer biology with the epithelial-mesenchymal transition (EMT) emerging as one of the hottest topics in medical science within the past few years. Snail not only acts primarily as a key inducer of EMT but also plays an important role in cell survival, immune regulation and stem cell biology. This review focuses on the regulation of Snail and discusses the EMT-dependent and -independent functions of Snail in development and disease. Unders...

  15. Phenotypic plasticity of the introduced New Zealand mud snail, Potamopyrgus antipodarum, compared to sympatric native snails.

    Directory of Open Access Journals (Sweden)

    Edward P Levri

    Full Text Available Phenotypic plasticity is likely to be important in determining the invasive potential of a species, especially if invasive species show greater plasticity or tolerance compared to sympatric native species. Here in two separate experiments we compare reaction norms in response to two environmental variables of two clones of the New Zealand mud snail, Potamopyrgus antipodarum, isolated from the United States, (one invasive and one not yet invasive with those of two species of native snails that are sympatric with the invader, Fossaria bulimoides group and Physella gyrina group. We placed juvenile snails in environments with high and low conductivity (300 and 800 mS in one experiment, and raised them at two different temperatures (16 °C and 22 °C in a second experiment. Growth rate and mortality were measured over the course of 8 weeks. Mortality rates were higher in the native snails compared to P. antipodarum across all treatments, and variation in conductivity influenced mortality. In both experiments, reaction norms did not vary significantly between species. There was little evidence that the success of the introduced species is a result of greater phenotypic plasticity to these variables compared to the sympatric native species.

  16. Overexpression of Snail is associated with lymph node metastasis and poor prognosis in patients with gastric cancer

    International Nuclear Information System (INIS)

    Shin, Na Ri; Lee, Jae Hyuk; Park, Do Youn; Jeong, Eun Hui; Choi, Chang In; Moon, Hyun Jung; Kwon, Chae Hwa; Chu, In Sun; Kim, Gwang Ha; Jeon, Tae Yong; Kim, Dae Hwan

    2012-01-01

    Epithelial–mesenchymal transition (EMT) plays a significant role in tumor progression and invasion. Snail is a known regulator of EMT in various malignant tumors. This study investigated the role of Snail in gastric cancer. We examined the effects of silenced or overexpressed Snail using lenti-viral constructs in gastric cancer cells. Immunohistochemical analysis of tissue microarrays from 314 patients with gastric adenocarcinoma (GC) was used to determine Snail’s clinicopathological and prognostic significance. Differential gene expression in 45 GC specimens with Snail overexpression was investigated using cDNA microarray analysis. Silencing of Snail by shRNA decreased invasion and migration in GC cell lines. Conversely, Snail overexpression increased invasion and migration of gastric cancer cells, in line with increased VEGF and MMP11. Snail overexpression (≥75% positive nuclear staining) was also significantly associated with tumor progression (P < 0.001), lymph node metastases (P = 0.002), lymphovascular invasion (P = 0.002), and perineural invasion (P = 0.002) in the 314 GC patients, and with shorter survival (P = 0.023). cDNA microarray analysis revealed 213 differentially expressed genes in GC tissues with Snail overexpression, including genes related to metastasis and invasion. Snail significantly affects invasiveness/migratory ability of GCs, and may also be used as a predictive biomarker for prognosis or aggressiveness of GCs

  17. Snail Shell Science.

    Science.gov (United States)

    Matthews, Catherine

    1992-01-01

    Presents three inquiry-based lessons to develop the science process skills of observation, identification, and classification. Activities use whelk eggs and snail shells as the focus of the students' inquiries. Provides a list of 19 facts about whelks and snails. (MDH)

  18. The Classroom Animal: Snails.

    Science.gov (United States)

    Kramer, David S.

    1985-01-01

    Points out that snails are interesting and easily-managed classroom animals. One advantage of this animal is that it requires no special attention over weekends or holidays. Background information, anatomy, reproduction, and feeding are discussed, along with suggestions for housing aquatic and/or land snails. (DH)

  19. Expression and activity of SNAIL transcription factor during Epithelial to Mesenchymal Transition (EMT in cancer progression

    Directory of Open Access Journals (Sweden)

    Izabela Papiewska-Pająk

    2016-09-01

    Full Text Available Inhibition of E-cadherin gene expression by transcription factor SNAIL is known to be a crucial element of Epithelial to Mesenchymal Transition; EMT. Epigenetic regulation of E-cadherin expression is regulated by SNAIL binding to E-box sequences in the CDH1 gene promoter and recruiting enzymes belonging to repressor complexes that are directly engaged in histone modifications and DNA methylation leading to the modification of chromatin structure. SNAIL involvement in cell acquisition of invasive phenotype is based on direct suppression of tight-junction and gap junction proteins.The nuclear localization of SNAIL is required for SNAIL activity and protects this factor fromproteasomal degradation in the cytoplasm. The main factor engaged in that process is GSK- 3β kinase. Expression and stability of SNAIL is regulated on the transctriptional and posttranscriptional levels by a number of signaling molecules and biological factors, for example: TGF-β, TNF-α, ILK and NFκB. The expression of SNAIL in cancer cells is also regulated by micro-RNA, mainly by miR-34.Increased expression of SNAIL, observed in many human cancers, has been correlated with increased resistance to chemio-, radio – or immunotherapy, gain of cancer stem cells features and migrative and invasive characteristics, which leads to tumor metastases. Understanding of the SNAIL’s mechanism of action may lead to new treatment strategies in cancer directed to interfere with signaling pathways that either activate SNAIL or are activated by SNAIL.

  20. Snail transcription factor negatively regulates maspin tumor suppressor in human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Neal Corey L

    2012-08-01

    Full Text Available Abstract Background Maspin, a putative tumor suppressor that is down-regulated in breast and prostate cancer, has been associated with decreased cell motility. Snail transcription factor is a zinc finger protein that is increased in breast cancer and is associated with increased tumor motility and invasion by induction of epithelial-mesenchymal transition (EMT. We investigated the molecular mechanisms by which Snail increases tumor motility and invasion utilizing prostate cancer cells. Methods Expression levels were analyzed by RT-PCR and western blot analyses. Cell motility and invasion assays were performed, while Snail regulation and binding to maspin promoter was analyzed by luciferase reporter and chromatin immunoprecipitation (ChIP assays. Results Snail protein expression was higher in different prostate cancer cells lines as compared to normal prostate epithelial cells, which correlated inversely with maspin expression. Snail overexpression in 22Rv1 prostate cancer cells inhibited maspin expression and led to increased migration and invasion. Knockdown of Snail in DU145 and C4-2 cancer cells resulted in up-regulation of maspin expression, concomitant with decreased migration. Transfection of Snail into 22Rv1 or LNCaP cells inhibited maspin promoter activity, while stable knockdown of Snail in C4-2 cells increased promoter activity. ChIP analysis showed that Snail is recruited to the maspin promoter in 22Rv1 cells. Conclusions Overall, this is the first report showing that Snail can negatively regulate maspin expression by directly repressing maspin promoter activity, leading to increased cell migration and invasion. Therefore, therapeutic targeting of Snail may be useful to re-induce expression of maspin tumor suppressor and prevent prostate cancer tumor progression.

  1. Widespread and persistent invasions of terrestrial habitats coincident with larval feeding behavior transitions during snail-killing fly evolution (Diptera: Sciomyzidae

    Directory of Open Access Journals (Sweden)

    Chapman Eric G

    2012-09-01

    Full Text Available Abstract Background Transitions in habitats and feeding behaviors were fundamental to the diversification of life on Earth. There is ongoing debate regarding the typical directionality of transitions between aquatic and terrestrial habitats and the mechanisms responsible for the preponderance of terrestrial to aquatic transitions. Snail-killing flies (Diptera: Sciomyzidae represent an excellent model system to study such transitions because their larvae display a range of feeding behaviors, being predators, parasitoids or saprophages of a variety of mollusks in freshwater, shoreline and dry terrestrial habitats. The remarkable genus Tetanocera (Tetanocerini occupies five larval feeding groups and all of the habitat types mentioned above. This study has four principal objectives: (i construct a robust estimate of phylogeny for Tetanocera and Tetanocerini, (ii estimate the evolutionary transitions in larval feeding behaviors and habitats, (iii test the monophyly of feeding groups and (iv identify mechanisms underlying sciomyzid habitat and feeding behavior evolution. Results Bayesian inference and maximum likelihood analyses of molecular data provided strong support that the Sciomyzini, Tetanocerini and Tetanocera are monophyletic. However, the monophyly of many behavioral groupings was rejected via phylogenetic constraint analyses. We determined that (i the ancestral sciomyzid lineage was terrestrial, (ii there was a single terrestrial to aquatic habitat transition early in the evolution of the Tetanocerini and (iii there were at least 10 independent aquatic to terrestrial habitat transitions and at least 15 feeding behavior transitions during tetanocerine phylogenesis. The ancestor of Tetanocera was aquatic with five lineages making independent transitions to terrestrial habitats and seven making independent transitions in feeding behaviors. Conclusions The preponderance of aquatic to terrestrial transitions in sciomyzids goes against the trend

  2. (snail repellent paint) on land snails

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... environmental pollution during summer when pesticide application rates increase in orchards. X. derbentina ... compared to other pesticides, such as insecticides, seem to overshadow research into their ..... is applied to soil as a pellet that also contains food grade attractants to lure snails and slugs. It is not ...

  3. Removal of cadmium from aqueous solution using waste shells of golden apple snail

    Science.gov (United States)

    Benliang Zhao; Jia-en Zhang; Wenbin Yan; Xiaowu Kang; Chaogang Cheng; Ying Ouyang

    2016-01-01

    Golden apple snail (GAS) is one of the 100 worst invasive alien species. With the application of molluscicides to kill and control the spreading of these snails, a large amount of dead GAS shells are remained in many farms. This study ascertained the characteristics and removal of cadmium (Cd) by the GAS shell (GASS) powders and the associate mechanisms....

  4. Snail meat: Significance and consumption

    Directory of Open Access Journals (Sweden)

    Dragićević Olgica

    2005-01-01

    Full Text Available The consumption of snail meat goes back to prehistoric times. Different ancient nations had snails on their menu, but Helices culture as a productive activity was born as a Roman culture. Some of the most economically important edible species are: Helix aspersa (Mtiller Helixpomatia (Linne, Helix iucorum (Linne, Helix aperta (Born, Eobania vermiculata (Miiller. Together with its tasie, snail meat has several advantages over others: quite low lipid rate and calorie values versus rich mineral, essential amino acid and fatty acid content. The composition of snail meat is presented. In addition, the composition of different snail species and the part analyzed (pedal mass and visceral mass is presented. Also, the differences in composition according to the species (snail meat horse/chicken meat, beef, swine meat, fish meat are presented. The French are the world's leading consumers of snails. !n France snails come to market in a variety of ways. Estimated consumption of snails in France is around 40 000 tones/year. Total French imports account for 25% of world imports. France is also the leading exporter of prepared snails, mainly sold as preserved snails and prepared dishes. Snail imports have been much higher than exports (65 tones exported in 2002. vs. 2.700 tones imported. Despite the large consumption, only 3% of snails in France come from production (farming. Italy is in second place in the world consumption of snails, and Spain and Germany are in the third and fourth place. The development of snails consumption in Italy is followed with the same amount of production of snails in the whole biological circle. In 2001, from 24,700 tons, 9,350 tons (37.8% came from production, 6 00 tons (2.4% came from nature, and 14,750 tons (59.70% came from imports (frozen, fresh and prepared snails. In Serbia, at the beginning of 2005, we had over 400 registered farms for snail production.

  5. An analysis of suppressing migratory effect on human urinary bladder cancer cell line by silencing of snail-1.

    Science.gov (United States)

    Salehi, Shima; Mansoori, Behzad; Mohammadi, Ali; Davoudian, Sadaf; Musavi Shenas, Seyed Mohammad Hossein; Shajari, Neda; Majidi, Jafar; Baradaran, Behzad

    2017-12-01

    Snail-1 actively participates in tumor progression, invasion, and migration. Targeting snail-1 expression can suppress the EMT process in cancer. The aim of this study was to investigate the effect of snail1 silencing on urinary bladder cancer. Quantitative RT-PCR was used to detect snail-1 and other related metastatic genes expression following siRNA knockdown in urinary bladder cancer EJ-138 cells. The protein level of snail1 was assessed by Western blot. MTT and TUNEL assays were assessed to understand if snail-1 had survival effects on EJ-138 cells. Scratch wound healing assay measured cell motility effects after snail1 suppression. The significant silencing of snail-1 reached 60pmol siRNA in a 48-h post-transfection. The result of scratch assay showed that snail-1 silencing significantly decreased Vimentin, MMPs, and CXCR4 expression; however, expression of E-cadherin was induced. The cell death assay indicated that snail-1 played the crucial role in bladder cancer survival rate. These results propose that snail-1 plays a major role in the progression and migration of urinary bladder cancer, and can be a potential therapeutic target for target therapy of invasive urinary bladder cancer. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Snail regulates BMP and TGFβ pathways to control the differentiation status of glioma-initiating cells.

    Science.gov (United States)

    Caja, Laia; Tzavlaki, Kalliopi; Dadras, Mahsa S; Tan, E-Jean; Hatem, Gad; Maturi, Naga P; Morén, Anita; Wik, Lotta; Watanabe, Yukihide; Savary, Katia; Kamali-Moghaddan, Masood; Uhrbom, Lene; Heldin, Carl-Henrik; Moustakas, Aristidis

    2018-02-16

    Glioblastoma multiforme is a brain malignancy characterized by high heterogeneity, invasiveness, and resistance to current therapies, attributes related to the occurrence of glioma stem cells (GSCs). Transforming growth factor β (TGFβ) promotes self-renewal and bone morphogenetic protein (BMP) induces differentiation of GSCs. BMP7 induces the transcription factor Snail to promote astrocytic differentiation in GSCs and suppress tumor growth in vivo. We demonstrate that Snail represses stemness in GSCs. Snail interacts with SMAD signaling mediators, generates a positive feedback loop of BMP signaling and transcriptionally represses the TGFB1 gene, decreasing TGFβ1 signaling activity. Exogenous TGFβ1 counteracts Snail function in vitro, and in vivo promotes proliferation and re-expression of Nestin, confirming the importance of TGFB1 gene repression by Snail. In conclusion, novel insight highlights mechanisms whereby Snail differentially regulates the activity of the opposing BMP and TGFβ pathways, thus promoting an astrocytic fate switch and repressing stemness in GSCs.

  7. Lumican Inhibits SNAIL-Induced Melanoma Cell Migration Specifically by Blocking MMP-14 Activity.

    Directory of Open Access Journals (Sweden)

    Marta Stasiak

    Full Text Available Lumican, a small leucine rich proteoglycan, inhibits MMP-14 activity and melanoma cell migration in vitro and in vivo. Snail triggers epithelial-mesenchymal transitions endowing epithelial cells with migratory and invasive properties during tumor progression. The aim of this work was to investigate lumican effects on MMP-14 activity and migration of Snail overexpressing B16F1 (Snail-B16F1 melanoma cells and HT-29 colon adenocarcinoma cells. Lumican inhibits the Snail induced MMP-14 activity in B16F1 but not in HT-29 cells. In Snail-B16F1 cells, lumican inhibits migration, growth, and melanoma primary tumor development. A lumican-based strategy targeting Snail-induced MMP-14 activity might be useful for melanoma treatment.

  8. Population estimate of Chinese mystery snail (Bellamya chinensis) in a Nebraska reservoir

    Science.gov (United States)

    Chaine, Noelle M.; Allen, Craig R.; Fricke, Kent A.; Haak, Danielle M.; Hellman, Michelle L.; Kill, Robert A.; Nemec, Kristine T.; Pope, Kevin L.; Smeenk, Nicholas A.; Stephen, Bruce J.; Uden, Daniel R.; Unstad, Kody M.; VanderHam, Ashley E.

    2012-01-01

    The Chinese mystery snail (Bellamya chinensis) is an aquatic invasive species in North America. Little is known regarding this species' impacts on freshwater ecosystems. It is be lieved that population densities can be high, yet no population estimates have been reported. We utilized a mark-recapture approach to generate a population estimate for Chinese mystery snail in Wild Plum Lake, a 6.47-ha reservoir in southeast Nebraska. We calculated, using bias-adjusted Lincoln-Petersen estimation, that there were approximately 664 adult snails within a 127 m2 transect (5.2 snails/m2). If this density was consistent throughout the littoral zone (test the utility of mark-recapture methods for aquatic snails and to better understand Chinese mystery snail distributions within reservoirs.

  9. Cten promotes epithelial-mesenchymal transition through the post-transcriptional stabilization of Snail.

    Science.gov (United States)

    Thorpe, Hannah; Asiri, Abdulaziz; Akhlaq, Maham; Ilyas, Mohammad

    2017-12-01

    Cten promotes cell migration however the knowledge of underlying signalling pathways is sparse. We have shown that Cten downregulates E-cadherin, a feature of epithelial to mesenchymal transition (EMT). This prompted us to investigate whether Cten further contributed to EMT processes to regulate cell motility. The regulation of Snail by Cten was investigated following overexpression, knockdown (by RNA-interference) or knockout of Cten in HCT116, Caco-2 and SW620 colorectal cancer (CRC) cell lines. Subsequently, the cycloheximide (CHX) pulse chase assay was used to investigate changes in Snail protein stability and the functional relevance of Cten-Snail signalling was investigated. Snail was identified as a downstream target of Cten signalling using multiple approaches of Cten expression manipulation. Furthermore, this activity was mediated through the SH2 domain of Cten. The CHX assay confirmed that Cten was regulating Snail at a post transcriptional level and this was through the prevention of Snail degradation. Cell migration, invasion and colony formation efficiency were increased following forced expression of GFP-Cten but subsequently lost when Snail was knocked down, demonstrating a functional Cten-Snail signalling axis. In conclusion, we have described a novel Cten-Snail signaling pathway that contributes to cell motility in CRC, mediated by the stabilization of Snail protein. This finding potentially furthers the understanding of EMT regulatory networks in cancer metastasis. © 2017 Wiley Periodicals, Inc.

  10. Reproductive anomalies in stenoglossan snails related to pollution from marinas.

    Science.gov (United States)

    Smith, B S

    1981-02-01

    Over 3090 snails of the dioecious intertidal species Nassarius obsoletus Say were collected from a total of 71 localities. Their reproductive anatomy was examined for a superimposition of male characteristics on to the normal female anatomy, an abnormality called 'imposex'. Imposex was rated numerically in terms of the fraction of the population affected and the intensity of expression in bearer snails. An initial survey of 22 localities in Fairfield and Westport, Connecticut, led to the hypothesis that imposex was related to a substance arising from marinas. This was tested at nine pairs of marina and control localities in Long Island Sound, as well as six pairs along a transect ranging from Rhode Island to Georgia. Imposex scores were significantly higher at the marina locality in every pair. Further confirmation was found in a detailed survey of the estuarine harbor at Southport, Connecticut, which showed that adjacent populations could differ in the amount of imposex to the extent that both the snails and the waters they lived in remained separated by natural or man-made barriers. Imposex has been found in populations of N. obsoletus ranging from Damariscotta, Maine, to Savannah, Georgia, and it has been reported from San Francisco Bay, California. Similar anatomical abnormalities have been reported in at least 27 other species of taenioglossan and stenoglossan snails, extending the range to the Atlantic and Mediterranean coast of Europe and the British Isles. Concern is raised regarding the possible existence of another global pollutant with novel effects on marina biota.

  11. Reproductive anomalies in stenoglossan snails related to pollution from marinas

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.S.

    1981-02-01

    Over 3090 snails of the dioecious intertidal species Nassarius obsoletus Say were collected from a total of 71 localities. Their reproductive anatomy was examined for a superimposition of male characteristics on to the normal female anatomy, an abnormality called 'imposex'. Imposex was rated numerically in terms of the fraction of the population affected and the intensity of expression in bearer snails. An initial survey of 22 localities in Fairfield and Westport, Connecticut, led to the hypothesis that imposex was related to a substance arising from marinas. This was tested at nine pairs of marina and control localities in Long Island Sound, as well as six pairs along a transect ranging from Rhode Island to Georgia. Imposex scores were significantly higher at the marina locality in every pair. Further confirmation was found in a detailed survey of the estuarine harbor at Southport, Connecticut, which showed that adjacent populations could differ in the amount of imposex to the extent that both the snails and the waters they lived in remained separated by natural or man-made barriers. Imposex has been found in populations of N. obsoletus ranging from Damariscotta, Maine, to Savannah, Georgia, and it has been reported from San Francisco Bay, California. Similar anatomical abnormalities have been reported in at least 27 other species of taenioglossan and stenoglossan snails, extending the range to the Atlantic and Mediterranean coast of Europe and the British Isles. Concern is raised regarding the possible existence of another global pollutant with novel effects on marina biota.

  12. Marine and Estuarine Pollution.

    Science.gov (United States)

    Reish, Donald J.

    1978-01-01

    Presents a literature review of the effects of various pollutants on marine and estuarine organisms, covering publications of 1976-77. This review includes: (1) effects of pesticides, dredging, dumping, sludge, and petroleum hydrocarbons; and (2) diseases and tissue abnormalities. A list of 441 references is also presented. (HM)

  13. Lichen Endozoochory by Snails

    Science.gov (United States)

    Boch, Steffen; Prati, Daniel; Werth, Silke; Rüetschi, Jörg; Fischer, Markus

    2011-01-01

    Endozoochory plays a prominent role for the dispersal of seed plants. However, for most other plant taxa it is not known whether this mode of dispersal occurs at all. Among those other taxa, lichens as symbiotic associations of algae and fungi are peculiar as their successful dispersal requires movement of propagules that leaves the symbiosis functional. However, the potential for endozoochorous dispersal of lichen fragments has been completely overlooked. We fed sterile thalli of two foliose lichen species (Lobaria pulmonaria and Physcia adscendens) differing in habitat and air-quality requirements to nine snail species common in temperate Europe. We demonstrated morphologically that L. pulmonaria regenerated from 29.0% of all 379 fecal pellets, whereas P. adscendens regenerated from 40.9% of all 433 fecal pellets, showing that lichen fragments survived gut passage of all snail species. Moreover, molecular analysis of regenerated lichens confirmed the species identity for a subset of samples. Regeneration rates were higher for the generalist lichen species P. adscendens than for the specialist lichen species L. pulmonaria. Furthermore, lichen regeneration rates varied among snail species with higher rates after gut passage of heavier snail species. We suggest that gastropods generally grazing on lichen communities are important, but so far completely overlooked, as vectors for lichen dispersal. This opens new ecological perspectives and questions the traditional view of an entirely antagonistic relationship between gastropods and lichens. PMID:21533256

  14. Experimental Test of Preferences for an Invasive Prey by an Endangered Predator: Implications for Conservation

    Science.gov (United States)

    Wilcox, Rebecca C.

    2016-01-01

    Identifying impacts of exotic species on native populations is central to ecology and conservation. Although the effects of exotic predators on native prey have received much attention, the role of exotic prey on native predators is poorly understood. Determining if native predators actively prefer invasive prey over native prey has implications for interpreting invasion impacts, identifying the presence of evolutionary traps, and predator persistence. One of the world’s most invasive species, Pomacea maculata, has recently established in portions of the endangered Everglade snail kite’s (Rostrhamus sociabilis plumbeus) geographic range. Although these exotic snails could provide additional prey resources, they are typically much larger than the native snail, which can lead to lower foraging success and the potential for diminished energetic benefits in comparison to native snails. Nonetheless, snail kites frequently forage on exotic snails. We used choice experiments to evaluate snail kite foraging preference in relation to exotic species and snail size. We found that snail kites do not show a preference for native or exotic snails. Rather, snail kites generally showed a preference for medium-sized snails, the sizes reflective of large native snails. These results suggest that while snail kites frequently forage on exotic snails in the wild, this behavior is likely driven simply by the abundance of exotic snails rather than snail kites preferring exotics. This lack of preference offers insights to hypotheses regarding effects of exotic species, guidance regarding habitat and invasive species management, and illustrates how native-exotic relationships can be misleading in the absence of experimental tests of such interactions. PMID:27829031

  15. Histone deacetylase inhibitors upregulate Snail via Smad2/3 phosphorylation and stabilization of Snail to promote metastasis of hepatoma cells.

    Science.gov (United States)

    Xu, Wei; Liu, Hao; Liu, Zhi-Gang; Wang, Hong-Sheng; Zhang, Fan; Wang, Hao; Zhang, Ji; Chen, Jing-Jing; Huang, Hong-Jun; Tan, Yuan; Cao, Meng-Ting; Du, Jun; Zhang, Qiu-Gui; Jiang, Guan-Min

    2018-04-28

    Hepatocellular carcinoma (HCC) remains the third most common cause of cancer-related mortality. Resection and transplantation are the only curative treatments available, but are greatly hampered by high recurrence rates. Histone deacetylase inhibitors (HDACIs) are considered to be promising anticancer agents in drug development. Currently, four HDACIs have been granted Food and Drug Administration (FDA) approval for cancer. HDACIs have shown significant efficacy in hematological malignancies. However, they have limited effects in epithelial cell-derived cancers, including HCC, and the mechanisms of these are not elucidated. In this study, our results demonstrated that HDACIs were able to induce epithelial-mesenchymal transitions (EMT) in hepatoma cells which are believed to trigger tumor cell invasion and metastasis. We found that HDACIs promoted the expression of Snail and Snail-induced EMT was critical for HDACI-initiated invasion and metastasis. We indicated that HDACIs upregulated Snail in two ways. Firstly, HDACIs upregulated Snail at the transcriptional level by promoting Smad2/3 phosphorylation and nuclear translocation, then combined with the promoter to activate the transcription of Snail. Secondly, we showed that HDACIs regulated the stabilization of Snail via upregulating the expression of COP9 signalosome 2 (CSN2), which combined with Snail and exposed its acetylation site, then promoted acetylation of Snail, thereby inhibiting its phosphorylation and ubiquitination to repress the degradation of Snail. All these results highlighted that HDACIs have limited effects in HCC, and the use of HDACIs combined with other targeted strategies to inhibit EMT, which explored in this study is a promising treatment method for treating HCC. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Shading decreases the abundance of the herbivorous California horn snail, Cerithidea californica

    Science.gov (United States)

    Lorda, Julio; Lafferty, Kevin D.

    2012-01-01

    Most of the intertidal zone in estuaries of California, USA and Baja California, Mexico is covered with vascular vegetation. Shading by these vascular plants influences abiotic and biotic processes that shape benthic community assemblages. We present data on the effects of shading on the California horn snail, Cerithidea californica. This species is important because it is the most common benthic macrofaunal species in these systems and acts as an obligate intermediate host of several species of rematode parasites that infect several other species. Using observational and experimental studies, we found a negative effect of shade on the distribution and abundance of the California horn snail. We hypothesized that shading reduces the abundance of the epipelic diatoms that the snails feeds on, causing snails to leave haded areas. We observed a negative relationship between vascular plant cover, sub-canopy light levels, and snail density in Mugu Lagoon. Then we experimentally manipulated light regimes, by clipping vegetation and adding shade structures, and found higher snail densities at higher light levels. In Goleta Slough, we isolated the effect of shade from vegetation by documenting a negative relationship between the shade created by two bridges and diatom and snail densities. We also found that snails moved the greatest distances over shaded channel banks compared to unshaded channel banks. Further, we documented the effect of water depth and channel bank orientation on shading in this system. An additional effect of shading is the reduction of temperature, providing an alternative explanation for some of our results. These results broaden our knowledge of how variation in the light environment influences the ecology of estuarine ecosystems.

  17. Real Snail Mail

    OpenAIRE

    Isley, Vicky; Smith, Paul; boredomresearch,

    2008-01-01

    boredomresearch exhibited the Real Snail Mail installation in Process as Paradigm Exhibition, LABoral Centro de Arte y Creacion, Gijon Spain (23rd April - 30th Aug 2010). A group exhibition which is showing artwork that is continually evolving and in a state of flux. the exhibition includes artworks by Ralf Baecker, Gregory Chatonsky, Peter Flemming, Roman Kirschner, C.E.B. Reas, Antoine Schmitt and Ralf Schreiber. Vicky Isley & Paul Smith (aka boredomresearch) in 2009 developed an installati...

  18. The transcription factor snail controls epithelial-mesenchymal transitions by repressing E-cadherin expression

    DEFF Research Database (Denmark)

    Cano, A; Pérez-Moreno, M A; Rodrigo, I

    2000-01-01

    The Snail family of transcription factors has previously been implicated in the differentiation of epithelial cells into mesenchymal cells (epithelial-mesenchymal transitions) during embryonic development. Epithelial-mesenchymal transitions are also determinants of the progression of carcinomas......, occurring concomitantly with the cellular acquisition of migratory properties following downregulation of expression of the adhesion protein E-cadherin. Here we show that mouse Snail is a strong repressor of transcription of the E-cadherin gene. Epithelial cells that ectopically express Snail adopt...... a fibroblastoid phenotype and acquire tumorigenic and invasive properties. Endogenous Snail protein is present in invasive mouse and human carcinoma cell lines and tumours in which E-cadherin expression has been lost. Therefore, the same molecules are used to trigger epithelial-mesenchymal transitions during...

  19. Deubiquitinating enzyme PSMD14 promotes tumor metastasis through stabilizing SNAIL in human esophageal squamous cell carcinoma.

    Science.gov (United States)

    Zhu, Rui; Liu, Yongshuo; Zhou, Honghong; Li, Lei; Li, Yi; Ding, Fang; Cao, Xiufeng; Liu, Zhihua

    2018-04-01

    The epithelial-mesenchymal transition (EMT) transcription factor SNAIL is associated with distant metastasis and poor prognosis of esophageal squamous cell carcinoma (ESCC) patients. The proteolysis of SNAIL is mediated by the ubiquitin-proteasome system. Several E3 ligases have been characterized to promote SNAIL ubiquitination and degradation. However, the reverse process - deubiquitination of SNAIL remains largely unknown. In this study, we performed a mass spectrometry to examine the interaction between SNAIL and deubiquitinating enzyme(s). Subsequently, the deubiquitinating enzyme PSMD14 was identified to target SNAIL for deubiquitination and stabilization. Furthermore, knockdown of PSMD14 significantly blocks SNAIL-induced EMT and then suppresses tumor cell migration and invasion in vitro and tumor metastasis in vivo. In addition, the high expression level of PSMD14 predicts poor prognosis for esophageal cancer patients. These findings suggest PSMD14 as a bona fide deubiquitinating enzyme to regulate SNAIL at the post-translational level and provide a promising therapeutic strategy against tumor metastasis of esophageal cancer. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. An artificial perch to help Snail Kites handle an exotic Apple Snail

    Science.gov (United States)

    Pias, Kyle E.; Welch, Zach C.; Kitchens, Wiley M.

    2012-01-01

    In the United States, the Snail Kite (Rostrhamus sociabilis plumbeus) is a federally endangered species and restricted to the wetlands of south-central Florida where the current population numbers less than 1,500. The Snail Kite is an extreme dietary specialist, previously feeding almost exclusively on one species of snail, the Florida Apple Snail (Pomacea paludosa). Within the past decade, an exotic species of apple snail, the Island Apple Snail (Pomacea insularum), has become established on lakes in central Florida. Island Apple Snails are larger than the native Florida Apple Snails, and Snail Kites handle the exotic snails less efficiently. Juvenile Snail Kites, in particular, have lower daily energy balances while feeding on Island Apple Snails. An inexpensive, easy-to-construct platform was developed that would provide Snail Kites with a flat, stable surface on which to extract snails. The platform has the potential to reduce the difficulties Snail Kites experience when handling exotic snails, and may benefit the Snail Kite population as a whole. Initial observations indicate that Snail Kites use the platforms frequently, and snails extracted at the platforms are larger than snails extracted at other perches.

  1. SHORT COMMUNICATION Challenges to increased Snail ...

    African Journals Online (AJOL)

    The commercial production of snails has not kept pace with the demand for it in Ibarapa Local Government Areas (ILGA) of Oyo State, Nigeria. A study was carried out to characterize the snail farmers, identify challenges to an increased snail production and suggest measures for sustainable snail production. Structured ...

  2. Targeted inactivation of Snail family EMT regulatory factors by a Co(III-Ebox conjugate.

    Directory of Open Access Journals (Sweden)

    Allison S Harney

    Full Text Available Snail family proteins are core EMT (epithelial-mesenchymal transition regulatory factors that play essential roles in both development and disease processes and have been associated with metastasis in carcinomas. Snail factors are required for the formation of neural crest stem cells in most vertebrate embryos, as well as for the migratory invasive behavior of these cells. Snail factors have recently been linked to the formation of cancer stem cells, and expression of Snail proteins may be associated with tumor recurrence and resistance to chemotherapy and radiotherapy. We report that Co(III-Ebox is a potent inhibitor of Snail-mediated transcriptional repression in breast cancer cells and in the neural crest of Xenopus. We further show that the activity of Co(III-Ebox can be modulated by temperature, increasing the utility of this conjugate as a Snail inhibitor in model organisms. We exploit this feature to further delineate the requirements for Snail function during neural crest development, showing that in addition to the roles that Snail factors play in neural crest precursor formation and neural crest EMT/migration, inhibition of Snail function after the onset of neural crest migration leads to a loss of neural crest derived melanocytes. Co(III-Ebox-mediated inhibition therefore provides a powerful tool for analysing the function of these core EMT factors with unparalleled temporal resolution. Moreover, the potency of Co(III-Ebox as a Snail inhibitor in breast cancer cells suggests its potential as a therapeutic inhibitor of tumor progression and metastasis.

  3. Effects of an exotic prey species on a native specialist: Eexample of the snail kite

    Science.gov (United States)

    Cattau, Christopher E.; Martin, J.; Kitchens, W.M.

    2010-01-01

    Despite acknowledging that exotic species can exhibit tremendous influence over native populations, few case studies have clearly demonstrated the effects of exotic prey species on native predators. We examined the effects of the recently introduced island apple snail (Pomacea insularum) on the foraging behavior and energetics of the endangered snail kite (Rostrhamus sociabilis plumbeus) in Florida. We conducted time-activity budgets: (i) on kites foraging for native Florida apple snails (Pomacea paludosa) in major wetland units within the kites' range that had not been invaded by the exotic island apple snail and (ii) on kites foraging for exotic apple snails in Lake Tohopekaliga, the only major wetland utilized by the snail kite that had suffered a serious invasion of P. insularum. When foraging for P. insularum, snail kites dropped a greater proportion of snails, and they experienced increased handling times and decreased consumption rates; however, kites foraging for P. insularum also spent a smaller proportion of the day in flight. Estimates of net daily energy balances between kites feeding on P. insularum versus P. paludosa were comparable for adults, but juveniles experienced energetic deficiencies when feeding on the exotic snail. Due to this discrepancy, we hypothesize that wetlands invaded by P. insularum, such as Lake Tohopekaliga, may function as ecological traps for the snail kite in Florida by attracting breeding adults but simultaneously depressing juvenile survival. This study highlights the conservation implications and importance of elucidating the effects that exotic species have on native specialists, especially those that are endangered, because subtle influences on behavior may have significant population consequences. ?? 2009 Elsevier Ltd.

  4. Effects of an exotic prey species on a native specialist: example of the snail kite

    Science.gov (United States)

    Cattau, Christopher E.; Martin, J.; Kitchens, Wiley M.

    2010-01-01

    Despite acknowledging that exotic species can exhibit tremendous influence over native populations, few case studies have clearly demonstrated the effects of exotic prey species on native predators. We examined the effects of the recently introduced island apple snail (Pomacea insularum) on the foraging behavior and energetics of the endangered snail kite (Rostrhamus sociabilis plumbeus) in Florida. We conducted time-activity budgets: (i) on kites foraging for native Florida apple snails (Pomacea paludosa) in major wetland units within the kites' range that had not been invaded by the exotic island apple snail and (ii) on kites foraging for exotic apple snails in Lake Tohopekaliga, the only major wetland utilized by the snail kite that had suffered a serious invasion of P. insularum. When foraging for P. insularum, snail kites dropped a greater proportion of snails, and they experienced increased handling times and decreased consumption rates; however, kites foraging for P. insularum also spent a smaller proportion of the day in flight. Estimates of net daily energy balances between kites feeding on P. insularum versus P. paludosa were comparable for adults, but juveniles experienced energetic deficiencies when feeding on the exotic snail. Due to this discrepancy, we hypothesize that wetlands invaded by P. insularum, such as Lake Tohopekaliga, may function as ecological traps for the snail kite in Florida by attracting breeding adults but simultaneously depressing juvenile survival. This study highlights the conservation implications and importance of elucidating the effects that exotic species have on native specialists, especially those that are endangered, because subtle influences on behavior may have significant population consequences.

  5. General assessment of estuarine pollution

    Indian Academy of Sciences (India)

    Agricultural runoff contributes to high nutrient loads in estuaries. Their impacts on estuarine ecology – particularly responses of plankton and the influence on the food chain needs to be investigated.

  6. Novel snail1 target proteins in human colon cancer identified by proteomic analysis.

    Directory of Open Access Journals (Sweden)

    María Jesús Larriba

    2010-04-01

    Full Text Available The transcription factor Snail1 induces epithelial-to-mesenchymal transition (EMT, a process responsible for the acquisition of invasiveness during tumorigenesis. Several transcriptomic studies have reported Snail1-regulated genes in different cell types, many of them involved in cell adhesion. However, only a few studies have used proteomics as a tool for the characterization of proteins mediating EMT.We identified by proteomic analysis using 2D-DIGE electrophoresis combined with MALDI-TOF-TOF and ESI-linear ion trap mass spectrometry a number of proteins with variable functions whose expression is modulated by Snail1 in SW480-ADH human colon cancer cells. Validation was performed by Western blot and immunofluorescence analyses. Snail1 repressed several members of the 14-3-3 family of phosphoserine/phosphothreonine binding proteins and also the expression of the Proliferation-associated protein 2G4 (PA2G4 that was mainly localized at the nuclear Cajal bodies. In contrast, the expression of two proteins involved in RNA processing, the Cleavage and polyadenylation specificity factor subunit 6 (CPSF6 and the Splicing factor proline/glutamine-rich (SFPQ, was higher in Snail1-expressing cells than in controls. The regulation of 14-3-3epsilon, 14-3-3tau, 14-3-3zeta and PA2G4 by Snail1 was reproduced in HT29 colon cancer cells. In addition, we found an inverse correlation between 14-3-3sigma and Snail1 expression in human colorectal tumors.We have identified a set of novel Snail1 target proteins in colon cancer that expand the cellular processes affected by Snail1 and thus its relevance for cell function and phenotype.

  7. First record of predation by the alien invasive freshwater fish ...

    African Journals Online (AJOL)

    First record of predation by the alien invasive freshwater fish Micropterus salmoides L. (Centrarchidae) on migrating estuarine fishes in South Africa. ... Estuarine fish species, Monodactylus falciformis, and two species of the family Mugilidae, Mugil cephalus and Myxus capensis, were the most common fish prey in both size ...

  8. Snail1 Expression Is Required for Sarcomagenesis

    Directory of Open Access Journals (Sweden)

    Lorena Alba-Castellón

    2014-05-01

    Full Text Available Snail1 transcriptional repressor is a major inducer of epithelial-to mesenchymal transition but is very limitedly expressed in adult animals. We have previously demonstrated that Snail1 is required for the maintenance of mesenchymal stem cells (MSCs, preventing their premature differentiation. Now, we show that Snail1 controls the tumorigenic properties of mesenchymal cells. Increased Snail1 expression provides tumorigenic capabilities to fibroblastic cells; on the contrary, Snail1 depletion decreases tumor growth. Genetic depletion of Snail1 in MSCs that are deficient in p53 tumor suppressor downregulates MSC markers and prevents the capability of these cells to originate sarcomas in immunodeficient SCID mice. Notably, an analysis of human sarcomas shows that, contrarily to epithelial tumors, these neoplasms display high Snail1 expression. This is particularly clear for undifferentiated tumors, which are associated with poor outcome. Together, our results indicate a role for Snail1 in the generation of sarcomas.

  9. Alterations of biochemical indicators in hepatopancreas of the golden apple snail, Pomacea canaliculata, from paddy fields in Taiwan.

    Science.gov (United States)

    Chiu, Yuh-Wen; Wu, Jui-Pin; Hsieh, Tsung-Chih; Liang, Shih-Hsiung; Chen, Chien-Min; Huang, Da-Ji

    2014-07-01

    The freshwater golden apple snail, Pomacea canaliculata, is one of the world's 100 worst invasive alien species. The snails' wide distribution, high abundance, and sensitivity to environmental pollution make them a potential bioindicator for environmental contamination. In this study, the biochemical status of golden apple snails collected from paddy fields throughout the island of Taiwan was examined. This study found that the biochemical status of apple snails collected from paddy fields differed from that of animals bred and maintained in the laboratory. Furthermore, certain biochemical endpoints of the snails collected from the paddy fields before and after agricultural activities were also different-hemolymphatic vitellogenin protein was induced in male snail after exposure to estrogen-like chemicals, the hepatic monooxygenase (1.97 +/- 0.50 deltaA(650mm) 30 min(-1) mg(-1) protein in control group) and glutathione S transferase (0.02 +/- 0.01 delta A(340mm) 30 min(-1) mg(-1) protein in control group) snails exposed to pesticides, as well as the hepatopancreatic levels of aspartate aminotransferase (450.00 +/- 59.40 U mg(-1) mg(-1) protein in control group) and alanine aminotransferase (233.27 +/- 42.09 U mg(-1) mg(-1) protein in control group) decreased the indicating that xenobiotics destroyed hepatopancreatic. The above findings reveal that apple snail could be used as a practical bioindicator to monitor anthropogenic environmental pollution.

  10. Interaction between Biomphalaria pfeifferi, the snail intermediate ...

    African Journals Online (AJOL)

    Biological control of snail intermediate host of human schistosome parasites has been suggested. In this study, the effect of Indoplanobis exustus a planorbid snail and possible competitor snail of Biomphalaria pfeifferi on the fecundity and growth rate of the later was evaluated. The results showed a significant difference in ...

  11. Algal stabilisation of estuarine sediments

    International Nuclear Information System (INIS)

    1992-01-01

    The presence of benthic microalgae can increase the stability of intertidal sediments and influence sediment fluxes within an estuarine environment. Therefore the relative importance of algal stabilisation needs to be understood to help predict the effects of a tidal barrage. The biogenic stabilisation of intertidal estuarine sediments by epipelic diatom films and the macrophyte Vaucheria was studied at three sites on the Severn Estuary. The cohesive strength meter (CSM) was developed to measure surface critical shear stress with varied algal density. A number of techniques have been used to determine the general in situ erodibility of cohesive estuarine sediments. The measurements of sediment shear strength and critical erosion velocity were investigated. Field experiments were undertaken to investigate the effect of algae on binding sediments, and a predictive method for the assessment of sediment stabilisation by algal binding was developed. (author)

  12. Estuarine and coastal connectivity of an estuarine-dependent fishery ...

    African Journals Online (AJOL)

    This study used acoustic telemetry to assess the usage of multiple estuaries and coastal waters by the estuarine-dependent spotted grunter Pomadasys commersonnii. Twenty-six adult fish were tagged with acoustic transmitters in the Kariega and Bushmans estuaries, South Africa, and their movements along a 300-km ...

  13. Population dynamics and biology of an invasive population of ...

    African Journals Online (AJOL)

    Population dynamics and biology of an invasive population of mosquitofish Gambusia affinis in a temperate estuarine lake system. Hans Sloterdijk, Nicola C. James, M Kyle S. Smith, Werner Ekau, Olaf L.F. Weyl ...

  14. Bacterial diversity in different regions of gastrointestinal tract of Giant African Snail (Achatina fulica)

    Science.gov (United States)

    Pawar, Kiran D; Banskar, Sunil; Rane, Shailendra D; Charan, Shakti S; Kulkarni, Girish J; Sawant, Shailesh S; Ghate, Hemant V; Patole, Milind S; Shouche, Yogesh S

    2012-01-01

    The gastrointestinal (GI) tract of invasive land snail Achatina fulica is known to harbor metabolically active bacterial communities. In this study, we assessed the bacterial diversity in the different regions of GI tract of Giant African snail, A. fulica by culture-independent and culture-dependent methods. Five 16S rRNA gene libraries from different regions of GI tract of active snails indicated that sequences affiliated to phylum γ-Proteobacteria dominated the esophagus, crop, intestine, and rectum libraries, whereas sequences affiliated to Tenericutes dominated the stomach library. On phylogenetic analysis, 30, 27, 9, 27, and 25 operational taxonomic units (OTUs) from esophagus, crop, stomach, intestine, and rectum libraries were identified, respectively. Estimations of the total bacterial diversity covered along with environmental cluster analysis showed highest bacterial diversity in the esophagus and lowest in the stomach. Thirty-three distinct bacterial isolates were obtained, which belonged to 12 genera of two major bacterial phyla namely γ-Proteobacteria and Firmicutes. Among these, Lactococcus lactis and Kurthia gibsonii were the dominant bacteria present in all GI tract regions. Quantitative real-time polymerase chain reaction (qPCR) analysis indicated significant differences in bacterial load in different GI tract regions of active and estivating snails. The difference in the bacterial load between the intestines of active and estivating snail was maximum. Principal component analysis (PCA) of terminal restriction fragment length polymorphism suggested that bacterial community structure changes only in intestine when snail enters estivation state. PMID:23233413

  15. Toxicity of copper sulfate and rotenone to Chinese mystery snail (Bellamya chinensis)

    Science.gov (United States)

    Haak, Danielle M.; Stephen, Bruce J.; Kill, Robert A.; Smeenk, Nicholas A.; Allen, Craig R.; Pope, Kevin L.

    2014-01-01

    The Chinese mystery snail (Bellamya chinensis) is a freshwater snail native to Southeast Asia, Japan, and Russia and is currently classified as an invasive species in at least 27 states in the USA. The species tolerates a wide range of environmental conditions, making management of established populations difficult. We tested the efficacy of two traditional chemical treatments, rotenone and copper sulfate, on the elimination of adult Chinese mystery snails in laboratory experiments. All snails (N=50) survived 72-hour exposure to rotenone-treated lake water, and 96% (N=25) survived 72-hour exposure to pre-determined rotenone concentrations of 0.25, 2.5, and 25.0 mg/L. All snails (N=10) survived exposure to 1.25 mg/L copper sulfate solution, 90% (N=10) survived exposure to 2.50 mg/L copper sulfate solution, and 80% (N=5) survived exposure to 5.0 mg/L copper sulfate solution. Neither rotenone nor copper sulfate effectively killed adult Chinese mystery snails in laboratory experiments, most likely due to their relatively large size, thick shell, and operculum. Therefore, it appears that populations will be very difficult to control once established, and management should focus on preventing additional spread or introductions of this species.

  16. Differential expression of transcription factors Snail, Slug, SIP1, and Twist in ameloblastoma.

    Science.gov (United States)

    Siar, Chong Huat; Ng, Kok Han

    2014-01-01

    Epithelial-to-mesenchymal transition (EMT) via the mechanism of transcription repression is a crucial process for the induction of invasiveness in many human tumors. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behavior. Twist, an EMT promoter, has been implicated in its invasiveness. The roles of the other transcription factors remain unclarified. Four transcription factors, namely Snail, Slug, SIP1, and Twist, were examined immunohistochemically in 64 ameloblastoma [18 unicystic (UA), 20 solid/multicystic (SA), 4 desmoplastic (DA), and 22 recurrent (RA)]. All four transcription factors were differentially expressed in ameloblastoma [Snail: n = 60/64 (94%); Slug: n = 21/64 (33%); SIP: n = 18/64 (28%); Twist: n = 26/64 (41%)] (P 0.05). Intracellular protein localization was predominantly nuclear for Snail, cytoplasmic>nuclear for Slug and SIP1, and cytoplasmic/nuclear for Twist. Overexpression of Snail in most subsets (UA = 18/18; SMA = 19/20; DA = 4/4; RA = 19/22) compared with the other transcription factors (P ameloblastoma. Overexpression of Snail in most subsets suggests that this molecule is most likely the prototype transcription factor involved in inducing EMT in the ameloblastoma. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  17. Snail1 induces epithelial-to-mesenchymal transition and tumor initiating stem cell characteristics

    International Nuclear Information System (INIS)

    Dang, Hien; Ding, Wei; Emerson, Dow; Rountree, C Bart

    2011-01-01

    Tumor initiating stem-like cells (TISCs) are a subset of neoplastic cells that possess distinct survival mechanisms and self-renewal characteristics crucial for tumor maintenance and propagation. The induction of epithelial-mesenchymal-transition (EMT) by TGFβ has been recently linked to the acquisition of TISC characteristics in breast cancer. In HCC, a TISC and EMT phenotype correlates with a worse prognosis. In this work, our aim is to elucidate the underlying mechanism by which cells acquire tumor initiating characteristics after EMT. Gene and protein expression assays and Nanog-promoter luciferase reporter were utilized in epithelial and mesenchymal phenotype liver cancer cell lines. EMT was analyzed with migration/invasion assays. TISC characteristics were analyzed with tumor-sphere self-renewal and chemotherapy resistance assays. In vivo tumor assay was performed to investigate the role of Snail1 in tumor initiation. TGFβ induced EMT in epithelial cells through the up-regulation of Snail1 in Smad-dependent signaling. Mesenchymal liver cancer post-EMT demonstrates TISC characteristics such as tumor-sphere formation but are not resistant to cytotoxic therapy. The inhibition of Snail1 in mesenchymal cells results in decreased Nanog promoter luciferase activity and loss of self-renewal characteristics in vitro. These changes confirm the direct role of Snail1 in some TISC traits. In vivo, the down-regulation of Snail1 reduced tumor growth but was not sufficient to eliminate tumor initiation. In summary, TGFβ induces EMT and TISC characteristics through Snail1 and Nanog up-regulation. In mesenchymal cells post-EMT, Snail1 directly regulates Nanog expression, and loss of Snail1 regulates tumor growth without affecting tumor initiation

  18. In What Form Does Global Capital Flow Leave Behind Memories? The Story of the Apple Snail Caught Between the Green Revolution and the Organic Food Movement

    Directory of Open Access Journals (Sweden)

    Chingling Wo

    2015-07-01

    Full Text Available Focusing on a study of Taiwan’s United News Daily archive and the shifting discourses of the Green Revolution and the organic food movement, the project analyzes the narrative frameworks produced on the apple snail (Pomacea canaliculata in Taiwan. Apple snail has become invasive to many East Asian countries since the 1980s; it is considered among the world’s 100 most invasive species. During the era of the Green Revolution, the economy of killing the apple snail with pesticide was generated by a narrative of how greedy merchants imported invasive apple snail and led to the systematic disruption of Taiwan’s ecology. The paper explores how the organic food movement responded to and was shaped by such a narrative of innocence lost, and emphasizes the importance of going beyond the hyper-real narratives of irreparable ecological destructions by recognizing sites of memories left behind by global capital flow.

  19. The transcription factors Snail and Slug activate the transforming growth factor-beta signaling pathway in breast cancer.

    Science.gov (United States)

    Dhasarathy, Archana; Phadke, Dhiral; Mav, Deepak; Shah, Ruchir R; Wade, Paul A

    2011-01-01

    The transcriptional repressors Snail and Slug are situated at the core of several signaling pathways proposed to mediate epithelial to mesenchymal transition or EMT, which has been implicated in tumor metastasis. EMT involves an alteration from an organized, epithelial cell structure to a mesenchymal, invasive and migratory phenotype. In order to obtain a global view of the impact of Snail and Slug expression, we performed a microarray experiment using the MCF-7 breast cancer cell line, which does not express detectable levels of Snail or Slug. MCF-7 cells were infected with Snail, Slug or control adenovirus, and RNA samples isolated at various time points were analyzed across all transcripts. Our analyses indicated that Snail and Slug regulate many genes in common, but also have distinct sets of gene targets. Gene set enrichment analyses indicated that Snail and Slug directed the transcriptome of MCF-7 cells from a luminal towards a more complex pattern that includes many features of the claudin-low breast cancer signature. Of particular interest, genes involved in the TGF-beta signaling pathway are upregulated, while genes responsible for a differentiated morphology are downregulated following Snail or Slug expression. Further we noticed increased histone acetylation at the promoter region of the transforming growth factor beta-receptor II (TGFBR2) gene following Snail or Slug expression. Inhibition of the TGF-beta signaling pathway using selective small-molecule inhibitors following Snail or Slug addition resulted in decreased cell migration with no impact on the repression of cell junction molecules by Snail and Slug. We propose that there are two regulatory modules embedded within EMT: one that involves repression of cell junction molecules, and the other involving cell migration via TGF-beta and/or other pathways.

  20. The transcription factors Snail and Slug activate the transforming growth factor-beta signaling pathway in breast cancer.

    Directory of Open Access Journals (Sweden)

    Archana Dhasarathy

    Full Text Available The transcriptional repressors Snail and Slug are situated at the core of several signaling pathways proposed to mediate epithelial to mesenchymal transition or EMT, which has been implicated in tumor metastasis. EMT involves an alteration from an organized, epithelial cell structure to a mesenchymal, invasive and migratory phenotype. In order to obtain a global view of the impact of Snail and Slug expression, we performed a microarray experiment using the MCF-7 breast cancer cell line, which does not express detectable levels of Snail or Slug. MCF-7 cells were infected with Snail, Slug or control adenovirus, and RNA samples isolated at various time points were analyzed across all transcripts. Our analyses indicated that Snail and Slug regulate many genes in common, but also have distinct sets of gene targets. Gene set enrichment analyses indicated that Snail and Slug directed the transcriptome of MCF-7 cells from a luminal towards a more complex pattern that includes many features of the claudin-low breast cancer signature. Of particular interest, genes involved in the TGF-beta signaling pathway are upregulated, while genes responsible for a differentiated morphology are downregulated following Snail or Slug expression. Further we noticed increased histone acetylation at the promoter region of the transforming growth factor beta-receptor II (TGFBR2 gene following Snail or Slug expression. Inhibition of the TGF-beta signaling pathway using selective small-molecule inhibitors following Snail or Slug addition resulted in decreased cell migration with no impact on the repression of cell junction molecules by Snail and Slug. We propose that there are two regulatory modules embedded within EMT: one that involves repression of cell junction molecules, and the other involving cell migration via TGF-beta and/or other pathways.

  1. The Medusa and the Snail

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. The Medusa and the Snail. Harini Nagendra. Book Review Volume 5 Issue 5 May 2000 pp 102-103. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/005/05/0102-0103. Author Affiliations.

  2. Current concepts of snail control

    Directory of Open Access Journals (Sweden)

    R. F. Sturrock

    1995-04-01

    Full Text Available Schistosomiasis control was impossible without effective tools. Synthetic molluscicides developed in the 1950s spearheaded community level control. Snail eradication proved impossible but repeated mollusciciding to manage natural snail populations could eliminate transmission. Escalating costs, logistical complexity, its labour-intensive nature and possible environmental effects caused some concern. The arrival of safe, effective, single-dose drugs in the 1970s offered an apparently better alternative but experience revealed the need for repeated treatments to minimise reinfection in programmes relying on drugs alone. Combining treatment with mollusciciding was more successful, but broke down if mollusciciding was withdrawn to save money. The provision of sanitation and safe water to prevent transmission is too expensive in poor rural areas where schistosomiasis is endemic; rendering ineffective public health education linked to primary health care. In the tropics, moreover, children (the key group in maintaining transmission will always play in water. Large scale destruction of natural snail habitats remains impossibly expensive (although proper design could render many new man-made habitats unsuitable for snails. Neither biological control agents nor plant molluscicides have proved satisfactory alternatives to synthetic molluscicides. Biologists can develop effective strategies for using synthetic molluscicides in different epidemiological situations if only, like drugs, their price can be reduced.

  3. Overexpression of snail induces epithelial-mesenchymal transition and a cancer stem cell-like phenotype in human colorectal cancer cells.

    Science.gov (United States)

    Fan, Fan; Samuel, Shaija; Evans, Kurt W; Lu, Jia; Xia, Ling; Zhou, Yunfei; Sceusi, Eric; Tozzi, Federico; Ye, Xiang-Cang; Mani, Sendurai A; Ellis, Lee M

    2012-08-01

    Epithelial-mesenchymal transition (EMT) is a critical process providing tumor cells with the ability to migrate and escape from the primary tumor and metastasize to distant sites. Recently, EMT was shown to be associated with the cancer stem cell (CSC) phenotype in breast cancer. Snail is a transcription factor that mediates EMT in a number of tumor types, including colorectal cancer (CRC). Our study was done to determine the role of Snail in mediating EMT and CSC function in CRC. Human CRC specimens were stained for Snail expression, and human CRC cell lines were transduced with a retroviral Snail construct or vector control. Cell proliferation and chemosensitivity to oxaliplatin of the infected cells were determined by the MTT (colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Migration and invasion were determined in vitro using modified Boyden chamber assays. EMT and putative CSC markers were analyzed using Western blotting. Intravenous injection of tumor cells was done to evaluate their metastatic potential in mice. Snail was overexpressed in human CRC surgical specimens. This overexpression induced EMT and a CSC-like phenotype in human CRC cells and enhanced cell migration and invasion (P cells were more chemoresistant to oxaliplatin than control cells. Increased Snail expression induces EMT and the CSC-like phenotype in CRC cells, which enhance cancer cell invasion and chemoresistance. Thus, Snail is a potential therapeutic target in metastatic CRC.

  4. Snail-mediated cancer stem cell-like phenotype in human CNE2 nasopharyngeal carcinoma cell.

    Science.gov (United States)

    Peng, Shan; Wu, Cheng; Sun, Wei; Liu, Dongbo; Luo, Min; Su, Beibei; Zhang, Linli; Mei, Qi; Hu, Guoqing

    2018-03-01

    Cancer stem cell (CSC)-like phenotype, which has been proven to play a critical role in invasion and metastasis of many kinds of cancers, has also been reported to be associated with epithelial-mesenchymal transition. Snail, a potent repressor of E-cadherin expression, was found to have a function to regulate the aforementioned processes. In the current study, expression of putative CSCs biomarkers and the ratio of CSC-like CNE2 (cancer cell line) in total CNE2 were measured, and CSC-like characteristics were analyzed with tumor-sphere self-renewal and colony-forming assays. Migration and invasion properties were determined by using transwell and wound healing assays. Xenograft tumor assays in vivo were done to evaluate the function of Snail and radiation in the tumor forming ability. In human nasopharyngeal carcinoma (NPC) cells, overexpression of Snail mediates a CSC-like phenotype, which enhances the initiation, invasion, and migration ability of cancer cells. Thus, Snail is a potential therapeutic target in NPC. © 2017 Wiley Periodicals, Inc.

  5. PLCE1 Promotes Esophageal Cancer Cell Progression by Maintaining the Transcriptional Activity of Snail

    Directory of Open Access Journals (Sweden)

    Shicong Zhai

    2017-03-01

    Full Text Available Esophageal cancer is among the most deadly malignant diseases. However, the genetic factors contributing to its occurrence are poorly understood. Multiple studies with large clinic-based cohorts revealed that variations of the phospholipase C epsilon (PLCE1 gene were associated with esophageal cancer susceptibility. However, the causative role of PLCE1 in esophageal cancer is not clear. We inactivated the functional alleles of PLCE1 by CRISPR/Cas9 genome editing technology. The resultant PLCE1 inactivated cells were analyzed both in vitro and in vivo. Our results showed that loss of PLCE1 dramatically decreased the invasion and proliferation capacity of esophageal carcinoma cells in vitro. Moreover, such PLCE1 inactivated tumor grafts exhibited significantly decreased tumor size in mice. We found that PLCE1 was required to maintain protein level of snail a key transcription factor responsible for invasion. Our further transcriptomic data revealed that deficient cells were significantly decreased in expression of genes enriched as targets of Snail. Strikingly, recovery of Snail protein at least partially rescued the invasion and proliferation capacity in PLCE1 inactivated cells. In ESCC clinical specimens, PLCE1 was correlated with tumor stage (P < .0001. Interestingly, PLCE1 expression was positively correlated Snail by immunohistochemistry in such specimens (P < .0001. Therefore, our functional experiments showed the essential roles of PLCE1 in esophageal carcinoma cells and provided evidences that targeting PLCE1 and its downstream molecules could be effective therapies for esophageal cancer.

  6. Fundamentals of estuarine physical oceanography

    CERN Document Server

    Bruner de Miranda, Luiz; Kjerfve, Björn; Castro Filho, Belmiro Mendes de

    2017-01-01

    This book provides an introduction to the complex system functions, variability and human interference in ecosystem between the continent and the ocean. It focuses on circulation, transport and mixing of estuarine and coastal water masses, which is ultimately related to an understanding of the hydrographic and hydrodynamic characteristics (salinity, temperature, density and circulation), mixing processes (advection and diffusion), transport timescales such as the residence time and the exposure time. In the area of physical oceanography, experiments using these water bodies as a natural laboratory and interpreting their circulation and mixing processes using theoretical and semi-theoretical knowledge are of fundamental importance. Small-scale physical models may also be used together with analytical and numerical models. The book highlights the fact that research and theory are interactive, and the results provide the fundamentals for the development of the estuarine research.

  7. Snail1, Snail2, and E47 promote mammary epithelial branching morphogenesis

    OpenAIRE

    Lee, KangAe; Gjorevski, Nikolce; Boghaert, Eline; Radisky, Derek C; Nelson, Celeste M

    2011-01-01

    While the roles of Snail transcription factors in epithelial-mesenchymal transition (EMT) are well established, their functions in other morphogenetic processes are less understood. Here, Snail, Snail2, and E47 are shown to promote mammary gland branching morphogenesis, via activation of an EMT-like gene expression program.

  8. Upregulation of lactate-inducible snail protein suppresses oncogene-mediated senescence through p16INK4ainactivation.

    Science.gov (United States)

    Li, Xiangrui; Zhang, Zhijian; Zhang, Yao; Cao, Yuxiang; Wei, Huijun; Wu, Zhihao

    2018-02-26

    The preferential use of aerobic glycolysis by tumor cells lead to high accumulation of lactate in tumor microenvironment. Clinical evidence has linked elevated lactate concentration with cancer outcomes. However, the role and molecular mechanisms of lactate in cellular senescence and tumor progression remain elusive. The function of Snail in lactate-induced EMT in lung cancer cells was explored by wound healing assay and cell invasion assay. The qRT-PCR and dual luciferase reporter assay were performed to investigate how lactate regulates Snail expression. The level of TGF-β1 in culture supernatant of cells was measured by ELISA for its correlation with extracellular levels of lactate. Ras activity assay and SA-β-gal activity assay were established to determine the effect of lactate on oncogene-induced senescence in human lung epithelial cells. ChIP assays were conducted to determine the binding of snail to p16 INK4a promoter. Two TCGA data sets (TCGA-LUAD and TCGA-LUSC) were used to explore the correlations between SNAI1 and CDKN2A expression. In this study, we showed the invasive and migratory potential of lung cancer cells was significantly enhanced by lactate and was directly linked to snail activity. We also demonstrated that extracellular acidification itself is a direct cause of the increased snail expression and physiologically coupled to LDHA-dependent conversion of pyruvate to lactate. Mechanistically, lactate exerts its central function in induction of snail and EMT by directly remodeling ECM and releasing activated TGF-β1. We also demonstrated that Snail help premalignant cells to escape the oncogene-induced senescence by directly targeting and inhibiting p16 INK4a expression. Our study extends the understanding of EMT in tumorigenesis by uncovering the role of snail in cellular senescence. This study also reveals lactate may be a potent tumor-promoting factor and provides the basis for the development of lactate-targeted therapy.

  9. Snail modulates cell metabolism in MDCK cells

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Misako, E-mail: haraguci@m3.kufm.kagoshima-u.ac.jp [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Indo, Hiroko P. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Iwasaki, Yasumasa [Health Care Center, Kochi University, Kochi 780-8520 (Japan); Iwashita, Yoichiro [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Fukushige, Tomoko [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Majima, Hideyuki J. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Izumo, Kimiko; Horiuchi, Masahisa [Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Kanekura, Takuro [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Furukawa, Tatsuhiko [Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Ozawa, Masayuki [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan)

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  10. Peroxisome Proliferator-Activated Receptor-γ Inhibits Transformed Growth of Non-Small Cell Lung Cancer Cells through Selective Suppression of Snail

    Directory of Open Access Journals (Sweden)

    Rashmi Choudhary

    2010-03-01

    Full Text Available Work from our laboratory and others has demonstrated that activation of the nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ inhibits transformed growth of non-small cell lung cancer (NSCLC cell lines in vitro and in vivo. We have demonstrated that activation of PPARγ promotes epithelial differentiation of NSCLC by increasing expression of E-cadherin, as well as inhibiting expression of COX-2 and nuclear factor-κB. The Snail family of transcription factors, which includes Snail (Snail1, Slug (Snail2, and ZEB1, is an important regulator of epithelial-mesenchymal transition, as well as cell survival. The goal of this study was to determine whether the biological responses to rosiglitazone, a member of the thiazolidinedione family of PPARγ activators, are mediated through the regulation of Snail family members. Our results indicate that, in two independent NSCLC cell lines, rosiglitazone specifically decreased expression of Snail, with no significant effect on either Slug or ZEB1. Suppression of Snail using short hairpin RNA silencing mimicked the effects of PPARγ activation, in inhibiting anchorage-independent growth, promoting acinar formation in three-dimensional culture, and inhibiting invasiveness. This was associated with the increased expression of E-cadherin and decreased expression of COX-2 and matrix metaloproteinases. Conversely, overexpression of Snail blocked the biological responses to rosiglitazone, increasing anchorage-independent growth, invasiveness, and promoting epithelial-mesenchymal transition. The suppression of Snail expression by rosiglitazone seemed to be independent of GSK-3 signaling but was rather mediated through suppression of extracellular signal-regulated kinase activity. These findings suggest that selective regulation of Snail may be critical in mediating the antitumorigenic effects of PPARγ activators.

  11. Celss nutrition system utilizing snails

    Science.gov (United States)

    Midorikawa, Y.; Fujii, T.; Ohira, A.; Nitta, K.

    At the 40th IAF Congress in Malaga, a nutrition system for a lunar base CELSS was presented. A lunar base with a total of eight crew members was envisaged. In this paper, four species of plants—rice, soybean, lettuce and strawberry—were introduced to the system. These plants were sufficient to satisfy fundamental nutritional needs of the crew members. The supply of nutrition from plants and the human nutritional requirements could almost be balanced. Our study revealed that the necessary plant cultivation area per crew member would be nearly 40 m 3 in the lunar base. The sources of nutrition considered in the study were energy, sugar, fat, amino acids, inorganic salt and vitamins; however, calcium, vitamin B 2, vitamin A and sodium were found to be lacking. Therefore, a subsystem to supply these elements is of considerable value. In this paper, we report on a study for breeding snails and utilizing meat as food. Nutrients supplied from snails are shown to compensate for the abovementioned lacking elements. We evaluate the snail breeder and the associated food supply system as a subsystem of closed ecological life support system.

  12. Characterisation of Reproduction-Associated Genes and Peptides in the Pest Land Snail, Theba pisana

    Science.gov (United States)

    Stewart, Michael J.; Wang, Tianfang; Harding, Bradley I.; Bose, U.; Wyeth, Russell C.; Storey, Kenneth B.; Cummins, Scott F.

    2016-01-01

    Increased understanding of the molecular components involved in reproduction may assist in understanding the evolutionary adaptations used by animals, including hermaphrodites, to produce offspring and retain a continuation of their lineage. In this study, we focus on the Mediterranean snail, Theba pisana, a hermaphroditic land snail that has become a highly invasive pest species within agricultural areas throughout the world. Our analysis of T. pisana CNS tissue has revealed gene transcripts encoding molluscan reproduction-associated proteins including APGWamide, gonadotropin-releasing hormone (GnRH) and an egg-laying hormone (ELH). ELH isoform 1 (ELH1) is known to be a potent reproductive peptide hormone involved in ovulation and egg-laying in some aquatic molluscs. Two other non-CNS ELH isoforms were also present in T. pisana (Tpi-ELH2 and Tpi-ELH3) within the snail dart sac and mucous glands. Bioactivity of a synthetic ELH1 on sexually mature T. pisana was confirmed through bioassay, with snails showing ELH1-induced egg-laying behaviours, including soil burrowing and oviposition. In summary, this study presents a detailed molecular analysis of reproductive neuropeptide genes in a land snail and provides a foundation for understanding ELH function. PMID:27706146

  13. Characterisation of Reproduction-Associated Genes and Peptides in the Pest Land Snail, Theba pisana.

    Directory of Open Access Journals (Sweden)

    Michael J Stewart

    Full Text Available Increased understanding of the molecular components involved in reproduction may assist in understanding the evolutionary adaptations used by animals, including hermaphrodites, to produce offspring and retain a continuation of their lineage. In this study, we focus on the Mediterranean snail, Theba pisana, a hermaphroditic land snail that has become a highly invasive pest species within agricultural areas throughout the world. Our analysis of T. pisana CNS tissue has revealed gene transcripts encoding molluscan reproduction-associated proteins including APGWamide, gonadotropin-releasing hormone (GnRH and an egg-laying hormone (ELH. ELH isoform 1 (ELH1 is known to be a potent reproductive peptide hormone involved in ovulation and egg-laying in some aquatic molluscs. Two other non-CNS ELH isoforms were also present in T. pisana (Tpi-ELH2 and Tpi-ELH3 within the snail dart sac and mucous glands. Bioactivity of a synthetic ELH1 on sexually mature T. pisana was confirmed through bioassay, with snails showing ELH1-induced egg-laying behaviours, including soil burrowing and oviposition. In summary, this study presents a detailed molecular analysis of reproductive neuropeptide genes in a land snail and provides a foundation for understanding ELH function.

  14. Production of apple snail for space diet

    Science.gov (United States)

    Yamashita, Masamichi; Motoki, Shigeru; Space Agriculture Task Force, J.; Katayama, Naomi

    For food production in space at recycling bio-elements under closed environment, appropriate organisms should be chosen to drive the closed materials recycle loop. We propose a combination of green algae, photosynthetic protozoa, and aquatic plants such as Wolffia spp., for the primary producer fixing solar energy to chemical form in biomass, and apple snail, Pomacea bridgesii, which converts this biomass to animal meat. Because of high proliferation rate of green algae or protozoa compared to higher plants, and direct conversion of them to apple snail, the efficiency of food production in this combination is high, in terms of energy usage, space for rearing, and yield of edible biomass. Furthermore, green algae and apple snail can form a closed ecological system with exchanging bio-elements between two member, i.e. excreta of snail turn to fertilizer of algae, and grown algae become feed for snail. Since apple snail stays in water or on wet substrate, control of rearing is easy to make. Mass production technology of apple snail has been well established to utilize it as human food. Nutrients of apple snail are also listed in the standard tables of food composition in Japan. Nutrients for 100 g of apple snail canned in brine are energy 340 kJ, protein 16.5 g, lipid 1.0 g, cholesterol 240 mg, carbohydrate 0.8 g, Ca 400 mg, Fe 3.9 mg, Zn 1.5 mg. It is rich in minerals, especially Ca and Fe. Vitamin contents are quite low, but K 0.005 mg, B2 0.09 mg, B12 0.0006 mg, folate 0.001 mg, and E 0.6 mg. The amino acid score of apple snail could not be found in literature. Overall, apple snail provides rich protein and animal lipid such as cholesterol. It could be a good source of minerals. However, it does not give enough vitamin D and B12 , which are supposed to be supplemented by animal origin foods. In terms of acceptance in food culture, escargot is a gourmet menu in French dishes, and six to ten snail, roughly 50 g, are served for one person. Apple snail reaches to 30 g

  15. Knockdown of Snail inhibits epithelial-mesenchymal transition of human laryngeal squamous cell carcinoma Hep-2 cells through the vitamin D receptor signaling pathway.

    Science.gov (United States)

    Zhao, Xue; Yu, Dan; Yang, Jingpu; Xue, Kai; Liu, Yan; Jin, Chunshun

    2017-12-01

    It has been well documented that Snail plays a decisive role in various tumors. However, the direct effect of Snail on laryngeal squamous cell carcinoma (LSCC) has not been elaborated. In this study, we firstly detected the expression of Snail in 14 samples of patients with LSCC and found that its content was high in cancer tissues compared with adjacent tissues. Then we established LSCC Hep-2 cells with Snail silencing and validated the knockdown efficiency by Western blotting and real-time PCR. Results showed that silencing of Snail significantly inhibited the ability of adhesion, migration, and invasion of Hep-2 cells. Further study revealed that knockdown of Snail suppressed the epithelial-mesenchymal transition (EMT) process of Hep-2 cells, as evidenced by downregulation of matrix metallopeptidase (MMP)-2, MMP-9, integrin subunit beta 1 (ITGβ1), β-catenin, vimentin, N-cadherin, and fibronectin and upregulation of vitamin D receptor (VDR) and E-cadherin. Additionally, transfection with the small interfering RNA of VDR reversed the effect induced by Snail silencing in Hep-2 cells. Taken together, these results demonstrate that knockdown of Snail can inhibit the EMT process of LSCC cells through the VDR signaling pathway in vitro.

  16. Invading freshwater snails and biological control in Martinique Island, French West Indies

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Pointier

    2001-09-01

    Full Text Available Eight alien freshwater snail species were introduced into Martinique Island during the last 50 years. The introduced snails include four planorbids (Biomphalaria straminea, Helisoma duryi, Amerianna carinata and Gyraulus sp., three thiarids (Melanoides tuberculata, M. amabilis and Tarebia granifera and one ampullarid (Marisa cornuarietis. Four of these species rapidly colonized the whole Martinican hydrographic system whereas the other four remained restricted to some particular sites. The invasion processes were documented during the last 20 years and showed (i a rapid invasion of the island by several morphs of M. tuberculata at the beginning of the 80's; (ii the introduction of T. granifera in 1991 and M. amabilis in 1997; and (iii the rapid spread of these last two species throughout the island. In the years following its introduction, M. tuberculata was used in biological control experiments against the snail hosts of schistosomiasis, B. glabrata and B. straminea. Experiments were conducted with success in several groups of water-cress beds which constituted the latest transmission sites for schistosomiasis at the beginning of the 80's. A malacological survey carried out in 2000 all over the island showed the absence of B. glabrata but the presence of some residual populations of B. straminea. Long-term studies carried out in Martinique have shown that the thiarids are able to maintain relatively stable populations over a long period of time, thus preventing recolonization by the snail hosts. Within this context the invasion of the hydrographic system of Martinique by thiarid snails has resulted in an efficient and sustainable control of the intermediate hosts of schistosomiasis.

  17. Estuarine Sediment Budgets for Chesapeake Bay Tributaries

    Science.gov (United States)

    2012-09-01

    2003. Estuarine sediment sources: A Summary Report of Sediment Processes in Chesapeake Bay and Watershed . Water-Resources Investigations Report 03...2007. Sources and transport of sediment in the watershed : Synthesis of US Geological Survey science for the Chesapeake Bay ecosystem and...originator. Estuarine Sediment Budgets for Chesapeake Bay Tributaries by Julie D. Herman PURPOSE. This Coastal and Hydraulics Engineering

  18. Characteristics and landcover of estuarine boundaries: implications ...

    African Journals Online (AJOL)

    This study investigated whether the current lateral boundary for estuaries in South Africa, i.e. the estuarine functional zone (EFZ), includes all estuarine habitats. The EFZ covers 173 930 ha in 304 estuaries/outlets nationally. Field surveys and analysis of available aerial images showed that 82 (12 956.70 ha) of these ...

  19. Molluscicide control of snail vectors of schistosomiasis

    Directory of Open Access Journals (Sweden)

    Cecília Pereira de Souza

    1995-04-01

    Full Text Available A review of the methodology recommended by the World Health Organization for the use of molluscicides for the control of snail vectors of schistosomiasis is presented. Discussion of the principle molluscicides used, their advantages and disadvantages, the techniques and equipment required for their application and evaluation of effect as well as the biological control of snails is included.

  20. Differential roles of the Drosophila EMT-inducing transcription factors Snail and Serpent in driving primary tumour growth.

    Science.gov (United States)

    Campbell, Kyra; Lebreton, Gaëlle; Franch-Marro, Xavier; Casanova, Jordi

    2018-02-01

    Several transcription factors have been identified that activate an epithelial-to-mesenchymal transition (EMT), which endows cells with the capacity to break through basement membranes and migrate away from their site of origin. A key program in development, in recent years it has been shown to be a crucial driver of tumour invasion and metastasis. However, several of these EMT-inducing transcription factors are often expressed long before the initiation of the invasion-metastasis cascade as well as in non-invasive tumours. Increasing evidence suggests that they may promote primary tumour growth, but their precise role in this process remains to be elucidated. To investigate this issue we have focused our studies on two Drosophila transcription factors, the classic EMT inducer Snail and the Drosophila orthologue of hGATAs4/6, Serpent, which drives an alternative mechanism of EMT; both Snail and GATA are specifically expressed in a number of human cancers, particularly at the invasive front and in metastasis. Thus, we recreated conditions of Snail and of Serpent high expression in the fly imaginal wing disc and analysed their effect. While either Snail or Serpent induced a profound loss of epithelial polarity and tissue organisation, Serpent but not Snail also induced an increase in the size of wing discs. Furthermore, the Serpent-induced tumour-like tissues were able to grow extensively when transplanted into the abdomen of adult hosts. We found the differences between Snail and Serpent to correlate with the genetic program they elicit; while activation of either results in an increase in the expression of Yorki target genes, Serpent additionally activates the Ras signalling pathway. These results provide insight into how transcription factors that induce EMT can also promote primary tumour growth, and how in some cases such as GATA factors a 'multi hit' effect may be achieved through the aberrant activation of just a single gene.

  1. Bioinvasion Triggers Rapid Evolution of Life Histories in Freshwater Snails.

    Science.gov (United States)

    Chapuis, Elodie; Lamy, Thomas; Pointier, Jean-Pierre; Juillet, Nicolas; Ségard, Adeline; Jarne, Philippe; David, Patrice

    2017-11-01

    Biological invasions offer interesting situations for observing how novel interactions between closely related, formerly allopatric species may trigger phenotypic evolution in situ. Assuming that successful invaders are usually filtered to be competitively dominant, invasive and native species may follow different trajectories. Natives may evolve traits that minimize the negative impact of competition, while trait shifts in invasives should mostly reflect expansion dynamics, through selection for colonization ability and transiently enhanced mutation load at the colonization front. These ideas were tested through a large-scale common-garden experiment measuring life-history traits in two closely related snail species, one invasive and one native, co-occurring in a network of freshwater ponds in Guadeloupe. We looked for evidence of recent evolution by comparing uninvaded or recently invaded sites with long-invaded ones. The native species adopted a life history favoring rapid population growth (i.e., increased fecundity, earlier reproduction, and increased juvenile survival) that may increase its prospects of coexistence with the more competitive invader. We discuss why these effects are more likely to result from genetic change than from maternal effects. The invader exhibited slightly decreased overall performances in recently colonized sites, consistent with a moderate expansion load resulting from local founder effects. Our study highlights a rare example of rapid life-history evolution following invasion.

  2. Nutritional Assessment of Some Nigerian Land and Water Snail ...

    African Journals Online (AJOL)

    Choice-Academy

    Mineral analysis of the snail species revealed relatively high amount of minerals in the water snails compared to the land snails. ... Key words: Land and water snails, minerals, chemical composition, and nutritive qualities. Introduction major task facing ... be found in Europe, South East Asia and the. United States of America ...

  3. Characteristics of snail farmers and constraints to increased ...

    African Journals Online (AJOL)

    Administrator

    high quality of protein obtained from snails they have secured high demand in ... Characteristics of snail farmers and marketers. Characteristics. Percentage (%). Sex. Male. 40. Female. 60. Level of education. Primary and/or secondary. 82. Source of snails .... practices (with snails, bee keeping etc. as components) in view of ...

  4. Public Health Implications of Aquatic Snails around Fish Ponds in ...

    African Journals Online (AJOL)

    A survey of aquatic snails around fish ponds in Okwe, Delta State was conducted to identify snails and their public health implications in the area. Snails were collected fortnightly within an hour of active snail search for a period of twelve months from randomly selected eight fish ponds using a scoop net attached to a long ...

  5. Miracidial infectivity of snail host ( Bulinus truncatus ) in the laboratory

    African Journals Online (AJOL)

    Miracidial infectivity rate of snail Bulinus truncatus collected from Agulu Lake was studied in the laboratory. The snails were maintained in the laboratory and eggs deposited were allowed to hatch and dates noted until snails of different ages were produced. These snails were consequently exposed to miracidia hatched ...

  6. Slug overexpression induces stemness and promotes hepatocellular carcinoma cell invasion and metastasis

    OpenAIRE

    SUN, YU; SONG, GUO-DONG; SUN, NING; CHEN, JIAN-QIU; YANG, SHAO-SHI

    2014-01-01

    Detection of metastasis of hepatocellular carcinoma (HCC) is crucial for early diagnosis. Epithelial-mesenchymal transition (EMT) is a common event in the metastasis of tumor cells. Slug and Snail are homologous proteins, which play an important role in EMT. The present study aimed to investigate whether Slug and Snail overexpression is associated with the invasiveness of HCC in vitro and in vivo. Invasion, colony formation and wound healing assays, as well as flow cytometry analysis, were pe...

  7. Current Situation of Edible Snails in Indonesia

    Directory of Open Access Journals (Sweden)

    Schneider, K.

    1999-01-01

    Full Text Available From March 7, 1995 to April 16, 1995 du ring the rainy season the utilisation of edible snails was investigated in Indonesia. To assess the current situation, the focus was put to answer the following questions : - Is it feasible under the present circumstances to domesticate these snails with the aim to conserve the natural resources ? - Could any individual or private initiative be enhanced or utilized ? - Would local disadvantaged groups (traditional animal farmers, women oryouths be benefitted through domestication of these snails ? - Is there any existing private organisation or NGO, which already gathers and trades the snails or would be interested to do this in the future ? Snails gatherers, -dealers and -farmers were visited and interviewed on the following topics using standardised questionnaires : Spreading and ecology ways of marketing, consumption habits, breeding and rearing. Diotopes were also visited and investigated. Results Spreading and ecology : Achatina fulica, Pomacea canaliculata, Pila ampullacea and Bellamia javanica are eaten. The snails can be found ail overJava. Ways of marketing : The snails gathered in the biotope are either marketed directly or through various marketing paths. A. fulica is exported in large quantifies. The population is therefore endangered. Consumption habits : Snails are not eaten regularly. Snail meat is known to be healthy. The consumption depends on the consumer's ethnie background. Breeding and rearing experience : with simple breeding systems for A. fulica and P. canaliculata are seldom found. The breeding of P. canaliculata is forbidden in Indonesia. There is no interest in breeding P. ampullacea or B. javanica. The breeding of A. fulica can ben-efit disadvantaged groups financially and help to conserving the natural snail population.

  8. Seasonal dynamics of snail populations in coastal Kenya: Model calibration and snail control

    Science.gov (United States)

    Gurarie, D.; King, C. H.; Yoon, N.; Wang, X.; Alsallaq, R.

    2017-10-01

    A proper snail population model is important for accurately predicting Schistosoma transmission. Field data shows that the overall snail population and that of shedding snails have a strong pattern of seasonal variation. Because human hosts are infected by the cercariae released from shedding snails, the abundance of the snail population sets ultimate limits on human infection. For developing a predictive dynamic model of schistosome infection and control strategies we need realistic snail population dynamics. Here we propose two such models based on underlying environmental factors and snail population biology. The models consist of two-stage (young-adult) populations with resource-dependent reproduction, survival, maturation. The key input in the system is seasonal rainfall which creates snail habitats and resources (small vegetation). The models were tested, calibrated and validated using dataset collected in Msambweni (coastal Kenya). Seasonal rainfall in Msambweni is highly variable with intermittent wet - dry seasons. Typical snail patterns follow precipitation peaks with 2-4-month time-lag. Our models are able to reproduce such seasonal variability over extended period of time (3-year study). We applied them to explore the optimal seasonal timing for implementing snail control.

  9. The application of a Biopollution Index in German Baltic estuarine and lagoon waters

    Directory of Open Access Journals (Sweden)

    Anne K. J. Wittfoth

    2013-01-01

    Full Text Available This paper assesses the status of three German Baltic estuarine and lagoon waters with respect to invasive species (macrozoobenthos andtheir impact. A Biological Pollution Index was applied and evaluated. Overall 130 macrozoobenthic species were identified, 17 of whichwere aquatic alien species. The Szczecin Lagoon had the highest number of invasive species (13. Most species were of Pontocaspian origin;inland waterways are likely to play a significant role in their migration. According to the Biological Pollution Index Level (BPL this lagoonwas ‘moderately influenced’ by invasive species. Warnow Estuary had 11 invasive species; their origin noted generally from North-America,suggesting shipping traffic as the major distribution vector; invasive species had the same BPL as in the Szczecin Lagoon. In theDarß-Zingst-Bodden-Chain only 6 invasive species were observed, having the highest relative abundance (9–71%. Furthermore, this areahad the highest BPL of all three areas, i.e. a strong negative impact. The BPL required a lot of data (including historical and some ratingswere subjective and comparisons with other areas assessed were difficult and often impossible. Due to these limitations, it is suggested thatthe BPL should only be used with restrictions as a universal assessment tool for invasive species in the estuarine and lagoon waters of theBaltic Sea.

  10. Degree of Acetylization Chitosan Gonggong Snail Shells

    Science.gov (United States)

    Horiza, H.; Iskandar, I.; Aldo, N.

    2018-04-01

    Chitosan is a polysaccharide obtained from the deacetylation of chitin, which is generally derived from crustacean animal waste and animal skins other sea. One marine animals that have compounds that can be processed chitin chitosan is derived from the snail Gonggong marine waters of Riau Islands province. The purpose of this study was to determine the degree of chitosan from the shells of snails asetilisasi Gonggong. This research is an experimental research laboratory. The results of this study indicate that the degree of chitosan shell snail deasetilisasi Gonggong is 70.27%.

  11. Prime waterfront real estate: Apple snails choose wild taro for oviposition sites

    Directory of Open Access Journals (Sweden)

    Colin H. KYLE, Alexis W. KROPF, Romi L. BURKS

    2011-10-01

    Full Text Available While difficult to prevent introductions, scientific research can help guide control efforts of exotic, invasive species. South American island apple snails Pomacea insularum have quickly spread across the United States Gulf Coast and few control measures exist to delay their spread. Usually occupying cryptic benthic habitats, female apple snails crawl out of the water to deposit large, bright pink egg clutches on emergent objects. To help identify the most likely place to find and remove clutches, we conducted four lab experiments to investigate what specific object qualities (i.e. material; shape and height; plant species; natural and artificial attracted P. insularum females to lay clutches. In our fourth experiment, we specifically examined the relationship between female size and reproductive output. To further understand reproductive output, we quantified experimental clutch chara- cteristics (height above water, dimensions, mass, approximate volume, number of eggs, hatching efficiency. Pomacea insularum females laid more clutches on plant material, chose round over flat surfaces and failed to differentiate between tall and short structures. In comparison to a common native plant in the eastern US, Pontederia cordata, snails clearly preferred to lay clutches on a widely distributed exotic, invasive plant (wild taro, Colocasia esculenta. Unexpectedly, smaller snails showed higher overall total fecundity as well as more eggs per clutch than larger snails. Therefore, hand removal efforts of large females may not be enough to slow down clutch production. Collectively, our results indicate that conservationists and managers should search emergent plants for P. insularum clutches carefully to guard against established populations [Current Zoology 57 (5: 630–641, 2011].

  12. Ecohydraulics and Estuarine Wetland Rehabilitation

    Science.gov (United States)

    Rodriguez, J. F.; Howe, A.; Saintilan, N.; Spencer, J.

    2004-12-01

    The hydraulics or water flow in wetlands is known to be a key factor influencing ecosystem development in estuarine wetland environments. The relationship is indirect, with the hydraulics of wetlands influencing a host of factors including soil salinity, waterlogging, sediment transport, sediment chemistry, vegetation dispersal and growth and nutrient availability and cycling. The relationship is also not one way, with the hydraulics of wetlands being influenced by plant and animal activity. Understanding these complex interactions is fundamental for the adequate management of estuarine wetlands. Listed as a Wetland of International Importance under the 1971 Ramsar Convention, the Hunter River estuary is regarded as the most significant site for migratory shorebirds in New South Wales, Australia. Over the past 20 years, the number of migratory shorebirds in the estuary has sharply declined from 8,000 to 4,000 approx. Alteration of bird habitat is believed to be one of the reasons for this alarming trend. In 2004 we started a three-year program to investigate the links between hydraulics, sediment, benthic invertebrates, vegetation and migratory shorebird habitat in the estuary. During the first year we have focused on a highly disturbed part of the Hunter estuary wetlands located on Ash Island. The area is one of the major roosting sites in the estuary and is characterized by a complex hydraulic regime due to a restricted tidal interchange with the Hunter River and the presence of infrastructure for the maintenance of power lines (i.e., roads, bridges, culverts). Salt marshes, mudflat and mangroves are the dominant vegetation types. The monitoring program includes measurements of water levels, salinity, discharge, velocity, turbulence, sediment transport and deposition, plant species and density, soil composition and benthic invertebrates coordinated with observations of bird habitat utilization on a number of locations throughout the wetland and for different flow

  13. Heregulin-beta1 promotes metastasis of breast cancer cell line SKBR3 through upregulation of Snail and induction of epithelial-mesenchymal transition.

    Science.gov (United States)

    Cheng, Liansheng; Zha, Zhao; Lang, Bo; Liu, Jing; Yao, Xuebiao

    2009-07-18

    HRG-beta1 stimulation of breast cancer cell line SKBR3 resulted in not only increased cell migration and invasion, upregulation of some mesenchymal markers, and downregulation of epithelial marker, but also upregulation of transcription factor Snail and its nuclear translocation. Similar results were acquired for cells transfected with Snail cDNA. Furthermore, downregulation of Snail by siRNA attenuated HRG-beta1 induced EMT-like phenotype. Inhibition of Akt kinase activation by a PI3K inhibitor LY294002, or exogenous expression of a kinase-dead mutant of Akt abrogated the increase of Snail expression induced by HRG-beta1. Conversely, expression of a constitutively active Akt resulted in increase of Snail expression. These results indicated that Snail upregulation by HRG-beta1 is mediated via the PI3K/Akt signaling pathway and that Snail plays a key role in HRG-beta1 induced breast cancer cell metastasis through induction of EMT.

  14. Meta-analysis of estuarine nurseries

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Densities of juvenile fishery species and other animals (all generally 100 mm total length) were summarized for shallow estuarine areas along coastal Texas and...

  15. Invasive Estuarine and Marine Animals of the North Atlantic

    Science.gov (United States)

    2005-08-01

    2 5 7 Bivalves 2 8 1 1 3 2 5 8 12 Gastropods 1 2 1 1 1 3 8 9 Nudibranchs 1...its colorful appearance. It bears poisonous dorsal, anal, and pelvic spines. The toxin is painful , but is generally not fatal. The lionfish was first...2003). “Salinity tolerance of larval Rapana venosa: implications for dispersal and establishment of an invading predatory gastropod on the North

  16. FBW7 loss promotes epithelial-to-mesenchymal transition in non-small cell lung cancer through the stabilization of Snail protein.

    Science.gov (United States)

    Zhang, Yong; Zhang, Xinxin; Ye, Mingxiang; Jing, Pengyu; Xiong, Jie; Han, Zhiping; Kong, Jing; Li, Mengyang; Lai, Xiaofeng; Chang, Ning; Zhang, Jian; Zhang, Jian

    2018-04-10

    The E3 ubiquitin ligase F-box and WD repeat domain containing 7 (FBW7α) functions as a putative tumor suppressor in non-small cell lung cancer (NSCLC) due to its regulation of a set of oncogenic proteins associated with cell proliferation and mitosis. Increasing efforts have been focused on the understanding of FBW7 in determining cell cycle progression and apoptosis induction, however, the correlation between FBW7 and tumor metastasis is not fully understood. In this study, we reported a potential anti-metastatic effect of FBW7 in non-small cell lung cancer (NSCLC). In this model, FBW7 inhibited cancer cell metastasis primarily by inducing ubiquitination and proteolysis of the transcriptional factor Snail, which suppressed E-cadherin cell tight junction protein expression. Loss of FBW7 would stabilize the Snail protein, thus, inhibit E-cadherin expression and promote metastasis in vitro and in vivo. Moreover, Snail ubiquitination and degradation were also achieved by pharmacological approach, in which the FBW7 agonist oridonin treatment led to Snail proteolysis. Furthermore, FBW7 silencing stabilized Snail protein and induced epithelial-to mesenchymal transition (EMT), and acquisition of migration and invasion properties in NSCLC. Overall, our study provides new insights into the FBW7-Snail axis in regulating cell migration and invasion, and suggests that targeting FBW7 may be a potent approach to inhibit metastasis in NSCLC. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  17. Characterizations of cholinesterases in golden apple snail (Pomacea canaliculata).

    Science.gov (United States)

    Zou, Xiang-Hui; Xie, Heidi Qun-Hui; Zha, Guang-Cai; Chen, Vicky Ping; Sun, Yan-Jie; Zheng, Yu-Zhong; Tsim, Karl Wah-Keung; Dong, Tina Ting-Xia; Choi, Roy Chi-Yan; Luk, Wilson Kin-Wai

    2014-07-01

    Cholinesterases (ChEs) have been identified in vertebrates and invertebrates. Inhibition of ChE activity in invertebrates, such as bivalve molluscs, has been used to evaluate the exposure of organophosphates, carbamate pesticides, and heavy metals in the marine system. The golden apple snail (Pomacea canaliculata) is considered as one of the worst invasive alien species harmful to rice and other crops. The ChE(s) in this animal, which has been found recently, but poorly characterized thus far, could serve as biomarker(s) for environmental surveillance as well as a potential target for the pest control. In this study, the tissue distribution, substrate preference, sensitivity to ChE inhibitors, and molecular species of ChEs in P. canaliculata were investigated. It was found that the activities of both AChE and BChE were present in all test tissues. The intestine had the most abundant ChE activities. Both enzymes had fair activities in the head, kidney, and gills. The BChE activity was more sensitive to tetra-isopropylpyrophosphoramide (iso-OMPA) than the AChE. Only one BChE molecular species, 5.8S, was found in the intestine and head, whereas two AChE species, 5.8S and 11.6S, were found there. We propose that intestine ChEs of this snail may be potential biomarkers for manipulating pollutions.

  18. CRCP-Prey choice of corallivorous snails

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The snail, Coralliophila abbreviata, is a common generalist corallivore and can be a major contributor to Caribbean acroporid tissue mortality. Considering the...

  19. Celastrol inhibits TGF-β1-induced epithelial–mesenchymal transition by inhibiting Snail and regulating E-cadherin expression

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyereen; Lee, Minjae [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Jang, Sung-Wuk, E-mail: swjang@amc.seoul.kr [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of)

    2013-08-09

    Highlights: •We investigated the effects of celastrol on TGF-β1-induced EMT in epithelial cells. •Celastrol regulates TGF-β1-induced morphological changes and E-cadherin expression. •Celastrol inhibits TGF-β1-induced Snail expression. •Celastrol strongly suppresses TGF-β1-induced invasion in MDCK and A549 cells. -- Abstract: The epithelial–mesenchymal transition (EMT) is a pivotal event in the invasive and metastatic potentials of cancer progression. Celastrol inhibits the proliferation of a variety of tumor cells including leukemia, glioma, prostate, and breast cancer; however, the possible role of celastrol in the EMT is unclear. We investigated the effect of celastrol on the EMT. Transforming growth factor-beta 1 (TGF-β1) induced EMT-like morphologic changes and upregulation of Snail expression. The downregulation of E-cadherin expression and upregulation of Snail in Madin–Darby Canine Kidney (MDCK) and A549 cell lines show that TGF-β1-mediated the EMT in epithelial cells; however, celastrol markedly inhibited TGF-β1-induced morphologic changes, Snail upregulation, and E-cadherin expression. Migration and invasion assays revealed that celastrol completely inhibited TGF-β1-mediated cellular migration in both cell lines. These findings indicate that celastrol downregulates Snail expression, thereby inhibiting TGF-β1-induced EMT in MDCK and A549 cells. Thus, our findings provide new evidence that celastrol suppresses lung cancer invasion and migration by inhibiting TGF-β1-induced EMT.

  20. Differential expression of the epithelial mesenchymal transition factors Snail, Slug, Twist, TGF-β, and E-cadherin in ameloblastoma.

    Science.gov (United States)

    Kurioka, Kagami; Wato, Masahiro; Iseki, Tomio; Tanaka, Akio; Morita, Shosuke

    2017-06-01

    Epithelial mesenchymal transition (EMT), the transition of epithelial cells into motile mesenchymal cells, plays an important role in embryogenesis, cancer invasion, and metastasis. Ameloblastomas are common epithelial odontogenic tumors, occurring exclusively in the mandible with locally invasive growth. Thirty-seven ameloblastoma cases were evaluated for the involvement of EMT by immunohistochemical staining and western blotting using antibodies against Slug, Snail, Twist, TGF-β, and E-cadherin. Double immunostaining was also performed. Slug and TGF-β were expressed in the nuclei of peripheral and stellate reticulum cells of ameloblastoma nests. Twenty cases of Snail, 36 of Slug, 8 of Twist, and 19 of TGF-β showed strong expression in tumor cells in follicular and plexiform patterns. Expression of Slug and TGF-β increased in regions where the expression of E-cadherin was reduced. EMT was found to be associated with the local invasive growth of ameloblastoma. These data suggest that reduced expression of E-cadherin and over-expression of Slug, Snail, and TGF-β induce EMT. Given that ameloblastomas are characterized by local invasiveness, EMT might be related to their development. Thus, strong expression of Slug and TGF-β and reduced expression of E-cadherin might be related to the local invasiveness of ameloblastoma.

  1. Modeling freshwater snail habitat suitability and areas of potential snail-borne disease transmission in Uganda

    DEFF Research Database (Denmark)

    Stensgaard, Anna-Sofie; Jørgensen, Aslak; Kabatereine, N B

    2006-01-01

    Geographic information system (GIS-based modeling of an intermediate host snail species environmental requirements using known occurrence records can provide estimates of its spatial distribution. When other data are lacking, this can be used as a rough spatial prediction of potential snail......-borne disease transmission areas. Furthermore, knowledge of abiotic factors affecting intra-molluscan parasitic development can be used to make "masks" based on remotely sensed climatic data, and these can in turn be used to refine these predictions. We used data from a recent freshwater snail survey from...... Uganda, environmental data and the genetic algorithm for rule-set prediction (GARP) to map the potential distribution of snail species known to act as intermediate hosts of several human and animal parasites. The results suggest that large areas of Uganda are suitable habitats for many of these snail...

  2. Behavioural responses of the snail Lymnaea acuminata to carbohydrates in snail-attractant pellets

    Science.gov (United States)

    Tiwari, Farindra; Singh, D. K.

    Snail control is one of the most important tools in the campaign to reduce the incidence of fascioliasis. In order to attain this objective, the method of bait formulation in order to contain an attractant and a molluscicide is an expedient approach to lure the target snail population to the molluscicide. This study identifies certain carbohydrates, namely sucrose, maltose, glucose, fructose and starch, for preparing such baits. These were tested on Lymnaea acuminata, an intermediate host of the digenean trematodes Fasciola hepatica and Fasciola gigantica. The behavioural responses of snails to these carbohydrates were examined. Significant variations in behavioural responses were observed in the snail even when the five carbohydrates were used in low concentrations in snail-attractant pellets. Starch emerged as the strongest attractant for Lymnaea acuminata, followed by maltose.

  3. Comparative Performance of three Edible Snail Species using ...

    African Journals Online (AJOL)

    Egg production was highest with (15-25 eggs/clutch at lay) for garden snail and least with the giant land snail (8-12 eggs/clutch at lay). Percentage hatchability of eggs was 100% for the giant land snail and slightly less for both the garden snail and fulica (92.86 %). The incubation period varied from 21 - 23 days for garden ...

  4. Energy saving through trail following in a marine snail

    OpenAIRE

    Davies, Mark S; Blackwell, Janine

    2007-01-01

    Most snails and slugs locomote over a layer of mucus and although the resultant mucus trail is expensive to produce, we show that this expense can be reduced by trail following. When tracking over fresh conspecific trails, the marine intertidal snail Littorina littorea (L.) produced only approximately 27% of the mucus laid by marker snails. When tracking over weathered trails, snails adjusted their mucus production to recreate a convex trail profile of similar shape and thickness to the trail...

  5. Determinants of production level of commercial snail farmers in Oyo ...

    African Journals Online (AJOL)

    The study investigates the determinants of productivity level among commercial snail farmers in Oyo State. A systematic sampling technique was employed to select one-hundred and forty–two snail farmers from the membership list provided by the Snail Farmers Association of Nigeria (SFAN), Oyo State Chapter.

  6. Toxicity appraisement of methaldehyde, ferricol®, snail repellent ...

    African Journals Online (AJOL)

    Different control methods have been applied to control the land snail (Xeropicta derbentina and Xeropicta krynickii) but the chemical method is realized to be the most effective method to control this pest. The main goal of this work was to determine the efficacy of methaldehyde Ferricol, Snail repellent tape and Snail ...

  7. Profitability of Snail Production in Osun State,Nigeria | Baba ...

    African Journals Online (AJOL)

    The study determined the features and profitability of snail farming in Osun State. To achieve the study objectives, 20 snail farmers each were randomly selected from Osogbo, Iwo and Ife-Ijesa townships, where majority of snail farmers in the State were located. Data collected from the farmers were analysed using ...

  8. Occurrence of digenean larvae in freshwater snails in the Ruvu ...

    African Journals Online (AJOL)

    Occurrence of digenean larvae in freshwater snails in the Ruvu basin, Tanzania. G Nkwengulila, ESP Kigadye. Abstract. A survey was carried out on digenean larvae infecting freshwater snails in five habitats in Dar es Salaam, Ruvu and Morogoro. 9424 snails belonging to 12 species from five families were examined for ...

  9. The occurrence of digenean larvae in freshwater snails at Mbezi ...

    African Journals Online (AJOL)

    The occurrence of digenean larvae in freshwater snails at Mbezi-Temboni pond, Dar es Salaam. ESP Kigadye, G Nkwengulila. Abstract. The abundance of digenean larvae in snails at a pond in Mbezi-Temboni, Dar es Salaam, was investigated from July 1996 to June 1997. A total of 2,112 snails belonging to three species, ...

  10. Growth performance of African Giant Land Snails (Archachatina ...

    African Journals Online (AJOL)

    This experiment was set up to assess the sensory evaluation of African giant land snails (Archachatina marginata) fed dried kola nut testa (DKT) and palm kernel cake mixture (PKC). A total of 72 snails were randomly distributed into four (4) dietary treatments which were replicated 3 times with 6 snails per replicate in a ...

  11. Freshwater Snails Of Niger-Cem, Nkalagu Eastern Nigeria ...

    African Journals Online (AJOL)

    The results of snail collections carried out in the freshwater habitats of Niger-Cem in Nkalagu from August to November 2002 are reported. Also repored are findings on abundance, diversity and age structure of the snails. A total of 3491 pulmonate snails were collected, belonging to 3 families: Planorbidae (3133); ...

  12. CYTOGENETIC STUDY OF FOUR SPECIES OF LAND SNAILS OF ...

    African Journals Online (AJOL)

    The chromosomal study of the four species of achatinid snails was carried out with the aim of determining their chromosome numbers as part of a preliminary attempt to understand the cytogenetics of land snails of Nigeria. The haploid chromosomes of various species of snails studied were obtained from their ovotestis ...

  13. Haemolymph Biochemical Parameters of the African Giant Snail ...

    African Journals Online (AJOL)

    ++, Cu++ and Zn++ levels were higher (P<0.05) in the haemolymph of the African giant snail than in that of the big black snail. The uses and implications of these data in the management of these two wild snail species for meat and research are ...

  14. Oxygen consumption and responses of the freshwater snail Bulinus ...

    African Journals Online (AJOL)

    Fig.3 Oxygen gradient chamber experiments with B. (P.) globosus at. 26°C. Graph A - Twenty snails with air in the mantle cavity tested for oxygen preferences. Graph B - Twenty snails tested without an air bubble in the mantle cavity. Each histogram represents the staying time of 20 snails per zone during a three hour period ...

  15. Characteristics and landcover of estuarine boundaries: implications for the delineation of the South African estuarine functional zone

    CSIR Research Space (South Africa)

    Veldkornet, DA

    2015-11-01

    Full Text Available Zulu-Natal), cultivation has removed estuarine habitat. Although delineation of boundaries can be complicated by landcover changes, the estuarine lateral boundary in Cape estuaries could be identified based on sediment characteristics (moisture content, organic content...

  16. Down-regulation of the transcription factor snail in the placentas of patients with preeclampsia and in a rat model of preeclampsia

    Directory of Open Access Journals (Sweden)

    Fedorova Larisa

    2012-02-01

    Full Text Available Abstract Background Placental malfunction in preeclampsia is believed to be a consequence of aberrant differentiation of trophoblast lineages and changes in utero-placental oxygenation. The transcription factor Snail, a master regulator molecule of epithelial-mesenchymal transition in embryonic development and in cancer, is shown to be involved in trophoblast differentiation as well. Moreover, Snail can be controlled by oxidative stress and hypoxia. Therefore, we examined the expression of Snail and its downstream target, e-cadherin, in human normal term, preterm and preeclamptic placentas, and in pregnant rats that developed preeclampsia-like symptoms in the response to a 20-fold increase in sodium intake. Methods Western blotting analysis was used for comparative expression of Snail and e- cadherin in total protein extracts. Placental cells expressing Snail and e-cadherin were identified by immunohistochemical double-labeling technique. Results The levels of Snail protein were decreased in human preeclamptic placentas by 30% (p compared to normal term, and in the rat model by 40% (p compared to control placentas. In preterm placentas, the levels of Snail expression varied, yet there was a strong trend toward statistical significance between preterm and preeclamptic placentas. In humans, e-cadherin protein level was 30% higher in preeclamptic (p placentas and similarly, but not significantly (p = 0.1, high in the preterm placentas compared to normal term. In the rat model of preeclampsia, e-cadherin was increased by 60% (p . Immunohistochemical examination of human placentas demonstrated Snail-positive staining in the nuclei of the villous trophoblasts and mesenchymal cells and in the invasive trophoblasts of the decidua. In the rat placenta, the majority of Snail positive cells were spongiotrophoblasts of the junctional zone, while in the labyrinth, Snail-positive sinusoidal giant trophoblasts cells were found in some focal areas located close

  17. The identity, distribution, and impacts of non-native apple snails in the continental United States

    Science.gov (United States)

    Rawlings, Timothy A; Hayes, Kenneth A; Cowie, Robert H; Collins, Timothy M

    2007-01-01

    Background Since the mid 1990s populations of non-native apple snails (Ampullariidae) have been discovered with increasing frequency in the continental United States. Given the dramatic effects that introduced apple snails have had on both natural habitats and agricultural areas in Southeast Asia, their introduction to the mainland U.S. is cause for concern. We combine phylogenetic analyses of mtDNA sequences with examination of introduced populations and museum collections to clarify the identities, introduced distributions, geographical origins, and introduction histories of apple snails. Results Based on sampling to date, we conclude there are five species of non-native apple snails in the continental U.S. Most significantly, we recognize three species within what has been called the channeled apple snail: Pomacea canaliculata (California and Arizona), Pomacea insularum, (Florida, Texas, and Georgia) and Pomacea haustrum (Florida). The first established populations of P. haustrum were discovered in the late 1970s in Palm Beach County Florida, and have not spread appreciably in 30 years. In contrast, populations of P. insularum were established in Texas by 1989, in Florida by the mid to late 1990s, and in Georgia by 2005, and this species continues to spread rapidly. Most introduced P. insularum haplotypes are a close match to haplotypes from the Río Uruguay near Buenos Aires, indicating cold tolerance, with the potential to spread from Florida, Georgia, and Texas through Louisiana, Alabama, Mississippi, and South Carolina. Pomacea canaliculata populations were first discovered in California in 1997. Haplotypes of introduced P. canaliculata match native-range haplotypes from near Buenos Aires, Argentina, also indicating cold tolerance and the potential to establish farther north. Conclusion The term "channeled apple snail" is descriptive of a morphology found in many apple snail species. It does not identify a single species or a monophyletic group. Clarifying

  18. The identity, distribution, and impacts of non-native apple snails in the continental United States

    Directory of Open Access Journals (Sweden)

    Hayes Kenneth A

    2007-06-01

    Full Text Available Abstract Background Since the mid 1990s populations of non-native apple snails (Ampullariidae have been discovered with increasing frequency in the continental United States. Given the dramatic effects that introduced apple snails have had on both natural habitats and agricultural areas in Southeast Asia, their introduction to the mainland U.S. is cause for concern. We combine phylogenetic analyses of mtDNA sequences with examination of introduced populations and museum collections to clarify the identities, introduced distributions, geographical origins, and introduction histories of apple snails. Results Based on sampling to date, we conclude there are five species of non-native apple snails in the continental U.S. Most significantly, we recognize three species within what has been called the channeled apple snail: Pomacea canaliculata (California and Arizona, Pomacea insularum, (Florida, Texas, and Georgia and Pomacea haustrum (Florida. The first established populations of P. haustrum were discovered in the late 1970s in Palm Beach County Florida, and have not spread appreciably in 30 years. In contrast, populations of P. insularum were established in Texas by 1989, in Florida by the mid to late 1990s, and in Georgia by 2005, and this species continues to spread rapidly. Most introduced P. insularum haplotypes are a close match to haplotypes from the Río Uruguay near Buenos Aires, indicating cold tolerance, with the potential to spread from Florida, Georgia, and Texas through Louisiana, Alabama, Mississippi, and South Carolina. Pomacea canaliculata populations were first discovered in California in 1997. Haplotypes of introduced P. canaliculata match native-range haplotypes from near Buenos Aires, Argentina, also indicating cold tolerance and the potential to establish farther north. Conclusion The term "channeled apple snail" is descriptive of a morphology found in many apple snail species. It does not identify a single species or a

  19. Calcium oxide from Pomacea canaliculata and Babylonia spirata snails

    Directory of Open Access Journals (Sweden)

    Triayu Septiani

    2017-07-01

    Full Text Available The preparation of CaO from golden snail (Pomacea canaliculata and lion snail (Babylonia spirata through decomposition at various temperature i.e 700o, 800o, 900o and 1000oC during 3 hours has been carried out. Calcium oxide from decomposition was characterized using X-Ray diffractometer.  Furthermore, the characterization was continued using FT-IR spectrophotometer and determination of surface area using BET analysis. The results showed that the optimum temperature for preparation of CaO from  golden snail and lion snail at  900oC with 2q values are: 32.2° , 37.4o , 54o , 64.2o , 67.3° and 32.4°, 37.5°, 67.5 °,  respectively. FT-IR spectra showed characteristic vibrations for the Ca-O in the sample golden snail and lion snail combustion products at a temperature of 900oC. Ca-O absorption of golden snail samples in the wavenumber around 362.62 cm-1 and lion snail seen in wavenumber around 384.76 cm-1 indicating the presence of Ca-O vibration of the metal oxide of preparation. Golden snail and the lion snail combustion at 900oC temperature of each sample which has a surface area of 20.495 m2/g, while the lion snail 17.308 m2/g.  The pore diameter of golden snail 3.753 nm and 11.319 nm of lion snail. All CaO can be categorized as mesoporous material. Keywords: golden snail, lion snail, decomposition, CaO

  20. Eosinophilic meningitis risk associated with raw Ampullarium canaliculatus snails consumption

    Directory of Open Access Journals (Sweden)

    Jiun-Jye Wang

    2011-05-01

    Full Text Available In Taiwan, Angiostrongylus cantonensis infection has been reported in foreign laborers who had consumed raw Ampullarium canaliculatus snails. This study analyzed three foreign laborers who had contracted enzyme-linked immunosorbent assay-confirmed A cantonensis infection while working in Taiwan. All three workers had consumed either roasted snails or raw snails flavored with seasoning while drinking wine. This study investigated possible risk factors for A cantonensis, including naturally occurring A cantonensis in A canaliculatus snails, viability of third-stage A cantonensis larvae in raw seasoned snails and in roasted snails, infectivity of larvae, and effects of alcohol while consuming snails. Positive infection rates in snails from five different irrigation canals in south Taiwan ranged from 12.3% to 29.4% and the average number of motile larvae per infected snail ranged from 36 to 65. The number of motile and coiled larvae in snail meat after 120 minutes seasoning was 93 (27.7% and 233 (69.3%, respectively. After 20 minutes of roasting, most larvae in the snail meat were dead. The infectivities of motile and coiled larvae from snail meat after 60 minutes seasoning were 53.2% and 33.2%, respectively, and those from snail meat after 5 minutes roasting were 33.2% and 7.0%, respectively. Eating Taiwan A canaliculatus snails raw is extremely risky given their high infection rates and infection intensities. Even after 120 minutes seasoning or after 20 minutes roasting, snail meat should be considered unsafe for human consumption. Finally, experimental rodent studies indicated that consuming alcohol while ingesting larvae does not significantly reduced infectivity.

  1. Can essential oils be used as novel drench treatments for the eggs and juveniles of the pest snail Cornu aspersum in potted plants?

    Science.gov (United States)

    The horticultural trade is an important pathway for the introduction and spread of invasive gastropods because potted plants are essentially portable microhabitats, which protect snails and slugs, especially buried eggs and juveniles, from desiccation and molluscicides. The identification of a drenc...

  2. The role of spatial and temporal heterogeneity and competition in structuring trematode communities in the great pond snail, Lymnaea stagnalis (L.)

    Science.gov (United States)

    Soldánová, Miroslava; Kuris, Armand M.; Scholz, Tomáš; Lafferty, Kevin D.

    2012-01-01

    We assessed how spatial and temporal heterogeneity and competition structure larval trematode communities in the pulmonate snail Lymnaea stagnalis. To postulate a dominance hierarchy, mark-release-recapture was used to monitor replacements of trematode species within snails over time. In addition, we sampled the trematode community in snails in different ponds in 3 consecutive years. A total of 7,623 snails (10,382 capture events) was sampled in 7 fishponds in the Jindřichův Hradec and Třeboň areas in South Bohemia (Czech Republic) from August 2006 to October 2008. Overall, 39% of snails were infected by a community of 14 trematode species; 7% of snails were infected with more than 1 trematode species (constituting 16 double- and 4 triple-species combinations). Results of the null-model analyses suggested that spatial heterogeneity in recruitment among ponds isolated trematode species from each other, whereas seasonal pulses in recruitment increased species interactions in some ponds. Competitive exclusion among trematodes led to a rarity of multiple infections compared to null-model expectations. Competitive relationships among trematode species were hypothesized as a dominance hierarchy based on direct evidence of replacement and invasion and on indirect evidence. Seven top dominant species with putatively similar competitive abilities (6 rediae and 1 sporocyst species) reduced the prevalence of the other trematode species developing in sporocysts only.

  3. Changes in chemical components in the freshwater apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae), in relation to the development of its cold hardiness.

    Science.gov (United States)

    Matsukura, Keiichiro; Tsumuki, Hisaaki; Izumi, Yohei; Wada, Takashi

    2008-04-01

    The apple snail, Pomacea canaliculata, is an invasive freshwater snail. It increases its cold hardiness before winter. However, the physiological mechanism of cold hardiness in molluscs is poorly understood, especially in freshwater molluscs. In this study, we examined the changes in low molecular weight compounds, glycogen and lipids, in the body of P. canaliculata in association with the development of cold hardiness. When snails without cold hardiness were experimentally cold-acclimated, the amount of glycerol, glutamine, and carnosine increased, while glycogen and phenylalanine decreased. Overwintering cold-tolerant snails collected from a drained paddy field in November also showed increased glycerol in their bodies with decreasing glycogen concentration, compared to summer snails collected from a submerged field. Water content also decreased during the cold acclimation, although the water loss was minimal. These results indicate that the freshwater snail, P. canaliculata enhances cold hardiness by accumulation of some kinds of low molecular weight compounds in its body as some insects do. However, the actual function of each low molecular compound is still unknown.

  4. Web-spinning caterpillar stalks snails.

    Science.gov (United States)

    Rubinoff, Daniel; Haines, William P

    2005-07-22

    Moths and butterflies compose one of the most diverse insect orders, but they are overwhelmingly herbivorous. Less than 0.2% are specialized predators, indicating that lepidopteran feeding habits are highly constrained. We report a Hawaiian caterpillar that specializes on snails, a unique food source requiring an unusual feeding strategy. The caterpillar uses silk to restrain live prey. All caterpillars have silk glands, but none are known to use silk in this spiderlike fashion. Considering the canalization of caterpillar diets, evolution to attack and feed on snails is an anomaly. Hawaii s isolation and consequently disharmonic biota likely promote evolutionary experiments that occur nowhere else.

  5. Statement on the identity of apple snails

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.

    2012-01-01

    Following a request by the European Commission, EFSA’s Panel on Plant Health was asked to deliver a statement to clarify the current scientific knowledge regarding the identity of the apple snails in the context of the evaluation of the pest risk analysis prepared by the Spanish Ministry of Envir......Following a request by the European Commission, EFSA’s Panel on Plant Health was asked to deliver a statement to clarify the current scientific knowledge regarding the identity of the apple snails in the context of the evaluation of the pest risk analysis prepared by the Spanish Ministry...

  6. Modeling snail breeding in a bioregenerative life support system

    Science.gov (United States)

    Kovalev, V. S.; Manukovsky, N. S.; Tikhomirov, A. A.; Kolmakova, A. A.

    2015-07-01

    The discrete-time model of snail breeding consists of two sequentially linked submodels: "Stoichiometry" and "Population". In both submodels, a snail population is split up into twelve age groups within one year of age. The first submodel is used to simulate the metabolism of a single snail in each age group via the stoichiometric equation; the second submodel is used to optimize the age structure and the size of the snail population. Daily intake of snail meat by crewmen is a guideline which specifies the population productivity. The mass exchange of the snail unit inhabited by land snails of Achatina fulica is given as an outcome of step-by-step modeling. All simulations are performed using Solver Add-In of Excel 2007.

  7. Modeling snail breeding in a bioregenerative life support system.

    Science.gov (United States)

    Kovalev, V S; Manukovsky, N S; Tikhomirov, A A; Kolmakova, A A

    2015-07-01

    The discrete-time model of snail breeding consists of two sequentially linked submodels: "Stoichiometry" and "Population". In both submodels, a snail population is split up into twelve age groups within one year of age. The first submodel is used to simulate the metabolism of a single snail in each age group via the stoichiometric equation; the second submodel is used to optimize the age structure and the size of the snail population. Daily intake of snail meat by crewmen is a guideline which specifies the population productivity. The mass exchange of the snail unit inhabited by land snails of Achatina fulica is given as an outcome of step-by-step modeling. All simulations are performed using Solver Add-In of Excel 2007. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  8. miR-34a inhibits pancreatic cancer progression through Snail1-mediated epithelial-mesenchymal transition and the Notch signaling pathway.

    Science.gov (United States)

    Tang, Yan; Tang, Yong; Cheng, Ying-Sheng

    2017-02-01

    Epithelial-mesenchymal transition (EMT) and Notch signaling are important for the growth and invasion of pancreatic cancer, which is a leading cause of cancer-related deaths worldwide. miR-34a has been shown to play pivotal roles in the progression of several types of cancer. However, little is known about the regulatory mechanisms of miR-34a in pancreatic cancer processes. The aim of this study was to determine whether miR-34a has negative effects on pancreatic cancer and whether these effects are related to EMT and Notch signaling. In vitro, we demonstrated that miR-34a inhibited, while miR-34a inhibitors enhanced, migration and invasion of pancreatic cancer cell lines (PANC-1 and SW-1990).These effects were reversed by Snail1 overexpression or Snail1 shRNA. Furthermore, the anti-apoptotic effects of the miR-34a inhibitors in pancreatic cancer cells were abrogated by Notch1 shRNA. Luciferase reporter assays revealed that the Snail1 and Notch1 genes were direct targets of miR-34a. In vivo, we also demonstrated that miR-34a inhibited pancreatic cancer growth by decreasing Snail1 and Notch1 expression. Therefore, our results indicate that miR-34a inhibits pancreatic cancer progression by post-transcriptionally regulating Snail1 and Notch1 expression.

  9. Modeling freshwater snail habitat suitability and areas of potential snail-borne disease transmission in Uganda

    DEFF Research Database (Denmark)

    Stensgaard, Anna-Sofie; Jørgensen, Aslak; Kabatereine, N B

    2006-01-01

    -borne disease transmission areas. Furthermore, knowledge of abiotic factors affecting intra-molluscan parasitic development can be used to make "masks" based on remotely sensed climatic data, and these can in turn be used to refine these predictions. We used data from a recent freshwater snail survey from...... Uganda, environmental data and the genetic algorithm for rule-set prediction (GARP) to map the potential distribution of snail species known to act as intermediate hosts of several human and animal parasites. The results suggest that large areas of Uganda are suitable habitats for many of these snail...... species, indicating a large potential for disease transmission. The lack of parasitological data still makes it difficult to determine the magnitude of actual disease transmission, but the predicted snail distributions might be used as indicators of potential present and future risk areas. Some...

  10. Survival and behavior of Chinese mystery snails (Bellamya chinensis) in response to simulated water body drawdowns and extended air exposure

    Science.gov (United States)

    Unstad, Kody M.; Uden, Daniel R.; Allen, Craig R.; Chaine, Noelle M.; Haak, Danielle M.; Kill, Robert A.; Pope, Kevin L.; Stephen, Bruce J.; Wong, Alec

    2013-01-01

    Nonnative invasive mollusks degrade aquatic ecosystems and induce economic losses worldwide. Extended air exposure through water body drawdown is one management action used for control. In North America, the Chinese mystery snail (Bellamya chinensis) is an invasive aquatic snail with an expanding range, but eradication methods for this species are not well documented. We assessed the ability of B. chinensis to survive different durations of air exposure, and observed behavioral responses prior to, during, and following desiccation events. Individual B. chinensis specimens survived air exposure in a laboratory setting for > 9 weeks, and survivorship was greater among adults than juveniles. Several B. chinensis specimens responded to desiccation by sealing their opercula and/or burrowing in mud substrate. Our results indicate that drawdowns alone may not be an effective means of eliminating B. chinensis. This study lays the groundwork for future management research that may determine the effectiveness of drawdowns when combined with factors such as extreme temperatures, predation, or molluscicides.

  11. Conservation Priority Index for Estuarine Fish (COPIEF)

    Science.gov (United States)

    Branco, Paulo; Costa, José Lino; Raposo de Almeida, Pedro

    2008-12-01

    Public awareness regarding environmental issues has increased in recent decades. The increasing number of impact assessment studies, management and conservation plans, as well as ecological monitoring studies, demand new and more efficient techniques. Indices are an important tool to aid biologists in these studies and should allow an easier comprehension of the data by managers, decision-makers and the general public. This study presents the first multi-metrical index able to establish a hierarchical ordination of the conservation priority of the estuarine fish species using 72 species from 16 estuarine systems (W and S coasts of Portugal). The index is composed of 10 metrics, comprising species life traits, distribution and population trends. The information needed to score each metric was gathered from the published literature and the index validation was done by external means. This methodology allowed the definition of those fish species most in need of conservation planning, and those less prone to extinction in Portuguese estuarine systems. The proposed index fills a gap in our knowledge and provides a useful tool to the scientific community and to the decision-makers, being a breakthrough in the field of conservation planning of estuarine fish species.

  12. Growth Characteristics of an Estuarine Heterocystous Cyanobacterium

    NARCIS (Netherlands)

    Guimarães, P.; Yunes, J.S.; Cretoiu, M.S.; Stal, L.J.

    2017-01-01

    A new estuarine filamentous heterocystous cyanobacterium was isolated from intertidal sediment of the Lagoa dos Patos estuary (Brazil). The isolate may represent a new genus related to Cylindrospermopsis. While the latter is planktonic, contains gas vesicles, and is toxic, the newly isolated strain

  13. 4 Prevalence of Snail.cdr

    African Journals Online (AJOL)

    Administrator

    to infection (Webbe, 1981) and about 131 million infected in Sub-Saharan Africa alone. The disease is endemic in Ghana and its public health importance was reported by. McCullough (1954), who noted then that approximately 20% of the total population of. Prevalence of Snail Vectors of Schistosomiasis in the Kpong.

  14. Optimal stocking densities of snails [ Archachatina marginata ...

    African Journals Online (AJOL)

    Optimal stocking densities of breeding and fattening snails [Archachatina marginata Saturalis A.m.s (Swainson)] were determined through two experiments (five treatments, four replicates and randomised complete block design each) between April and December 1998.Experiment 1 had 3,6, 12, 17 and 22 A.m.s. adult ...

  15. Calcium, snails, and birds: a case study

    Directory of Open Access Journals (Sweden)

    R. Mänd

    2000-10-01

    Full Text Available Recent studies have shown that wild birds breeding in acidified areas have difficulties with obtaining sufficient calcium for their eggshells, and that the cause of it is the shortage of land snails. Many birds have to search for Ca-rich snail shells on a daily basis during egg production. Molluscs depend on litter calcium, which has decreased due to acidification of the environment. Calcium limitation may be a widespread phenomenon also in non-acidified, naturally Ca-poor areas. The problem is that while in the latter areas the time for development of specific adaptations may have been sufficient, then in acidified areas, on the contrary, calcium shortage is a recent phenomenon. Therefore, since the extent of calcium limitation in non-acidified areas is hard to derive from observational data, experimental approach is needed. We provide experimental evidence that specific calcium deficit does affect reproductive traits also in the birds breeding in naturally base-poor habitats. Our study was conducted in a heterogeneous woodland area in Estonia containing deciduous forest patches as well as base-poor pine forest with low snail abundance. Ca supplementation, using snail shell and chicken eggshell fragments, was carried out for pied flycatchers and great tits. Extra calcium affected positively several reproductive traits like egg volume and eggshell thickness, start of breeding, and fledglings’ parameters. The negative relationship between calcium availability and lay-date suggests that birds adjust their breeding tactics to conditions of Ca deficiency, for example, by postponing laying.

  16. Learning from a Sea Snail: Eric Kandel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 6. Learning from a Sea Snail: Eric Kandel. Rohini Balakrishnan. Research News Volume 6 Issue 6 June 2001 pp 86-90. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/006/06/0086-0090 ...

  17. Identification and characterization of a goose-type lysozyme from sewage snail Physa acuta.

    Science.gov (United States)

    Guo, Yunhai; He, Hongxuan

    2014-08-01

    Freshwater snail Physa acuta has been considered as an important invasive species and medical mollusc. Field investigation has shown that this snail could survive better than other snails in polluted water bodies. To understand the immune mechanisms of P. acuta, suppression subtractive hybridization hepatopancreas cDNA library has been constructed with bacterial challenge. In this study, a full-length cDNA of a novel goose-type lysozyme (PALysG) has been identified from P. acuta by EST and RACE technique. The conservative structure domains share high homology with other molluscan g-type lysozymes including the SLT domain, the substrate binding sites, the catalytic residues, three alpha-helices structures and six molluscan specific cysteines. Meanwhile, PALysG is the first record of goose-type lysozyme in Gastropoda. Real-time PCR indicated that PALysG mRNA had been expressed significantly at high levels in hepatopancreas for 8-48 h. PALysG recombinant protein displayed the lytic activity of g-type lysozyme with other organisms against Micrococcus lysodikicus. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Slug overexpression induces stemness and promotes hepatocellular carcinoma cell invasion and metastasis.

    Science.gov (United States)

    Sun, Yu; Song, Guo-Dong; Sun, Ning; Chen, Jian-Qiu; Yang, Shao-Shi

    2014-06-01

    Detection of metastasis of hepatocellular carcinoma (HCC) is crucial for early diagnosis. Epithelial-mesenchymal transition (EMT) is a common event in the metastasis of tumor cells. Slug and Snail are homologous proteins, which play an important role in EMT. The present study aimed to investigate whether Slug and Snail overexpression is associated with the invasiveness of HCC in vitro and in vivo . Invasion, colony formation and wound healing assays, as well as flow cytometry analysis, were performed to examine the invasiveness and proliferation capabilities of HepG2 cells following transfection with cNDA or the siRNA of Slug or Snail. The effects of Slug on HCC in vivo were examined using a xenograft model. Slug upregulation increased the percentage of cluster of differentiation (CD)133 + cells among HepG2 cells, and induced cell invasion and proliferation; whereas Snail upregulation did not affect the cells in vitro . The Slug overexpression group exhibited the highest rate of tumor growth compared with the Snail overexpression and control groups in vivo . These findings demonstrated that Slug increases the percentage of CD133 + cells, promotes the clonigenicity of HCC cells and induces a stronger stemness in Slug-overexpressing cells. These changes activate dormant developmental pathways in invading tumor cells. Thus, Slug may serve as a novel target for HCC prognosis and therapy.

  19. Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France

    Directory of Open Access Journals (Sweden)

    Dreyfuss G.

    2002-06-01

    Full Text Available Four freshwater pulmonate species (Lymnaea ovata, L. stagnalis, Physa acuta, Planorbis leucostomawere living in several watercress beds known for their relationships with human cases of fasciolosis, whereas L. truncatula was never found. The aims of these studies were to determine the prevalence of natural infections with Fasciola hepatica in snails and to verify if these species might ensure the full larval development of this trematode (with cercarial shedding] when they were experimentally subjected to F. hepatica only, or to co-infections with an other trematode species. Investigations were so carried out in six snail populations living in watercress beds (including three for P. acuta and in four others originating from three brooks or a pond (as controls. Snails naturally infected with F. hepatica were found in two watercress beds inhabited by L. ovata (prevalence of infection: 1.4 % and P. leucostoma (0.1 %, respectively. The L. ovata from the watercress bed could be infected at a higher size than those from the control population and the prevalence of this infection was greater in the bed population. Similar findings were noted for L. stagnalis. Despite single or dual infections, the results obtained with the four populations of P. acuta were unsuccessful. In contrast, the co-infections of young P. leucostoma with Paramphistomum daubneyi and F. hepatica resulted in the shedding of some F. hepatica cercariae. According to the authors, the occurrence of fasciolosis in these watercress beds would be the consequence of frequent natural encounters between parasite and snails (L. ovata, L. stagnalis, or of co-infections with P. daubneyi and F. hepatica (P. leucostoma. In watercress beds only colonized by P. acuta, a lymnaeid species would have ensured the larval development of F. hepatica but it would have been eliminated by P. acuta, as this last species was known to be invasive and could colonize open drainage ditches on siliceous soil.

  20. EMT transcription factors snail and slug directly contribute to cisplatin resistance in ovarian cancer

    International Nuclear Information System (INIS)

    Haslehurst, Alexandria M; Weberpals, Johanne; Davey, Scott; Squire, Jeremy; Park, Paul C; Feilotter, Harriet; Koti, Madhuri; Dharsee, Moyez; Nuin, Paulo; Evans, Ken; Geraci, Joseph; Childs, Timothy; Chen, Jian; Li, Jieran

    2012-01-01

    The epithelial to mesenchymal transition (EMT) is a molecular process through which an epithelial cell undergoes transdifferentiation into a mesenchymal phenotype. The role of EMT in embryogenesis is well-characterized and increasing evidence suggests that elements of the transition may be important in other processes, including metastasis and drug resistance in various different cancers. Agilent 4 × 44 K whole human genome arrays and selected reaction monitoring mass spectrometry were used to investigate mRNA and protein expression in A2780 cisplatin sensitive and resistant cell lines. Invasion and migration were assessed using Boyden chamber assays. Gene knockdown of snail and slug was done using targeted siRNA. Clinical relevance of the EMT pathway was assessed in a cohort of primary ovarian tumours using data from Affymetrix GeneChip Human Genome U133 plus 2.0 arrays. Morphological and phenotypic hallmarks of EMT were identified in the chemoresistant cells. Subsequent gene expression profiling revealed upregulation of EMT-related transcription factors including snail, slug, twist2 and zeb2. Proteomic analysis demonstrated up regulation of Snail and Slug as well as the mesenchymal marker Vimentin, and down regulation of E-cadherin, an epithelial marker. By reducing expression of snail and slug, the mesenchymal phenotype was largely reversed and cells were resensitized to cisplatin. Finally, gene expression data from primary tumours mirrored the finding that an EMT-like pathway is activated in resistant tumours relative to sensitive tumours, suggesting that the involvement of this transition may not be limited to in vitro drug effects. This work strongly suggests that genes associated with EMT may play a significant role in cisplatin resistance in ovarian cancer, therefore potentially leading to the development of predictive biomarkers of drug response or novel therapeutic strategies for overcoming drug resistance

  1. Snail acetylation by histone acetyltransferase p300 in lung cancer

    OpenAIRE

    Chang, Rui; Zhang, Yinjie; Zhang, Peng; Zhou, Qinghua

    2017-01-01

    Background Epithelial to mesenchymal transition (EMT) is a complex and dynamic molecular event in lung cancer metastasis that has not yet been thoroughly investigated. EMT transcriptional factors, such as Snail, play a central role in regulation of the EMT process. In this study, we sought to identify an association between p300 and Snail in lung cancer, as well as the engagement of p300 in Snail acetylation. Methods We transfected p300 small interfering RNA into lung cancer cells to detect S...

  2. Crawling beneath the free surface: Water snail locomotion

    OpenAIRE

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric

    2008-01-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being g...

  3. Inheritance of Schistosoma mansoni infection incompatibility in Biomphalaria alexandrina snails

    Directory of Open Access Journals (Sweden)

    Iman F Abou El Naga

    2010-03-01

    Full Text Available In this study, we looked at the inheritance of susceptibility and resistance to Schistosoma mansoni infection in the first generation of crossbred Biomphalaria alexandrina snails. Our ultimate goal is to use such information to develop a biological method of controlling schistosomiasis. We infected laboratory-bred snails with S. mansoni miracidia and examined cercarial shedding to determine susceptibility and resistance. Five parental groups were used: Group I contained 30 susceptible snails, Group II contained 30 resistant snails, Group III contained 15 susceptible and 15 resistant snails, Group IV contained 27 susceptible and three resistant snails and Group V contained three susceptible and 27 resistant snails. The percentage of resistant snails in the resulting progeny varied according to the ratio of susceptible and resistant parents per group; they are 7%, 100%, 68%, 45% and 97% from Groups I, II, III, IV and V, respectively. On increasing the percentage of resistant parent snails, the percentage of resistant progeny increased, while cercarial production in their susceptible progeny decreased.

  4. Characterization of snail1 and pten transcriptional regulation by snail1: New insights into epithelial-to-mesenchymal transition and cell resistance to apoptosis

    OpenAIRE

    Escrivà Izquierdo, María

    2008-01-01

    The product of the snail1 gene (SNAIL1) is a transcriptional repressor required for triggering the epithelial-to-mesenchymal transition (EMT). SNAIL1 transcription is induced when epithelial cells are forced to acquire a mesenchymal phenotype. Furthermore, ectopic expression of snail1 in epithelial cells promotes resistance to apoptosis. In this study, we demonstrate that this resistance to ã radiation-induced apoptosis caused by Snail1 is associated with the transcriptional inhibition of PTE...

  5. Development and characterization of 17 polymorphic microsatellite loci in the faucet snail, Bithynia tentaculata (Gastroposa: Caenogastropoda; Bithyniidae)

    Science.gov (United States)

    Henningsen, Justin P.; Lance, Stacey L.; Jones, Kenneth L.; Hagen, Chris; Laurila, Joshua; Cole, Rebecca A.; Perez, Kathryn E.

    2010-01-01

    Bithynia tentaculata (Linnaeus, 1758), a snail native to Europe, was introduced into the US Great Lakes in the 1870's and has spread to rivers throughout the Northeastern US and Upper Mississippi River (UMR). Trematode parasites, for which B. tentaculata is a host, have also been introduced and are causing widespread waterfowl mortality in the UMR. Waterfowl mortality is caused by ingestion of trematode-infected B. tentaculata or insects infected with parasites released from the snails. We isolated and characterized 17 microsatellite loci from the invasive faucet snail, B. tentaculata (Gastropoda: Caenogastropoda: Bithyniidae). Loci were screened in 24 individuals of B. tentaculata. The number of alleles per locus ranged from 2 to 6, observed heterozygosity ranged from 0.050 to 0.783, and the probability of identity values ranged from 0.10 to 0.91. These new loci provide tools for examining the origin and spread of invasive populations in the US and management activities to prevent waterfowl mortality.

  6. Isolation and characterization of sixteen polymorphic microsatellite loci in the golden apple snail Pomacea canaliculata.

    Science.gov (United States)

    Chen, Lian; Xu, Haigen; Li, Hong; Wu, Jun; Ding, Hui; Liu, Yan

    2011-01-01

    We report the characterization of 16 polymorphic microsatellite markers in the golden apple snail, Pomacea canaliculata, a pest registered in the list of "100 of the world's worst invasive alien species". The fast isolation by AFLP (Amplified Fragment Length Polymorphism) of sequences containing repeats (FIASCO) method was used to isolate microsatellite loci, and polymorphism was explored with 29 individuals collected in an invasive region from China. These primers showed a number of alleles per locus ranging from three to 13. The ranges of observed and expected heterozygosity were 0.310-0.966 and 0.523-0.898, respectively. These microsatellite markers described here will be useful for population genetic studies of P. canaliculata.

  7. Isolation and Characterization of Sixteen Polymorphic Microsatellite Loci in the Golden Apple Snail Pomacea canaliculata

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2011-09-01

    Full Text Available We report the characterization of 16 polymorphic microsatellite markers in the golden apple snail, Pomacea canaliculata, a pest registered in the list of “100 of the world’s worst invasive alien species”. The fast isolation by AFLP (Amplified Fragment Length Polymorphism of sequences containing repeats (FIASCO method was used to isolate microsatellite loci, and polymorphism was explored with 29 individuals collected in an invasive region from China. These primers showed a number of alleles per locus ranging from three to 13. The ranges of observed and expected heterozygosity were 0.310–0.966 and 0.523–0.898, respectively. These microsatellite markers described here will be useful for population genetic studies of P. canaliculata.

  8. Estuarine consumers utilize marine, estuarine and terrestrial organic matter and provide connectivity among these food webs

    Science.gov (United States)

    The flux of organic matter (OM) across ecosystem boundaries can influence estuarine food web dynamics and productivity. However, this process is seldom investigated taking into account all the adjacent ecosystems (e.g. ocean, river, land) and different hydrological settings (i.e....

  9. Survival and behavior of Chinese mystery snails (Bellamya chinensis in response to simulated water body drawdowns and extended air exposure

    Directory of Open Access Journals (Sweden)

    Kody M. Unstad

    2013-04-01

    Full Text Available Nonnative invasive mollusks degrade aquatic ecosystems and induce economic losses worldwide. Extended air exposure through water bodydrawdown is one management action used for control. In North America, the Chinese mystery snail (Bellamya chinensis is an invasiveaquatic snail with an expanding range, but eradication methods for this species are not well documented. We assessed the ability ofB. chinensis to survive different durations of air exposure, and observed behavioral responses prior to, during, and following desiccationevents. Individual B. chinensis specimens survived air exposure in a laboratory setting for > 9 weeks, and survivorship was greater amongadults than juveniles. Several B. chinensis specimens responded to desiccation by sealing their opercula and/or burrowing in mud substrate.Our results indicate that drawdowns alone may not be an effective means of eliminating B. chinensis. This study lays the groundwork forfuture management research that may determine the effectiveness of drawdowns when combined with factors such as extreme temperatures,predation, or molluscicides.

  10. Short Communication: Comparative effect of snail shell, limestone ...

    African Journals Online (AJOL)

    Short Communication: Comparative effect of snail shell, limestone and oyster shell as sources of dietary calcium on performance and egg quality characteristics of laying. ... egg production, internal and external qualities of eggs of hens. The 6-week ... Key words: Laying hens, oyster shell, limestone, snail shell, egg quality ...

  11. Effects of artificially induced aestivation on edible tropical land snail ...

    African Journals Online (AJOL)

    Aestivated snails showed significant (p<0.05) weight loss of between 37-39% when compared with the control. Aestivated snails underwent reversible biochemical mechanism, becoming active upon sensory stimuli of contact with water at the end of experimentation. Animal Production Research Avancees Vol. 3 (1) 2007: ...

  12. Whole genome analysis of a schistosomiasis-transmitting freshwater snail

    NARCIS (Netherlands)

    Adema, Coen M; Hillier, LaDeana W; Jones, Catherine S; Loker, Eric S; Knight, Matty; Minx, Patrick; Oliveira, Guilherme; Raghavan, Nithya; Shedlock, Andrew; do Amaral, Laurence Rodrigues; Arican-Goktas, Halime D; Assis, Juliana G; Baba, Elio Hideo; Baron, Olga L; Bayne, Christopher J; Bickham-Wright, Utibe; Biggar, Kyle K; Blouin, Michael; Bonning, Bryony C; Botka, Chris; Bridger, Joanna M; Buckley, Katherine M; Buddenborg, Sarah K; Lima Caldeira, Roberta; Carleton, Julia; Carvalho, Omar S; Castillo, Maria G; Chalmers, Iain W; Christensens, Mikkel; Clifton, Sandra; Cosseau, Celine; Coustau, Christine; Cripps, Richard M; Cuesta-Astroz, Yesid; Cummins, Scott F; di Stephano, Leon; Dinguirard, Nathalie; Duval, David; Emrich, Scott; Feschotte, Cédric; Feyereisen, Rene; FitzGerald, Peter; Fronick, Catrina; Fulton, Lucinda; Galinier, Richard; Gava, Sandra G; Geusz, Michael; Geyer, Kathrin K; Giraldo-Calderón, Gloria I; de Souza Gomes, Matheus; Gordy, Michelle A; Gourbal, Benjamin; Grunau, Christoph; Hanington, Patrick C; Hoffmann, Karl F; Hughes, Daniel; Humphries, Judith; Jackson, Daniel J; Jannotti-Passos, Liana K; de Jesus Jeremias, Wander; Jobling, Susan; Kamel, Bishoy; Kapusta, Aurélie; Kaur, Satwant; Koene, Joris M; Kohn, Andrea B; Lawson, Dan; Lawton, Scott P; Liang, D.C.; Limpanont, Yanin; Liu, Sijun; Lockyer, Anne E; Lovato, TyAnna L; Ludolf, Fernanda; Magrini, Vince; McManus, Donald P; Medina, Monica; Misra, Milind; Mitta, Guillaume; Mkoji, Gerald M; Montague, Michael J; Montelongo, Cesar; Moroz, Leonid L; Munoz-Torres, Monica C; Niazi, Umar; Noble, Leslie R; Oliveira, Francislon S; Pais, Fabiano S; Papenfuss, Anthony T; Peace, Rob; Pena, Janeth J; Pila, Emmanuel A; Quelais, Titouan; Raney, Brian J; Rast, Jonathan P; Rollinson, David; Rosse, Izinara C; Rotgans, Bronwyn; Routledge, Edwin J; Ryan, Kathryn M; Scholte, Larissa L S; Storey, Kenneth B; Swain, Martin; Tennessen, Jacob A; Tomlinson, Chad; Trujillo, Damian L; Volpi, Emanuela V; Walker, Anthony J; Wang, Tianfang; Wannaporn, Ittiprasert; Warren, Wesley C; Wu, Xiao-Jun; Yoshino, Timothy P; Yusuf, Mohammed; Zhang, Si-Ming; Zhao, Min; Wilson, Richard K

    2017-01-01

    Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of

  13. Comparative Studies of two Fresh Water Snail Distributions and ...

    African Journals Online (AJOL)

    Combinations of abiotic and biotic factors exert their influences on fecundity, hence population density of snail hosts living in fresh water. However, only few distinct relationships have been established in snail ecology due to lack of precise data and difficulty in defining and evaluating the significance of an individual ...

  14. Snail fauna and investigations into the incidence of schistosoma ...

    African Journals Online (AJOL)

    A study aimed at identifying the current snail fauna of Oguta Lake in Oguta 1 of Oguta LGA, Imo State, was carried out between May 2012 and January 2013. Four sites were surveyed using standard scoop method consisting of flat wire mesh and iron handle. The species of snails were identified based on shell morphology.

  15. Proximate and chemical composition of three species of snails in ...

    African Journals Online (AJOL)

    This trial was conducted to determine the proximate and chemical composition of three common species of snails in Nigeria. The species were Archachatina marginata (T1), Achatina achatina (T2), and Achatina fulica (T3). The three species constituted the three treatments and thirty-six adult snails were used for this trial ...

  16. Socio-Economic Characteristics Of Snail Farmers, Consumers And ...

    African Journals Online (AJOL)

    The socio-economic characteristic of snail farmers in Oyo State Agricultural Development Programme (ADP) was evaluated in two out of the four zones that were available. The two zones selected were Ibadan/Ibarapa and Oyo zones, to determine the factors related to snail production, consumption and marketing in the ...

  17. Population biology of the common land snail Limicolaria flammea in ...

    African Journals Online (AJOL)

    A population study to determine the number of and distribution of the common land snail Limicolari flammea in a selected garden habitat is reported. A total snail population of 859 and 975 using the Lincoln index and Welch formula respectively were obtained for a farm garden measuring 1250m2 while the distribution of the ...

  18. Snail arboreality: the microdistribution of Sitala jenynsi (Gastropoda ...

    African Journals Online (AJOL)

    The habitats and patterns of vertical migration of the shell banding morphs of the snail Sitala jenynsi (Pfeiffer) were studied in Dar es Salaam and Wazo regions of central coastal Tanzania Both dimorphic and trimorphic populations were arboreal throughout the year. The snails occurred randomly within mid-heights 180 to ...

  19. Demographic characteristics related to consumption of snail meat ...

    African Journals Online (AJOL)

    ... and percentages) and inferential (chi-square) statistics. Findings of the study revealed that most of the respondents are male, single, between 20 and 30 years and have formal education. Also it was found that most respondents earn between N1, 000 and N10, 000 as income. Consumption level (number of snails) of snail ...

  20. Management of shells of giant African snails (Achatinidae) from the ...

    African Journals Online (AJOL)

    Objective: this study aimed to estimate the amount of snail's shells produced in the Abidjan City and the mode of management of empty shells for possible reuse. Methodology and Results: An investigation was carried out by a questionnaire on 120 snail retailers' in the markets of Abidjan. The data was stripped by Sphinx ...

  1. Management of shells of giant African snails (Achatinidae) from the ...

    African Journals Online (AJOL)

    SARAH

    2014-12-01

    Dec 1, 2014 ... Conclusion and application of results: A better understanding of the snail's marketing chain is essential for eventual use of the shell by-product. ... reach the final consumer, the snail follows a circuit that includes a large number of ... information gathered was stripped by Sphinx Plus2 software. RESULTS.

  2. Predatory Poiretia (Stylommatophora, Oleacinidae) snails: histology and observations

    NARCIS (Netherlands)

    Helwerda, Renate A.

    2015-01-01

    The predatory behaviour of Poiretia snails is studied. One aspect of this behaviour is the ability to make holes in the shells of prey snails. The radula and the histology of the mucous glands support the assumption that Poiretia secretes acidic mucus to produce these holes. Observation of a

  3. Nutritive potentials and utilization of garden snail (Limicolaria aurora ...

    African Journals Online (AJOL)

    The possibility of using garden snail (Limicolaria aurora) meat meal as a protein source in fish feeds was tested in Clarias gariepinus fingerlings. Five isonitrogenous (43% crude protein) diets in which garden snail meat meal was used to replace fish meal at 0%, (control diet), 25, 50, 75 and 100% inclusion levels were used ...

  4. Community ecology of tropical forest snails: 30 years after Solem

    NARCIS (Netherlands)

    Schilthuizen, M.

    2011-01-01

    Since Solem’s provocative claim in the early 1980s that land snails in tropical forests are neither abundant nor diverse, at least 30 quantitative-ecological papers on tropical land snail communities have appeared. Jointly, these papers have shown that site diversity is, in fact, high in tropical

  5. Biochemical evaluation of aestivation and starvation in two snail ...

    African Journals Online (AJOL)

    hope&shola

    2010-11-08

    Nov 8, 2010 ... aestivation and starvation on endogenous metabolic reserves in haemolymph of two snail species namely: Bulinus globosus (Morelet) ... food uptake ceases, water loss occurs and the snails are not able to rid themselves of their ..... Heart rate and body weight alteration in juvenile specimens of the tropical ...

  6. Whole genome analysis of a schistosomiasis-transmitting freshwater snail

    DEFF Research Database (Denmark)

    Adema, Coen M; Hillier, Ladeana W; Jones, Catherine S

    2017-01-01

    Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome...

  7. Effects of feeding adult snails Stylosanthes guianensis or Lablab ...

    African Journals Online (AJOL)

    SERVER

    2007-08-20

    Aug 20, 2007 ... The feeding trial assessed the performance, carcass and sensory evaluation of adult snails fed solely on leaves of Stylosanthes guianensis or Lablab purpureus as substitute for pawpaw leaf. Ninety-six (96) adult snails were used for the trial, and they were shared into three groups. Each group was ...

  8. A Practical Approach To Backyard Snail - Farming | Akinnusi ...

    African Journals Online (AJOL)

    The housing and feeding requirements necessary for quick multiplication of snails were studied using fifty mature African giant land snails of the species Archachatina marginata (Swainson). Their initial weights ranged from 250g to 450g. The feeding materials used were green pawpaw fruits and leaves (Carico papaya), ...

  9. Staurosporine augments EGF-mediated EMT in PMC42-LA cells through actin depolymerisation, focal contact size reduction and Snail1 induction – A model for cross-modulation

    Directory of Open Access Journals (Sweden)

    Thompson Erik W

    2009-07-01

    correlation with lower expression values being predictive of increased risk. Conclusion ST in combination with EGF directed a greater EMT via actin depolymerisation and focal contact size reduction, resulting in a loosening of cell-ECM attachment along with Snail1-Zeb1/δEF1 induction. This appeared fundamentally different to the EGF-induced EMT, highlighting the multiple pathways which can regulate EMT. Our findings add support for a functional role for Snail1 in invasive breast cancer.

  10. Staurosporine augments EGF-mediated EMT in PMC42-LA cells through actin depolymerisation, focal contact size reduction and Snail1 induction – A model for cross-modulation

    International Nuclear Information System (INIS)

    Hugo, Honor J; Wafai, Razan; Blick, Tony; Thompson, Erik W; Newgreen, Donald F

    2009-01-01

    of increased risk. ST in combination with EGF directed a greater EMT via actin depolymerisation and focal contact size reduction, resulting in a loosening of cell-ECM attachment along with Snail1-Zeb1/δEF1 induction. This appeared fundamentally different to the EGF-induced EMT, highlighting the multiple pathways which can regulate EMT. Our findings add support for a functional role for Snail1 in invasive breast cancer

  11. The role of estuarine type in characterizing early stage fish ...

    African Journals Online (AJOL)

    Assemblages of early stage fishes (larval and early juvenile stages) were investigated and compared in seven permanently open and five intermittently open estuarine systems on the warm temperate Eastern Cape coast of South Africa. Estuarine type, by virtue of mouth state and prevailing physico chemical conditions, ...

  12. Whole genome analysis of a schistosomiasis-transmitting freshwater snail

    Science.gov (United States)

    Adema, Coen M.; Hillier, LaDeana W.; Jones, Catherine S.; Loker, Eric S.; Knight, Matty; Minx, Patrick; Oliveira, Guilherme; Raghavan, Nithya; Shedlock, Andrew; do Amaral, Laurence Rodrigues; Arican-Goktas, Halime D.; Assis, Juliana G.; Baba, Elio Hideo; Baron, Olga L.; Bayne, Christopher J.; Bickham-Wright, Utibe; Biggar, Kyle K.; Blouin, Michael; Bonning, Bryony C.; Botka, Chris; Bridger, Joanna M.; Buckley, Katherine M.; Buddenborg, Sarah K.; Lima Caldeira, Roberta; Carleton, Julia; Carvalho, Omar S.; Castillo, Maria G.; Chalmers, Iain W.; Christensens, Mikkel; Clifton, Sandra; Cosseau, Celine; Coustau, Christine; Cripps, Richard M.; Cuesta-Astroz, Yesid; Cummins, Scott F.; di Stefano, Leon; Dinguirard, Nathalie; Duval, David; Emrich, Scott; Feschotte, Cédric; Feyereisen, Rene; FitzGerald, Peter; Fronick, Catrina; Fulton, Lucinda; Galinier, Richard; Gava, Sandra G.; Geusz, Michael; Geyer, Kathrin K.; Giraldo-Calderón, Gloria I.; de Souza Gomes, Matheus; Gordy, Michelle A.; Gourbal, Benjamin; Grunau, Christoph; Hanington, Patrick C.; Hoffmann, Karl F.; Hughes, Daniel; Humphries, Judith; Jackson, Daniel J.; Jannotti-Passos, Liana K.; de Jesus Jeremias, Wander; Jobling, Susan; Kamel, Bishoy; Kapusta, Aurélie; Kaur, Satwant; Koene, Joris M.; Kohn, Andrea B.; Lawson, Dan; Lawton, Scott P; Liang, Di; Limpanont, Yanin; Liu, Sijun; Lockyer, Anne E.; Lovato, TyAnna L.; Ludolf, Fernanda; Magrini, Vince; McManus, Donald P.; Medina, Monica; Misra, Milind; Mitta, Guillaume; Mkoji, Gerald M.; Montague, Michael J.; Montelongo, Cesar; Moroz, Leonid L.; Munoz-Torres, Monica C.; Niazi, Umar; Noble, Leslie R.; Oliveira, Francislon S.; Pais, Fabiano S.; Papenfuss, Anthony T.; Peace, Rob; Pena, Janeth J.; Pila, Emmanuel A.; Quelais, Titouan; Raney, Brian J.; Rast, Jonathan P.; Rollinson, David; Rosse, Izinara C.; Rotgans, Bronwyn; Routledge, Edwin J.; Ryan, Kathryn M.; Scholte, Larissa L. S.; Storey, Kenneth B.; Swain, Martin; Tennessen, Jacob A.; Tomlinson, Chad; Trujillo, Damian L.; Volpi, Emanuela V.; Walker, Anthony J.; Wang, Tianfang; Wannaporn, Ittiprasert; Warren, Wesley C.; Wu, Xiao-Jun; Yoshino, Timothy P.; Yusuf, Mohammed; Zhang, Si-Ming; Zhao, Min; Wilson, Richard K.

    2017-01-01

    Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis. PMID:28508897

  13. Land Snail Extinctions at Kalaeloa, O`ahu

    Directory of Open Access Journals (Sweden)

    T.S. Dye

    2001-06-01

    Full Text Available In this article we show that the interpretation of Polynesian influence drawn from the stratigraphic record of sub-fossil land snails at Kalaeloa (O'ahu, Hawai'i is based on a unique stratigraphic sequence at a single sinkhole. The interpretation was then applied to other land snail sequences, despite their lack of evidence for Polynesian influence. We present a reanalysis of the stratigraphic record to conclude that Polynesians had little, if any, effect on land snail populations in sinkholes. We show that directional change in land snail populations was underway before Polynesians colonised the islands. Decreases in the diversity of snail populations, possibly indicative of environmental stress, do occur near the end of the stratigraphic sequence. Based on available dating evidence, however, these changes probably took place in the post-Contact period when the regional environment was radically altered by sugar cane cultivation.

  14. A survey of snail farms in Cross River State, Nigeria | Ogogo | Global ...

    African Journals Online (AJOL)

    The existence of snail in the wild has become threatened, and information on the efficiency and effectiveness of ex - situ management of snails in many areas is urgently needed for consistent supply of snails. This work, therefore surveyed the practice and adoption of snail farming technology in Cross River State, Nigeria.

  15. How parasitism, stream substrate, and movement patterns mediate response to disturbance in the snail Elimia flava

    Science.gov (United States)

    Tomba, A. M.; Feminella, J. W.

    2005-05-01

    Snails in the genus Elimia are abundant in southeastern USA streams, and also serve as intermediate hosts to parasitic trematodes. Previous work indicated that high-flows decrease snail abundance and trematode prevalence, and others have shown substrate type and snail size affect likelihood of snail dislodgement. To investigate how parasitism, size, substrate, and snail behavior influenced dislodgement, we placed Elimia flava in artificial streams containing tile or gravel substrates, and then exposed them to progressively increasing flow velocities ( ~10, 40, 90 cm/s) for 5 minutes each. We recorded snail behavior and time to dislodgement, and then preserved snails to quantify their size and parasite load. Snails on tile dislodged significantly faster than snails on gravel, and snails with high parasite loads also dislodged faster than snails without parasites. Parasitism also appeared to affect movement patterns: snails showing predominantly downstream movement had higher parasite loads than those that did not. Behavior also affected dislodgement probability, as snails moving upstream or to the waterline remained on the substrate longer than snails not showing those behaviors. Parasitism, substrate composition, and snail movement are useful predictors of the likelihood of dislodgement, and parasitism and substrate may both increase snail vulnerability to flow disturbance.

  16. Invasive Species

    Science.gov (United States)

    Invasive species have significantly changed the Great Lakes ecosystem. An invasive species is a plant or animal that is not native to an ecosystem, and whose introduction is likely to cause economic, human health, or environmental damage.

  17. [Establishment of Oncomelania hupensis snail database based on smartphone and Google Earth].

    Science.gov (United States)

    Wang, Wei-chun; Zhan, Ti; Zhu, Ying-fu

    2015-02-01

    To establish an Oncomelania hupensis snail database based on smartphone and Google Earth. The HEAD GPS software was loaded in the smartphone first. The GPS data of the snails were collected by the smartphone. The original data were exported to the computer with the format of KMIUKMZ. Then the data were converted into Excel file format by using some software. Finally, the results based on laboratory were filled, and the digital snail data were established. The data were converted into KML, and then were showed by Google Earth visually. The snail data of a 5 hm2-beach along the Yangtze River were collected and the distribution of the snails based on Google Earth was obtained. The database of the snails was built. The query function was implemented about the number of the total snails, the living snails and the schistosome infected snails of each survey frame. The digital management of the snail data is realized by using the smartphone and Google Earth.

  18. Effects of sewage sludge amendment on snail growth and trace metal transfer in the soil-plant-snail food chain.

    Science.gov (United States)

    Bourioug, Mohamed; Gimbert, Frédéric; Alaoui-Sehmer, Laurence; Benbrahim, Mohammed; Badot, Pierre-Marie; Alaoui-Sossé, Badr; Aleya, Lotfi

    2015-11-01

    Cu, Zn, Pb, and Cd concentrations in a soil plant (Lactuca sativa) continuum were measured after sewage sludge amendment. The effects of sewage sludge on growth and trace metal bioaccumulation in snails (Cantareus aspersus) were investigated in a laboratory experiment specifically designed to identify contamination sources (e.g., soil and leaves). Application of sewage sludge increased trace metal concentrations in topsoil. However, except Zn, metal concentrations in lettuce leaves did not reflect those in soil. Lettuce leaves were the main source of Zn, Cu, and Cd in exposed snails. Bioaccumulation of Pb suggested its immediate transfer to snails via the soil. No apparent toxic effects of trace metal accumulation were observed in snails. Moreover, snail growth was significantly stimulated at high rates of sludge application. This hormesis effect may be due to the enhanced nutritional content of lettuce leaves exposed to sewage sludge.

  19. Modeling snail breeding in Bioregenerative Life Support System

    Science.gov (United States)

    Kovalev, Vladimir; Tikhomirov, Alexander A.; Nickolay Manukovsky, D..

    It is known that snail meat is a high quality food that is rich in protein. Hence, heliciculture or land snail farming spreads worldwide because it is a profitable business. The possibility to use the snails of Helix pomatia in Biological Life Support System (BLSS) was studied by Japanese Researches. In that study land snails were considered to be producers of animal protein. Also, snail breeding was an important part of waste processing, because snails were capable to eat the inedible plant biomass. As opposed to the agricultural snail farming, heliciculture in BLSS should be more carefully planned. The purpose of our work was to develop a model for snail breeding in BLSS that can predict mass flow rates in and out of snail facility. There are three linked parts in the model called “Stoichiometry”, “Population” and “Mass balance”, which are used in turn. Snail population is divided into 12 age groups from oviposition to one year. In the submodel “Stoichiometry” the individual snail growth and metabolism in each of 12 age groups are described with stoichiometry equations. Reactants are written on the left side of the equations, while products are written on the right side. Stoichiometry formulas of reactants and products consist of four chemical elements: C, H, O, N. The reactants are feed and oxygen, products are carbon dioxide, metabolic water, snail meat, shell, feces, slime and eggs. If formulas of substances in the stoichiometry equations are substituted with their molar masses, then stoichiometry equations are transformed to the equations of molar mass balance. To get the real mass balance of individual snail growth and metabolism one should multiply the value of each molar mass in the equations on the scale parameter, which is the ratio between mass of monthly consumed feed and molar mass of feed. Mass of monthly consumed feed and stoichiometry coefficients of formulas of meat, shell, feces, slime and eggs should be determined experimentally

  20. Impact of estuarine pollution on birds

    Science.gov (United States)

    Blus, L.J.; Wiemeyer, Stanley N.; Kerwin, J.A.; Stendell, R.C.; Ohlendorf, H.M.; Stickel, L.F.

    1977-01-01

    Pollution of estuaries affects bird populations indirectly through changes in habitat and food supply. The multi-factor pollution of Chesapeake Bay has resulted in diminution of submerged aquatic plants and consequent change in food habits of the canvasback duck. Although dredge-spoil operations can improve wildlife habitat, they often result in its demise. Pollution of estuaries also affects birds directly, through chemical toxication, which may result in outright mortality or in reproductive impairment. Lead from industrial sources and roadways enters the estuaries and is accumulated in tissues of birds. Lead pellets deposited in estuaries as a result of hunting are consumed by ducks with sufficient frequency .to result m large annual die-offs from lead poisoning. Fish in certain areas, usually near industrial sources, may contain levels of mercury high enough to be hazardous to birds that consume them. Other heavy metals are present in estuarine birds, but their significance is poorly known. Oil exerts lethal or sublethal effects on birds by oiling their feathers, oiling eggs and young by contaminated parents, and by ingestion of oil-contaminated food. Organochlorine chemicals, of both agricultural and industrial origin, travel through the food chains and reach harmful levels in susceptible species of birds in certain estuarine ecosystems. Both outright mortality and reproductive impairment have occurred.

  1. Estimating flood exceedance probabilities in estuarine regions

    Science.gov (United States)

    Westra, Seth; Leonard, Michael

    2016-04-01

    Flood events in estuarine regions can arise from the interaction of extreme rainfall and storm surge. Determining flood level exceedance probabilities in these regions is complicated by the dependence of these processes for extreme events. A comprehensive study of tide and rainfall gauges along the Australian coastline was conducted to determine the dependence of these extremes using a bivariate logistic threshold-excess model. The dependence strength is shown to vary as a function of distance over many hundreds of kilometres indicating that the dependence arises due to synoptic scale meteorological forcings. It is also shown to vary as a function of storm burst duration, time lag between the extreme rainfall and the storm surge event. The dependence estimates are then used with a bivariate design variable method to determine flood risk in estuarine regions for a number of case studies. Aspects of the method demonstrated in the case studies include, the resolution and range of the hydraulic response table, fitting of probability distributions, computational efficiency, uncertainty, potential variation in marginal distributions due to climate change, and application to two dimensional output from hydraulic models. Case studies are located on the Swan River (Western Australia), Nambucca River and Hawkesbury Nepean River (New South Wales).

  2. Triclosan alterations of estuarine phytoplankton community structure.

    Science.gov (United States)

    Pinckney, James L; Thompson, Laura; Hylton, Sarah

    2017-06-15

    Antimicrobial additives in pharmaceutical and personal care products are a major environmental concern due to their potential ecological impacts on aquatic ecosystems. Triclosan (TCS) has been used as an antiseptic, disinfectant, and preservative in various media. The sublethal and lethal effects of TCS on estuarine phytoplankton community composition were investigated using bioassays of natural phytoplankton communities to measure phytoplankton responses to different concentrations of TCS ranging from 1 to 200μgl -1 . The EC 50 (the concentration of an inhibitor where the growth is reduced by half) for phytoplankton groups (diatoms, chlorophytes, cryptophytes) examined in this ranged from 10.7 to 113.8μg TCS l -1 . Exposures resulted in major shifts in phytoplankton community composition at concentrations as low as 1.0μg TCS l -1 . This study demonstrates estuarine ecosystem sensitivity to TCS exposure and highlights potential alterations in phytoplankton community composition at what are typically environmental concentrations of TCS in urbanized estuaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Physical stress, not biotic interactions, preclude an invasive grass from establishing in forb-dominated salt marshes.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available Biological invasions have become the focus of considerable concern and ecological research, yet the relative importance of abiotic and biotic factors in controlling the invasibility of habitats to exotic species is not well understood. Spartina species are highly invasive plants in coastal wetlands; however, studies on the factors that control the success or failure of Spartina invasions across multiple habitat types are rare and inconclusive.We examined the roles of physical stress and plant interactions in mediating the establishment of the smooth cordgrass, Spartina alterniflora, in a variety of coastal habitats in northern China. Field transplant experiments showed that cordgrass can invade mudflats and low estuarine marshes with low salinity and frequent flooding, but cannot survive in salt marshes and high estuarine marshes with hypersaline soils and infrequent flooding. The dominant native plant Suaeda salsa had neither competitive nor facilitative effects on cordgrass. A common garden experiment revealed that cordgrass performed significantly better when flooded every other day than when flooded weekly. These results suggest that physical stress rather than plant interactions limits cordgrass invasions in northern China.We conclude that Spartina invasions are likely to be constrained to tidal flats and low estuarine marshes in the Yellow River Delta. Due to harsh physical conditions, salt marshes and high estuarine marshes are unlikely to be invaded. These findings have implications for understanding Spartina invasions in northern China and on other coasts with similar biotic and abiotic environments.

  4. Influence of age and body size on alarm responses in a freshwater snail Pomacea canaliculata.

    Science.gov (United States)

    Ichinose, Katsuya

    2002-10-01

    A hypothesis that size selection of prey by predators elicits size-specific responses from prey was examined. Freshwater snails, Pomacea canaliculata, ages 1, 3, 7, 15, 30, or 60 days, were given an extract of 3-day-old snails, and 3-day-old snails were given extracts of snails of the otherages oreggs. Snails 15 days or younger crawled out of the water in response to the 3-day-old snail extract, but older ones did not. The 3-day-old snails responded to the extracts of snails of all examined ages, but not to the extract of eggs. Snails of four size classes, 3-days-old, small (shell lengths 8-12 mm), medium (13-20 mm), and large (>28 mm) were given extracts of snails of each of these four classes. The 3-day-old snails crawled out of the water in response to the extract of 3-day-old snails, but showed a lower or no response to other extracts. Larger snails buried themselves in the soil in response to the extract of snails of similar sizes. These responses are discussed in the context of the evolution of the snail's avoidance behavior in response to the size-dependent prey choice by the predator.

  5. Crawling beneath the free surface: Water snail locomotion

    Science.gov (United States)

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric

    2008-08-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small-amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be nonzero for moderate values of the capillary number but vanishes in the limits of high and low capillary number. Physically, this force arises because the snail's foot deforms the free surface, thereby generating curvature pressures and lubrication flows inside the mucus layer that couple to the topography of the foot.

  6. Spatial mosaic evolution of snail defensive traits

    Directory of Open Access Journals (Sweden)

    de León Francisco

    2007-03-01

    Full Text Available Abstract Background Recent models suggest that escalating reciprocal selection among antagonistically interacting species is predicted to occur in areas of higher resource productivity. In a putatively coevolved interaction between a freshwater snail (Mexipyrgus churinceanus and a molluscivorous cichlid (Herichthys minckleyi, we examined three components of this interaction: 1 spatial variation in two putative defensive traits, crushing resistance and shell pigmentation; 2 whether abiotic variables or frequency of molariform cichlids are associated with spatial patterns of crushing resistance and shell pigmentation and 3 whether variation in primary productivity accounted for small-scale variation in these defensive traits. Results Using spatial autocorrelation to account for genetic and geographic divergence among populations, we found no autocorrelation among populations at small geographic and genetic distances for the two defensive traits. There was also no correlation between abiotic variables (temperature and conductivity and snail defensive traits. However, crushing resistance and frequency of pigmented shells were negatively correlated with molariform frequency. Crushing resistance and levels of pigmentation were significantly higher in habitats dominated by aquatic macrophytes, and both traits are phenotypically correlated. Conclusion Crushing resistance and pigmentation of M. churinceanus exhibit striking variation at small spatial scales often associated with differences in primary productivity, substrate coloration and the frequency of molariform cichlids. These local geographic differences may result from among-habitat variation in how resource productivity interacts to promote escalation in prey defenses.

  7. Prey-tracking behavior in the invasive terrestrial planarian Platydemus manokwari (Platyhelminthes, Tricladida).

    Science.gov (United States)

    Iwai, Noriko; Sugiura, Shinji; Chiba, Satoshi

    2010-11-01

    Platydemus manokwari is a broadly distributed invasive terrestrial flatworm that preys heavily on land snails and has been credited with the demise of numerous threatened island faunas. We examined whether P. manokwari tracks the mucus trails of land snail prey, investigated its ability to determine trail direction, and evaluated prey preference among various land snail species. A plastic treatment plate with the mucus trail of a single species and a control plate without the trail were placed side by side at the exit of cages housing P. manokwari. All trials were then videotaped overnight. The flatworms moved along plates with mucus trails, but did not respond to plates without trails, blank control (distilled water), or with conspecific flatworm trails. When presented at the midpoint of a snail mucus trail, the flatworms followed the trail in a random direction. The flatworms showed a preference when choosing between two plates, each with a mucus trail of different land snail species. Our results suggest that P. manokwari follows snail mucus trails based on chemical cues to increase the chance of encountering prey; however, trail-tracking behavior showed no directionality.

  8. Prey-tracking behavior in the invasive terrestrial planarian Platydemus manokwari (Platyhelminthes, Tricladida)

    Science.gov (United States)

    Iwai, Noriko; Sugiura, Shinji; Chiba, Satoshi

    2010-11-01

    Platydemus manokwari is a broadly distributed invasive terrestrial flatworm that preys heavily on land snails and has been credited with the demise of numerous threatened island faunas. We examined whether P. manokwari tracks the mucus trails of land snail prey, investigated its ability to determine trail direction, and evaluated prey preference among various land snail species. A plastic treatment plate with the mucus trail of a single species and a control plate without the trail were placed side by side at the exit of cages housing P. manokwari. All trials were then videotaped overnight. The flatworms moved along plates with mucus trails, but did not respond to plates without trails, blank control (distilled water), or with conspecific flatworm trails. When presented at the midpoint of a snail mucus trail, the flatworms followed the trail in a random direction. The flatworms showed a preference when choosing between two plates, each with a mucus trail of different land snail species. Our results suggest that P. manokwari follows snail mucus trails based on chemical cues to increase the chance of encountering prey; however, trail-tracking behavior showed no directionality.

  9. Response to phosphorus limitation varies among lake populations of the freshwater snail Potamopyrgus antipodarum.

    Directory of Open Access Journals (Sweden)

    Amy C Krist

    Full Text Available Local adaptation--typically recognized as higher values of fitness-related traits for native vs. non-native individuals when measured in the native environment--is common in natural populations because of pervasive spatial variation in the intensity and type of natural selection. Although local adaptation has been primarily studied in the context of biotic interactions, widespread variation in abiotic characteristics of environments suggests that local adaptation in response to abiotic factors should also be common. Potamopyrgus antipodarum, a freshwater New Zealand snail that is an important model system for invasion biology and the maintenance of sexual reproduction, exhibits local adaptation to parasites and rate of water flow. As an initial step to determining whether P. antipodarum are also locally adapted to phosphorus availability, we examined whether populations differ in their responses to phosphorus limitation. We found that field-collected juvenile P. antipodarum grew at a lower rate and reached an important size threshold more slowly when fed a relatively low vs. a relatively high-phosphorus diet. We also detected significant across-population variation in individual growth rate. A marginally significant population-by-dietary phosphorus interaction along with a two-fold difference across populations in the extent of suppression of growth by low phosphorus suggests that populations of P. antipodarum may differ in their response to phosphorus limitation. Local adaptation may explain this variation, with the implication that snails from lakes with relatively low phosphorus availability should be less severely affected by phosphorus limitation than snails from lakes with higher phosphorus availability.

  10. Assessment of the potential of competitor snails and African catfish (Clarias gariepinus) as biocontrol agents against snail hosts transmitting schistosomiasis.

    Science.gov (United States)

    Gashaw, Fikru; Erko, Berhanu; Teklehaymanot, Tilahun; Habtesellasie, Redeat

    2008-08-01

    The objective of this study was to assess the potential of the snails Physa acuta and Melanoides tuberculata and the African catfish Clarias gariepinus as biological control agents against the Schistosoma mansoni intermediate host Biomphalaria pfeifferi under laboratory conditions. Groups of five target and five competitor snails were raised together in experimental aquaria and same number in separate aquaria as controls. Shell size, number of eggs and mortality rate were recorded for twelve consecutive weeks. The stocking density for C. gariepinus was one fish per aquarium. Fish were provided with adequate or inadequate supplementary food and fifteen B. pfeifferi were added to each aquarium. The snails and their eggs were counted daily. Significant differences in shell growth and fecundity were noted between B. pfeifferi and M. tuberculata. Physa acuta was noted to be voracious in food consumption. Snail consumption was faster by fish provided with inadequate supplementary food. Based on the present findings, it is suggested that the two competitor snails and African catfish could be used as biological control agents against B. pfeifferi. Nevertheless, the susceptibility of the competitor snails to other trematodes in Ethiopia must first be ruled out before introducing these snails into new habitats. Follow-up field observation and rigorous laboratory studies remain areas for further research.

  11. [Influence regarding micro-ecological environment of snail habitats in lake area on the distribution of snails].

    Science.gov (United States)

    Li, Yuan-pei; Wang, Hai-yin; Zhou, Yi-biao; He, Zhong; Wan, Wei; Jiang, Jie; Jiang, Qing-wu

    2010-02-01

    To explore the relationships between micro-ecological environmental factors and the density of Snails so as to provide information for the elimination of Snails and control of Schistosomiasis disease, under ecological methods. A bottomland close to Junshan Park in Yueyang city, Hunan province was selected as the field for survey during 10, 2007 - 10, 2008, and a systematic sampling method was applied to determine the specific sites of Snail investigation. All the Snails in each frames were collected and the soil surface temperature and vegetation coverage in several frames were measured. 30 g soil sample in each selected frames were also collected simultaneously. The number of live Snails in each frame was counted by dissection, and soil measured pH value and soil moisture were tested in the laboratory. The distribution of Snails and microecological environmental factors, fitted general additive model for the relationship of these factors and the Snail density were described. 104 frames were surveyed, with pH value as between 4.70 - 7.92, vegetation coverage as in 1% to 96%, soil surface temperature as in 14.5 - 32.7°C, the soil moisture as in 0.07 - 2.00. Under General additive model, data showed that there was no significant difference for vegetation coverage. However, other factors were all significantly different (P micro-ecological environmental factors. It's suggested to fit general additive model to study the relationship between the distribution of Snails and its influencing factors, so as to adopt appropriate measures to change the related ecology to control the diffusion and reproduction of Snails.

  12. Characterization of soil salinization in typical estuarine area of the Jiaozhou Bay, China

    Science.gov (United States)

    Li, Qifei; Xi, Min; Wang, Qinggai; Kong, Fanlong; Li, Yue

    2018-02-01

    In this study, the characteristics of soil salinization and the effects of main land use/land cover and other factors in typical estuarine area of the Jiaozhou Bay are investigated. Soil samples were collected in the parallel coastal zone, vertical coastal zone and longitudinal profile depth in the area to determine the soil salt content. The correlation analysis and principal component analysis are used to address the general characteristics of soil salinization in the study area. In the horizontal direction, there are moderate salinization, severe salinization and saline soil state. The farther from the sea (within 1.1 km), the lower the soil salinization degree. In the direction of longitudinal profile depth, there are severe salinization and saline soil state, and the soil salt content is accumulated in the surface and bottom. The Na+ and Cl- are the dominant cation and anion, respectively, the distributions of which are consistent with that of salt content. All the salinization indexes, except for soil pH, are of moderate/strong variability. The invasion of Spartina alterniflora results in the increase of soil salt content and salinization degree, the effects of which are mainly determined by the physiological characteristics and the growth years. The degree of soil salinization increased significantly in the aquaculture ponds, which is mainly caused by the use of chemicals. The correlation between soil salt content and Na+, Cl- is particularly significant. From the results of principal component analysis, Na+, Cl-, Ca2+, Mg2+ and SO42- could be used as main diagnostic factors for salinization in typical estuarine area of the Jiaozhou Bay. The effects of NaCl and sulfate on salt content further affect the degree of salinization in the estuarine area.

  13. Snail Farming in Mature Rubber Plantation : 4. Studies on some Artificial Methods for Hatching of Snail Eggs and Protection of Young Snails during the Dry Season

    Directory of Open Access Journals (Sweden)

    Awah, AA.

    2001-01-01

    Full Text Available Three species of edible land snails of the moist forest belt of Nigeria, Archachatina marginata (Swainson, Archachatina papyracae (Pfeiffer and two phenotypes of Limicolaria species, sometimes named Limicolaria flammae (Muller and Limicolaria aurora (Jay, were used in the study of three methods of artificial hatching of snail eggs and their young ones for the study of two methods of reduction of mortality during the dry season. The results of egg laying performance by the three species of snails showed a significantly (p <0.01 higher population explosion in a given breeding season for L. flammae/aurora than for either A. papyracae or A. marginata. The results of artificial methods for hatching of snail eggs indicated that the use of plastic containers, plus either loose topsoil or cotton wool for the incubator mediums or the use of cellophane containers (bag plus loose topsoil for the incubator medium, were in each case suitable for adoption in successful hatching of snail eggs artificially. Leaking coagulation pans or wooden boxes, half filled with heat sterilized loose topsoil and placed on the ground under shade of rubber tree canopy as dry season protection methods for the snails, were again in each case effective in the reduction of field mortality of the young snails. The survival rates were 100 % ; 90.6 % and 71.2 % for youngs of A. marginata, A. papyracae and L. flammae/aurora respectively. The results further indicated that the dry season protection method deemed optimum for the youngs of A. marginata may not necessarily be optimum for the youngs of either A. papyracae orL. flammae/aurora.

  14. Sediment measurement in estuarine and coastal areas

    Science.gov (United States)

    Shelley, P. E.

    1976-01-01

    A survey of uses of estuarine and coastal areas is given. Problems associated with these uses are discussed, and data needs for intelligent management of these valuable areas are outlined. Suspended sediment measurements are seen to be one of the greatest needs. To help understand the complexity of the problem, a brief discussion of sediment mechanics is given, including sediment sources, characteristics, and transport. The impact of sediment mechanics on its direct measurement (sampling and analysis) is indicated, along with recommendations for directly obtaining representative data. Indirect measurement of suspended sediment by remote sensors is discussed both theoretically and in the light of some recent experiences. The need for an integrated, multidisciplinary program to solve the problem of quantitatively measuring suspended sediment with remote sensors is stressed, and several important considerations of such a program and benefits to be derived therefrom are briefly addressed.

  15. Relationship between snail population density and infection status of snails and fish with zoonotic trematodes in Vietnamese carp nurseries

    DEFF Research Database (Denmark)

    Clausen, Jesper Hedegaard; Madsen, Henry; Murrell, Kenneth Darwin

    2012-01-01

    ponds. Previous risk assessment on FZT transmission in the Red River Delta of Vietnam identified carp nursery ponds as major sites of transmission. In this study, we analyzed the association between snail population density and heterophyid trematode infection in snails with the rate of FZT transmission......Fish-borne zoonotic trematodes (FZT) are a food safety and health concern in Vietnam. Humans and other final hosts acquire these parasites from eating raw or under-cooked fish with FZT metacercariae. Fish raised in ponds are exposed to cercariae shed by snail hosts that are common in fish farm...

  16. A soft microenvironment protects from failure of midbody abscission and multinucleation downstream of the EMT-promoting transcription factor Snail.

    Science.gov (United States)

    Simi, Allison K; Anlas, Alisya A; Stallings-Mann, Melody; Zhang, Sherry; Hsia, Tiffaney; Cichon, Magdalena A; Radisky, Derek C; Nelson, Celeste M

    2018-02-26

    Multinucleation is found in more than one third of tumors and is linked to increased tolerance for mutation, resistance to chemotherapy, and invasive potential. The integrity of the genome depends on proper execution of the cell cycle, which can be altered through mechanotransduction pathways as the tumor microenvironment stiffens during tumorigenesis. Here we show that signaling downstream of matrix metalloproteinase-3 (MMP3) or transforming growth factor-beta (TGFbeta), known inducers of epithelial-mesenchymal transition (EMT), also promotes multinucleation in stiff microenvironments through Snail-dependent expression of the filament-forming protein septin-6, resulting in midbody persistence, abscission failure, and multinucleation. Consistently, we observed elevated expression of Snail and septin-6 as well as multinucleation in a human patient sample of metaplastic carcinoma of the breast, a rare classification characterized by deposition of collagen fibers and active EMT. In contrast, a soft microenvironment protected mammary epithelial cells from becoming multinucleated by preventing Snail-induced upregulation of septin-6. Our data suggest that tissue stiffening during tumorigenesis synergizes with oncogenic signaling to promote genomic abnormalities that drive cancer progression. Copyright ©2018, American Association for Cancer Research.

  17. Evidence of oligogenic sex determination in the apple snail Pomacea canaliculata.

    Science.gov (United States)

    Yusa, Yoichi; Kumagai, Natsumi

    2018-02-26

    A small number of genes may interact to determine sex, but few such examples have been demonstrated in animals, especially through comprehensive mating experiments. The highly invasive apple snail Pomacea canaliculata is gonochoristic and shows a large variation in brood sex ratio, and the involvement of multiple genes has been suggested for this phenomenon. We conducted mating experiments to determine whether their sex determination involves a few or many genes (i.e., oligogenic or polygenic sex determination, respectively). Full-sib females or males that were born from the same parents were mated to an adult of the opposite sex, and the brood sex ratios of the parents and their offspring were investigated. Analysis of a total of 4288 offspring showed that the sex ratios of offspring from the full-sib females were variable but clustered into only a few values. Similar patterns were observed for the full-sib males, although the effect was less clear because fewer offspring were used (n = 747). Notably, the offspring sex ratios of all full-sib females in some families were nearly 0.5 (proportion of males) with little variation. These results indicate that the number of genotypes of the full-sibs, and hence genes involved in sex determination, is small in this snail. Such oligogenic systems may be a major sex-determining system among animals, especially those with variable sex ratios.

  18. GoM Coastal and Estuarine Biopsy Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Small vessel surveys are conducted within estuarine and nearshore coastal waters to collect tissue biopsy samples from bottlenose dolphins. Visual surveys are...

  19. Estuarine response of fluoride - Investigations in Azhikode Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Joseph, T.; Sankaranarayanan, V.N.

    Concentrations of fluoride in Azhikode estuarine region (Kerala, India) were measured as a function of chlorinity during the different seasons. The type of behaviour indicated that fluoride was regulated by sea water incursion alone. Fluoride...

  20. SPECIES INTERACTIONS BETWEEN ESTUARINE DETRITIVORES: INHIBITION OR FACILITATION?

    Science.gov (United States)

    Native Hawaiian estuarine detritivores; the prawn Macrobrachium grandimanus, and the neritid gastropod Neritina vespertina, were maintained in flow-through microcosms with conditioned leaves from two riparian tree species, Hau (Hibiscus tiliaceus) and guava (Psidium guajava). Th...

  1. Connecting fishery sustainability to estuarine habitats and nutrient loading

    Science.gov (United States)

    The production of several important fishery species depends on critical estuarine habitats, including seagrasses and salt marshes. Relatively simple models can be constructed to relate fishery productivity to the extent and distribution of these habitats by linking fishery-depend...

  2. Brackishwater shrimp farming: Possible impacts on estuarine ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Sreepada, R.A.

    , most the developments have been confined to the estuarine and brackishwater areas. Tropical estuaries being the most productive ecosystem and subjected to a variety of developmental activities, most of which bring in some environmental changes...

  3. Shrimp farming in estuarine environment: Points to ponder

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.

    of the expansion has taken place around the estuarine area as it facilitates water exchange and waste disposal. In semi-intensive and extensive type of farming practices, use of different types of chemicals and antibiotics, artificial feeds, probiotics...

  4. Benthic foraminiferal biocoenoses in the estuarine regimes of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    Benthic Foraminifera are highly responsive to subtle changes in the estuarine environment. Keeping this in view, a qualitative analysis of living benthic Foraminifera was made of the samples collected from the Mandovi-Zuari estuaries...

  5. NOAA's Estuarine Living Marine Resources (ELMR) Data Base

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1985, NOAA launched the Estuarine Living Marine Resources (ELMR) Program to develop a consistent data base on the distribution, relative abundance, and life...

  6. Fungal activity in Mangalvan: an estuarine mangrove ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

    Prabhakaran, N.; Gupta, R.; Kutty, M.K.

    of the mangrove vegetation by these fungi the detritus load is increased, contributing substantially to the food web of this important estuarine ecosystem. Thirty-one fungal isolates were recorded from the soil and 27 from decaying leaves, stems, roots...

  7. Biochemical evaluation of aestivation and starvation in two snail ...

    African Journals Online (AJOL)

    hope&shola

    2010-11-08

    3. 1Department of Biochemistry, College of Medicine, University of Lagos, Nigeria. ... aestivation and starvation on endogenous metabolic reserves in haemolymph of two snail species .... authority in Abeokuta, Ogun state.

  8. Nutritional Assessment of Some Nigerian Land and Water Snail ...

    African Journals Online (AJOL)

    Archachatina marginata ovum, Archachatina marginata saturalis and Limicolaria spp) and two fresh water (Lanistes varicus and Nucella lapillus) snail species for nutritional assessment using their muscular foot tissues. The mean of crude protein ...

  9. Differences in predatory pressure on terrestrial snails by birds and ...

    Indian Academy of Sciences (India)

    by birds and mammals. ZUZANNA M ROSIN( PAULINA OLBORSKA( ADRIAN SURMACKI AND PIOTR TRYJANOWSKI. Supplementary table 1. Number of analysed individuals of particular species with specification of undamaged and damaged snails. Species. Total number of individuals. Undamaged individuals.

  10. Energy saving through trail following in a marine snail.

    Science.gov (United States)

    Davies, Mark S; Blackwell, Janine

    2007-05-07

    Most snails and slugs locomote over a layer of mucus and although the resultant mucus trail is expensive to produce, we show that this expense can be reduced by trail following. When tracking over fresh conspecific trails, the marine intertidal snail Littorina littorea (L.) produced only approximately 27% of the mucus laid by marker snails. When tracking over weathered trails, snails adjusted their mucus production to recreate a convex trail profile of similar shape and thickness to the trail as originally laid. Maximum energy saving occurs when following recently laid trails which are little weathered. Many and diverse ecological roles for trail following have been proposed. Energy saving is the only role that applies across the Gastropoda and so may help to explain why trail following is such a well-established behaviour.

  11. CRCP-Acropora palmata snail corallivore removal evaluation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Corallivorous snail feeding scars are a common source of tissue loss for the threatened coral Acropora palmata, accounting for roughly one quarter of tissue loss in...

  12. Diversity and stability of an estuarine trophic network

    OpenAIRE

    Lobry, Jeremy; David, V; Pasquaud, S; Lepage, M; Sautour, B; Rochard, E

    2008-01-01

    Estuarine areas provide highly valuable ecosystem benefits for human populations, despite being under intense demographic, economic and ecological pressures. Hence, an understanding of the structure and function of estuarine ecosystems is essential for understanding the persistence and stability of these ecosystems and their response to perturbations. This study synthesises available data and knowledge about the Gironde estuary (SW France) in a mass-balanced trophic model to illustrate potent...

  13. Molluscicidal activity of chlorophyll extraction against the freshwater snails

    Directory of Open Access Journals (Sweden)

    Mona Said Mahmoud

    2013-09-01

    Full Text Available Objective: To evaluate the molluscicidal activity of chlorophyll extract as a photodynamic substance against the snails Lymnaea stagnalis, Biomphalaria spp. and Physa marmorata. Methods: Chlorophyllin was extracted from deep-frozen spinach. Snails were incubated in chlorophyllin containing water with 2.5, 5.0, 10.0 and 15.0 µg/mL. All samples were kept in darkness overnight for incubation. After incubation, three samples were irradiated with simulated solar radiation for 3 h. After irradiation, the vitality of the organisms was determined. Results: The photodynamically active chlorophyllin, at low concentrations, was able to kill snails within a few hours under exposure of solar radiation. Besides, it had a killing effect by about 70% and 100% on the snails’ eggs and the newly hatched snails, respectively, after 3 h exposure to solar radiation. Conclusion: The derivates of chlorophyll was a very interesting substance for photodynamic freshwater snail control. Hence, it might be a promising and cheap new strategy which probably had the potential to replace the synthetic molluscicides for snail control.

  14. Comparative proteomics and codon substitution analysis reveal mechanisms of differential resistance to hypoxia in congeneric snails.

    Science.gov (United States)

    Mu, Huawei; Sun, Jin; Cheung, Siu Gin; Fang, Ling; Zhou, Haiyun; Luan, Tiangang; Zhang, Huoming; Wong, Chris K C; Qiu, Jian-Wen

    2018-02-10

    Although high-throughput proteomics has been widely applied to study mechanisms of environmental adaptation, the conclusions from studies that are based on one species can be confounded by phylogeny. We compare the freshwater snail Pomacea canaliculata (a notorious invasive species) and its congener Pomacea diffusa (a non-invasive species) to understand the molecular mechanisms of their differential resistance to hypoxia. A 72-h acute exposure experiment showed that P. canaliculata is more tolerant to hypoxia than P. diffusa. The two species were then exposed to three levels of dissolved oxygen (6.7, 2.0 and 1.0mgL -1 ) for 8h, and their gill proteins were analyzed using iTRAQ-coupled LC-MS/MS. The two species showed striking differences in protein expression profiles, with the more hypoxia tolerant P. canaliculata having more up-regulated proteins in signal transduction and down-regulated proteins in glycolysis and the tricarboxylic acid cycle. Evolutionary analysis revealed five orthologous genes encoding differentially expressed proteins having clear signal of positive selection, indicating selection has acted on some of the hypoxia responsive genes. Our case study has highlighted the potential of integrated proteomics and comparative evolutionary analysis for understanding the genetic basis of adaptation to global environmental change in non-model species. Rapid globalization in recent decades has greatly facilitated species introduction around the world. Successfully established introduced species, so-called invasive species, have threatened the invaded ecosystems. There has been substantial interest in studying how invasive species respond to extreme environmental conditions because the results can help not only predict their range of expansion and manage their impact, but also may reveal the adaptive mechanisms underlying their invasiveness. Our study has adopted a comparative approach to study the differential physiological and proteomic responses of two

  15. Comparative proteomics and codon substitution analysis reveal mechanisms of differential resistance to hypoxia in congeneric snails

    KAUST Repository

    Mu, Huawei

    2017-11-06

    Although high-throughput proteomics has been widely applied to study mechanisms of environmental adaptation, the conclusions from studies that are based on one species can be confounded by phylogeny. We compare the freshwater snail Pomacea canaliculata (a notorious invasive species) and its congener Pomacea diffusa (a non-invasive species) to understand the molecular mechanisms of their differential resistance to hypoxia. A 72-h acute exposure experiment showed that P. canaliculata is more tolerant to hypoxia than P. diffusa. The two species were then exposed to three levels of dissolved oxygen (6.7, 2.0 and 1.0mgL−1) for 8h, and their gill proteins were analyzed using iTRAQ-coupled LC-MS/MS. The two species showed striking differences in protein expression profiles, with the more hypoxia tolerant P. canaliculata having more up-regulated proteins in signal transduction and down-regulated proteins in glycolysis and the tricarboxylic acid cycle. Evolutionary analysis revealed five orthologous genes encoding differentially expressed proteins having clear signal of positive selection, indicating selection has acted on some of the hypoxia responsive genes. Our case study has highlighted the potential of integrated proteomics and comparative evolutionary analysis for understanding the genetic basis of adaptation to global environmental change in non-model species. SignificanceRapid globalization in recent decades has greatly facilitated species introduction around the world. Successfully established introduced species, so-called invasive species, have threatened the invaded ecosystems. There has been substantial interest in studying how invasive species respond to extreme environmental conditions because the results can help not only predict their range of expansion and manage their impact, but also may reveal the adaptive mechanisms underlying their invasiveness. Our study has adopted a comparative approach to study the differential physiological and proteomic

  16. Identification of trophic interactions within an estuarine food web (northern New Zealand) using fatty acid biomarkers and stable isotopes

    Science.gov (United States)

    Alfaro, Andrea C.; Thomas, François; Sergent, Luce; Duxbury, Mark

    2006-10-01

    Fatty acid biomarkers and stable isotope signatures were used to identify the trophic dynamics of a mangrove/seagrass estuarine food web at Matapouri, northern New Zealand. Specific fatty acids were used to identify the preferred food sources (i.e., mangroves, seagrass, phytoplankton, macroalgae, bacteria, and zooplankton) of dominant fauna (i.e., filter feeders, grazing snails, scavenger/predatory snails, shrimp, crabs, and fish), and their presence in water and sediment samples throughout the estuary. The diets of filter feeders were found to be dominated by dinoflagellates, whereas grazers showed a higher diatom contribution. Bacteria associated with organic debris on surface sediments and brown algal ( Hormosira banksii) material in the form of suspended organic matter also accounted for a high proportion of most animal diets. Animals within higher trophic levels had diverse fatty acid profiles, revealing their varied feeding strategies and carbon sources. The stable isotope (δ 13C and δ 15N) analyses of major primary producers and consumers/predators revealed a trend of 15N enrichment with increasing trophic level, while δ 13C values provided a generally good description of carbon flow through the food web. Overall results from both fatty acid profiles and stable isotopes indicate that a variety of carbon sources with a range of trophic pathways typify this food web. Moreover, none of the animals studied was dependent on a single food source. This study is the first to use a comprehensive fatty acid biomarker and stable isotope approach to investigate the food web dynamics within a New Zealand temperate mangrove/seagrass estuary. This quantitative research may contribute to the currently developing management strategies for estuaries in northern New Zealand, especially for those perceived to have expanding mangrove fringes.

  17. Differential expression of Snail1 transcription factor and Snail1-related genes in alveolar and embryonal rhabdomyosarcoma subtypes

    Directory of Open Access Journals (Sweden)

    Miroslawa Püsküllüoglu

    2010-04-01

    Full Text Available Rhabdomyosarcoma (RMS represents the most common sarcoma of soft tissue among children. Two main RMSsubtypes are alveolar (ARMS and embryonal (ERMS. The major goal of this study was to find differentially expressedgenes between RMS subtypes that could explain higher metastatic potential in ARMS and would be useful for the differentialdiagnosis. Using RQ-PCR analysis we compared expression of Snail1 and Snail-related genes among 7 ARMS and 8ERMS patients' samples obtained from the primary tumors and among 2 alveolar and 2 embryonal cell lines. Our resultsshow that Snail1 is highly expressed both in ARMS patients' samples and the alveolar cell lines. We also found that theexpression of E-Cadherin was downregulated and the expression of Matrix Metalloproteinases 2 and 9 (MMP-2 and MMP-9 was upregulated in ARMS. We assume that, as in many tumors, also in RMS Snail1 acts as a regulator for pathwaysknown for their role in cells' metastasis and that Snail1 activity results in increased MMPs and decreased E-Cadherin expression.Our findings may explain higher ARMS aggressiveness. Moreover, we suggest that further studies should be performedto verify if Snail1 can be considered as a potential target for ARMS therapy.

  18. Mercury bioaccumulation in estuarine food webs.

    Science.gov (United States)

    Fry, Brian; Chumchal, Matthew M

    2012-03-01

    We tested for unintended mercury contamination problems associated with estuarine floodplain restoration projects of the Louisiana coastal zone, USA. Barataria Bay and Breton Sound are two neighboring deltaic estuaries that were isolated by levees from the Mississippi River about 100 years ago. These estuaries recently have been reconnected to the nutrient-rich Mississippi River, starting major river diversion (input) flows in 1991 for Breton Sound and in 2004 for Barataria Bay. We collected > 2100 fish over five years from 20 stations in these estuaries to test two hypotheses about Hg bioaccumulation: (H1) Background Hg bioaccumulation in fish would be highest in low-salinity upper reaches of estuaries, and (H2) recent river inputs to these upper estuarine areas would increase Hg bioaccumulation in fish food webs. For H1, we surveyed fish Hg concentrations at several stations along a salinity gradient in Barataria Bay in 2003-2004, a time when this estuary lacked strong river inputs. Results showed that average Hg concentrations in fish communities were lowest (150 ng/g dry mass) in higher salinity areas and -2.4x higher (350 ng/g) in low-salinity oligohaline and freshwater upper reaches of the estuary. For H2, we tested for enhanced Hg bioaccumulation following diversion onset in both estuaries. Fish communities from Breton Sound that had long-term (> 10 years) diversion inputs had -1.7x higher average Hg contents of 610 ng/g Hg vs. 350 ng/g background values. Shorter-term diversion inputs over 2-3 years in upper Barataria Bay did not result in strong Hg enrichments or stable C isotope increases seen in Breton Sound, even though N and S stable-isotope values indicated strong river inputs in both estuaries. It may be that epiphyte communities on abundant submerged aquatic vegetation (SAV) are important hotspots for Hg cycling in these estuaries, and observed lesser development of these epiphyte communities in upper Barataria Bay during the first years of diversion

  19. [Monitoring report of Oncomelania hupensis snail distribution and diffusion in main drainages of Hexi Reservoir].

    Science.gov (United States)

    Zhang, Liu-hong; Xu, Feng-ming; Lu, Hong-mei; Qin, Jia-sheng; Cao, Wei-min; Jiang, Ya-juan; Lu, Qin-nan

    2015-02-01

    To understand the status of Oncomelania hupensis snail distribution and diffusion in main drainages of Hexi Reservoir and evaluate the snail control effect of the schistosomiasis control engineering of Hexi Reservoir. The O. hupensis snails were investigated by using the straw curtain method and fishing net method in different areas of the main drainages of Hexi Reservoir, and the results were analyzed. A total of 1 800 straw curtains were used and 37 snails were found in Naxi stream. Totally 5 870 kg floats were salved and no snails were found. The schistosomiasis control engineering of Hexi Reservoir is effective in the prevention of the snail diffusion, but there are still snails in the upstream. rherefore, the snail surveillance and control need to be strengthened.

  20. [Application of electronic fence technology based on GIS in Oncomelania hupensis snail monitoring].

    Science.gov (United States)

    Zhi-Hua, Chen; Yi-Sheng, Zhu; Zhi-Qiang, Xue; Xue-Bing, Li; Yi-Min, Ding; Li-Jun, Bi; Kai-Min, Gao; You, Zhang

    2017-07-27

    To study the application of Geographic Information System (GIS) electronic fence technique in Oncomelania hupensis snail monitoring. The electronic fence was set around the history and existing snail environments in the electronic map, the information about snail monitoring and controlling was linked to the electronic fence, and the snail monitoring information system was established on these bases. The monitoring information was input through the computer and smart phone. The electronic fence around the history and existing snail environments was set in the electronic map (Baidu map), and the snail monitoring information system and smart phone APP were established. The monitoring information was input and upload real-time, and the snail monitoring information was demonstrated in real time on Baidu map. By using the electronic fence technology based on GIS, the unique "environment electronic archives" for each snail monitoring environment can be established in the electronic map, and real-time, dynamic monitoring and visual management can be realized.

  1. Functional changes in the snail statocyst system elicited by microgravity.

    Science.gov (United States)

    Balaban, Pavel M; Malyshev, Aleksey Y; Ierusalimsky, Victor N; Aseyev, Nikolay; Korshunova, Tania A; Bravarenko, Natasha I; Lemak, M S; Roshchin, Matvey; Zakharov, Igor S; Popova, Yekaterina; Boyle, Richard

    2011-03-29

    The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations. In terrestrial gastropod snail we studied the impact of 16- (Foton M-2) and 12-day (Foton M-3) exposure to microgravity in unmanned orbital missions on: (i) the whole animal behavior (Helix lucorum L.), (ii) the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L.), and (iii) the differential expression of the Helix pedal peptide (HPep) and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.). Experiments were performed 13-42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed. Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism's ability to adapt to gravity changes. This simple animal model offers the possibility to describe general

  2. Functional changes in the snail statocyst system elicited by microgravity.

    Directory of Open Access Journals (Sweden)

    Pavel M Balaban

    Full Text Available BACKGROUND: The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations. METHODOLOGY/PRINCIPAL FINDINGS: In terrestrial gastropod snail we studied the impact of 16- (Foton M-2 and 12-day (Foton M-3 exposure to microgravity in unmanned orbital missions on: (i the whole animal behavior (Helix lucorum L., (ii the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L., and (iii the differential expression of the Helix pedal peptide (HPep and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.. Experiments were performed 13-42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed. CONCLUSIONS/SIGNIFICANCE: Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism's ability to adapt to gravity

  3. Ecotoxicology of bromoacetic acid on estuarine phytoplankton.

    Science.gov (United States)

    Gordon, Ana R; Richardson, Tammi L; Pinckney, James L

    2015-11-01

    Bromoacetic acid is formed when effluent containing chlorine residuals react with humics in natural waters containing bromide. The objective of this research was to quantify the effects of bromoacetic acid on estuarine phytoplankton as a proxy for ecosystem productivity. Bioassays were used to measure the EC50 for growth in cultured species and natural marine communities. Growth inhibition was estimated by changes in chlorophyll a concentrations measured by fluorometry and HPLC. The EC50s for cultured Thalassiosira pseudonana were 194 mg L(-1), 240 mg L(-1) for Dunaliella tertiolecta and 209 mg L(-1) for Rhodomonas salina. Natural phytoplankton communities were more sensitive to contamination with an EC50 of 80 mg L(-1). Discriminant analysis suggested that bromoacetic acid additions cause an alteration of phytoplankton community structure with implications for higher trophic levels. A two-fold EC50 decrease in mixed natural phytoplankton populations affirms the importance of field confirmation for establishing water quality criteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Hydrocarbon pollution from marinas in estuarine sediments

    Science.gov (United States)

    Voudrias, Evangelos A.; Smith, Craig L.

    1986-03-01

    A measure of the impact of marinas on three Eastern Virginia estuarine creeks was obtained by a study of hydrocarbons in their sediments. Two of the creeks support considerable marine activity, including pleasure boat marinas, boat repair facilities, and commercial fishing operations. The third creek, which served as a control, is seldom used by boats, and is surrounded by marsh and woodland. Sediments from the creeks with marinas contained significantly higher levels of both aromatic and aliphatic hydrocarbons than did the control. Differences in the concentrations of certain oil-pollution indicators, such as the 17α,21β-hopane homologs and phytane, and low molecular weight aromatic hydrocarbons, are indicative of light petroleum fractions. Most of the aromatic hydrocarbons from all creeks, however, appear to have a pyrogenic origin. Although hydrocarbons from three probable origins (petroleum, pyrogenesis, and recent biosynthesis) were detected in all locations, the petroleum-derived and pyrogenic hydrocarbons were of only minor importance relative to the biogenic hydrocarbons in the control creek.

  5. A user's guide to coping with estuarine management bureaucracy: An Estuarine Planning Support System (EPSS) tool.

    Science.gov (United States)

    Lonsdale, Jemma; Nicholson, Rose; Weston, Keith; Elliott, Michael; Birchenough, Andrew; Sühring, Roxana

    2018-02-01

    Estuaries are amongst the most socio-economically and ecologically important environments however, due to competing and conflicting demands, management is often challenging with a complex legislative framework managed by multiple agencies. To facilitate the understanding of this legislative framework, we have developed a GISbased Estuarine Planning Support System tool. The tool integrates the requirements of the relevant legislation and provides a basis for assessing the current environmental state of an estuary as well as informing and assessing new plans to ensure a healthy estuarine state. The tool ensures that the information is easily accessible for regulators, managers, developers and the public. The tool is intended to be adaptable, but is assessed using the Humber Estuary, United Kingdom as a case study area. The successful application of the tool for complex socio-economic and environmental systems demonstrates that the tool can efficiently guide users through the complex requirements needed to support sustainable development. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  6. The role of river flow and tidal asymmetry on 1-D estuarine morphodynamics

    NARCIS (Netherlands)

    Guo, L.; Van der Wegen, M.; Roelvink, J.A.; He, Q.

    2014-01-01

    Numerous research efforts have been devoted to understanding estuarine morphodynamics under tidal forcing. However, the impact of river discharge on estuarine morphodynamics is insufficiently examined. Inspired by the Yangtze Estuary, this work explores the morphodynamic impact of river discharge in

  7. Studies on growth and age of bivalves from temperate and tropical estuarine ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.

    Comparison of growth progression and age composition of Abra alba and Nuculana minuta from temperate estuarine ecosystem with Meretrix casta and Paphia malabarica from tropical estuarine environment, revealed that the annual growth rate in tropical...

  8. Reversing tidal flow and estuarine morphodynamics in the Metronome laboratory flume

    NARCIS (Netherlands)

    Kleinhans, M.G.; Leuven, J.R.F.W.; Braat, L.; van der Vegt, M.; van Maarseveen, M.C.G.; Markies, H.; Roosendaal, C.; van Eijk, A.M.

    2016-01-01

    Our objective is to test a novel experimental principle for creating reversing tidal flows of sufficient strength to cause estuarine morphodynamics. The study of estuarine morphodynamics has hitherto been limited to field observation and numerical modelling, whilst fluvial morphodynamics have

  9. The feeding habits of the snail kite in Florida, USA

    Science.gov (United States)

    Sykes, P.W.

    1987-01-01

    The feeding habits of the Snail Kite (Rostrhamus sociabilis) were observed intermittently from 1967-1980 in Florida, USA. Approximately 97% of all observed foraging bouts were over marshes having sparse emergent vegetation. The visually-hunting kite was unable to forage over floating mats of exotic water hyacinth (Eichhornia crassipes). Male kites had shorter hunting bouts than females. For still-hunting, the birds' perches ranged from 0.15-4.6 m high and captures occurred an average of 5.8 m from perches. Females were significantly more successful (70%) for course-hunting than males (48%), but I found no difference for still-hunting. Birds tended to forage throughout the day, except for occasional inactive periods by some individuals during midday. On cooler days, foraging commenced slightly later in the morning than on warmer days. Kites probably capture freshwater apple snails (Pomacea paludosa) as deep as 16 cm. Capture rates for adults generally ranged from 1.7-3.4 snails per hour. Kites usually foraged over a common hunting area, and defense of foraging sites was rare. Handling of snails, from the kite's arrival at the feeding perch unit consumption, averaged 2.7 min, with no significant difference between sexes. However, adult females were more efficient at the extraction portion of this process than were adult males. Snails were usually extracted before being brought to the nest, except in the latter part of the nestling period when some snails were extracted at or near the nest and some were brought intact. Adults feed small chicks bill to bill, and both parents generally shared equally in care of the young, except at two nests where the females did 67% or more of the feeding. Mean length of snails taken by kites was 42.8 mm (range 25.2-71.3 n=697) and mean diameter was 45.8 mm (range 27.4-82.4, n=697). The most common size classes tkaen were 30-60 mm in length and diameter. Nutritional and gross energy values were determined for apple snails. Female

  10. [The influence of the trematode invasion on the average daily rations and electoral nourishment of Planorbarius corneus (Mollusca: Pulmonata: Bulinidae)].

    Science.gov (United States)

    Stadnichenko, A P; Girin, V K

    2005-01-01

    The influence of the Trematode invasion on the average daily rations and electoral nourishment of the two size groups in the great ramshorn snail Planorbarius corneus, "young" (12-24 mm in diameter) and "old" (24-36.5 mm in diameter), have been investigated.

  11. New scope on the relationship between rotifers and Biomphalaria alexandrina snails

    Science.gov (United States)

    Mossallam, Shereen Farouk; Amer, Eglal Ibrahim; Abou-El-Naga, Iman Fathy

    2013-01-01

    Objective To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes. Methods Susceptible laboratory-bred Biomphalaria alexandrina (B. alexandrina) snails were exposed to lab-maintained rotifers; Philodina spp., two weeks before and after being infected with Schistosoma mansoni (S. mansoni) miracidia. The consequent histopathological impact on snail tissues and cercarial biology were investigated before and after emergence from snails. Results Contamination of B. alexandrina snails with philodina, two weeks before miracidial exposure, was found to hinder the preliminary development of S. mansoni cercariae inside the snail tissues. Furthermore, when snails were contaminated with rotifers two weeks post miracidial exposure; growth of already established cercariae was found to be retarded. The consequent influence of internalized rotifers within the snail tissue was clearly reflected on cercarial emergence, activity and infectivity along the four weeks duration of shedding. In the present study, comparison of snail histopathological findings and altered cercarial biology observed between the experimental and control groups indicated that the rotifers may have affected the levels of snail's energy reservoirs, which eventually was found to have had an adverse impact on reproduction, growth and survival of the parasite within the snail host, coupled with its performance outside the snail. Conclusions In future biological control strategies of schistosomiasis, ritifers should be considered as a parasitic scourge of humanity. PMID:23905015

  12. Vineyard snail allergy possibly induced by sensitization to house-dust mite (Dermatophagoides pteronyssinus)

    NARCIS (Netherlands)

    de Maat-Bleeker, F.; Akkerdaas, J. H.; van Ree, R.; Aalberse, R. C.

    1995-01-01

    A female patient experienced a severe allergic reaction after consumption of vineyard snails. The patient proved to be sensitized to house-dust mite (HDM) and demonstrated a positive skin test and specific IgE to snail (Eobania vermiculata, Lofarma). The snail RAST was > 80% inhibited by HDM,

  13. Aquatic snail species of two adjoining rivers in Owerri, Imo State ...

    African Journals Online (AJOL)

    Aquatic snail species of two adjoining Rivers (Otamiri and Nwaorie Rivers) in Owerri Southeastern Nigeria was surveyed between December 2008 and May 2009. The study identified 231 aquatic snail species. Snail species collected were Bulinus globosus (29.9%), Lymnaea natalensis (59.3%), and Melanoides sp.

  14. Evaluation Of Snail Mucin Dispersed In Brachystegia Gum Gel As A ...

    African Journals Online (AJOL)

    Snail mucin was obtained from the mucilage of Archachatina marginata (Family Arionidae). The wound healing effect of the snail mucin was evaluated wth special attention to the effect when combined with honey in Brachystegia eurychoma gel preparation. Brachystegia eurycoma gum, snail mucin and honey were ...

  15. Survey of snail intermediate hosts of trematodes in Jos South Local ...

    African Journals Online (AJOL)

    Streams and irrigation schemes in selected areas of Jos South Local Government Area, Plateau State, Nigeria were surveyed for snail intermediate hosts of Trematodes. A total of 1045 snails were collected from streams with long handled scoop net and in some areas manually with hand in gloves. The snails were put in ...

  16. Analysis of land snail marketing in Owerri agricultural zone of Imo ...

    African Journals Online (AJOL)

    Animal Production Research Advances ... The study was conducted in Owerri Agricultural Zone of Imo state, Nigeria to assess the profitability of snail marketing during wet and dry seasons, examine the socioeconomic ... Ten snail marketers were randomly selected from a list of snail marketers compiled for each Market.

  17. Helix and Drugs: Snails for Western Health Care From Antiquity to the Present.

    Science.gov (United States)

    Bonnemain, Bruno

    2005-03-01

    The land helix, or snail, has been used in medicine since antiquity and prepared according to several formulations. This historical report traces the understanding of their properties from the time of Hippocrates, who proposed the use of snail mucus against protoccle and Pliny who thought that the snail increased the speed of delivery and was "a sovereign remedy to treat pain related to burns, abscesses and other wounds", Galien recommended snails against hydrops foetails. In the 18th century, various snail "preparations" were also recommended for external use with dermatological disorders and internally for symptoms associated with tuberculosis and nephritis. Surprisingly, the 19th century saw a renewed interest in the pharmaceutical and medical use of snails with numerous indications for snail preparations. This interest in snails did not stop at the end of the 19th century. The 1945 edition of Dorvault devotes an entire paragraph to snails, indicating that the therapeutic usage of snails was still alive at that time. Recently the FDA has also shown an interest in snails. Ziconotide (SNXIII), a synthetic peptide coming from snail venom, has been under FDA review since 1999. Pre-clinical and clinical studies of this new drug are promising.

  18. Helix and Drugs: Snails for Western Health Care From Antiquity to the Present

    Directory of Open Access Journals (Sweden)

    Bruno Bonnemain

    2005-01-01

    Full Text Available The land helix, or snail, has been used in medicine since antiquity and prepared according to several formulations. This historical report traces the understanding of their properties from the time of Hippocrates, who proposed the use of snail mucus against protoccle and Pliny who thought that the snail increased the speed of delivery and was “a sovereign remedy to treat pain related to burns, abscesses and other wounds”, Galien recommended snails against hydrops foetails. In the 18th century, various snail “preparations” were also recommended for external use with dermatological disorders and internally for symptoms associated with tuberculosis and nephritis. Surprisingly, the 19th century saw a renewed interest in the pharmaceutical and medical use of snails with numerous indications for snail preparations. This interest in snails did not stop at the end of the 19th century. The 1945 edition of Dorvault devotes an entire paragraph to snails, indicating that the therapeutic usage of snails was still alive at that time. Recently the FDA has also shown an interest in snails. Ziconotide (SNXIII, a synthetic peptide coming from snail venom, has been under FDA review since 1999. Pre-clinical and clinical studies of this new drug are promising.

  19. Snails promote methane release from a freshwater lake ecosystem

    Directory of Open Access Journals (Sweden)

    Xiao eXu

    2014-05-01

    Full Text Available Benthic fauna, as ecosystem engineers, can strongly affect microbial-driven ecosystem biogeochemical cycling. However, the effects of benthic fauna, especially epifauna, on CH4 cycling remain still elusive. In this study, CH4 effluxes were both measured along a gradient of snail density in a freshwater lake ecosystem in China, and monitored in manipulated laboratory microcosms with and without snails. Field CH4 efflux was significantly increased with snail density. Likewise, the stimulating effects of freshwater snails on CH4 effluxes were evident in the homogenised indoor microcosms. These results show that snails can stimulate CH4 efflux in the freshwater lake ecosystem. Moreover, the average efflux of CH4 emitted from snails’ habitats has reached 15.33 mg CH4-C m-2 d-1. By comparing with those emitted from vegetated coastal marsh and alpine wetland, this data indicates that snails’ habitats are strong sources of CH4 in a freshwater ecosystem. This study suggests identifying and modeling epifauna activity as a function of CH4 cycling could improve the mechanistic understanding of wetland biogeochemical cycling responses to climate change.

  20. Venomics-Accelerated Cone Snail Venom Peptide Discovery.

    Science.gov (United States)

    Himaya, S W A; Lewis, Richard J

    2018-03-09

    Cone snail venoms are considered a treasure trove of bioactive peptides. Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. To overcome the limitations of the traditional low-throughput bio-discovery approaches, multi-omics systems approaches have been introduced to accelerate venom peptide discovery and characterisation. This "venomic" approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. The main challenge for venomics is the effective integration of transcriptomics, proteomics, and pharmacological data and the efficient analysis of big datasets. Novel database search tools and visualisation techniques are now being introduced that facilitate data exploration, with ongoing advances in related omics fields being expected to further enhance venomics studies. Despite these challenges and future opportunities, cone snail venomics has already exponentially expanded the number of novel venom peptide sequences identified from the species investigated, although most novel conotoxins remain to be pharmacologically characterised. Therefore, efficient high-throughput peptide production systems and/or banks of miniaturized discovery assays are required to overcome this bottleneck and thus enhance cone snail venom bioprospecting and accelerate the identification of novel drug leads.

  1. Implication of snail in metabolic stress-induced necrosis.

    Directory of Open Access Journals (Sweden)

    Cho Hee Kim

    2011-03-01

    Full Text Available Necrosis, a type of cell death accompanied by the rupture of the plasma membrane, promotes tumor progression and aggressiveness by releasing the pro-inflammatory and angiogenic cytokine high mobility group box 1. It is commonly found in the core region of solid tumors due to hypoxia and glucose depletion (GD resulting from insufficient vascularization. Thus, metabolic stress-induced necrosis has important clinical implications for tumor development; however, its regulatory mechanisms have been poorly investigated.Here, we show that the transcription factor Snail, a key regulator of epithelial-mesenchymal transition, is induced in a reactive oxygen species (ROS-dependent manner in both two-dimensional culture of cancer cells, including A549, HepG2, and MDA-MB-231, in response to GD and the inner regions of a multicellular tumor spheroid system, an in vitro model of solid tumors and of human tumors. Snail short hairpin (sh RNA inhibited metabolic stress-induced necrosis in two-dimensional cell culture and in multicellular tumor spheroid system. Snail shRNA-mediated necrosis inhibition appeared to be linked to its ability to suppress metabolic stress-induced mitochondrial ROS production, loss of mitochondrial membrane potential, and mitochondrial permeability transition, which are the primary events that trigger necrosis.Taken together, our findings demonstrate that Snail is implicated in metabolic stress-induced necrosis, providing a new function for Snail in tumor progression.

  2. Venomics-Accelerated Cone Snail Venom Peptide Discovery

    Science.gov (United States)

    Himaya, S. W. A.

    2018-01-01

    Cone snail venoms are considered a treasure trove of bioactive peptides. Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. To overcome the limitations of the traditional low-throughput bio-discovery approaches, multi-omics systems approaches have been introduced to accelerate venom peptide discovery and characterisation. This “venomic” approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. The main challenge for venomics is the effective integration of transcriptomics, proteomics, and pharmacological data and the efficient analysis of big datasets. Novel database search tools and visualisation techniques are now being introduced that facilitate data exploration, with ongoing advances in related omics fields being expected to further enhance venomics studies. Despite these challenges and future opportunities, cone snail venomics has already exponentially expanded the number of novel venom peptide sequences identified from the species investigated, although most novel conotoxins remain to be pharmacologically characterised. Therefore, efficient high-throughput peptide production systems and/or banks of miniaturized discovery assays are required to overcome this bottleneck and thus enhance cone snail venom bioprospecting and accelerate the identification of novel drug leads. PMID:29522462

  3. Venomics-Accelerated Cone Snail Venom Peptide Discovery

    Directory of Open Access Journals (Sweden)

    S. W. A. Himaya

    2018-03-01

    Full Text Available Cone snail venoms are considered a treasure trove of bioactive peptides. Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. To overcome the limitations of the traditional low-throughput bio-discovery approaches, multi-omics systems approaches have been introduced to accelerate venom peptide discovery and characterisation. This “venomic” approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. The main challenge for venomics is the effective integration of transcriptomics, proteomics, and pharmacological data and the efficient analysis of big datasets. Novel database search tools and visualisation techniques are now being introduced that facilitate data exploration, with ongoing advances in related omics fields being expected to further enhance venomics studies. Despite these challenges and future opportunities, cone snail venomics has already exponentially expanded the number of novel venom peptide sequences identified from the species investigated, although most novel conotoxins remain to be pharmacologically characterised. Therefore, efficient high-throughput peptide production systems and/or banks of miniaturized discovery assays are required to overcome this bottleneck and thus enhance cone snail venom bioprospecting and accelerate the identification of novel drug leads.

  4. Fluorescent pigment distinguishes between sibling snail species.

    Science.gov (United States)

    Seki, Keiichi; Wiwegweaw, Amporn; Asami, Takahiro

    2008-12-01

    Traditional taxonomy of shell-bearing molluscs does not generally use soft-body coloration. However, the land snails Bradybaena pellucida and B. similaris have been distinguished only on the basis of the color of the soft-body visible through the shell. Thus, the taxonomic status of the two species has traditionally been questionable. We found that dense spots of pigments embedded in the dorsal mantle are responsible for the yellow coloration of B. pellucida . Similar spots in B. similaris are white and less densely aggregated in whorls further from the apex, and the brown color of the hepatopancreas is visible through the shell. The yellow pigments of B. pellucida seep out with mucus from the body in natural and laboratory conditions. The two species became externally indistinguishable after 30 days of laboratory feeding, because the yellow spots disappeared in B. pellucida and the color of the hepatopancreas changed from dark brown to pale brown in both species. Irradiation with ultraviolet A demonstrated that the yellow pigment of B. pellucida fluoresces. Adult specimens of the two species were distinct in penial microsculpture, with F(1) hybrids intermediate in form. Populations of the two species differed significantly in allelic frequencies at four allozyme loci. Therefore, B. pellucida and B. similaris are morphologically and genetically distinct. The fluorescent yellow pigment distinguishes B. pellucida from B. similaris under natural conditions despite its environmental dependence.

  5. 78 FR 12346 - Jennings Low-Effect Habitat Conservation Plan for the Morro Shoulderband Snail, Community of Los...

    Science.gov (United States)

    2013-02-22

    ... Snail, Community of Los Osos, San Luis Obispo County, CA AGENCY: U.S. Fish and Wildlife Service...'' of the federally endangered Morro shoulderband snail (= banded dune snail; Helminthoglypta walkeriana... mitigate project activities that are likely to result in take of the Morro shoulderband snail as described...

  6. Movements of florida apple snails in relation to water levels and drying events

    Science.gov (United States)

    Darby, P.C.; Bennetts, R.E.; Miller, S.J.; Percival, H.F.

    2002-01-01

    Florida apple snails (Pomacea Paludosa) apparently have only a limited tolerance to wetland drying events (although little direct evidence exists), but their populations routinely face dry downs under natural and managed water regimes. In this paper, we address speculation that apple snails respond to decreasing water levels and potential drying events by moving toward refugia that remain inundated. We monitored the movements of apple snails in central Florida, USA during drying events at the Blue Cypress Marsh (BC) and at Lake Kissimmee (LK). We monitored the weekly movements of 47 BC snails and 31 LK snails using radio-telemetry. Snails tended to stop moving when water depths were 10 cm. Snails moved along the greatest positive depth gradient (i.e., towards deeper water) when they encountered water depths between 10 and 20 cm. Snails tended to move toward shallower water in water depths ???50 cm, suggesting that snails were avoiding deep water areas such as canals and sloughs. Of the 11 BC snails originally located in the area that eventually went dry, three (27%) were found in deep water refugia by the end of the study. Only one of the 31 LK snails escaped the drying event by moving to deeper water. Our results indicate that some snails may opportunistically escape drying events through movement. The tendency to move toward deeper water was statistically significant and indicates that this behavioral trait might enhance survival when the spatial extent of a dry down is limited. However, as water level falls below 10 cm, snails stop moving and become stranded. As the spatial extent of a dry down increases, we predict that the number of snails stranded would increase proportionally. Stranded Pomacea paludosa must contend with dry marsh conditions, possibly by aestivation. Little more than anecdotal information has been published on P. paludosa aestivation, but it is a common adaptation among other apple snails (Caenogastropoda: Ampullaridae). ?? 2002, The Society

  7. MTA3 regulates CGB5 and Snail genes in trophoblast

    International Nuclear Information System (INIS)

    Chen, Ying; Miyazaki, Jun; Nishizawa, Haruki; Kurahashi, Hiroki; Leach, Richard; Wang, Kai

    2013-01-01

    Highlights: •Impaired MTA3, raised CGB5 and Snail expression are associated with preeclampsia. •Knock-down of MTA3 causes up-regulation of CGB5 and Snail genes in BeWo cells. •MTA3 occupies CGB5 and Snail gene promoters in BeWo cells. -- Abstract: Secreted by the placental trophoblast, human chorionic gonadotropin (hCG) is an important hormone during pregnancy and is required for the maintenance of pregnancy. Previous studies have shown that dys-regulation of hCG expression is associated with preeclampsia. However, the exact relationship between altered hCG levels and development of preeclampsia is unknown. Metastasis associated protein 3 (MTA3), a chromatin remodeling protein, is abundantly expressed in the placental trophoblasts, but its function is unknown. In breast cancer, MTA3 has been shown to repress the expression of Snail and cell migration. However, whether MTA3 acts similarly in the trophoblast has not been investigated. In the present study, we examined the role of MTA3 in regulating the hCG β-subunit gene (gene name: CGB5) and Snail expression in the trophoblast cell line, BeWo, as well as its relevance to the high hCG expression levels seen in preeclampsia. First, we investigated MTA3 expression in preeclamptic placenta as compared to normal control placenta via gene expression microarray and qRT-PCR and found that MTA3 was significantly down-regulated, whereas both CGB5 and Snail were up-regulated in preeclamptic placenta. Secondly, we knocked down MTA3 gene in trophoblast cell line BeWo and found Snail and hCG were both up-regulated, suggesting that MTA3 represses Snail and hCG gene expression in trophoblasts. Next, we cloned the CGB5 and Snail promoters into the pGL3-basic vector individually and found that silencing of MTA3 by siRNA resulted in an increase of both CGB5 and Snail promoter activities. To confirm that this MTA3 inhibition is a direct effect, we performed a chromatin immune-precipitation (ChIP) assay and found that MTA3

  8. MTA3 regulates CGB5 and Snail genes in trophoblast

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids, MI 49503 (United States); Miyazaki, Jun [Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Fujita Health University, Toyoake (Japan); Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake (Japan); Nishizawa, Haruki [Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Fujita Health University, Toyoake (Japan); Kurahashi, Hiroki [Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake (Japan); Leach, Richard, E-mail: Richard.Leach@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids, MI 49503 (United States); Department of Obstetrics, Gynecology and Women’s Health, Spectrum Health Medical Group, Grand Rapids, MI 49503 (United States); Wang, Kai, E-mail: Kai.Wang@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids, MI 49503 (United States)

    2013-04-19

    Highlights: •Impaired MTA3, raised CGB5 and Snail expression are associated with preeclampsia. •Knock-down of MTA3 causes up-regulation of CGB5 and Snail genes in BeWo cells. •MTA3 occupies CGB5 and Snail gene promoters in BeWo cells. -- Abstract: Secreted by the placental trophoblast, human chorionic gonadotropin (hCG) is an important hormone during pregnancy and is required for the maintenance of pregnancy. Previous studies have shown that dys-regulation of hCG expression is associated with preeclampsia. However, the exact relationship between altered hCG levels and development of preeclampsia is unknown. Metastasis associated protein 3 (MTA3), a chromatin remodeling protein, is abundantly expressed in the placental trophoblasts, but its function is unknown. In breast cancer, MTA3 has been shown to repress the expression of Snail and cell migration. However, whether MTA3 acts similarly in the trophoblast has not been investigated. In the present study, we examined the role of MTA3 in regulating the hCG β-subunit gene (gene name: CGB5) and Snail expression in the trophoblast cell line, BeWo, as well as its relevance to the high hCG expression levels seen in preeclampsia. First, we investigated MTA3 expression in preeclamptic placenta as compared to normal control placenta via gene expression microarray and qRT-PCR and found that MTA3 was significantly down-regulated, whereas both CGB5 and Snail were up-regulated in preeclamptic placenta. Secondly, we knocked down MTA3 gene in trophoblast cell line BeWo and found Snail and hCG were both up-regulated, suggesting that MTA3 represses Snail and hCG gene expression in trophoblasts. Next, we cloned the CGB5 and Snail promoters into the pGL3-basic vector individually and found that silencing of MTA3 by siRNA resulted in an increase of both CGB5 and Snail promoter activities. To confirm that this MTA3 inhibition is a direct effect, we performed a chromatin immune-precipitation (ChIP) assay and found that MTA3

  9. Building a better snail: Lubrication and adhesive locomotion

    Science.gov (United States)

    Chan, Brian; Balmforth, N. J.; Hosoi, A. E.

    2005-11-01

    Many gastropods, such as slugs and snails, crawl via an unusual mechanism known as adhesive locomotion. We investigate this method of propulsion using two mathematical models: one for direct waves and one for retrograde waves. We then test the effectiveness of both proposed mechanisms by constructing two mechanical crawlers. Each crawler uses a different mechanical strategy to move on a thin layer of viscous fluid. The first uses a flexible flapping sheet to generate lubrication pressures in a Newtonian fluid, which in turn propel the mechanical snail. The second generates a wave of compression on a layer of Laponite, a non-Newtonian, finite-yield stress fluid with characteristics similar to those of snail mucus. This second design can climb smooth vertical walls and perform an inverted traverse.

  10. Uncharismatic Invasives

    Directory of Open Access Journals (Sweden)

    Clark, Jonathan L.

    2015-05-01

    Full Text Available Although philosophers have examined the ethics of invasive species management, there has been little research approaching this topic from a descriptive, ethnographic perspective. In this article I examine how invasive species managers think about the moral status of the animals they seek to manage. I do so through a case study of Oregon’s efforts to manage the invasive species that are rafting across the Pacific attached to tsunami debris in the wake of the Japanese tsunami of 2011. Focusing on the state’s response to a dock that washed ashore on Agate Beach with various marine invertebrates attached to it, I argue that these animals’ position on two intersecting scales of moral worth—the sociozoologic scale and the phylogenetic scale—rendered them unworthy of moral consideration.

  11. Influence of snail feces and mucus on oviposition and larval behavior ofPherbellia cinerella (Diptera: Sciomyzidae).

    Science.gov (United States)

    Coupland, J B

    1996-02-01

    Larvae of the sciomyzid flyPherbellia cinerella are voracious predators of terrestrial helicid snails. Eggs are deposited in areas where snails occur and larvae hunt actively for their prey. Snail feces and mucus were tested to determine if they had any kairomone or stimulatory effects onP. cinerella. Adult flies oviposited more frequently on substrates containing fresh snail feces than on substrates containing snail mucus or water (control). However, mucus and feces both stimulated increased search behaviour in first instar larvae. These results are discussed in relation to snail biology, and the potential for augmentation of these flies in areas affected by pest snails.

  12. Efficacy of euphorbia hirta latex as plant derived molluscicides against freshwater snails

    Directory of Open Access Journals (Sweden)

    Ram P. Yadav

    2011-04-01

    Full Text Available The toxic effect of binary and tertiary combinations of Euphorbia hirta Linn latex powder with other plant molluscicidal compounds, were evaluated against the freshwater snails Lymnaea (Radix acuminata and Indoplanorbis exustus in pond. These combinations showed significant time and dose dependent effect against both the snails. These compounds at higher doses were also lethal to freshwater fish Channa punctatus (Bloch (Channidae {Ophicephalidae}, which shares the habitat with these snails, but the LC90 (24h doses of snails have no apparent killing properties in fish populations when treated in mixed population of snails and fish.

  13. Efficacy of Euphorbia hirta latex as plant derived molluscicides against freshwater snails.

    Science.gov (United States)

    Yadav, Ram P; Singh, Ajay

    2011-01-01

    The toxic effect of binary and tertiary combinations of Euphorbia hirta Linn latex powder with other plant molluscicidal compounds, were evaluated against the freshwater snails Lymnaea (Radix) acuminata and Indoplanorbis exustus in pond. These combinations showed significant time and dose dependent effect against both the snails. These compounds at higher doses were also lethal to freshwater fish Channa punctatus (Bloch) (Channidae {Ophicephalidae}), which shares the habitat with these snails, but the LC90 (24h) doses of snails have no apparent killing properties in fish populations when treated in mixed population of snails and fish.

  14. Finding and recognition of the snail intermediate hosts by 3 species of echinostome cercariae.

    Science.gov (United States)

    Haas, W; Körner, M; Hutterer, E; Wegner, M; Haberl, B

    1995-02-01

    Finding and recognition of snail second intermediate hosts was studied in cercariae of 3 echinostome species. The cercariae of the 3 species accumulated in snail-conditioned water (SCW) with 2 types of orientation mechanisms and responded to different small molecular weight ( snails and to disperse. Attachments occurred specifically to snail hosts in the 3 species and were stimulated by macromolecular mucus compounds, probably mainly by viscoelastic properties of the mucus. The results of this study show, that host-finding mechanisms and the stimulating host cues of snail invading echinostome cercariae differ considerably from those of schistosome miracidia.

  15. Molecular diversity of avian schistosomes in Danish freshwater snails

    DEFF Research Database (Denmark)

    Christiansen, Anne Ø.; Olsen, Annette; Buchmann, Kurt

    2016-01-01

    Avian schistosomes are widespread parasites of snails and waterfowl and may cause cercarial dermatitis (swimmer's itch) in humans, a disease that is frequently reported in European countries. These parasites are known to occur in Denmark, but here, we applied a new approach using molecular tools...... to identify the parasites at species level. In order to do that, 499 pulmonate freshwater snails (Radix sp., Lymnaea stagnalis, Stagnicola sp. and Planorbarius corneus) were sampled from 12 lakes, ponds, and marshes in the greater Copenhagen area. Avian schistosome cercariae were identified by microscopy...

  16. Calcium oxide from Pomacea canaliculata and Babylonia spirata snails

    OpenAIRE

    Triayu Septiani; Nurlisa Hidayati; Risfidian Mohadi

    2017-01-01

    The preparation of CaO from golden snail (Pomacea canaliculata) and lion snail (Babylonia spirata) through decomposition at various temperature i.e 700o, 800o, 900o and 1000oC during 3 hours has been carried out. Calcium oxide from decomposition was characterized using X-Ray diffractometer.  Furthermore, the characterization was continued using FT-IR spectrophotometer and determination of surface area using BET analysis. The results showed that the optimum temperature for preparation of CaO f...

  17. Microstructure analysis of snail trails in photovoltaic modules

    Science.gov (United States)

    Tao, J.; Shi, Z. X.; Chen, S. Y.; Kong, J. X.; Huang, Q. S.; Gou, X. Fg

    2018-01-01

    Snail trails on photovoltaic modules are a source of enormous concern to the solar industry as few scientific reports on the mechanisms producing this global phenomenon were previously available. The samples surface were treated with CH3OH/CH2Cl2 and used the SEM and Raman for material analysis. The size of the discoloration silver grid is about 80-200 nm. From the Raman spectroscopy can be seen snail trails and the surrounding discoloration of silver on the Ag2CO3 generation.

  18. Some quality parameters of land snail meat - Helix pomatia

    Directory of Open Access Journals (Sweden)

    Tojagić Slobodan N.

    2004-01-01

    Full Text Available Considering the tradition in our regions to collect land snails (Helix pomatia for export, which is "disrupted" by social control resulting in limited possibilities to develop this attractive activity, there is a great interest lately for land snail breeding and fattening at farms. For this reason it is necessary to investigate systematically the possibilities to develop this activity in a longer period and in larger areas. The first investigations, although covering only nutritive and health safety aspects of the edible parts yielded the results presented in this work. Chemical composition, the content of some elements and organochlorine insecticides were followed as unavoidable in human living and environment.

  19. Effect of radiation on Lymnnea auricularia rubiginosa snails

    International Nuclear Information System (INIS)

    Cruz, B. de la; Yumul, B.V.; Anden, A.; Perpuse, W.G.

    1976-03-01

    As a means of checking the spread of fascioliasis, the intermediate host of F. hepatica and F. gigantica which is the Lumnea auricularia rubiginosa is exposed to different doses of radioisotopes. Radioisotopes used were 32 P, 3 H-thymidine, and 137 Cs. Findings show that at different concentration and doses of radioisotopes, there is a reduced viability and increase mortality in the eggs laid by the parent snails exposed to radiation. The effects on the development of irradiated eggs are also being studied as well as the effects of irradiation on the reproductive apparatus of the snails

  20. Purification and characterization of an antibacterial factor from snail mucus.

    Science.gov (United States)

    Kubota, Y; Watanabe, Y; Otsuka, H; Tamiya, T; Tsuchiya, T; Matsumoto, J J

    1985-01-01

    The antibacterial factor from the body surface of the African giant snail, Achatina fulica Férussac, was isolated by DEAE-Toyopearl 650M ion exchange chromatography. The isolated preparation exhibited highly positive antibacterial activity both for the Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus and for the Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, but it lost such activity when heated at 75 degrees C for 5 min. The antibacterial factor of the snail mucus was a glycoprotein whose molecular weight (MW) was about 160,000. It was composed of two subunits of MW 70,000-80,000.

  1. Microbiological quality of raw and processed wild and cultured edible snails.

    Science.gov (United States)

    Parlapani, Foteini F; Neofitou, Christos; Boziaris, Ioannis S

    2014-03-15

    An increasing interest in snail farming in Greece and other European countries has been observed. Despite the fact that edible snails have been involved with problems of Salmonella spp. contamination, there are to our knowledge only limited studies regarding microbiological safety and hygiene of such products. Enumeration of microbial populations and presence/absence of Salmonella spp. in snail meat and intestines of wild Cornu aspersum, Helix lucorum and cultured Cornu aspersum snails from indoor/outdoor type farms was conducted. Furthermore, snail-processing steps were simulated in the laboratory and the population reduction in snail meat was determined. Microbial populations were higher in intestines than snail meat in almost all cases. Escherichia coli/coliforms and Enterococcus spp. populations were lower in the intestines and snail meat of cultured C. aspersum. Salmonella spp. were detected in the intestines and snail meat of wild snails only. The high levels of bacterial populations were considerably reduced after the appropriate processing. The lower populations of E. coli/coliforms, Enterococcus spp. and especially the absence of Salmonella spp. in cultured snails show that the controlled conditions decrease the possibility of pathogen presence and contribute to food safety and public health. © 2013 Society of Chemical Industry.

  2. OTUB1 promotes esophageal squamous cell carcinoma metastasis through modulating Snail stability.

    Science.gov (United States)

    Zhou, Honghong; Liu, Yongshuo; Zhu, Rui; Ding, Fang; Cao, Xiufeng; Lin, Dongxin; Liu, Zhihua

    2018-03-21

    Snail is a key regulator of epithelial-mesenchymal transition (EMT) and plays an important role in tumor progression and metastasis. Snail is rapidly degraded in the cells and its protein level is critically controlled. Although several E3 ligases regulating Snail degradation have been defined, the deubiquitinases (DUBs) responsible for Snail deubiquitination are less studied. We identified ovarian tumor domain-containing ubiquitin aldehyde binding protein 1 (OTUB1) as a DUB that stabilizes Snail through preventing its ubiquitination and proteasomal degradation. Functionally, OTUB1 facilitates metastasis of esophageal squamous cell carcinoma (ESCC) through promoting Snail protein stability. Moreover, OTUB1 is highly expressed in ESCC and higher expression of OTUB1 predicts poor prognosis. These findings suggest that OTUB1 is an essential regulator of Snail and plays a critical role in facilitating esophageal cancer progression.

  3. Fatty acids in an estuarine mangrove ecosystem

    Directory of Open Access Journals (Sweden)

    Nabeel M Alikunhi

    2010-06-01

    Full Text Available Los ácidos grasos se han utilizado con éxito para estudiar la transferencia de materia orgánica en las redes alimentarias costeras y estuarinas. Para delinear las interacciones tróficas en las redes, se analizaron perfiles de ácidos grasos en las especies de microbios (Azotobacter vinelandii y Lactobacillus xylosus, camarones (Metapenaeus monoceros y Macrobrachium rosenbergii y peces (Mugil cephalus, que están asociadas con la descomposición de las hojas de dos especies de mangle, Rhizophora apiculata y Avicennia marina. Los ácidos grasos, con excepción de los de cadena larga, exhiben cambios durante la descomposición de las hojas de mangle, con una reducción de los ácidos grasos saturados y un aumento de los monoinsaturados. Los ácidos grasos ramificados están ausentes en las hojas de mangle sin descomponer, pero presentes de manera significativa en las hojas descompuestas, en camarones y peces, representando una fuente importante para ellos. Esto revela que los microbios son productores dominantes que contribuyen significativamente con los peces y camarones en el ecosistema de manglar. Este trabajo demuestra que los marcadores biológicos de los ácidos grasos son una herramienta eficaz para la identificación de las interacciones tróficas entre los productores dominantes y consumidores en este manglar.Fatty acids have been successfully used to trace the transfer of organic matter in coastal and estuarine food webs. To delineate these web connections, fatty acid profiles were analyzed in species of microbes (Azotobacter vinelandii, and Lactobacillus xylosus, prawns (Metapenaeus monoceros and Macrobrachium rosenbergii and finfish (Mugil cephalus, that are associated with decomposing leaves of two mangrove species, Rhizophora apiculata and Avicennia marina. The fatty acids, except long chain fatty acids, exhibit changes during decomposition of mangrove leaves with a reduction of saturated fatty acids and an increase of

  4. An ecological study of Bithynia snails, the first intermediate host of Opisthorchis viverrini in northeast Thailand.

    Science.gov (United States)

    Wang, Yi-Chen; Ho, Richard Cheng Yong; Feng, Chen-Chieh; Namsanor, Jutamas; Sithithaworn, Paiboon

    2015-01-01

    Infection with the food-borne trematodiasis, liver fluke Opisthorchis viverrini, is a major public health concern in Southeast Asia. While epidemiology and parasitic incidence in humans are well studied, ecological information on the O. viverrini intermediate hosts remains limited. This study aimed to investigate the factors affecting the distribution and abundance of the first intermediate host, Bithynia siamensis goniomphalos snails. Water quality and snails were sampled in 31 sites in Muang District, Khon Kaen Province, Thailand from June 2012 to January 2013 to characterize the B.s. goniomphalos snail habitats. Species relative abundance and Shannon's diversity and evenness indices were employed to describe snail compositions and diversities across different habitat types. Statistical analyses were conducted to examine the extent to which the water quality variables and species interactions account for the relative abundance of B.s. goniomphalos snails. The results showed that the freshwater habitats of ponds, streams and rice paddies possessed significantly different abiotic water qualities, with water temperature and pH showing distinct statistical differences (P<0.05). Different habitats had different snail diversity and species evenness, with high B.s. goniomphalos snail abundance at rice paddy habitats. The differences in snail abundance might be due to the distinct sets of abiotic water qualities associated with each habitat types. The relative abundance of B.s. goniomphalos snails was found to be negatively correlated with that of Filopaludina martensi martensi snails (r=-0.46, P<0.05), underscoring the possible influence of species interaction on B.s. goniomphalos snail population. Field work observations revealed that rice planting seasons and irrigation could regulate snail population dynamics at rice paddy habitats. This study provides new ecological insights into the factors affecting Bithynia snail distribution and abundance. It bridges the

  5. Abiotic water quality control on mangrove distribution in estuarine ...

    African Journals Online (AJOL)

    Abiotic water quality control on mangrove distribution in estuarine river channels assessed by a novel boat-mounted electromagnetic- induction technique. Melissa A .... of operation depends on coil orientation, spacing and operation. * To whom all .... the visual estimation method in proportion (%) to the total site area ...

  6. The biology and taxonomic status of an estuarine population of ...

    African Journals Online (AJOL)

    The biology and taxonomic status of an estuarine population of Pranesus pinguis (Lacépède) (Teleostei: Atherinidae) in south east Africa. ... The structure and dimensions of the gill rakers related to the diet indicate that, although P. pinguis feeds mainly by capturing individual prey, it is also a facultative filter feeder.

  7. Monitoring nekton as a bioindicator in shallow estuarine habitats

    Science.gov (United States)

    Raposa, K.B.; Roman, C.T.; Heltshe, J.F.

    2003-01-01

    Long-term monitoring of estuarine nekton has many practical and ecological benefits but efforts are hampered by a lack of standardized sampling procedures. This study provides a rationale for monitoring nekton in shallow (< 1 m), temperate, estuarine habitats and addresses some important issues that arise when developing monitoring protocols. Sampling in seagrass and salt marsh habitats is emphasized due to the susceptibility of each habitat to anthropogenic stress and to the abundant and rich nekton assemblages that each habitat supports. Extensive sampling with quantitative enclosure traps that estimate nekton density is suggested. These gears have a high capture efficiency in most habitats and are small enough (e.g., 1 m(2)) to permit sampling in specific microhabitats. Other aspects of nekton monitoring are discussed, including spatial and temporal sampling considerations, station selection, sample size estimation, and data collection and analysis. Developing and initiating long-term nekton monitoring programs will help evaluate natural and human-induced changes in estuarine nekton over time and advance our understanding of the interactions between nekton and the dynamic estuarine environment.

  8. Management options for restoring estuarine dynamics and implications for ecosystems

    NARCIS (Netherlands)

    Ysebaert, Tom; Hoek, van der Dirk Jan; Wortelboer, Rick; Wijsman, Jeroen W.M.; Tangelder, Marijn; Nolte, Arno

    2016-01-01

    The Delta Works, a series of dams and barriers constructed in the 1960's-1980's changed the estuarine landscape of the Rhine-Meuse-Scheldt delta (SW Netherlands) into more stagnant and disengaged freshwater, brackish water or saltwater lakes. The remaining tidal systems were adapted by building a

  9. The vertical migration behaviour of estuarine plankton | Grindley ...

    African Journals Online (AJOL)

    A series of investigations on the vertical migration behaviour of estuarine zooplankton have been carried out in recent years. Several of these investigations have been carried out in collaboration with other zoologists and the detailed findings are being published separately. The work is reviewed here and an attempt is ...

  10. The population dynamics of the estuarine isopod Exosphaeroma ...

    African Journals Online (AJOL)

    The population dynamics of the estuarine isopod, Exosphaeroma hylocoetes, was investigated monthly from February 2006 to August 2007 in three temporarily open/closed Eastern Cape estuaries, the East and West Kleinemonde and Kasouga Estuaries. Mean isopod abundances and biomasses ranged between 0 and ...

  11. Minimal incorporation of Deepwater Horizon oil by estuarine filter feeders

    International Nuclear Information System (INIS)

    Fry, Brian; Anderson, Laurie C.

    2014-01-01

    Highlights: • Oil from the Deepwater Horizon oil spill entered Louisiana bays in mid-2010. • Oil was used minimally (<1%) in diets of mussels and barnacles. • Also, oil did not enhance planktonic respiration rates. • Use of oil carbon was relatively small in these productive estuarine food webs. - Abstract: Natural abundance carbon isotope analyses are sensitive tracers for fates and use of oil in aquatic environments. Use of oil carbon in estuarine food webs should lead to isotope values approaching those of oil itself, −27‰ for stable carbon isotopes reflecting oil origins and −1000‰ for carbon-14 reflecting oil age. To test for transfer of oil from the 2010 Deepwater Horizon spill into estuarine food webs, filter-feeding barnacles (Balanus sp.) and marsh mussels (Geukensia demissa) were collected from Louisiana estuaries near the site of the oil spill. Carbon-14 analyses of these animals from open waters and oiled marshes showed that oil use was <1% and near detection limits estimated at 0.3% oil incorporation. Respiration studies showed no evidence for enhanced microbial activity in bay waters. Results are consistent with low dietary impacts of oil for filter feeders and little overall impact on respiration in the productive Louisiana estuarine systems

  12. Oxygen consumption of the estuarine round herring Gilchristella ...

    African Journals Online (AJOL)

    important, in estuarine ecological studies, to assess the response of the metabolic rate to changes in environmental factors. In this study, which forms part of a detailed research programme into .... homeostasis within the salinity range investigated here. Effect of temperature. Temperature effects on the metabolic rate of G.

  13. Assessment of Godavari estuarine mangrove ecosystem through trace metal studies

    Digital Repository Service at National Institute of Oceanography (India)

    Ray, A.K.; Tripathy, S.C; Patra, S.; Sarma, V.V.

    that organic matter is acting as a metal carrier. The values of Pollution Load Index (PLI) were found to be very low, and varied between 0.34-0.60 in KKD bay, 0.47-0.97 in GGE and 0.62-1.03 in CGME indicating that this estuarine ecosystem is not a pollution...

  14. Estuarine use by spotted grunter Pomadasys commersonnii in a ...

    African Journals Online (AJOL)

    Factors influencing estuarine use and marine excursions by spotted grunter Pomadasys commersonnii in the Great Fish Estuary, South Africa, were studied using manual and automated telemetry methods. In all, 20 individuals, ranging from 362 mm to 698 mm total length (TL), were caught and tagged with acousticcoded ...

  15. Marine and Estuarine Ecology. Man and the Gulf of Mexico.

    Science.gov (United States)

    Irby, Bobby N.; And Others

    "Man and the Gulf of Mexico (MGM)" is a marine science curriculum developed to meet the marine science needs of tenth through twelfth grade students in Mississippi and Alabama schools. This MGM unit, which focuses on marine and estuarine ecology, is divided into six sections. The first section contains unit objectives, discussions of the…

  16. Lead distribution in coastal and estuarine sediments around India

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, S.; Chakraborty, P.; Nath, B.N.

    in estuarine sediments near Cua Ong harbor, Ha Long Bay, Vietnam, Geologica Belgica, 13 (1-2) 37–47. Jena, M., 2008. Pollution in the Mahanadi: Urban Sewage, Industrial Effluents and Biomedical Waste. Econ. Polit. Wkly. 88–93. Jonathan, M.P., Ram-Mohan, V...

  17. Arsenic Trioxide Modulates the Central Snail Neuron Action Potential

    Directory of Open Access Journals (Sweden)

    Guan-Ling Lu

    2009-09-01

    Conclusion: As2O3 at 10 mM elicits BoPs in central snail neurons and this effect may relate to the PLC activity of the neuron, rather than protein kinase A activity, or calcium influxes of the neuron. As2O3 at higher concentration irreversibly abolishes the spontaneous action potentials of the neuron.

  18. Macro-invertebrate predatorsof freshwater pulmonate snails in Africa ...

    African Journals Online (AJOL)

    A range of African and alien macro-invertebrates has been reported preying on freshwater pulmonate snails, including those that serve as intermediate hosts for bloodflukes of the genus Schistosoma. Predation by five molluscivorous taxa is reviewed here: indigenous leeches (Glossiphoniidae), marsh fly larvae ...

  19. Furcocercous cercariae shed by the freshwater snails Pila ...

    African Journals Online (AJOL)

    During July 2009 and 2010 surveys of snail-borne larval trematodes of the Okavango Delta floodplains and lagoons were undertaken. Cercaria mohemboense were shed by Pila occidentalis (Mousson, 1887) and Cercaria dubaensis and Cercaria indistinctus were shed by Biomphalaria pfeifferi (Krauss, 1848), respectively.

  20. Dispersion factors in the arboreal snail Sitala jenynsi (Gastropoda ...

    African Journals Online (AJOL)

    The coefficient was enhanced by grassy habitats, continuous vegetation cover, absence of edible plants and rainy weather; conversely, dispersion was ... of S jenynsi may warrant the mixing of individuals in a population, they seem insufficient to facilitate appreciable migration of snails between neighboring populations.

  1. Biochemical evaluation of aestivation and starvation in two snail ...

    African Journals Online (AJOL)

    There is resurgence in incidence of schistosomiasis in Nigeria with attendant socio-economic and health impact. The agents transmitting this disease are the Bulinus snails which employ aestivation to survive conditions of unfavourable weather such as lack of food and water. The mechanism of aestivation under aridity and ...

  2. Hydrocarbons in the land snail Cepaea nemoralis (L.) (gastropoda, pulmonata)

    NARCIS (Netherlands)

    Horst, D.J. van der; Oudejans, R.C.H.M.

    1972-01-01

    1. 1. The biosynthesis of hydrocarbons in the snail Cepaea nemoralis was studied after injection of the 14C-labelled precursors acetate, valine, isoleucine and palmitic acid. 2. 2. The highest incorporation was achieved with palmitic acid, although with the other precursors the hydrocarbons were

  3. Observations on parastrongyliasis in two land snails Achatina ...

    African Journals Online (AJOL)

    Between December 2001 and August 2002, a study on the prevalence of Parastrongylus cantonensis nematode infection in two edible land snails Achatina marginata and Achatina achatina were carried out in Owerri, Imo State, Nigeria. Of the 350 A. marginata examined, 209 (59.7%) were infected with a mean worm load ...

  4. Fossil snail shells tell story about Tibetan Plateau

    Science.gov (United States)

    Wendel, JoAnna

    2014-09-01

    Ancient and modern snail shells have given scientists a unique look at the evolution of the Tibetan Plateau, confirming that parts of the plateau have actually lost elevation over time, despite its immense height. A new paper detailing the research was published on 29 August in the Geological Society of America Bulletin (doi:10.1130/B31000.1).

  5. Snail abundance in freshwater canals in the eastern province of ...

    African Journals Online (AJOL)

    The present study aimed to investigate the distribution of three species of freshwater snails, namely; Biomphalaria Arabica; Planorbidae, Lymnaea auricularia; Lymnaeidae and Melanoides tuberculatus; Thiaridae in two different parallel canals (the concrete irrigation and the earthen drainage canals) in the eastern province ...

  6. Researching snails on holiday: An agenda for caravanning and ...

    African Journals Online (AJOL)

    The potential mobility, yet homelike structures, can be said to offer a base of security when staying away. Like snails, caravanners travel taking their domestic space with them, and ... a need for more research on campgrounds and their owners. Keywords: caravanning, caravanners, outdoor hospitality, self-drive tourism ...

  7. Dispersion factors in the arboreal snail Sitala jenynsi (Gastropoda ...

    African Journals Online (AJOL)

    Drastic spatial changes in the morph-frequencies of adjacent populations have been reported in several species of land snails (LzlIllOUe 1959; O\\ven 1965: Clarke 1968: Jones 1973: Cowie 1984a) Explanations of these distributions invoked genetic sampling urin (Goodhart 1963: Hickson 1972), the founder process (Mayr ...

  8. Differences in predatory pressure on terrestrial snails by birds and ...

    Indian Academy of Sciences (India)

    Supplementary table 2. Number of collected individuals of particular morph categories of C. nemoralis and C. hortensis with specification of undamaged and damaged snails. Morph. Total number of individuals. Undamaged individuals. Shells damaged by. Mice. Birds. Mouse + bird. Cepaea nemoralis. 732. 172. 105. 436.

  9. Geographical distribution and habitats of the freshwater snail ...

    African Journals Online (AJOL)

    A brief account is given of the geographical distribution and habitats of Bulinus reticulatus as reflected by the 278 samples currently on record in the database of the National Freshwater Snail Collection, Potchefstroom University. The susceptibility of field specimens and their F1 generation offspring to miracidia of ...

  10. Adsorption of heavy metals on modified snail ( Archachatina ...

    African Journals Online (AJOL)

    Adsorption of heavy metals on modified snail (Archachatina marginata) shell. EU Ikhuoria, C Uyammadu. Abstract. No Abstract Available Ghana J. Sci, Vol.41 2001: 29-33. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/gjs.v41i1.15882.

  11. Differences in predatory pressure on terrestrial snails by birds and ...

    Indian Academy of Sciences (India)

    The evolution of shell polymorphism in terrestrial snails is a classic textbook example of the effect of natural selection in which avian and mammalian predation represents an important selective force on gene frequency. However, many questions about predation remain unclear, especially in the case of mammals.

  12. The role of snail aestivation in transmission of schistosomiasis in ...

    African Journals Online (AJOL)

    Aestivation therefore plays an important role in maintaining the transmission of schistosomiasis. This review assesses the possible impacts of climate change on the temporal and spatial distribution of schistosomiasis-transmitting snails with special emphasis on aestivation, and discusses the effect of schistosome infection ...

  13. Ecology and distribution of gastropod snails of medical and ...

    African Journals Online (AJOL)

    A study on the ecology and distribution of snails of medical importance was conducted in water bodies from four different communities (Old Karmo, Gwagwa, ... The following floras were identified from the study-sites; Megathyrsus maximus, Guinea grass and Commelina nigritana (African dayflower) were identified from the ...

  14. Growth, Age Determination and Longevity in the Giant African Snail ...

    African Journals Online (AJOL)

    Growth rates in terms of shell lengths were investigated in four subspecies of Archachatina marginata (Swainson) under culture conditions. Number of shell whorls, shell pigmentation and microsculpture were also studied to assess their usefulness in age determination. The snails displayed a sigmoid growth pattern, with ...

  15. Spatially-resolved thermoluminescence from snail opercula using an EMCCD

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Kook, Myung Ho; Stirling, R.J.

    2015-01-01

    In recent years opercula of the snail species Bithynia tentaculata have been shown to emit thermoluminescence (TL) signals that can be used to determine equivalent dose, and may be capable of dating events throughout the entire Quaternary period. Concentric growth lines are a notable feature of a...

  16. A snail-eating snake recognizes prey handedness.

    Science.gov (United States)

    Danaisawadi, Patchara; Asami, Takahiro; Ota, Hidetoshi; Sutcharit, Chirasak; Panha, Somsak

    2016-04-05

    Specialized predator-prey interactions can be a driving force for their coevolution. Southeast Asian snail-eating snakes (Pareas) have more teeth on the right mandible and specialize in predation on the clockwise-coiled (dextral) majority in shelled snails by soft-body extraction. Snails have countered the snakes' dextral-predation by recurrent coil reversal, which generates diverse counterclockwise-coiled (sinistral) prey where Pareas snakes live. However, whether the snake predator in turn evolves any response to prey reversal is unknown. We show that Pareas carinatus living with abundant sinistrals avoids approaching or striking at a sinistral that is more difficult and costly to handle than a dextral. Whenever it strikes, however, the snake succeeds in predation by handling dextral and sinistral prey in reverse. In contrast, P. iwasakii with little access to sinistrals on small peripheral islands attempts and frequently misses capturing a given sinistral. Prey-handedness recognition should be advantageous for right-handed snail-eating snakes where frequently encountering sinistrals. Under dextral-predation by Pareas snakes, adaptive fixation of a prey population for a reversal gene instantaneously generates a sinistral species because interchiral mating is rarely possible. The novel warning, instead of sheltering, effect of sinistrality benefitting both predators and prey could further accelerate single-gene ecological speciation by left-right reversal.

  17. Aspects of Water Quality of Freshwater Systems Harbouring Snail ...

    African Journals Online (AJOL)

    A study of some aspects of water quality of freshwater systems harbouring snail vectors of schistosome parasites was conducted in Jos, Nigeria. Calcium ion concentration of the water bodies was a mean value of 31 mg.l-1. The range of temperature was 15 - 30OC. The occurrence of Biomphalaria pferifferi was attributed to ...

  18. Zoonotic helminths in fresh water snail ( Melanoides tuberculata ...

    African Journals Online (AJOL)

    We investigated 3 study sites of rural wetland communities of Ikpa, Ibikpe and Ikot Udo for helminth parasites using water snail Melanoides tuberculata fresh specimens. Parasitological gut examination were significant (p<0.05), and revealed that Ikpa community with 90.90% was hyper-endemic for schistosomiasis, while all ...

  19. Nutritive potentials and utilization of garden snail (Limicolaria aurora ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-16

    Oct 16, 2006 ... The high cost and scarcity of fish meal in formulated feeds has led to the use of other protein sources such as earthworms, insects, snail, mussels, periwinkle, lizard, maggot, frog and plants in fish feeds. (Bonderi and Shepherd, 1981; Tacon et al., 1983;. Guerrero, 1985; Faturoti and Akinbote, 1986; Lim and.

  20. DNA probes for the detection of Fasciola hepatica in snails.

    Science.gov (United States)

    Heussler, V; Kaufmann, H; Strahm, D; Liz, J; Dobbelaere, D

    1993-08-01

    Fasciola hepatica, also called the large liver fluke, is a trematode which can infect most mammals. Monitoring the infection rate of snails, which function as intermediate hosts and harbour larval stages of F. hepatica, is an important component of epidemiological studies on fascioliasis. For this purpose, DNA probes were generated which can be used for the detection of F. hepatica larvae in snails. Four highly repetitive DNA fragments were cloned in a plasmid vector and tested by Southern blot hybridization to the DNA of various trematodes for specificity and sensitivity. The probes Fhr-I, Fhr-II and Fhr-III hybridized only to F. hepatica DNA. Fhr-IV contained ribosomal RNA gene sequences and cross-hybridize with the DNA from various other trematode species. Squash blot analysis showed that the different probes were able to detect the parasite larvae in trematode-infected snails even as isolated single larvae. No signals were obtained in squash blots of uninfected snails. Probes Fhr-I, Fhr-II and Fhr-III are thus useful specific tools for studying the epidemiology of fascioliasis. The probe Fhr-IV, because of its broader spectrum, can be used to detect the larvae of a wide range of trematode species of waterbirds, which are the causative agents of swimmer's itch.

  1. Oxygen consumption and responses of the freshwater snail Bulinus ...

    African Journals Online (AJOL)

    A gradient or choice apparatus, based on the 'fluvarium' principle and suitable for testing the responses of the freshwater snail Bulinus (Physopsis) globosus to different partial oxygen tensions was used. In a gradual oxygen gradient established with this apparatus, B. (P.) globosus shows a significant preference for ...

  2. Food Choice in the Common Snail (Helix Aspersa).

    Science.gov (United States)

    Gill, John; Howell, Pauline

    1985-01-01

    The easily obtained common snail shows interesting dietary preferences which can be the source of several simple experiments. Specific student instructions are given for quantitative and comparative studies using cabbage, lettuce, carrot, rutabaga, and onion. Suggestions for laboratory setup and further work are included. (DH)

  3. Regulation of tentacle length in snails by odor concentration.

    Science.gov (United States)

    Nikitin, E S; Zakharov, I S; Balaban, P M

    2006-01-01

    The upper tentacle of the snail, bearing the olfactory organ, produces complex movements when the snail explores a new environment. Tentacle trajectories were reconstructed in the presence and absence of odors using two simultaneous video recordings. Reconstructions showed that in the absence of odor, snails constantly scanned the surrounding space with the extended tentacles. Presentation of an odor elicited rapid flexion, independent of the odor concentration, accompanied by concentration-dependent tentacle contractions. Activation of identified motoneuron MtC3 is known to elicit tentacle contraction. Recordings made in semi-intact preparations showed that the dynamics and duration of the spike activity of MtC3 produced in response to odors correlated with the degree of tentacle contraction in response to odors. These data suggest that the central motoneuron MtC3, which triggers tentacle contraction, is involved in controlling the margins of the scanning field. Slow contraction or extension of the tentacle, associated with the level of MtC3 activity, may operate to tune the snail's investigative behavior to the conditions of the sensory environment.

  4. Response of Oncomelania snail distribution on land use in Sichuan ...

    African Journals Online (AJOL)

    Response of Oncomelania snail distribution on land use in Sichuan, China. Q Sun, Z Peng, J Zhang, J Jiang. Abstract. Schistosomiasis is one of the four major infectious diseases that require prevention and control in China. It is mainly distributed along the middle and downstream areas of the Yangtze River and some hilly ...

  5. Freshwater snail distribution related to environmental factors in ...

    African Journals Online (AJOL)

    This station which received domestic sewage from the neighbouring cities was characterized by the highest conductivity and pH and the lowest values of dissolved oxygen. Multiple stepwise regression analysis showed that snail densities were probably influenced by conductivity, dissolved oxygen, pH, and canopy cover.

  6. Silencing of CEMIP suppresses Wnt/β-catenin/Snail signaling transduction and inhibits EMT program of colorectal cancer cells.

    Science.gov (United States)

    Liang, Guodong; Fang, Xuedong; Yang, Yubo; Song, Yan

    2018-01-01

    Cell migration inducing hyaluronan binding protein (CEMIP) is a hyaluronic acid binding protein, the abnormal elevation of which is suggested as a contributor in the carcinogenesis of colorectal cancer (CRC). Cancer cells lose their adhesive properties and acquire an enhanced mobility by undergoing epithelial-mesenchymal transition (EMT). This study is performed to investigate whether and how CEMIP orchestrates the EMT process of CRC cells. To avoid the unexpected off-target effects possibly caused by one single shRNA, two shRNAs targeting different mRNA regions of CEMIP gene were used to knock down the mRNA and protein expression of CEMIP. Our data showed that the proliferation, migration and invasion of two CRC cell lines, HCT116 and SW480 cells, were inhibited by CEMIP shRNA. We here defined EMT as the complete or partial loss of E-cadherin and zona occludens protein 1 (ZO-1) (epithelial markers) and the gain of Vimentin and N-cadherin (mesenchymal markers), and found that the EMT process was attenuated in CEMIP-silenced SW480 cells. Snail, a direct target of β-catenin/T cell factor complex, is known to activate the EMT program during cancer metastasis. CEMIP shRNA was further found to suppress the Wnt/β-catenin/Snail signaling transduction in CRC cells as manifested by the decreased nuclear β-catenin and Snail. Collectively, our work demonstrates that CEMIP contributes to metastatic phenotype of CRC cells in vitro. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. Antioxidant and molecular chaperone defences during estivation and arousal in the South American apple snail Pomacea canaliculata.

    Science.gov (United States)

    Giraud-Billoud, Maximiliano; Vega, Israel A; Tosi, Martín E Rinaldi; Abud, María A; Calderón, María L; Castro-Vazquez, Alfredo

    2013-02-15

    The invasive Pomacea canaliculata estivates during periods of drought and should cope with harmful effects of reoxygenation during arousal. We studied thiobarbituric acid reactive substances (TBARS), enzymatic (superoxide dismutase, SOD and catalase, CAT) and non-enzymatic antioxidants (uric acid and reduced glutathione), and heat shock protein expression (Hsc70, Hsp70 and Hsp90) in (1) active control snails, (2) snails after 45 days of estivation, and (3) aroused snails 20 min and (4) 24 h after water exposure, in midgut gland, kidney and foot. Both kidney and foot (but not the midgut gland) showed a TBARS increase during estivation and a decrease after arousal. Tissue SOD and CAT did not change in any experimental groups. Uric acid increased during estivation in all tissues, and it decreased after arousal in the kidney. Allantoin, the oxidation product of uric acid, remained constant in the midgut gland but it decreased in the kidney until 20 min after arousal; however, allantoin levels rose in both kidney and foot 24 h after arousal. Reduced glutathione decreased during estivation and arousal, in both midgut gland and kidney, and it remained constant in the foot. Hsc70 and Hsp70 kidney levels were stable during the activity-estivation cycle and Hsp90 expression decreases during estivation and recovers in the early arousal. In foot, the expression of Hsp70 and Hsp90 was high during activity and estivation periods and disminished after arousal. Results indicate that a panoply of antioxidant and molecular chaperone defences may be involved during the activity-estivation cycle in this freshwater gastropod.

  8. Snail heterogeneity in clear cell renal cell carcinoma.

    Science.gov (United States)

    Zaldumbide, Laura; Erramuzpe, Asier; Guarch, Rosa; Pulido, Rafael; Cortés, Jesús M; López, José I

    2016-03-08

    Intratumor heterogeneity may be responsible of the unpredictable aggressive clinical behavior that some clear cell renal cell carcinomas display. This clinical uncertainty may be caused by insufficient sampling, leaving out of histological analysis foci of high grade tumor areas. Although molecular approaches are providing important information on renal intratumor heterogeneity, a focus on this topic from the practicing pathologist' perspective is still pending. Four distant tumor areas of 40 organ-confined clear cell renal cell carcinomas were selected for histopathological and immunohistochemical evaluation. Tumor size, cell type (clear/granular), Fuhrman's grade, Staging, as well as immunostaining with Snail, ZEB1, Twist, Vimentin, E-cadherin, β-catenin, PTEN, p-Akt, p110α, and SETD2, were analyzed for intratumor heterogeneity using a classification and regression tree algorithm. Cell type and Fuhrman's grade were heterogeneous in 12.5 and 60 % of the tumors, respectively. If cell type was homogeneous (clear cell) then the tumors were low-grade in 88.57 % of cases. Immunostaining heterogeneity was significant in the series and oscillated between 15 % for p110α and 80 % for Snail. When Snail immunostaining was homogeneous the tumor was histologically homogeneous in 100 % of cases. If Snail was heterogeneous, the tumor was heterogeneous in 75 % of the cases. Average tumor diameter was 4.3 cm. Tumors larger than 3.7 cm were heterogeneous for Vimentin immunostaining in 72.5 % of cases. Tumors displaying negative immunostaining for both ZEB1 and Twist were low grade in 100 % of the cases. Intratumor heterogeneity is a common event in clear cell renal cell carcinoma, which can be monitored by immunohistochemistry in routine practice. Snail seems to be particularly useful in the identification of intratumor heterogeneity. The suitability of current sampling protocols in renal cancer is discussed.

  9. Trematode communities in snails can indicate impact and recovery from hurricanes in a tropical coastal lagoon.

    Science.gov (United States)

    Aguirre-Macedo, María Leopoldina; Vidal-Martínez, Victor M; Lafferty, Kevin D

    2011-11-01

    In September 2002, Hurricane Isidore devastated the Yucatán Peninsula, Mexico. To understand its effects on the parasites of aquatic organisms, we analyzed long-term monthly population data of the horn snail Cerithidea pliculosa and its trematode communities in Celestún, Yucatán, Mexico before and after the hurricane (February 2001 to December 2009). Five trematode species occurred in the snail population: Mesostephanus appendiculatoides, Euhaplorchis californiensis, two species of the genus Renicola and one Heterophyidae gen. sp. Because these parasites use snails as first intermediate hosts, fishes as second intermediate hosts and birds as final hosts, their presence in snails depends on food webs. No snails were present at the sampled sites for 6 months after the hurricane. After snails recolonised the site, no trematodes were found in snails until 14 months after the hurricane. It took several years for snail and trematode populations to recover. Our results suggest that the increase in the occurrence of hurricanes predicted due to climate change can impact upon parasites with complex life cycles. However, both the snail populations and their parasite communities eventually reached numbers of individuals and species similar to those before the hurricane. Thus, the trematode parasites of snails can be useful indicators of coastal lagoon ecosystem degradation and recovery. Copyright © 2011 Australian Society for Parasitology Inc. All rights reserved.

  10. Snail recruits Ring1B to mediate transcriptional repression and cell migration in pancreatic cancer cells.

    Science.gov (United States)

    Chen, Jiangzhi; Xu, Hong; Zou, Xiuqun; Wang, Jiamin; Zhu, Yi; Chen, Hao; Shen, Baiyong; Deng, Xiaxing; Zhou, Aiwu; Chin, Y Eugene; Rauscher, Frank J; Peng, Chenghong; Hou, Zhaoyuan

    2014-08-15

    Transcriptional repressor Snail is a master regulator of epithelial-mesenchymal transition (EMT), yet the epigenetic mechanism governing Snail to induce EMT is not well understood. Here, we report that in pancreatic ductal adenocarcinoma (PDAC), elevated levels of the ubiquitin E3 ligase Ring1B and Snail, along with elevated monoubiquitination of H2A at K119 (H2AK119Ub1), are highly correlated with poor survival. Mechanistic investigations identified Ring1B as a Snail-interacting protein and showed that the carboxyl zinc fingers of Snail recruit Ring1B and its paralog Ring1A to repress its target promoters. Simultaneous depletion of Ring1A and Ring1B in pancreatic cancer cells decreased Snail binding to the target chromatin, abolished H2AK119Ub1 modification, and thereby compromised Snail-mediated transcriptional repression and cell migration. We found that Ring1B and the SNAG-associated chromatin modifier EZH2 formed distinct protein complexes with Snail and that EZH2 was required for Snail-Ring1A/B recruitment to the target promoter. Collectively, our results unravel an epigenetic mechanism underlying transcriptional repression by Snail, suggest Ring1A/B as a candidate therapeutic target, and identify H2AK119Ub1 as a potential biomarker for PDAC diagnosis and prognosis. ©2014 American Association for Cancer Research.

  11. The Use of Golden Snail (Pomacea sp. as Animal Feed in the Philippines

    Directory of Open Access Journals (Sweden)

    Serra, AB.

    1997-01-01

    Full Text Available The golden snail is introduced to the Philippines in early 80's for culture as food source. This herbivorous snail, a voracious feeder of live and fresh plant materials become a serious rice pest. Its elimination in the ecosystems is impossible. To use them as animal feed is much better alternative for their control and more environmentally friendly than the use of chemicals. Thus, this mini review paper aimed to collate any existing information on the use of golden snail as animal feed. The different meal forms that can be extracted are golden snail meal (30 % calcium and 15 % crude protein, golden snail meat meal (62 % crude protein and 3336 kcal/kg and golden shell meal (35 % calcium. Feeding trials indicate that golden snail meal can be a part of swine and chicken layer diets up to 15 %. Golden snail meat meal can be a part of broiler chicken diet up to 12 %. Feeding fresh and ground golden snail to ducks can replace 50 % of their diet under total confinement system. Whereas, golden snail meat meal (75 % of the diet plus rice bran can be beneficially fed to tilapia. With the information collated, golden snail can be a promising animal feed in the Philippines.

  12. Tufted Puffins nesting in estuarine habitat

    Science.gov (United States)

    Gill, Robert E.; Sanger, Gerald A.

    1979-01-01

    The Tufted Puffin (Lunda cirrhata) apparently has the most extensive breeding distribution of any North Pacific seabird, extending in the western North Pacific from Hokkaido to the north Chukotsk Peninsula on the Chukchi Sea, and in North America from Cape Lisburne on the Chukchi Sea, south to the Farallon Islands off central California (Udvardy 1963). Despite this wide breeding distribution, the reported nesting habitat is generally restricted to steep, rocky islands and continental headlands (see Dement’ev and Gladkov 1951, Kozlova 1957, Gabrielson and Lincoln 1959, Portenko 1973, Sealy 1973, and Sowls et al. 1978). Nests are typically excavated in steep slopes and/or on vegetated plateaus, well above normal tidal influence but occasionally within the spray or storm-wash zone. Nowhere has L. cirrhata or any other puffin species been reported to nest in a flat, estuarine habitat in substrate normally affected by tides during the breeding season. Portenko (1973: 137) refers to Tufted Puffins breeding on Alyumka Island in the Anadyr "estuary" (64°40'N, 177°37'E), but Alyumka Island is a rocky coastal island having immediate offshore waters between 3-18 m deep (A.A. Kistchinski, The Ringing Center, Moscow, and George Tyner, U.S. Defense Mapping Agency, pers. comm.).During the summers of 1976, 1977, and 1978, we found 14-18 pairs of Tufted Puffins nesting on 4 narrow sand islands (5-7 ha each) along the northcentral Alaska Peninsula at Nelson Lagoon (56°00'N, 161°10'W). As of June 1979, 25 active burrows had been reported there (Margaret R. Petersen, pers. comm.). The islands lie approximately 1.3 km from the Bering Sea coast and are protected from the sea by a long, narrow (0.5 kin) sand peninsula. The main deepwater channel in the lagoon, 3-7 m deep and 100-300 m wide at mean low water (MLW), separates the islands from the peninsula. The islands, which are free of permafrost, have a uniformly low profile with the highest elevation 1-2 m above mean high water

  13. Overexpression of Snail in retinal pigment epithelial triggered epithelial–mesenchymal transition

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui; Li, Min; Xu, Ding; Zhao, Chun; Liu, Guodong; Wang, Fang, E-mail: milwang_122@msn.com

    2014-03-28

    Highlights: • First reported overexpression of Snail in RPE cells could directly trigger EMT. • Further confirmed the regulator role of Snail in RPE cells EMT in vitro. • Snail may be a potential therapeutic target to prevent the fibrosis of PVR. - Abstract: Snail transcription factor has been implicated as an important regulator in epithelial–mesenchymal transition (EMT) during tumourigenesis and fibrogenesis. Our previous work showed that Snail transcription factor was activated in transforming growth factor β1 (TGF-β1) induced EMT in retinal pigment epithelial (RPE) cells and may contribute to the development of retinal fibrotic disease such as proliferative vitreoretinopathy (PVR). However, whether Snail alone has a direct role on retinal pigment epithelial–mesenchymal transition has not been investigated. Here, we analyzed the capacity of Snail to drive EMT in human RPE cells. A vector encoding Snail gene or an empty vector were transfected into human RPE cell lines ARPE-19 respectively. Snail overexpression in ARPE-19 cells resulted in EMT, which was characterized by the expected phenotypic transition from a typical epithelial morphology to mesenchymal spindle-shaped. The expression of epithelial markers E-cadherin and Zona occludin-1 (ZO-1) were down-regulated, whereas mesenchymal markers a-smooth muscle actin (a-SMA) and fibronectin were up-regulated in Snail expression vector transfected cells. In addition, ectopic expression of Snail significantly enhanced ARPE-19 cell motility and migration. The present data suggest that overexpression of Snail in ARPE-19 cells could directly trigger EMT. These results may provide novel insight into understanding the regulator role of Snail in the development of retinal pigment epithelial–mesenchymal transition.

  14. Overexpression of Snail in retinal pigment epithelial triggered epithelial–mesenchymal transition

    International Nuclear Information System (INIS)

    Li, Hui; Li, Min; Xu, Ding; Zhao, Chun; Liu, Guodong; Wang, Fang

    2014-01-01

    Highlights: • First reported overexpression of Snail in RPE cells could directly trigger EMT. • Further confirmed the regulator role of Snail in RPE cells EMT in vitro. • Snail may be a potential therapeutic target to prevent the fibrosis of PVR. - Abstract: Snail transcription factor has been implicated as an important regulator in epithelial–mesenchymal transition (EMT) during tumourigenesis and fibrogenesis. Our previous work showed that Snail transcription factor was activated in transforming growth factor β1 (TGF-β1) induced EMT in retinal pigment epithelial (RPE) cells and may contribute to the development of retinal fibrotic disease such as proliferative vitreoretinopathy (PVR). However, whether Snail alone has a direct role on retinal pigment epithelial–mesenchymal transition has not been investigated. Here, we analyzed the capacity of Snail to drive EMT in human RPE cells. A vector encoding Snail gene or an empty vector were transfected into human RPE cell lines ARPE-19 respectively. Snail overexpression in ARPE-19 cells resulted in EMT, which was characterized by the expected phenotypic transition from a typical epithelial morphology to mesenchymal spindle-shaped. The expression of epithelial markers E-cadherin and Zona occludin-1 (ZO-1) were down-regulated, whereas mesenchymal markers a-smooth muscle actin (a-SMA) and fibronectin were up-regulated in Snail expression vector transfected cells. In addition, ectopic expression of Snail significantly enhanced ARPE-19 cell motility and migration. The present data suggest that overexpression of Snail in ARPE-19 cells could directly trigger EMT. These results may provide novel insight into understanding the regulator role of Snail in the development of retinal pigment epithelial–mesenchymal transition

  15. JNK signaling maintains the mesenchymal properties of multi-drug resistant human epidermoid carcinoma KB cells through snail and twist1

    International Nuclear Information System (INIS)

    Zhan, Xia; Feng, Xiaobing; Kong, Ying; Chen, Yi; Tan, Wenfu

    2013-01-01

    In addition to possess cross drug resistance characteristic, emerging evidences have shown that multiple-drug resistance (MDR) cancer cells exhibit aberrant metastatic capacity when compared to parental cells. In this study, we explored the contribution of c-Jun N-terminal kinases (JNK) signaling to the mesenchymal phenotypes and the aberrant motile capacity of MDR cells utilizing a well characterized MDR cell line KB/VCR, which is established from KB human epidermoid carcinoma cells by vincristine (VCR), and its parental cell line KB. Taking advantage of experimental strategies including pharmacological tool and gene knockdown, we showed here that interference with JNK signaling pathway by targeting JNK1/2 or c-Jun reversed the mesenchymal properties of KB/VCR cells to epithelial phenotypes and suppressed the motile capacity of KB/VCR cells, such as migration and invasion. These observations support a critical role of JNK signaling in maintaining the mesenchymal properties of KB/VCR cells. Furthermore, we observed that JNK signaling may control the expression of both snail and twist1 in KB/VCR cells, indicating that both snail and twist1 are involved in controlling the mesenchymal characteristics of KB/VCR cells by JNK signaling. JNK signaling is required for maintaining the mesenchymal phenotype of KB/VCR cells; and JNK signaling may maintain the mesenchymal characteristics of KB/VCR cells potentially through snail and twist1

  16. Describing shell shape variations and sexual dimorphism of Golden Apple Snail, Pomacea caniculata (Lamarck, 1822 using geometric morphometric analysis

    Directory of Open Access Journals (Sweden)

    C.C. Cabuga

    2017-09-01

    Full Text Available Pomacea caniculata or Golden Apple Snail (GAS existed to be a rice pest in the Philippines and in Asia. Likewise, geographic location also contributes its increasing populations thus making it invasive among freshwater habitats and rice field areas. This study was conducted in order to describe shell shape variations and sexual dimorphism among the populations of P. caniculata. A total of 180 were randomly collected in the three lakes of Esperanza, Agusan del Sur (Lake Dakong Napo, Lake Oro, and Lake Cebulan, of which each lake comprised of 60 samples (30 males and 30 females. To determine the variations and sexual dimorphism in the shell shape of golden apple snail, coordinates was administered to relative warp analysis and the resulting data were subjected to Multivariate Analysis of Variance (MANOVA, Principal Component Analysis (PCA and Canonical Variate Analysis (CVA. The results show statistically significant (P<0.05 from the appended male and female dorsal and ventral/apertural portion. While male and female spire height, body size, and shell shape opening also shows significant variations. These phenotypic distinctions could be associated with geographic isolation, predation and nutrient component of the gastropods. Thus, the importance of using geometric morphometric advances in describing sexual dimorphism in the shell shape of P. caniculata.

  17. Biofouling growth in cold estuarine waters and evaluation of some chitosan and copper anti-fouling paints.

    Science.gov (United States)

    Pelletier, Emilien; Bonnet, Claudie; Lemarchand, Karine

    2009-07-14

    Ecological concerns about antifouling paints containing non-green tin and copper compounds have highlighted the need for environmentally friendly alternatives. We report here a field test conducted in estuarine waters over two months designed to evaluate the efficiency of a number of active natural and man-made chemical ingredients added into a silicon-polyurethane marine paint. Early steps of biofouling in cold seawater of the St. Lawrence Estuary (Canada) were observed. Analyses, including dry biomass, flow cytometry and spectrofluorimetry, demonstrated a short-term antibacterial action of chitosan-based paints although no significant anti-algal action was observed. Cuprous oxide paints were efficient against bacteria and algae invasion in the first two weeks, especially those with added organic biocides such as isothiazolone and copper pyrithione. However, the overall dry biomass and chlorophyll a content were similar for all chitosan-and copper-based paints after 63 days. Microscopic observations revealed variation in the highly diverse benthic diatom population including species Navicula, Melosira, Cocconeis, Nitshzcia, Fragilaria and Amphora. Results suggest no real long-term efficiency for tested antifouling paints and highlight a particular need for green antifouling ingredients that are active under northern estuarine conditions.

  18. Biofouling Growth in Cold Estuarine Waters and Evaluation of Some Chitosan and Copper Anti-Fouling Paints

    Directory of Open Access Journals (Sweden)

    Karine Lemarchand

    2009-07-01

    Full Text Available Ecological concerns about antifouling paints containing non-green tin and copper compounds have highlighted the need for environmentally friendly alternatives. We report here a field test conducted in estuarine waters over two months designed to evaluate the efficiency of a number of active natural and man-made chemical ingredients added into a silicon-polyurethane marine paint. Early steps of biofouling in cold seawater of the St. Lawrence Estuary (Canada were observed. Analyses, including dry biomass, flow cytometry and spectrofluorimetry, demonstrated a short-term antibacterial action of chitosan-based paints although no significant anti-algal action was observed. Cuprous oxide paints were efficient against bacteria and algae invasion in the first two weeks, especially those with added organic biocides such as isothiazolone and copper pyrithione. However, the overall dry biomass and chlorophyll a content were similar for all chitosan- and copper-based paints after 63 days. Microscopic observations revealed variation in the highly diverse benthic diatom population including species Navicula, Melosira, Cocconeis, Nitshzcia, Fragilaria and Amphora. Results suggest no real long-term efficiency for tested antifouling paints and highlight a particular need for green antifouling ingredients that are active under northern estuarine conditions.

  19. Effects of Snail Density on Growth, Reproduction and Survival of Biomphalaria alexandrina Exposed to Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    T. D. Mangal

    2010-01-01

    Full Text Available The effects of snail density on Biomphalaria alexandrina parasitized with Schistosoma mansoni were investigated. Laboratory experiments were used to quantify the impact of high density on snail growth, fecundity, and survival. Density-dependent birth rates of snails were determined to inform mathematical models, which, until now, have assumed a linear relationship between density and fecundity. The experiments show that the rate of egg-laying followed a negative exponential distribution with increasing density and this was significantly affected by exposure to parasitic infection. High density also affected the weight of snails and survival to a greater degree than exposure to parasitic infection. Although snail growth rates were initially constrained by high density, they retained the potential for growth suggesting a reversible density-dependent mechanism. These experimental data can be used to parameterise models and confirm that snail populations are regulated by nonlinear density-dependent mechanisms.

  20. Epithelial-mesenchymal transition, a novel target of sulforaphane via COX-2/MMP2, 9/Snail, ZEB1 and miR-200c/ZEB1 pathways in human bladder cancer cells.

    Science.gov (United States)

    Shan, Yujuan; Zhang, Lanwei; Bao, Yongping; Li, Baolong; He, Canxia; Gao, Mingming; Feng, Xue; Xu, Weili; Zhang, Xiaohong; Wang, Shuran

    2013-06-01

    Metastasis and recurrence of bladder cancer are the main reasons for its poor prognosis and high mortality rates. Because of its biological activity and high metabolic accumulation in urine, sulforaphane, a phytochemical exclusively occurring in cruciferous vegetables, has a powerful and specific potential for preventing bladder cancer. In this paper, sulforaphane is shown to significantly suppress a variety of biochemical pathways including the attachment, invasion, migration and chemotaxis motion in malignant transitional bladder cancer T24 cells. Transfection with cyclooxygenase-2 (COX-2) overexpression plasmid largely abolished inhibition of MMP2/9 expression as well as cell invasive capability by sulforaphane. Moreover, sulforaphane inhibited the epithelial-to-mesenchymal transition (EMT) process which underlies tumor cell invasion and migration mediated by E-cadherin induction through reducing transcriptional repressors, such as ZEB1 and Snail. Under conditions of over-expression of COX-2 and/or MMP2/9, sulforaphane was still able to induce E-cadherin or reduce Snail/ZEB1 expression, suggesting that additional pathways might be involved. Further studies indicated that miR-200c played a role in the regulation of E-cadherin via the ZEB1 repressor but not by the Snail repressor. In conclusion, the EMT and two recognized signaling pathways (COX-2/MMP2,9/ ZEB1, Snail and miR-200c/ZEB1) are all targets for sulforaphane. This study indicated that sulforaphane may possess therapeutic potential in preventing recurrence of human bladder cancer. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Molecular insights into land snail neuropeptides through transcriptome and comparative gene analysis

    OpenAIRE

    Adamson, Kevin J; Wang, Tianfang; Zhao, Min; Bell, Francesca; Kuballa, Anna V; Storey, Kenneth B; Cummins, Scott F

    2015-01-01

    Background Snails belong to the molluscan class Gastropoda, which inhabit land, freshwater and marine environments. Several land snail species, including Theba pisana, are crop pests of major concern, causing extensive damage to agriculture and horticulture. A deeper understanding of their molecular biology is necessary in order to develop methods to manipulate land snail populations. Results The present study used in silico gene data mining of T. pisana tissue transcriptomes to predict 24,92...

  2. Removal of corallivorous snails as a proactive tool for the conservation of acroporid corals

    Directory of Open Access Journals (Sweden)

    Dana E. Williams

    2014-11-01

    Full Text Available Corallivorous snail feeding is a common source of tissue loss for the threatened coral, Acropora palmata, accounting for roughly one-quarter of tissue loss in monitored study plots over seven years. In contrast with larger threats such as bleaching, disease, or storms, corallivory by Coralliophila abbreviata is one of the few direct sources of partial mortality that may be locally managed. We conducted a field experiment to explore the effectiveness and feasibility of snail removal. Long-term monitoring plots on six reefs in the upper Florida Keys were assigned to one of three removal treatments: (1 removal from A. palmata only, (2 removal from all host coral species, or (3 no-removal controls. During the initial removal in June 2011, 436 snails were removed from twelve 150 m2 plots. Snails were removed three additional times during a seven month “removal phase”, then counted at five surveys over the next 19 months to track recolonization. At the conclusion, snails were collected, measured and sexed. Before-After-Control-Impact analysis revealed that both snail abundance and feeding scar prevalence were reduced in removal treatments compared to the control, but there was no difference between removal treatments. Recolonization by snails to baseline abundance is estimated to be 3.7 years and did not differ between removal treatments. Recolonization rate was significantly correlated with baseline snail abundance. Maximum snail size decreased from 47.0 mm to 34.6 mm in the removal treatments. The effort required to remove snails from A. palmata was 30 diver minutes per 150 m2 plot, compared with 51 min to remove snails from all host corals. Since there was no additional benefit observed with removing snails from all host species, removals can be more efficiently focused on only A. palmata colonies and in areas where C. abbreviata abundance is high, to effectively conserve A. palmata in targeted areas.

  3. Removal of corallivorous snails as a proactive tool for the conservation of acroporid corals.

    Science.gov (United States)

    Williams, Dana E; Miller, Margaret W; Bright, Allan J; Cameron, Caitlin M

    2014-01-01

    Corallivorous snail feeding is a common source of tissue loss for the threatened coral, Acropora palmata, accounting for roughly one-quarter of tissue loss in monitored study plots over seven years. In contrast with larger threats such as bleaching, disease, or storms, corallivory by Coralliophila abbreviata is one of the few direct sources of partial mortality that may be locally managed. We conducted a field experiment to explore the effectiveness and feasibility of snail removal. Long-term monitoring plots on six reefs in the upper Florida Keys were assigned to one of three removal treatments: (1) removal from A. palmata only, (2) removal from all host coral species, or (3) no-removal controls. During the initial removal in June 2011, 436 snails were removed from twelve 150 m(2) plots. Snails were removed three additional times during a seven month "removal phase", then counted at five surveys over the next 19 months to track recolonization. At the conclusion, snails were collected, measured and sexed. Before-After-Control-Impact analysis revealed that both snail abundance and feeding scar prevalence were reduced in removal treatments compared to the control, but there was no difference between removal treatments. Recolonization by snails to baseline abundance is estimated to be 3.7 years and did not differ between removal treatments. Recolonization rate was significantly correlated with baseline snail abundance. Maximum snail size decreased from 47.0 mm to 34.6 mm in the removal treatments. The effort required to remove snails from A. palmata was 30 diver minutes per 150 m(2) plot, compared with 51 min to remove snails from all host corals. Since there was no additional benefit observed with removing snails from all host species, removals can be more efficiently focused on only A. palmata colonies and in areas where C. abbreviata abundance is high, to effectively conserve A. palmata in targeted areas.

  4. Creosote compounds in snails obtained from Pensacola Bay, Florida, near an onshore hazardous-waste site

    Science.gov (United States)

    Rostad, C.E.; Pereira, W.E.

    1987-01-01

    Snails, Thais haemostoma, were collected from two areas offshore in Pensacola Bay, Florida, near an onshore hazardous-waste site. Tissue from the snails was extracted to isolate the lipophilic compounds and analyzed by gas chromatography/mass spectrometry. Along with naturally occurring compounds, the snail tissue contained large concentrations of polycyclic aromatic compounds, such as phenanthrene, acridine, dibenzothiophene, dibenzofuran, and benzo[a]pyrene. Many of these compounds were characteristic of creosote contamination associated with the onshore hazardous-waste site.

  5. Current advances on the study of snail-snail interactions, with special emphasis on competition process

    Directory of Open Access Journals (Sweden)

    José Rabelo de Freitas

    1995-04-01

    Full Text Available Field work research on population dynamic of snails from the regions of Belo Horizonte and Lagoa Santa give much information about interactions among two or more species of mollusks: Pomacea haustrum, Biomphalaria glabrata, B. tenagophila, B. straminea and Melanoides tuberculata. Data ranging from two years to several decades ago suggest that the Pampulha reservoir is like a cemetery of B. glabrata and B. straminea, species that coexist for more than 14 years in a small part of a stream, whereas only B. glabrata lives in all the streams of the basin. In the last ten to twenty years B. tenagophila has coexisted with P. haustrum and M. tuberculata in the Serra Verde ponds and in the Pampulha dam. However these species have not settled in any of the brooks, except temporarily. The data suggest that the kind of biotope and the habitat conditions are decisive factors for the permanence of each species in its preferencial biotope. B. glabrata, natural from streams and riverheads, quickly disappears from the reservoirs and ponds where it coexists with other species for a short time, independently of the competitive process. Competition needs to be better studied, since in Central America and Caribean islands this kind of study has favored the biological control of planorbid species.

  6. The Virginia Institute of Marine Science Estuarine Observing System

    Science.gov (United States)

    Friedrichs, C.; Anderson, B.; Brasseur, L.; Brubaker, J.; Moore, K.; Nelson, T.; Reay, W.; Vandever, J.; Wright, D.

    2006-05-01

    The estuarine observing system centered at the Virginia Institute of Marine Science (VIMS) aims to provide real-time and archived data in the Lower Chesapeake Bay to help guide the management of natural resources, enable planning for extreme events, facilitate maritime operations, support military security, and advance science and education. The VIMS observing system consists of a growing network of buoy and platform mounted sensors providing data on water quality, currents, winds and waves. Funding has been provided by the Commonwealth of Virginia, the National Oceanic and Atmospheric Administration, the National Science Foundation, the Office of Naval Research, and the U.S. Coast Guard. This presentation will provide an overview of the VIMS estuarine observing system.

  7. Methodology for impact assessment in the estuarine/marine environment

    International Nuclear Information System (INIS)

    Haven, K.F.

    1975-01-01

    Impacts on the estuarine/marine environment can be assessed in economic terms by tracing the impact flow out of the economic sector through the marine environment and back into the economic sector as changes in natural resource availability. An impact can then be measured by the changes created in the economic sector by changes in resource availability. Primary emphasis is placed on the development of an appropriate ecological model of the estuarine environment for this purpose. Two types, an ecological input/output model and a dynamic (difference equation) model, are proposed. Acceptability criteria for these models include the ability to track lethal and sublethal, direct and indirect (food web), and short- and long-term effects of a variety of pollutants related to the production and use of various energy resources

  8. Marine and estuarine natural microbial biofilms: ecological and biogeochemical dimensions

    Directory of Open Access Journals (Sweden)

    O. Roger Anderson

    2016-08-01

    Full Text Available Marine and estuarine microbial biofilms are ubiquitously distributed worldwide and are increasingly of interest in basic and applied sciences because of their unique structural and functional features that make them remarkably different from the biota in the plankton. This is a review of some current scientific knowledge of naturally occurring microbial marine and estuarine biofilms including prokaryotic and microeukaryotic biota, but excluding research specifically on engineering and applied aspects of biofilms such as biofouling. Because the microbial communities including bacteria and protists are integral to the fundamental ecological and biogeochemical processes that support biofilm communities, particular attention is given to the structural and ecological aspects of microbial biofilm formation, succession, and maturation, as well as the dynamics of the interactions of the microbiota in biofilms. The intent is to highlight current state of scientific knowledge and possible avenues of future productive research, especially focusing on the ecological and biogeochemical dimensions.

  9. Coastal and estuarine resources of Bangladesh: management and conservation issues

    Directory of Open Access Journals (Sweden)

    Abu Hena M. Kamal

    2009-07-01

    Full Text Available The coastal area of Bangladesh includes a number of bays into which different types of rivers empty, creating an estuarine ecosystem adjacent to the shore. The main estuarine systems are Brahmaputra-Megna (Gangetic delta, Karnaphuly, Matamuhuri, Bakkhali and Naf rivers, which are comprised of mangroves, salt marshes, seagrass, seaweeds, fisheries, coastal birds, animals, coral reefs, deltas, salt beds, minerals and sand dunes. The estuarine environment, which serves as feeding, breeding and nursery grounds for a variety of animals, varies according to the volume of discharge of the river and tidal range. It is highly productive in terms of nutrient input from different sources that promotes other living resources in the estuaries. Drought conditions exist during the winter months, i.e. November to February, and effective rainfall is confined to the monsoon period, i.e. May to June. Changes in salinity and turbidity depend on annual rainfall. The colour of most estuarine waters is tea brown or brown due to heavy outflows during the monsoon. The tidal mixing and riverine discharge governs the distribution of the hydrological parameters. The pH of these waters is reported to be slightly alkaline (>7.66 and dissolved oxygen (<6.0 mg/l shows an inverse relationship to temperature. Studies of plankton have indicated two periods of maximum abundance, i.e. February-March and August-September. The abundance of fish and shrimp larvae varies in number and composition with season. Many marine and freshwater species are available in various types of coastal brackish water, which depend on monsoonal activities and local environmental conditions.

  10. Defense Coastal/Estuarine Research Program (DCERP1)

    Science.gov (United States)

    2013-05-10

    Davenport. 2006. The impact of tourism and personal leisure transport on coastal environments: A review. Estuarine, Coastal and Shelf Science 67:280–292... volunteers during high-use periods (on weekends and especially during holiday weekends) for educational outreach and to monitor critical foraging areas might...could be implemented that might be more effective. For example, interns or volunteers could be used during high-use periods (i.e., on summer weekends

  11. Paradigms in the Recovery of Estuarine and Coastal Ecosystems

    OpenAIRE

    Duarte, Carlos M.; Borja, Ángel; Carstensen, Jacob; Elliott, Michael S.; Krause-Jensen, Dorte; Marbà, Núria

    2015-01-01

    © 2013, Coastal and Estuarine Research Federation. Following widespread deterioration of coastal ecosystems since the 1960s, current environmental policies demand ecosystem recovery and restoration. However, vague definitions of recovery and untested recovery paradigms complicate efficient stewardship of coastal ecosystems. We critically examine definitions of recovery and identify and test the implicit paradigms against well-documented cases studies based on a literature review. The study hi...

  12. Diet quality affects chemical tolerance in the freshwater snail Lymnaea stagnalis.

    Science.gov (United States)

    Fidder, Bridgette N; Reátegui-Zirena, Evelyn G; Salice, Christopher J

    2017-12-20

    Organisms generally select high-quality diets to obtain maximal energy while devoting the least amount of time and energy. Diets, however, can vary in natural systems. In ecotoxicological testing, the effect of diet type on organismal responses to toxicants has not been explored despite the potential for dietary effects to influence toxicological endpoints. We first evaluated diet quality using growth rate and sensitivity to the fungicide pyraclostrobin of Lymnaea stagnalis fed lettuce (common laboratory diet), turtle pellets (high nutrient composition), and a combination diet of both food items. We also measured the macronutrient content of snails raised on the multiple diets to determine how diet may have impacted energy allocation patterns. Finally, we evaluated whether snails discernibly preferred a particular diet. Snails fed high-nutrient and combination diets grew larger overall than snails fed a lettuce-only diet. Snails fed the high-nutrient and combination diets, both juvenile and adult, were significantly more tolerant to pyraclostrobin than snails fed lettuce. When measured for macronutrient content, snails raised on high-nutrient and combination diets had significantly higher carbohydrate content than snails fed lettuce. Despite the strong effects of diet type, snails did not exhibit a clear diet choice in preference trials. Dietary composition clearly influences growth rate, sensitivity, and macronutrient content of Lymnaea stagnalis. These results suggest that the nutritional environment has potentially strong impacts on toxicant sensitivity. Environ Toxicol Chem 2018;9999:1-10. © 2017 SETAC. © 2017 SETAC.

  13. Activity of the mangrove snail Cerithidea decollata (Gastropoda: Potamididae) in a warm temperate South African estuary

    Science.gov (United States)

    Hodgson, Alan N.; Dickens, John

    2012-08-01

    A population of Cerithidea decollata, an intertidal marine gastropod usually found within mangroves, was studied within an area of Juncus kraussii in the upper reaches of the warm temperate Knysna estuary, which is at the southern-most limit of the recorded distribution of this snail. Activity (migratory and homing behaviour, distances travelled during foraging) of the snails was monitored over spring and neap tides in four seasons. Migratory patterns of the snails were affected by season, time of low tide (day vs night), tidal magnitude (spring vs neap) and zonation. In the summer and spring, a greater proportion of snails migrated from J. kraussii leaves onto the mud during the day at spring low tide. During neap tides in these two seasons, most snails did not climb J. kraussii leaves and remained on the mud, which was nearly always exposed. In autumn a few snails only were active and in winter snails were almost completely inactive, probably due to low air temperatures. Snails travelled greater distances on the mud on spring tides, during the diurnal low tides, and in the summer. No snails were found to home to individual J. kraussii leaves; however, homing behaviour was recorded to wooden poles within the Juncus wetland.

  14. Fasciola hepatica in snails collected from water-dropwort fields using PCR.

    Science.gov (United States)

    Kim, Hwang-Yong; Choi, In-Wook; Kim, Yeon-Rok; Quan, Juan-Hua; Ismail, Hassan Ahmed Hassan Ahmed; Cha, Guang-Ho; Hong, Sung-Jong; Lee, Young-Ha

    2014-12-01

    Fasciola hepatica is a trematode that causes zoonosis mainly in cattle and sheep and occasionally in humans. Fascioliasis has been reported in Korea; however, determining F. hepatica infection in snails has not been done recently. Thus, using PCR, we evaluated the prevalence of F. hepatica infection in snails at 4 large water-dropwort fields. Among 349 examined snails, F. hepatica-specific internal transcribed space 1 (ITS-1) and/or ITS-2 markers were detected in 12 snails and confirmed using sequence analysis. Morphologically, 213 of 349 collected snails were dextral shelled, which is the same aperture as the lymnaeid snail, the vectorial host for F. hepatica. Among the 12 F. hepatica-infected snails, 6 were known first intermediate hosts in Korea (Lymnaea viridis and L. ollula) and the remaining 6 (Lymnaea sp.) were potentially a new first intermediate host in Korea. It has been shown that the overall prevalence of the snails contaminated with F. hepatica in water-dropwort fields was 3.4%; however, the prevalence varied among the fields. This is the first study to estimate the prevalence of F. hepatica infection using the vectorial capacity of the snails in Korea.

  15. Copper uptake and depuration by juvenile and adult Florida apple snails (Pomacea paludosa).

    Science.gov (United States)

    Hoang, Tham C; Rogevich, Emily C; Rand, Gary M; Frakes, Robert A

    2008-10-01

    The present study characterized copper (Cu) uptake and depuration by juvenile and adult Florida apple snails (Pomacea paludosa) from water, soil, and diet. During a 28-day uptake period, juvenile apple snails were exposed to aqueous Cu and adult apple snails were exposed to Cu-contaminated soil, water, and food. In the follow-up 14-day depuration period, both juvenile and adult apple snails were held in laboratory freshwater with background Cu concentrations<4 microg/l. For juvenile apple snails, whole body Cu concentrations increased with time and reached a plateau after 14 days. The data followed Michaelis-Menten kinetics rather than a one compartment first order kinetics model. The mean Cu bioconcentration factor (BCF) for juvenile apple snails was 1493 and the depuration half-life was 10.5-13.8 days. For adult snails, dietary uptake of Cu resulted in higher bioaccumulation factors (BAFs) compared to uptake from soil. Most of the accumulated Cu was located in soft tissue (about 60% in the viscera and 40% in the foot). The shell contained <1% of the total accumulated copper. Soft tissue is usually consumed by predators of the apple snail. Therefore, the results of the present study show that Cu transfer through the food chain to the apple snail may lead to potential risk to its predators.

  16. Trace metallic elements in Helix aspersa terrestrial snails of a semiarid ecosystem

    International Nuclear Information System (INIS)

    Gaso P, M.I.; Segovia, N.; Zarazua, G.; Montes, F.; Morton, O.; Armienta, M.A.; Hernandez, E.

    2001-01-01

    The concentration of some major elements and traces in soil samples and of Helix aspersa eatable terrestrial snails were analysed at the Radioactive Wastes Storage Center (CADER) and in other reference sites. The methodology includes the use of an atomic absorption spectrophotometer, an X-ray fluorescence equipment and an Icp-mass spectroscope. The concentrations of some toxic elements (Ba, Cd, Cr, Ni, Pb and V) in the soft tissue of the snails were greater than the toxic levels reported in the literature for such trace elements. The snails compared with another wild eatable foods present transfer coefficients soil-snail high relatively. (Author)

  17. Effect of thermal shock on developmental stages of estuarine fish. Final report

    International Nuclear Information System (INIS)

    Dean, J.M.

    1978-12-01

    Physiological data and ecological data show that the few estuarine spawners have a higher thermal tolerance in the embryonic and larval stages than do the freshwater, coastal, or oceanic spawning species. However, since all three groups (freshwater, estuarine, and oceanic spawners) occupy the estuary and coastal waters at different times of the year, knowledge of their physiology and ecology at different developmental or life cycle stages is critical for estuarine management decisions

  18. Invasive Marine and Estuarine Animals of the South Atlantic and Puerto Rico

    Science.gov (United States)

    2005-09-01

    1 7 13 Gastropods 8 4 10 Nudibranchs 2 2 4 Copepods 2 1 1 1 2 Barnacles 2 1 1 3 4...Lionfish bear poisonous dorsal, anal, and pelvic spines. The toxin is painful , but is generally not fatal. It was first noticed in Florida waters in 1994...and establishment of an invading predatory gastropod on the North American Atlantic coast,” Biological Bulletin 204, 96-103. McDermott, J. J. (1991

  19. MODULATION OF DEFENSIVE REFLEX CONDITIONING IN SNAILS BY SEROTONIN

    Directory of Open Access Journals (Sweden)

    Vyatcheslav V Andrianov

    2015-10-01

    Full Text Available We studied the role of serotonin in the mechanisms of learning in terrestrial snails. To produce a serotonin deficit, the neurotoxic analogues of serotonin, 5,6- or 5,7-dihydroxytryptamine (5,6/5,7-DHT were used. Injection of 5,6/5,7-DHT was found to disrupt defensive reflex conditioning. Within two weeks of neurotoxin application, the ability to learn had recovered. Daily injection of serotonin before a training session accelerated defensive reflex conditioning and daily injections of 5-HTP in snails with a deficiency of serotonin induced by 5,7-DHT restored the snail’s ability to learn. We discovered that injections of the neurotoxins 5,6/5,7-DHT as well as serotonin, caused a decrease in the resting and threshold potentials of the premotor interneurons LPa3 and RPa3.

  20. Managing bay and estuarine ecosystems for multiple services

    Science.gov (United States)

    Needles, Lisa A.; Lester, Sarah E.; Ambrose, Richard; Andren, Anders; Beyeler, Marc; Connor, Michael S.; Eckman, James E.; Costa-Pierce, Barry A.; Gaines, Steven D.; Lafferty, Kevin D.; Lenihan, Junter S.; Parrish, Julia; Peterson, Mark S.; Scaroni, Amy E.; Weis, Judith S.; Wendt, Dean E.

    2013-01-01

    Managers are moving from a model of managing individual sectors, human activities, or ecosystem services to an ecosystem-based management (EBM) approach which attempts to balance the range of services provided by ecosystems. Applying EBM is often difficult due to inherent tradeoffs in managing for different services. This challenge particularly holds for estuarine systems, which have been heavily altered in most regions and are often subject to intense management interventions. Estuarine managers can often choose among a range of management tactics to enhance a particular service; although some management actions will result in strong tradeoffs, others may enhance multiple services simultaneously. Management of estuarine ecosystems could be improved by distinguishing between optimal management actions for enhancing multiple services and those that have severe tradeoffs. This requires a framework that evaluates tradeoff scenarios and identifies management actions likely to benefit multiple services. We created a management action-services matrix as a first step towards assessing tradeoffs and providing managers with a decision support tool. We found that management actions that restored or enhanced natural vegetation (e.g., salt marsh and mangroves) and some shellfish (particularly oysters and oyster reef habitat) benefited multiple services. In contrast, management actions such as desalination, salt pond creation, sand mining, and large container shipping had large net negative effects on several of the other services considered in the matrix. Our framework provides resource managers a simple way to inform EBM decisions and can also be used as a first step in more sophisticated approaches that model service delivery.

  1. Progress and challenges in coupled hydrodynamic-ecological estuarine modeling.

    Science.gov (United States)

    Ganju, Neil K; Brush, Mark J; Rashleigh, Brenda; Aretxabaleta, Alfredo L; Del Barrio, Pilar; Grear, Jason S; Harris, Lora A; Lake, Samuel J; McCardell, Grant; O'Donnell, James; Ralston, David K; Signell, Richard P; Testa, Jeremy M; Vaudrey, Jamie M P

    2016-03-01

    Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear, because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a "theory of everything" for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.

  2. Nutritive potentials and utilization of garden snail (Limicolaria aurora ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-16

    Oct 16, 2006 ... in formulated feeds has led to the use of other protein sources such as earthworms, insects, snail, ... plastic tanks of fifty litres capacity were used for the trials, carried out in the Fish Nutrition Laboratory of the ... They were acclimatized for one week in aerated plastic holding tanks of 2.0 m x 0.5 m x 0.4 m in ...

  3. The Non-Linear Flow Properties of Snail Mucus

    OpenAIRE

    Clasen, Christian; Kulicke, W.-M.

    2006-01-01

    Biopolymers in aqueous solution have a wide range of applications as their highly tailored designs lead to sophisticated material properties [1] for the daily fight of survival. Snails employ a unique combination of polysaccharides and proteins to produce a mucus with material properties that allow for the stunning capability to crawl on vertical walls or even overhead without loosing contact to the surface. In this paper we present rheological investigations [2] of the material properties of...

  4. The maintenance of hybrids by parasitism in a freshwater snail.

    Science.gov (United States)

    Guttel, Yonathan; Ben-Ami, Frida

    2014-11-01

    Hybrids have often been labelled evolutionary dead-ends due to their lower fertility and viability. However, there is growing awareness that hybridisation between different species may play a constructive role in animal evolution as a means to create variability. Thus, hybridisation and introgression may contribute to adaptive evolution, for example with regards to natural antagonists (parasites, predators, competitors) and adaptation to local environmental conditions. Here we investigated whether parasite intensity contributes to the continuous recreation of hybrids in 74 natural populations of Melanopsis, a complex of freshwater snails with three species. We also examined, under laboratory conditions, whether hybrids and their parental taxa differ in their tolerance of low and high temperatures and salinity levels. Infections were consistently less prevalent in males than in females, and lower in snails from deeper habitats. Infection prevalence in hybrids was significantly lower than in the parental taxa. Low hybrid infection rates could not be explained by sediment type, snail density or geographic distribution of the sampling sites. Interestingly, infected hybrid snails did not show signs of parasite-induced gigantism, whereas all parental taxa did. We found that hybrids mostly coped with extreme temperatures and salinity levels as well as their parental taxa did. Taken together, our results suggest that Melanopsis hybrids perform better in the presence of parasites and environmental stress. This may explain the widespread and long-term occurrence of Melanopsis hybrids as evidenced by paleontological and biogeographic data. Hybridisation may be an adaptive host strategy, reducing infection rates and resisting gigantism. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  5. Snail mediates crosstalk between TGFβ and LXRα in hepatocellular carcinoma.

    Science.gov (United States)

    Bellomo, Claudia; Caja, Laia; Fabregat, Isabel; Mikulits, Wolfgang; Kardassis, Dimitris; Heldin, Carl-Henrik; Moustakas, Aristidis

    2017-12-11

    Understanding the complexity of changes in differentiation and cell survival in hepatocellular carcinoma (HCC) is essential for the design of new diagnostic tools and therapeutic modalities. In this context, we have analyzed the crosstalk between transforming growth factor β (TGFβ) and liver X receptor α (LXRα) pathways. TGFβ is known to promote cytostatic and pro-apoptotic responses in HCC, and to facilitate mesenchymal differentiation. We here demonstrate that stimulation of the nuclear LXRα receptor system by physiological and clinically useful agonists controls the HCC response to TGFβ. Specifically, LXRα activation antagonizes the mesenchymal, reactive oxygen species and pro-apoptotic responses to TGFβ and the mesenchymal transcription factor Snail mediates this crosstalk. In contrast, LXRα activation and TGFβ cooperate in enforcing cytostasis in HCC, which preserves their epithelial features. LXRα influences Snail expression transcriptionally, acting on the Snail promoter. These findings propose that clinically used LXR agonists may find further application to the treatment of aggressive, mesenchymal HCCs, whose progression is chronically dependent on autocrine or paracrine TGFβ.

  6. Phenoloxidase activity of Helix aspersa maxima (garden snail, gastropod) hemocyanin.

    Science.gov (United States)

    Raynova, Yuliana; Doumanova, Lyuba; Idakieva, Krassimira Nikolova

    2013-12-01

    The oxygen-transporting protein, hemocyanin (Hc), of the garden snail Helix aspersa maxima (HaH) was isolated and kinetically characterized. Kinetic parameters of the reaction of catalytic oxidation of catechol to quinone, catalyzed by native HaH were determined: the V max value amounted to 22 nmol min(-1) mg(-1), k cat to 1.1 min(-1). Data were compared to those reported for other molluscan Hcs and phenoloxidases (POs). The o-diphenoloxidase activity of the native HaH is about five times higher than the activity determined for the Hcs of the terrestrial snail Helix pomatia and of the marine snail Rapana thomasiana (k cat values of 0.22 and 0.25 min(-1), respectively). The K m values obtained for molluscan Hcs from different species are comparable to those for true POs, but the low catalytic efficiency of Hcs is probably related to inaccessibility of the active sites to potential substrates. Upon treatment of HaH with subtilisin DY, the enzyme activity against substrate catechol was considerably increased. The relatively high proteolytically induced o-diPO activity of HaH allowed using it for preparation of a biosensor for detection of catechol.

  7. Impact of cigarette butt leachate on tidepool snails.

    Science.gov (United States)

    Booth, David J; Gribben, Paul; Parkinson, Kerryn

    2015-06-15

    In urban areas, cigarette butts are the most common discarded refuse articles. In marine intertidal zones, they often fall into tidepools. We tested how common intertidal molluscs were affected by butt leachate in a laboratory experiment, where snails were exposed to various leachate concentrations. Mortality was very high, with all species showing 100% mortality at the full leachate concentration (5 butts per litre and 2h soak time) after 8days. However, Austrocochlea porcata showed higher mortality than the other 2 species at lower concentrations (10%, 25%) which may affect the relative abundance of the 3 snails under different concentrations of leachate pollution. Also, sublethal effects of leachate on snail activity were observed, with greater activity of Nerita atramentosa than the other 2 species at higher concentrations, suggesting it is more resilient than the other 2 species. While human health concerns predominate with respect to smoking, we show strong lethal and sublethal (via behavioural modifications) impacts of discarded butts on intertidal organisms, with even closely-related taxa responding differently. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Antimicrobial properties of terrestrial snail and slug mucus.

    Science.gov (United States)

    Cilia, Giovanni; Fratini, Filippo

    2018-03-27

    Snail and slug mucus is a viscous-elastic substance secreted by specific glands with adhesive and lubricants properties that allows them to adhere tenaciously to many different surfaces. It has been used since ancient times for care and human health and it is still very important in traditional and folkloristic medicine. Recently, mucus from snail and slugs and its protein and components have been subjected to some investigations on their antibacterial, antiviral and antifungal activity due to extensive traditional uses and for a future application in medicine. Antimicrobial activities of crude mucus, and its components, against different microorganism have been reported, showing antimicrobial activities that lead their potential employment in several fields as natural additives. The purpose of this Review is to summarize the results of antimicrobial studies of snail and slug mucus and its compounds from the first scientific applications to the isolation of the single components in order to better understand its application and propose an employment in future studies as a natural antimicrobial agent.

  9. Impact of the age of Biomphalaria alexandrina snails on Schistosoma mansoni transmission: modulation of the genetic outcome and the internal defence system of the snail

    Directory of Open Access Journals (Sweden)

    Iman Fathy Abou-El-Naga

    2015-08-01

    Full Text Available Of the approximately 34 identified Biomphalariaspecies,Biomphalaria alexandrinarepresents the intermediate host of Schistosoma mansoniin Egypt. Using parasitological and SOD1 enzyme assay, this study aimed to elucidate the impact of the age of B. alexandrinasnails on their genetic variability and internal defence against S. mansoniinfection. Susceptible and resistant snails were reared individually for self-reproduction; four subgroups of their progeny were used in experiment. The young susceptible subgroup showed the highest infection rate, the shortest pre-patent period, the highest total cercarial production, the highest mortality rate and the lowest SOD1 activity. Among the young and adult susceptible subgroups, 8% and 26% were found to be resistant, indicating the inheritance of resistance alleles from parents. The adult resistant subgroup, however, contained only resistant snails and showed the highest enzyme activity. The complex interaction between snail age, genetic background and internal defence resulted in great variability in compatibility patterns, with the highest significant difference between young susceptible and adult resistant snails. The results demonstrate that resistance alleles function to a greater degree in adults, with higher SOD1 activity and provide potential implications for Biomphalariacontrol. The identification of the most susceptible snail age enables determination of the best timing for applying molluscicides. Moreover, adult resistant snails could be beneficial in biological snail control.

  10. THE BIOCIDE TRIBUTYLTIN REDUCES THE ACCUMULATION OF TESTOSTERONE AS FATTY ACID ESTERS IN THE MUD SNAIL (ILYANASSA OBSOLETA)

    Science.gov (United States)

    Imposex, the development of male sex characteristics by female gonochoristic snails, has been documented globally and is causally associated with exposure to the ubiquitous environmental contaminant tributyltin (TBT). Elevated testosterone levels in snails also are associated wit...

  11. Immunological and physiological parameters of Biomphalaria alexandrina snails exposed to Azadirachta indica plant.

    Science.gov (United States)

    Bakry, F A; El-Hommossany, K; Mossalem, H S

    2012-07-01

    Plant molluscicides could be appropriate for snail control measures against schistosomiasis in endemic areas. The present study was undertaken to evaluate the immunological and physiological responses of Biomphalaria (B.) alexandrina snails to the effect of methanol extract of Azadirachta (A.) indica plant. Haemolymph samples were collected from snails treated with LC25 from methanol extract for 1 month and untreated snails. The collected haemolymph samples from treated and untreated snails with tested plant were used for flow cytometric analysis of cell cycle. The obtained results indicated that hemolymph samples from B. alexandrina snails contained two morphologically distinct types of hemocytes, designated as Hyalinocyte and Granulocyte cells. In addition, the number of both snail's hyalinocytes and granulocytes and the mortality rate was significantly increased with treatment with A. indica extract. Phagocytosis in group treated with tested plant was highly significant increased than control one indicating a highly increase response of snail against the treatment. The lipid peroxide and glucose levels in hemolymph of treated snails were elevated while the protein and glycogen contents showed a decrease in soft tissues when compared with the control group. In addition, the activity level of some enzymes representing glycolytic enzymes as hexokinase (HK), pyruvate kinase (PK), phosphofructokinase (PFK), lactate dehydrogenase (LDH),and glucose phosphate isomerase (GPI); glycogenolytic enzymes as glycogen phosphorylase, glucose-6-phosphatase (G-6-Pase); gluconeogenic enzymes as fructose-1-6 diphosphatase (F-D-P ase), phosphoenolpyruvate carboxykinase (PEPCK) was also significantly reduced in response to treatment. It was concluded that the application of methanol extracts of A. indica plant may be helpful in snail control as it interferes with the snails'immunology and physiology.

  12. Characteristics of snail farming in Edo South Agricultural Zone of Edo State, Nigeria.

    Science.gov (United States)

    Chah, Jane Mbolle; Inegbedion, Grace

    2013-02-01

    The study was carried out to determine the characteristics of snail farming in Edo South Agricultural Zone of Edo State Nigeria. The interview schedule was used to collect data from 60 snail farmers randomly selected from six cells in the study area. Information on the socioeconomic status of the farmers, production system, management practices and production constraints in the snail farms were elicited. The constraints were determined using a four-point Likert-type scale; a mean score of ≥ 2.5 was considered as a production constraint. Majority (85.0 %) of the respondents were part-time snail farmers. The major species of snails reared were Achatina achatina and Archachatina marginata, reared by 43.3 and 26.7 % of the farmers, respectively. Semi-intensive system of production was practised by 40.0 % of the farmers. Majority (78.0 %) of the respondents used car tyres to house their snails. About 56 % of the respondents kept their snails for 1-2 years before sale. Up to 51.7 % of the respondents separated their snails into different pens according to their size/age. The most commonly used feeds were vegetables (71.2 %), plant leaves (67.8 %) and kitchen waste (59.3 %). Records of snail production activities were kept by 75.0 % of respondents. The major constraints identified were lack of capital (3.31), inability to get good laying stock (3.00), lack of formulated feed to buy (2.98) and slow growth rate of snails (2.52). The potentials of snail farming in the study area have not been fully exploited as farmers produced at subsistence level.

  13. North Inlet-Winyah Bay National Estuarine Research Reserve’s (NERR) Estuarine Surface Water Nutrient, Suspended Sediment, and Chlorophyll a Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 2002-2004

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — National Estuarine Research Reserve System The National Estuarine Research Reserve System was established by the Coastal Zone Management Act of 1972 (as amended) and...

  14. Ambrosia artemisiifolia as a potential resource for management of golden apple snails, Pomacea canaliculata (Lamarck).

    Science.gov (United States)

    Ding, Wenbing; Huang, Rui; Zhou, Zhongshi; He, Hualiang; Li, Youzhi

    2018-04-01

    Ambrosia artemisiifolia, an invasive weed in Europe and Asia, is highly toxic to the golden apple snail (GAS; Pomacea canaliculata) in laboratory tests. However, little is known about the chemical components of A. artemisiifolia associated with the molluscicidal activity or about its potential application for GAS control in rice fields. This study evaluated the molluscicidal activities of powders, methanol extracts, and individual compounds from A. artemisiifolia against GAS in rice fields and under laboratory conditions. Ambrosia artemisiifolia powders did not negatively affect the growth and development of rice but they reduced damage to rice caused by GAS. Extracts had moderate acute toxicity but potent chronic toxicity. The 24-h 50% lethal concentration (LC 50 ) of the extracts against GAS was 194.0 mg L -1 , while the weights, lengths and widths of GAS were significantly affected by exposure to a sublethal concentration (100 mg/mL). Psilostachyin, psilostachyin B, and axillaxin were identified as the most active molluscicide components in the aerial parts of A. artemisiifolia, and the 24-h LC 50 values of these purified compounds were 15.9, 27.0, and 97.0 mg/L, respectively. The results indicate that chemical compounds produced by A. artemisiifolia may be useful for population management of GAS in rice fields. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Mortality estimate of Chinese mystery snail, Bellamya chinensis (Reeve, 1863) in a Nebraska reservoir

    Science.gov (United States)

    Haak, Danielle M.; Chaine, Noelle M.; Stephen, Bruce J.; Wong, Alec; Allen, Craig R.

    2013-01-01

    The Chinese mystery snail (Bellamya chinensis) is an aquatic invasive species found throughout the USA. Little is known about this species’ life history or ecology, and only one population estimate has been published, for Wild Plum Lake in southeast Nebraska. A recent die-off event occurred at this same reservoir and we present a mortality estimate for this B. chinensis population using a quadrat approach. Assuming uniform distribution throughout the newly-exposed lake bed (20,900 m2), we estimate 42,845 individuals died during this event, amounting to approximately 17% of the previously-estimated population size of 253,570. Assuming uniform distribution throughout all previously-reported available habitat (48,525 m2), we estimate 99,476 individuals died, comprising 39% of the previously-reported adult population. The die-off occurred during an extreme drought event, which was coincident with abnormally hot weather. However, the exact reason of the die-off is still unclear. More monitoring of the population dynamics of B. chinensis is necessary to further our understanding of this species’ ecology.

  16. Development and Evaluation of Poly Herbal Molluscicidal Extracts for Control of Apple Snail (Pomacea maculata

    Directory of Open Access Journals (Sweden)

    Guruswamy Prabhakaran

    2017-03-01

    Full Text Available Golden Apple Snail (GAS is the most destructive invasive rice pest in Southeast Asia. The cost of synthetic molluscicides, their toxicity to non-target organisms, and their persistence in the environment have propelled the research of plant-derived molluscicides. Most research efforts have focused on individual plant extracts for their molluscicidal potency against GAS and have not been proven to be entirely effective in rice field conditions. Selective combination of synergistically acting molluscicidal compounds from various plant extracts might be an effective alternative. In this direction, ethanolic extracts from six different plants (Neem, Tobacco, Nerium, Pongamia, Zinger, and Piper were evaluated against Pomacea maculata Perry. Of the various combinations studied, a binary extract (1:1 of nerium and tobacco (LC90 177.71 mg/L, 48 h, and two tri-herbal extract formulations (1:1:1 of (nerium + tobacco + piper and (nerium + tobacco + neem were found to be most effective, with LC90 values of 180.35 mg/L and 191.52 mg/L, respectively, in laboratory conditions. The synergistic effect of combined herbal extracts resulted in significant reduction in LC90 values of the individual extracts. The findings of this study demonstrate that the selective combinations of potent molluscicidal herbal extracts are effective for management of P. maculata under laboratory conditions.

  17. Trichobilharzia ocellata: influence of infection on the fecundity of its intermediate snail host Lymnaea stagnalis and cercarial induction of the release of schistosomin, a snail neuropeptide antagonizing female gonadotropic hormones

    NARCIS (Netherlands)

    Schallig, H. D.; Sassen, M. J.; Hordijk, P. L.; de Jong-Brink, M.

    1991-01-01

    Subadult and adult specimens of the pond snail Lymnaea stagnalis were infected with the schistosome Trichobilharzia ocellata. Egg production and growth of the snails were monitored over an 8-week period post-infection (p.i.). Snail haemolymph was collected and analysed for the presence of

  18. Perspectives on land snails - sampling strategies for isotopic analyses

    Science.gov (United States)

    Kwiecien, Ola; Kalinowski, Annika; Kamp, Jessica; Pellmann, Anna

    2017-04-01

    Since the seminal works of Goodfriend (1992), several substantial studies confirmed a relation between the isotopic composition of land snail shells (d18O, d13C) and environmental parameters like precipitation amount, moisture source, temperature and vegetation type. This relation, however, is not straightforward and site dependent. The choice of sampling strategy (discrete or bulk sampling) and cleaning procedure (several methods can be used, but comparison of their effects in an individual shell has yet not been achieved) further complicate the shell analysis. The advantage of using snail shells as environmental archive lies in the snails' limited mobility, and therefore an intrinsic aptitude of recording local and site-specific conditions. Also, snail shells are often found at dated archaeological sites. An obvious drawback is that shell assemblages rarely make up a continuous record, and a single shell is only a snapshot of the environmental setting at a given time. Shells from archaeological sites might represent a dietary component and cooking would presumably alter the isotopic signature of aragonite material. Consequently, a proper sampling strategy is of great importance and should be adjusted to the scientific question. Here, we compare and contrast different sampling approaches using modern shells collected in Morocco, Spain and Germany. The bulk shell approach (fine-ground material) yields information on mean environmental parameters within the life span of analyzed individuals. However, despite homogenization, replicate measurements of bulk shell material returned results with a variability greater than analytical precision (up to 2‰ for d18O, and up to 1‰ for d13C), calling for caution analyzing only single individuals. Horizontal high-resolution sampling (single drill holes along growth lines) provides insights into the amplitude of seasonal variability, while vertical high-resolution sampling (multiple drill holes along the same growth line

  19. The effect of isolation on reproduction and growth of Pseudosuccinea columella (Pulmonata: Lymnaeidae: a snail-conditioned water experiment

    Directory of Open Access Journals (Sweden)

    Gutiérrez Alfredo

    2002-01-01

    Full Text Available A snail-conditioned water experiment was conducted in Pseudosuccinea columella to test the possible role of a chemical interaction between snails on the diminished growth and fecundity rates found for snails raised in pairs compared to those raised in complete isolation. The results permit to discard the hypothesis of an inhibition of growth and reproduction between snails due to factors released into the water.

  20. CHEMOSENSORY ATTRACTION OF ZOOSPORES OF THE ESTUARINE DINOFLAGELLATES, PFIESTERIA PISCICIDA AND P. SHUMWAYAE, TO FINFISH MUCUS AND EXCRETA. (R825551)

    Science.gov (United States)

    Toxic strains of the estuarine dinoflagellates, Pfiesteria piscicida and P. shumwayae, can cause fish death and disease, whereas other estuarine `lookalike' species such as cryptoperidiniopsoids have not been ichthyotoxic under ecologically rel...

  1. 77 FR 54605 - Longworth Low-Effect Habitat Conservation Plan for the Morro Shoulderband Snail, Community of Los...

    Science.gov (United States)

    2012-09-05

    ... for the Morro Shoulderband Snail, Community of Los Osos, San Luis Obispo County, CA AGENCY: Fish and... addresses the potential for ``take'' of the federally endangered Morro shoulderband snail that is likely to... project activities that are likely to result in take of the Morro shoulderband snail as described in their...

  2. Snail Enhances Glycolysis in the Epithelial-Mesenchymal Transition Process by Targeting FBP1 in Gastric Cancer.

    Science.gov (United States)

    Yu, Jie; Li, Jing; Chen, Yong; Cao, Wenmiao; Lu, Yuanyuan; Yang, Jianqi; Xing, Enmin

    2017-01-01

    Snail is a key regulator of epithelial-mesenchymal transition (EMT) in cancer. However, the regulatory role and underlying mechanisms of Snail in gastric cancer metabolism are unknown. In this study, we characterized the regulation of aerobic glycolysis by Snail in gastric cancer. The impact of Snail on glucose metabolism was studied in vitro. Combining maximum standardized uptake value (SUVmax), which was obtained preoperatively via a PET/CT scan, with immunohistochemistry staining, we further analyzed the correlation between SUVmax and Snail expression in gastric cancer tissues. Increased expression of Snail promoted lactate production, glucose utilization, and decreased FBP1 expression at both mRNA and protein level. The expression level of Snail was positively associated with SUVmax in gastric cancer patients (P=0.022). Snail and FBP1 expression were inversely correlated at both mRNA and protein level (P=0.002 and P=0.015 respectively) in gastric cancer tissues. Further studies demonstrated that Snail inhibited the FBP1 gene expression at the transcriptional level. Restoring FBP1 expression reversed the effects of glycolysis and EMT induced by Snail in gastric cancer cells. Our results thus reveal that Snail serves as a positive regulator of glucose metabolism through regulation of the FBP1 in gastric cancer. Disrupting the Snail-FBP1 signaling axis may be effective to prevent primary tumor EMT and glycolysis process. © 2017 The Author(s). Published by S. Karger AG, Basel.

  3. Effects of pollution on land snail abundance, size and diversity as resources for pied flycatcher, Ficedula hypoleuca.

    Science.gov (United States)

    Eeva, Tapio; Rainio, Kalle; Suominen, Otso

    2010-09-01

    Passerine birds need extra calcium during their breeding for developing egg shells and proper growth of nestling skeleton. Land snails are an important calcium source for many passerines and human-induced changes in snail populations may pose a severe problem for breeding birds. We studied from the bird's viewpoint how air pollution affects the shell mass, abundance and diversity of land snail communities along a pollution gradient of a copper smelter. We sampled remnant snail shells from the nests of an insectivorous passerine, the pied flycatcher, Ficedula hypoleuca, to find out how the availability of land snails varies along the pollution gradient. The total snail shell mass increased towards the pollution source but declined abruptly in the vicinity of the smelter. This spatial variation in shell mass was evident also within a single snail species and could not be wholly explained by spatially varying snail numbers or species composition. Instead, the total shell mass was related to their shell size, individuals being largest at the moderately polluted areas. Smaller shell size suggests inferior growth of snails in the most heavily polluted area. Our study shows that pollution affects the diversity, abundance (available shell mass) and individual quality of land snails, posing reproductive problems for birds that rely on snails as calcium sources during breeding. There are probably both direct pollution-related (heavy metal and calcium levels) and indirect (habitat change) effects behind the observed changes in snail populations. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Infection with schistosome parasites in snails leads to increased predation by prawns: implications for human schistosomiasis control.

    Science.gov (United States)

    Swartz, Scott J; De Leo, Giulio A; Wood, Chelsea L; Sokolow, Susanne H

    2015-12-01

    Schistosomiasis - a parasitic disease that affects over 200 million people across the globe - is primarily transmitted between human definitive hosts and snail intermediate hosts. To reduce schistosomiasis transmission, some have advocated disrupting the schistosome life cycle through biological control of snails, achieved by boosting the abundance of snails' natural predators. But little is known about the effect of parasitic infection on predator-prey interactions, especially in the case of schistosomiasis. Here, we present the results of laboratory experiments performed on Bulinus truncatus and Biomphalaria glabrata snails to investigate: (i) rates of predation on schistosome-infected versus uninfected snails by a sympatric native river prawn, Macrobrachium vollenhovenii, and (ii) differences in snail behavior (including movement, refuge-seeking and anti-predator behavior) between infected and uninfected snails. In predation trials, prawns showed a preference for consuming snails infected with schistosome larvae. In behavioral trials, infected snails moved less quickly and less often than uninfected snails, and were less likely to avoid predation by exiting the water or hiding under substrate. Although the mechanism by which the parasite alters snail behavior remains unknown, these results provide insight into the effects of parasitic infection on predator-prey dynamics and suggest that boosting natural rates of predation on snails may be a useful strategy for reducing transmission in schistosomiasis hotspots. © 2015. Published by The Company of Biologists Ltd.

  5. Invasive amebiasis.

    Science.gov (United States)

    Grecu, F; Bulgariu, Teodora; Blanaru, Oana; Dragomir, C; Lunca, Claudia; Stratan, I; Manciuc, Carmen; Luca, V

    2006-01-01

    Digestive amoebiasis with his invasive form is an unusual pathology encountered in the temperate zone. This could lead to a life threatening complication: systemic amoebiasis. A 55-year-old male was treated successfully of systemic amoebiasis in a third referral hospital. The diagnosis was established based on epidemiology data and microscopical identification of trophozoites of Entamoeba histolytica. The amoebicidal, antibiotic and supportive treatments was firstly administrated. The clinical picture of intestinal amoebiasis raised from dysenteric syndrome to necrotizing enteritis. The bowel perforation with localized peritonitis was followed by chronic enteric fistula. Amoebic liver abscess, as the most frequent extraintestinal complication, was concomitantly diagnosed and treated. Urinary amoebiasis was considered as complication in the context of systemic dissemination: any other location could become a site of an amoebic abscess. Multidisciplinary approach was the successful key in the management of the patient, including antiparasitic therapy and antibiotic prophylaxis, intensive care and multiple surgical approaches. The diagnosis of digestive amoebiasis and systemic complication may be delayed in nonendemic areas, leading to advanced and complicated stages of the disease. The surgical approach is most efficiently to treat a large liver amoebic abscess and intraperitoneal collections.

  6. The butterflies and land snails of Ndere Island National Park, Kenya ...

    African Journals Online (AJOL)

    After a survey of Ndere Island National Park between October and November 2004, we recorded 18 species of butterflies and 3 species of land snails. Eurema brigitta brigitta was the most abundant butterfly whereas Thapsia karamwegasensis was the most abundant land snail. Majority of the butterfly species are found in ...

  7. Microbial flora associated with the soils of edible snail farms in ...

    African Journals Online (AJOL)

    Microbial analysis of soil samples collected from snail farms in two different locations (Ughelli, Delta State and Obokofia, Imo State) in southern Nigeria were carried out and compared with that of soil samples collected from ordinary farmlands in these locations.The snail species encountered in this study were Achatina ...

  8. Evidence for genetic control of adult weight plasticity in the snail Helix aspersa

    DEFF Research Database (Denmark)

    Ros, Mathieu; Sorensen, Daniel; Waagepetersen, Rasmus Plenge

    2004-01-01

    of adult weight in the snail Helix aspersa. Several models of heterogeneous variance are fitted using a Bayesin, MCMC approach. Exploratory analyses using posterior predictive model checking and model comparisons based on the deviance information criterion favor a model postulating a genetically structured...... is illustrated numerically using estimates of parameters derived from the snail data set....

  9. The non-native faucet snail (Bithynia tentaculata) makes the leap to Lake Superior

    Science.gov (United States)

    The European-origin faucet snail (Bithynia tentaculata) has been present in the lower Great Lakes since the late 1800s but only very recently reached Lake Superior. Surveys from 2011 through 2013 found faucet snail to be abundant and wide-spread in the St. Louis River Estuary wi...

  10. Local adaptation of the trematode Fasciola hepatica to the snail Galba truncatula

    Directory of Open Access Journals (Sweden)

    Dreyfuss G.

    2012-08-01

    Full Text Available Experimental infections of six riverbank populations of Galba truncatula with Fasciola hepatica were carried out to determine if the poor susceptibility of these populations to this digenean might be due to the scarcity or the absence of natural encounters between these snails and the parasite. The first three populations originated from banks frequented by cattle in the past (riverbank group whereas the three others were living on islet banks without any known contact with local ruminants (islet group. After their exposure, all snails were placed in their natural habitats from the end of October up to their collection at the beginning of April. Compared to the riverbank group, snails, which died without cercarial shedding clearly predominated in the islet group, while the other infected snails were few in number. Most of these last snails released their cercariae during a single shedding wave. In islet snails dissected after their death, the redial and cercarial burdens were significantly lower than those noted in riverbank G. truncatula. Snails living on these islet banks are thus able to sustain larval development of F. hepatica. The modifications noted in the characteristics of snail infection suggest the existence of an incomplete adaptation between these G. truncatula and the parasite, probably due to the absence of natural contact between host and parasite.

  11. Behaviour of freshwater snails (Radix balthica) exposed to the pharmaceutical sertraline under simulated predation risk.

    Science.gov (United States)

    Hedgespeth, Melanie Lea; Karasek, Tomasz; Ahlgren, Johan; Berglund, Olof; Brönmark, Christer

    2018-03-01

    Due to their potential for affecting the modulation of behaviour, effects of selective serotonin reuptake inhibitors (SSRIs) in the environment are particularly interesting regarding interspecies interactions and non-consumptive effects (NCEs) induced by predator cues in prey organisms. We evaluated the effects of sertraline (0.4, 40 ng/L, 40 µg/L) over 8 days on activity and habitat choice in the freshwater snail Radix balthica, on snails' boldness in response to mechanical stimulation (simulating predator attack), and their activity/habitat choice in response to chemical cues from predatory fish. We hypothesised that sertraline exposure would detrimentally impact NCEs elicited by predator cues, increasing predation risk. Although there were no effects of sertraline on NCEs, there were observed effects of chemical cue from predatory fish on snail behaviour independent of sertraline exposure. Snails reduced their activity in which the percentage of active snails decreased by almost 50% after exposure to fish cue. Additionally, snails changed their habitat use by moving away from open (exposed) areas. The general lack of effects of sertraline on snails' activity and other behaviours in this study is interesting considering that other SSRIs have been shown to induce changes in gastropod behaviour. This raises questions on the modes of action of various SSRIs in gastropods, as well as the potential for a trophic "mismatch" of effects between fish predators and snail prey in aquatic systems.

  12. [Effects of molluscicides at different environments on Oncomelania hupensis snail control in Danyang City].

    Science.gov (United States)

    Jiang, Tao; Zhu, Tao; Wang, Zhi-Jian; Wang, Yue-Jin; Wang, Jian-Ming

    2014-02-01

    To evaluate the effects of continuous application of niclosamide ethanolamine salt on Oncomelania hupensis snail control in a marshland, river and channel. The Beiwei marshland in Houxiang Town, the Xiaoliang River in Lingkou Town and Laomiao channel in Yunyang Town in Danyang City were selected as study sites, and 4% niclosamide ethanolamine salt and 26% niclosamide powder were used to kill the snails. Based on the historical records and field investigations, the effects of continuous application of niclosamide ethanolamine salt on snail control were evaluated. Compared with the first time of snail repetition, the snail areas decreased by 82.80%, 63.14% and 70.00% in the Beiwei marshland, Xiaoliang River and Laomiao channel, respectively, in 2013. There was a positive correlation between the area and density of snails (r = 0.931, 0.975 and 0.916, respectively; all P values Molluscicides plays an important role in compressing the snail area, reducing the snail density, and controlling the schistosomiasis transmission.

  13. Loss of Snail2 favors skin tumor progression by promoting the recruitment of myeloid progenitors

    DEFF Research Database (Denmark)

    Villarejo, Ana; Molina-Ortiz, Patricia; Montenegro, Yenny

    2015-01-01

    Snail2 is a zinc finger transcription factor involved in driving epithelial to mesenchymal transitions. Snail2 null mice are viable, but display defects in melanogenesis, gametogenesis and hematopoiesis, and are markedly radiosensitive. Here, using mouse genetics, we have studied the contribution...

  14. Effect of feed on the growth rate of African giant land snail ...

    African Journals Online (AJOL)

    The effects of three feed combinations on the growth rate of the African Giant snail, Archachatina marginata, were investigated at the snailery unit of Forestry and Wildlife Department of University of Uyo, Akwa Ibom State, Nigeria. Growth parameters measured included; changes in snail weight, shell length and shell height.

  15. Nuclear Expression of Snail Is an Independent Negative Prognostic Factor in Human Breast Cancer

    Directory of Open Access Journals (Sweden)

    S. Muenst

    2013-01-01

    Full Text Available Background. Snail is a key regulator of epithelial-mesenchymal transition of tumor cells. Several studies have shown nuclear Snail expression to be a negative prognostic factor in human cancer, where it is generally associated with more aggressive tumor behavior and worse survival. Objectives and Methods. To further explore the role of Snail expression in breast cancer, we conducted a study on a tissue microarray, encompassing 1043 breast cancer cases. Results. A total of 265 (25.4% breast cancers were positive for Snail. Snail expression was significantly associated with greater tumor size, higher tumor stage and grade, positive lymph node status, and hormone receptor negative status and was differently expressed in the intrinsic subtypes of breast cancer, being the highest in the basal-like subtype and the lowest in the luminal A subtype. In multivariate analysis, Snail proved to be an independent negative prognostic factor for OS. In the intrinsic subtypes, Snail expression was a negative prognostic factor for OS in the luminal B HER2−, the luminal B HER2+, and the basal-like subtype. Conclusions. This is the first study demonstrating that nuclear Snail expression is an independent negative predictor of prognosis in breast cancer, thus suggesting that it may represent a potential therapeutic target.

  16. Land snail species richness in a cocoa agroforest in Ile-Oluji, Ondo ...

    African Journals Online (AJOL)

    The land snail community of an agro-forest in Ile-Oluji, Ondo State, Nigeria, was studied using a combination of direct search and leaf litter sieving techniques. A total of 33 ... The land snail species inventory will increase our knowledge of the molluscan fauna of the forest region and assist in conservation management.

  17. Physiological response to low temperature in the freshwater apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae).

    Science.gov (United States)

    Matsukura, Keiichiro; Tsumuki, Hisaaki; Izumi, Yohei; Wada, Takashi

    2009-08-01

    Cold hardiness of the freshwater apple snail, Pomacea canaliculata, varies seasonally. We investigated lethal factors and physiological changes arising from exposure of P. canaliculata to low temperatures. Snails did not survive freezing. The supercooling point of cold-acclimated (cold tolerant) snails (-6.6+/-0.8 degrees C) did not differ significantly from that of non-acclimated ones (-7.1+/-1.5 degrees C) under laboratory conditions. Furthermore, snails died even under more moderately low temperatures approaching 0 degrees C. These results indicate that indirect chilling injury is a factor in the death of P. canaliculata at low temperatures. Regardless of whether the snails were acclimated to low temperatures, all of the dead, and even some of the snails still alive at 0 degrees C, had injured mantles, indicating that the mantle may be the organ most susceptible to the effects of low temperatures. The concentration of glucose in the posterior chamber of the kidney and concentration of glycerol in the digestive gland were significantly higher in cold-acclimated snails than in non-acclimated ones, suggesting carbohydrate metabolic pathways are altered in snails during cold acclimation.

  18. Dry down impacts on apple snail (Pomacea paludosa) demography: Implications for wetland water management

    Science.gov (United States)

    Darby, P.C.; Bennetts, R.E.; Percival, H.F.

    2008-01-01

    Florida apple snails (Pomacea paludosa Say) are prey for several wetland-dependent predators, most notably for the endangered Florida snail kite (Rostrhamus sociabilis Vieillot). Management concerns for kites have been raised regarding the impacts of wetland dry downs on snails, but little data exists to validate these concerns. We simulated drying events in experimental tanks, where we observed that snail survival patterns, regardless of hydrology, were driven by a post-reproductive die off. In contrast to earlier reports of little to no dry down tolerance, we found that 70% of pre-reproductive adult-sized snails survived a 12-week dry down. Smaller size classes of snails exhibited significantly lower survival rates (< 50% after eight weeks dry). Field surveys showed that 77% of egg production occurs in April-June. Our hydrologic analyses of six peninsular Florida wetlands showed that most dry downs overlapped a portion of the peak snail breeding season, and 70% of dry downs were ??? 12 weeks in duration. Dry down timing can affect recruitment by truncating annual egg production and stranding juveniles. Dry down survival rates and seasonal patterns of egg cluster production helped define a range of hydrologic conditions that support robust apple snail populations, and illustrate why multiple characteristics of dry down events should be considered in developing target hydrologic regimes for wetland fauna. ?? 2008, The Society of Wetland Scientists.

  19. Exploring the temporal effects of seasonal water availability on the snail kite of Florida: Part III

    Science.gov (United States)

    Mooij, Wolf M.; Martin, Julien; Kitchens, Wiley M.; DeAngelis, Donald L.; Bissonette, John A.; Storch, Ilse

    2007-01-01

    The Florida snail kite (Rostrhamus sociabilis) is an endangered raptor that occurs as an isolated population, currently of about 2,000 birds, in the wetlands of southern and central Florida, USA. Its exclusive prey species, the apple snail (Pomacea paludosa) is strongly influenced by seasonal changes in water abundance. Droughts during the snail kite breeding season have a direct negative effect on snail kite survival and reproduction, but droughts are also needed to maintain aquatic vegetation types favorable to snail kite foraging for snails. We used a spatially explicit matrix model to explore the effects of temporal variation in water levels on the viability of the snail kite population under different temporal drought regimes in its wetland breeding habitat. We focused on three aspects of variations in water levels that were likely to affect kites: (1) drought frequency; (2) drought duration; and (3) drought timing within the year. We modeled a 31-year historical scenario using four different scenarios in which the average water level was maintained constant, but the amplitude of water level fluctuations was modified. Our results reveal the complexity of the effects of temporal variation in water levels on snail kite population dynamics. Management implications of these results are discussed. In particular, management decisions should not be based on annual mean water levels alone, but must consider the intra-annual variability.

  20. Snail/beta-catenin signaling protects breast cancer cells from hypoxia attack

    Energy Technology Data Exchange (ETDEWEB)

    Scherbakov, Alexander M., E-mail: alex.scherbakov@gmail.com [Laboratory of Clinical Biochemistry, Institute of Clinical Oncology, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Stefanova, Lidia B.; Sorokin, Danila V.; Semina, Svetlana E. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Berstein, Lev M. [Laboratory of Oncoendocrinology, N.N. Petrov Research Institute of Oncology, St. Petersburg 197758 (Russian Federation); Krasil’nikov, Mikhail A. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation)

    2013-12-10

    The tolerance of cancer cells to hypoxia depends on the combination of different factors – from increase of glycolysis (Warburg Effect) to activation of intracellular growth/apoptotic pathways. Less is known about the influence of epithelial–mesenchymal transition (EMT) and EMT-associated pathways on the cell sensitivity to hypoxia. The aim of this study was to explore the role of Snail signaling, one of the key EMT pathways, in the mediating of hypoxia response and regulation of cell sensitivity to hypoxia, using as a model in vitro cultured breast cancer cells. Earlier we have shown that estrogen-independent HBL-100 breast cancer cells differ from estrogen-dependent MCF-7 cells with increased expression of Snail1, and demonstrated Snail1 involvement into formation of hormone-resistant phenotype. Because Snail1 belongs to hypoxia-activated proteins, here we studied the influence of Snail1 signaling on the cell tolerance to hypoxia. We found that Snail1-enriched HBL-100 cells were less sensitive to hypoxia-induced growth suppression if compared with MCF-7 line (31% MCF-7 vs. 71% HBL-100 cell viability after 1% O{sub 2} atmosphere for 3 days). Snail1 knock-down enhanced the hypoxia-induced inhibition of cell proliferation giving the direct evidence of Snail1 involvement into cell protection from hypoxia attack. The protective effect of Snail1 was shown to be mediated, at least in a part, via beta-catenin which positively regulated expression of HIF-1-dependent genes. Finally, we found that cell tolerance to hypoxia was accompanied with the failure in the phosphorylation of AMPK – the key energy sensor, and demonstrated an inverse relationship between AMPK and Snail/beta-catenin signaling. Totally, our data show that Snail1 and beta-catenin, besides association with loss of hormone dependence, protect cancer cells from hypoxia and may serve as an important target in the treatment of breast cancer. Moreover, we suggest that the level of these proteins as well

  1. A survey of Vibrio cholerae O1 and O139 in estuarine waters and ...

    African Journals Online (AJOL)

    This study determined whether the estuarine and freshwater environment in Beira, Mozambique, serves as a reservoir of Vibrio cholerae O1 and O139. Ninety-nine estuarine water samples were collected at 6 sites in Beira. An additional 54 samples were collected from rural areas around Beira which included 3 freshwater ...

  2. Temporal changes of accretion rates on an estuarine salt marsh during the late Holocene

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, A. S.; Andersen, Thorbjørn Joest

    2007-01-01

    The temporal variability of estuarine sedimentation has been investigated in the northernmost part of theWadden Sea (Denmark), using an estuarine sedimentary sequence at Ho Havn. The sedimentary sequence appears to have been deposited within the last ~2000 yr based on detailed luminescence dating...

  3. Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

    NARCIS (Netherlands)

    Booij, P.; Sjollema, S.B.; van der Geest, H.G.; Leonards, P.E.G.; Lamoree, M.H.; de Voogt, P.; Admiraal, W.; Laane, R.W.P.M.; Vethaak, A.D.

    2015-01-01

    For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and

  4. The predation impact of juvenile herring Clupea harengus and sprat Sprattus sprattus on estuarine zooplankton

    NARCIS (Netherlands)

    Maes, J.; Tackx, M.; Soetaert, K.E.R.

    2005-01-01

    The consumption of estuarine copepods by juvenile herring and sprat during estuarine residency was estimated using fish biomass data and daily rations calculated from two models of feeding in fish: a bioenergetic model and a gastric evacuation model. The bioenergetic model predicted daily rations

  5. Macrobenthic species response surfaces along estuarine gradients: prediction by logistic regression

    NARCIS (Netherlands)

    Ysebaert, T.; Meire, P.; Herman, P.M.J.; Verbeek, H.

    2002-01-01

    This study aims at contributing to the development of statistical models to predict macrobenthic species response to environmental conditions in estuarine ecosystems. Ecological response surfaces are derived for 10 estuarine macrobenthic species. Logistic regression is applied on a large data set,

  6. The neuropeptide schistosomin and haemolymph from parasitized snails induce similar changes in excitability in neuroendocrine cells controlling reproduction and growth in a freshwater snail

    NARCIS (Netherlands)

    Hordijk, P. L.; de Jong-Brink, M.; ter Maat, A.; Pieneman, A. W.; Lodder, J. C.; Kits, K. S.

    1992-01-01

    Infection of the snail Lymnaea stagnalis with the schistosome parasite Trichobilharzia ocellata results in inhibition of reproduction and in giant growth. Parasite-related effects on the neuroendocrine centres that control these processes were studied electrophysiologically. Haemolymph from infected

  7. To Reduce the Global Burden of Human Schistosomiasis, Use 'Old Fashioned' Snail Control.

    Science.gov (United States)

    Sokolow, Susanne H; Wood, Chelsea L; Jones, Isabel J; Lafferty, Kevin D; Kuris, Armand M; Hsieh, Michael H; De Leo, Giulio A

    2018-01-01

    Control strategies to reduce human schistosomiasis have evolved from 'snail picking' campaigns, a century ago, to modern wide-scale human treatment campaigns, or preventive chemotherapy. Unfortunately, despite the rise in preventive chemotherapy campaigns, just as many people suffer from schistosomiasis today as they did 50 years ago. Snail control can complement preventive chemotherapy by reducing the risk of transmission from snails to humans. Here, we present ideas for modernizing and scaling up snail control, including spatiotemporal targeting, environmental diagnostics, better molluscicides, new technologies (e.g., gene drive), and 'outside the box' strategies such as natural enemies, traps, and repellants. We conclude that, to achieve the World Health Assembly's stated goal to eliminate schistosomiasis, it is time to give snail control another look. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. OCCURRENCE OF SALMONELLA, VIBRO AND E. COLI IN EDIBLE LAND SNAIL IN NIGER DELTA, NIGERIA

    Directory of Open Access Journals (Sweden)

    Ime Ebenso

    2012-10-01

    Full Text Available We determined the presence of foodborne pathogens from proximal gut of edible land snail (Archachatina marginata sampled from Itam, Akpan Andem, Afaha and Ikpa markets in Uyo metropolis during the dry season. Fresh snail samples were collected from open market tables presented for sale were screened in the laboratory for microbial load. The total bacteria, Salmonella, Vibrio and Escherichia coli pathogens were measured. The results showed (p<0.05 pathogens in snail meat were found to be above 102cfu-g recommended microbiological limits. The foodborne pathogenic bacteria rating of sampled markets was Itam < Akpan Andem < Afaha < Ikpa. Edible snail can be a bioindicator and vector of foodborne pathogens. It is critical that producers, retailers, processors and consumers take responsibility to prevent contamination, cross-contamination, mishandling, as well as proper holding, storage and cooking of snail meat to eradicate foodborne pathogenic incidence.

  9. [Neurochemical mechanisms of food aversion conditioning consolidation in snail Helix lucorum].

    Science.gov (United States)

    Solntseva, S V; Nikitin, v P

    2008-11-01

    Effects of cycloheximide, protein synthesis inhibitors, as well as serotonin receptor antagonist and NMDA receptor antagonist on food aversion conditioning consolidation were studied in snail Helix lucorum. Food aversion conditioning was absent in snails after application of cycloheximide. Repeated produced no food aversion conditioning for the same type of food in these snails without cycloheximide application. Food aversion conditioning was absent in snails after applications of metiotepin, nonselective serotonin receptors antagonist, or after MK-801, NMDA glutamate receptors antagonist. At the same time, repeated training produced facilitated food aversion conditioning for the same type of food in these snails. Our experiments were the first which showed that effect on different molecular mechanisms evoked reversible or irreversible disruption of long-term memory consolidation during the same learning. It was suggested that suppression of retrieval produced reversible effect, whereas disruption of memory storage initiated irreversible effect on long-term memory consolidation.

  10. To reduce the global burden of human schistosomiasis, use ‘old fashioned’ snail control

    Science.gov (United States)

    Sokolow, Susanne H.; Wood, Chelsea L.; Jones, Isabel J.; Lafferty, Kevin D.; Kuris, Armand; Hsieh, Michael H.; De Leo, Giulio A.

    2018-01-01

    Control strategies to reduce human schistosomiasis have evolved from ‘snail picking’ campaigns, a century ago, to modern wide-scale human treatment campaigns, or preventive chemotherapy. Unfortunately, despite the rise in preventive chemotherapy campaigns, just as many people suffer from schistosomiasis today as they did 50 years ago. Snail control can complement preventive chemotherapy by reducing the risk of transmission from snails to humans. Here, we present ideas for modernizing and scaling up snail control, including spatiotemporal targeting, environmental diagnostics, better molluscicides, new technologies (e.g., gene drive), and ‘outside the box’ strategies such as natural enemies, traps, and repellants. We conclude that, to achieve the World Health Assembly’s stated goal to eliminate schistosomiasis, it is time to give snail control another look.

  11. Land snails (Mollusca: Gastropoda of India: status, threats and conservation strategies

    Directory of Open Access Journals (Sweden)

    S. Sen

    2012-09-01

    Full Text Available Land snails form an important component in the forest ecosystem. In terms of number of species, the phylum Mollusca, to which land snails belong, is the largest phylum after Arthropoda. Mollusca provide unique ecosystem services including recycling of nutrients and they provide a prey base for small mammals, birds, snakes and other reptiles. However, land snails have the largest number of documented extinctions, compared to any other taxa. Till date 1,129 species of land snails are recorded from Indian territory. But only basic information is known about their taxonomy and little is known of their population biology, ecology and their conservation status. In this paper, we briefly review status, threats and conservation strategies of land snails of India.

  12. North Inlet-Winyah Bay National Estuarine Research Reserve's (NERR) Estuarine Water Quality Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 1993-2002

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of the Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve...

  13. Invasion of Flukes of the Echinostomatidae Family in Racing Pigeon ( Columba livia var. domestica) Lofts.

    Science.gov (United States)

    Ledwoń, Aleksandra; Dolka, Beata; Piasecki, Tomasz; Dolka, Izabella; Szeleszczuk, Piotr

    2016-06-01

    Over 4 years, only two known cases of fluke invasions were diagnosed in racing pigeons ( Columba livia ) originating from different regions of Poland. In both cases, the invasion was characterized by a very high mortality (approximately 70%), and the source of the infestation was snails of the Lymnaeidae family eaten by pigeons. Fluke invasions in pigeons are extremely rare and to date have not been described in Poland. Therefore, the occurrence of the symptoms of hemorrhagic diarrhea and sudden deaths of either adult pigeons or nestlings were suspected to be associated with poisoning. Autopsy revealed an invasion of flukes causing hemorrhagic enteritis. Renal failure and spleen atrophy were also found in the birds. Using molecular biology techniques, infestation with the fluke Echinostoma revolutum was determined in the second case.

  14. Snail as a Potential Target Molecule in Cardiac Fibrosis: Paracrine Action of Endothelial Cells on Fibroblasts Through Snail and CTGF Axis

    OpenAIRE

    Lee, Sae-Won; Won, Joo-Yun; Kim, Woo Jean; Lee, Jaewon; Kim, Kyung-Hee; Youn, Seock-Won; Kim, Ju-Young; Lee, Eun Ju; Kim, Yong-Jin; Kim, Kyu-Won; Kim, Hyo-Soo

    2013-01-01

    Ischemia/reperfusion (I/R) injury to myocardium induces death of cardiomyocytes and destroys the vasculature, leading to cardiac fibrosis that is mainly mediated by the transdifferentiation of fibroblasts to myofibroblasts and the collagen deposition. Snail involvement in fibrosis is well known; however, the contribution of Snail to cardiac fibrosis during I/R injury and its underlying mechanisms have not been defined. We showed that I/R injury to mouse hearts significantly increases the expr...

  15. Phenotypic plasticity in the common garden snail: big guts and heavier mucus glands compete in snails faced with the dual challenge of poor diet and coarse substrate.

    Science.gov (United States)

    Munn, Adam J; Treloar, Marguerite

    2017-05-01

    Phenotypic plasticity allows animals to manage environmental challenges. Studies aimed at quantifying plasticity often focus on one challenge, such as diet, and one organ system, such the gastrointestinal tract, but this approach may not adequately reflect how plasticity could buffer multiple challenges. Thus, we investigated the outcomes of a dual challenge experiment that fed land snails either a high-fibre (low quality) or a low-fibre (high quality) diet, and simultaneously exercised them daily over 1.2 m on either a smooth surface of polyvinyl chloride (PVC) or a rough sandpaper. By the end of 20 days, snails fed the poor quality diet had a longer crop and oesophagus and a heavier intestine and rectum than those offered a low-fibre diet. Additionally, high-fibre fed snails had a smaller spermoviduct and oviduct. When also exercised on sandpaper, high-fibre fed snails had a smaller digestive gland, a main energy store, than those exercised on PVC. All snails exercised on sandpaper had a heavier pedal mucus gland, used a loping gait and used less mucus than those on PVC plastic, but there was no difference in the average speed of snails on either surface, supporting the conclusion that loping is a mucus conserving gait. Notably, snails faced with both a diet and substrate challenge had a smaller kidney, which could directly effect fecundity. This demonstrates that our dual challenge approach has potential for evaluating the costs and limits of the plasticity necessary to fully appreciate the evolutionary significance of plasticity in snails and other species.

  16. [Comparison of molluscicidal effects of two snail control methods with plastic film covering in hilly regions].

    Science.gov (United States)

    Zhou, Yun; Zhang, Biao; Wang, Zhi-Mei; Zhao, Jia-Huei; Mao, Shu; Xie, De-Bing; Mei, Zhi-Zhong; Zhang, Jun; Hong, Qing-Biao; Wang, Wei; Sun, Le-Ping

    2013-12-01

    To evaluate and compare the molluscicidal effects of colorless and black plastic film covering methods against Oncomelania hupensis snails in hilly regions. A hilly setting with high snail density was selected as the study area, and three groups including the colorless plastic film covering method, black plastic film covering method and control were designed. The snail surveys were conducted 1, 3, 7, 15 days and 30 days in each group following plastic film covering, and the mortality of snails and reduction of snail density were investigated. The air temperature, soil surface temperature in the control group, as well as the soil surface temperature and the temperatures 5 cm and 15 cm under the soil within the film were recorded. The mortality rates of snails were 36.84%, 78.94%, 95.92%, 100.00% and 99.45% 1, 3, 7, 15 days and 30 days following colorless plastic film covering, respectively, and the snail density after 30 days of covering reduced by 99.36% as compared to that before covering, while the mortality rates of snails were 10.08%, 8.94%, 6.11%, 26.15% and 49.32% 1, 3, 7, 15 days and 30 days following black plastic film covering, respectively, and the snail density after 30 days of covering reduced by 58.10% as compared to that before covering. There were significant differences in the 1-, 3-, 7-, 15-day and 30-day snail mortality rates between the colorless and black film covering groups (all P values plastic film covering method is significantly superior to that of the black plastic film covering method in summer in hilly regions.

  17. Changes in frequency of spontaneous oscillations in procerebrum correlate to behavioural choice in terrestrial snails

    Directory of Open Access Journals (Sweden)

    Elena Samarova

    2009-08-01

    Full Text Available The aim of our study was to understand functional significance of spontaneous oscillations of local field potential in the olfactory brain lobe of terrestrial snail, the procerebrum (PC. We compared changes in frequency of oscillations in semi-intact preparations from snails trained to percept the same conditioned odor as positive (associated with food reinforcement or negative (associated with noxious reinforcement. In vivo recordings in freely behaving naïve snails showed a significant decrease of spontaneous PC oscillations frequency during a stage of tentacle withdrawal to odor presentation. In in vitro preparations from naïve snails, a similar decrease in frequency of the PC oscillations to odor presentation was observed. Changes in frequency of the oscillations to cineole presentations in the “aversive” group of snails (demonstrating withdrawal were much more pronounced than in naïve snails. No significant difference in responses to 5 and 20% cineole was noted. Changes in the spontaneous oscillations frequency in the snails trained to respond with positive reaction (approach to cineole depended on the concentration of the applied odor, and these responses were qualitatively similar to responses of other groups during the first 10 s of responses to odor, but significantly different (increase in PC oscillations frequency from the responses of the aversively trained and naïve snails in the interval 11-30 s, which corresponds to the end of the tentacle withdrawal and timing of decision making (approach or escape in the free behaving snails. Obtained results suggest that frequency of the PC lobe spontaneous oscillations correlate to the choice of behavior in snails: withdrawal (decrease in frequency or approach (increase in frequency to the source of odor.

  18. Use of a saponin based molluscicide to control Pomacea canaliculata snails in Southern Brazil.

    Science.gov (United States)

    San Martíns, R; Gelmi, Claudio; de Oliveira, Jaime Vargas; Galo, José Luis; Pranto, Honorio

    2009-10-01

    Pomacea canaliculata snails pose a severe problem to direct seeded rice cultivated in Southern Brazil. Control of this snail is nowadays performed with toxic chemicals such as copper sulfate and fungicides such as fentin. A novel natural molluscicide based on alkali modified quinoa (Chenopodium quinoa) saponins was tested under laboratory conditions. Snails were collected in rice fields close to Porto Alegre (State of Rio Grande do Sul) and in Brusque (State of Santa Catarina, 400 km north of Porto Alegre). In Santa Catarina the product was very effective, while in Porto Alegre it had no effect. This unexpected behavior was probably due to the respiratory habits of the snails under different contents of dissolved oxygen in the water. Near Porto Alegre the water used in rice fields is heavily polluted, with dissolved oxygen levels of 1-2 ppm, and the snails rely primarily on their siphon and lungs to breathe. Since saponin control is probably due to an interaction between saponins with the sterols present in the cell walls in the gills, no control was observed. By contrast, in Santa Catarina the dissolved oxygen level of the water is 5-6 ppm, and the snails remain mostly underwater, breathing with their gills. In this case the snails died within 24 h at a dose of 20 and 30 ppm of product. To test this observation, snails grown in polluted waters were forced to remain underwater in saponin solutions and water (control) preventing the use of their siphon to breathe. The snails exposed to saponin solutions died, while the control snails survived, indicating that they were still able to use their gills to breathe. These results indicate that the use of the saponin product is limited to rice fields not irrigated with heavily polluted waters.

  19. Tributyltin-resistant bacteria from estuarine and freshwater sediments.

    OpenAIRE

    Wuertz, S; Miller, C E; Pfister, R M; Cooney, J J

    1991-01-01

    Resistance to tributyltin (TBT) was examined in populations from TBT-polluted sediments and nonpolluted sediments from an estuary and from fresh water as well as in pure cultures isolated from those sediments. The 50% effective concentrations (EC50s) for populations were higher at a TBT-polluted freshwater site than at a site without TBT, suggesting that TBT selected for a TBT-resistant population. In contrast, EC50s were significantly lower for populations from a TBT-contaminated estuarine s...

  20. Tidal variations in the Sundarbans estuarine system, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterjee, M.; Shankar, D.; Sen, G.K.; Sanyal, P.; Sundar, D.; Michael, G.S.; Chatterjee, A.; Amol, P.; Mukherjee, D.; Suprit, K.; Mukherjee, A.; Vijith, V.; Chatterjee, S.; Basu, A.; Das, M.; Chakraborti, S.; Kalla, A.; Misra, S.K.; Mukhopadhyay, S.; Mandal, G.; Sarkar, K.

    ). The map was prepared by digitizing the 1967–1969 toposheets (1:50,000 scale) of the Survey of India. The symbols (an ‘S’ with arrows on either end) indicating the presence of the tide were filled in from these toposheets and the more recent map (1... the Gomdi Khaal or the Gomor), Gos- aba, Gona, Harinbhanga and Raimangal (figure 2). Interconnecting these estuaries and forming the complex estuarine network are numerous west–east flowing channels, canals and creeks. Some of these interlinking channels...

  1. A checklist of malacofauna of the Vellar Estuarine Mangroves, India

    Directory of Open Access Journals (Sweden)

    K. Kesavan

    2009-07-01

    Full Text Available A survey conducted to know the diversity of malacofauna in Vellar estuarine mangroves (southeast coast of India. In this study, 13 species of molluscs (10 species of gastropods - Melampus ceylonicus, Cerithidea cingulata, Cassidula nucleus, Pythia plicata, Neritina (Dostia violacea, Littorina scabra, Littorina melanostoma, Ellobium aurisjudae, C. obtusa T. telescopium and Assiminea nitida and 3 species of bivalves - Perna viridis, Crassostrea madrasensis and Modiolus metcalfei were recorded. M. pulchella, C. obtusa, L. scabra and N. violacea were found arboreal. T. telescopium, C. cingulata and E. aurisjudae were found crawling on the intertidal mud.

  2. Molluscicidal activity of Bacillus thuringiensis strains against Biomphalaria alexandrina snails

    Directory of Open Access Journals (Sweden)

    Amany M. Abd El-Ghany

    2017-12-01

    Full Text Available Schistosomiasis is a parasitic disease transmitted to man and different warm blooded animals by means of snails. Great effort has been made to control the transmission of the disease by many strategies. Consequently, the utilization of particular molluscicides is viewed as a standout amongst the best measures for molluscs control. Recently, microbial pathogen used as non-traditional molluscicides which have attracted significant research attention due to the increasing, worldwide development of resistance to chemical molluscicides in molluscs populations. The present work aimed to study the molluscicidal impacts of eleven isolates of Bacillus thuringiensis which were isolated from soils of six Egyptian governorates toward Biomphalaria alexandrina snails. Results showed that, B. thuringiensis provides an effective biological control agent against B. alexandrina snails. Out of the tested isolates, four isolates; Qalyubia, Asyut 1, Qena and North Sinai 2 isolates show high-level molluscicidal activity. The obtained results indicated that LC50 and LC90 values were ranged between 133.27–457.74 mg/mL and 270.32–781.05 mg/mL, respectively. The most noteworthy molluscicidal impact was displayed by Qalyubia isolate which isolated from Qalyubia governorate with mortality rate extended from 20% to100% at five treatment concentrations of 100–500 mg/mL. The LC50 and LC90 values for Qalyubia isolate were 133.27 mg/mL and 270.32 mg/mL, respectively. Keywords: Biomphalaria alexandrina, Bacillus thuringiensis, Molluscicidal activity, Biological control

  3. A flavonol present in cocoa [(-)epicatechin] enhances snail memory.

    Science.gov (United States)

    Fruson, Lee; Dalesman, Sarah; Lukowiak, Ken

    2012-10-15

    Dietary consumption of flavonoids (plant phytochemicals) may improve memory and neuro-cognitive performance, though the mechanism is poorly understood. Previous work has assessed cognitive effects in vertebrates; here we assess the suitability of Lymnaea stagnalis as an invertebrate model to elucidate the effects of flavonoids on cognition. (-)Epicatechin (epi) is a flavonoid present in cocoa, green tea and red wine. We studied its effects on basic snail behaviours (aerial respiration and locomotion), long-term memory (LTM) formation and memory extinction of operantly conditioned aerial respiratory behaviour. We found no significant effect of epi exposure (15 mg l(-1)) on either locomotion or aerial respiration. However, when snails were operantly conditioned in epi for a single 0.5 h training session, which typically results in memory lasting ~3 h, they formed LTM lasting at least 24 h. Snails exposed to epi also showed significantly increased resistance to extinction, consistent with the hypothesis that epi induces a more persistent LTM. Thus training in epi facilitates LTM formation and results in a more persistent and stronger memory. Previous work has indicated that memory-enhancing stressors (predator kairomones and KCl) act via sensory input from the osphradium and are dependent on a serotonergic (5-HT) signalling pathway. Here we found that the effects of epi on LTM were independent of osphradial input and 5-HT, demonstrating that an alternative mechanism of memory enhancement exists in L. stagnalis. Our data are consistent with the notion that dietary sources of epi can improve cognitive abilities, and that L. stagnalis is a suitable model with which to elucidate neuronal mechanisms.

  4. Toxic effects of Cadmium on the garden snail (Helix aspersa)

    Energy Technology Data Exchange (ETDEWEB)

    Russell, L.K. (Northrop Services Inc., Corvallis, OR); DeHaven, J.I.; Botts, R.P.

    1981-05-01

    Spreading treated municipal wastes on agricultural and forest lands is becoming an established method of disposal. However, there is concern about the deleterious effects of toxicants, particularly cadmium, in the sludges. Cadmium concentrations in sewage sludge have been reported as high as 1500 ppM. The work reported here is a part of a larger project to investigate the ecological effects of municipal wastes on forest lands. Snails, Helix aspersa, were chosen to examine the entrance of cadmium into terrestrial food chains. This experiment was designed to determine cadmium accumulation, acute toxicity, and behavioral, reproductive and growth responses with increasing levels of cadmium.

  5. Toxicity of botanical insecticides on golden apple snail (Pomacea canaliculata).

    Science.gov (United States)

    Ruamthum, W; Visetson, S; Milne, J R; Bullangpoti, V

    2010-01-01

    The molluscicidal activity of crude extracts from five highly potential plants, Annona squamosa seed, Nerium indicum Leaves, Stemona tuberose root, Cyperus rotundus corm and Derris elliptica root was assessed to Pomacea canaliculata. D. elliptica root and C. rotundus corm extracts showed the highest toxicity against 3-month old snails which have LC50 as 23.68 +/- 2.96 mg/l and 133.20 +/- 7.94 mg/l, respectively. The C. rotundus corm extracts were chosen for detoxification enzyme in vivo assay which shows esterase and glutathione S-transferase activity in stomach, intestinal tracts and digestive glands of survival treated P. canaliculata were inhibited.

  6. THE USE OF Pomacea canaliculata SNAILS IN FEED TO IMPROVE QUALITY OF ALABIO DUCK (Anas plathyrinchos Borneo MEAT

    Directory of Open Access Journals (Sweden)

    A. Subhan

    2016-03-01

    Full Text Available This research was aimed to improve the physical and chemical quality of Alabio ducks which was fed with Pomacea canaliculata snails. Those ducks were raised intensively. There were nine treatments  included R0 (control feed, R1 (control feed + 2.5% Pomacea canaliculata snails from swampy area, R2 (control feed + 5% Pomacea canaliculata snails from swampy area, R3 (control feed + 7.5% Pomacea canaliculata snails from swampy area R4 (control feed + 10% Pomacea canaliculata snails from swampy area R5 (control feed + 2.5% Pomacea canaliculata snails from tidal swampy area, R6 (control feed + 5% Pomacea canaliculata snails from tidal swampy area, R7 (control feed + 7.5% Pomacea canaliculata snails from tidal swampy area, and R8 (control feed + 10% Pomacea canaliculata snails from tidal swampy area. The variables observed included meat chemical and physical quality. A Completely Randomized Design was used in this study. Analysis of variance and Duncan’s multiple range test were used to analyze data. The research results revealed that using Pomacea canaliculata snails in duck feed had a significant effect (P<0.05 towards the physical characteristics (water holding capacity, cooking loss, and tenderness, and chemical characteristics of Alabio duck meat (water, protein, collagen, fat, and cholesterol content. However, there was no significant effect towards meat pH. It can be concluded that using 5% Pomacea canaliculata snails in a mixture of Alabio duck feed decreased cooking loss and meat cholesterol content.

  7. Snail regulates p21WAF/CIP1 expression in cooperation with E2 A and Twist

    International Nuclear Information System (INIS)

    Takahashi, Eishi; Funato, Noriko; Higashihori, Norihisa; Hata, Yuiro; Gridley, Thomas; Nakamura, Masataka

    2004-01-01

    Snail, a zinc-finger transcriptional repressor, is essential for mesoderm and neural crest cell formation and epithelial-mesenchymal transition. The basic helix-loop-helix transcription factors E2A and Twist have been linked with Snail during embryonic development. In this study, we examined the role of Snail in cellular differentiation through regulation of p21 WAF/CIP1 expression. A reporter assay with the p21 promoter demonstrated that Snail inhibited expression of p21 induced by E2A. Co-expression of Snail with Twist showed additive inhibitory effects. Deletion mutants of the p21 promoter revealed that sequences between -270 and -264, which formed a complex with unidentified nuclear factor(s), were critical for E2A and Snail function. The E2A-dependent expression of the endogenous p21 gene was also inhibited by Snail

  8. Microbial degradation of pharmaceuticals in estuarine and coastal seawater

    Energy Technology Data Exchange (ETDEWEB)

    Benotti, Mark J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States); Brownawell, Bruce J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States)], E-mail: bruce.brownawell@sunysb.edu

    2009-03-15

    Microbial degradation rates were measured for 19 pharmaceuticals in estuarine and coastal surface water samples. Antipyrine, carbamazepine, cotinine, sulfamethoxazole, and trimethoprim were the most refractory (half-lives, t{sub 1/2} = 35 to >100 days), making them excellent candidates for wastewater tracers. Nicotine, acetaminophen, and fluoxetine were labile across all treatments (t{sub 1/2} = 0.68-11 days). Caffeine, diltiazem, and nifedipine were also and relatively labile in all but one of the treatments (t{sub 1/2} = 3.5-13 days). Microbial degradation of caffeine was further confirmed by production {sup 14}CO{sub 2}. The fastest decay of non-refractory compounds was always observed in more sewage-affected Jamaica Bay waters. Degradation rates for the majority of these pharmaceuticals are much slower than reported rates for small biomolecules, such as glucose and amino acids. Batch sorption experiments indicate that removal of these soluble pharmaceuticals from the water column to sediments is a relatively insignificant removal process in these receiving waters. - Microbial degradation rates were measured for 19 structurally variable pharmaceuticals in wastewater-impacted estuarine and coastal seawater.

  9. Geochronology of the Rio Formoso estuarine by {sup 210}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Arruda, Gilberto N.; Lyra, Denilson T.; Melo, Julyanne T.B.; Farias, Emerson E.G.; Franca, Elvis J.; Santos, Thiago O., E-mail: gnarruda@cnen.gov.br, E-mail: denilsonengseg@gmail.com, E-mail: julyanne.melo@ufpe.br, E-mail: emersonemiliano@yahoo.com.br, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Souza Neto, Joao A., E-mail: adauto@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2015-07-01

    Uranium series disequilibrium is useful for dating methods, in which profile sediments can be considered as historical records of anthropogenic events regarding the distribution and impacts of chemical substances on the environment. In this study, 2 deep sediment profiles (about 1 m) were collected, layered at each 3 cm, oven-dried and homogenized. The radiochemical separation of {sup 210}Pb consisted of using hydrobromic acid and an ion exchange resin (DOWEX) for precipitating {sup 210}Pb in the form of lead chromate. After 10 days, the radioactivity was therefore measured by means of the low level gas flow proportional counter, model S5-XLB, from Canberra. Sedimentation rate were obtained by CIC (Constant Initial Concentration) model assumes a constant sedimentation rate throughout the period over which unsupported {sup 210}Pb is measurable. Some sediment profiles were not dated since the percentage of sand was quite high in top layers or a high percentage of organic matter and water in excess were observed in the all sediment samples. {sup 210}Pb geochronology was successfully applied to age nine sediment profiles, in which higher sedimentation rates were observed in the middle portion of the estuarine probably related to shrimp farming impacts. By using geochronology, the detection of human impacts on chemical element distribution could be enhanced in the case of environmental monitoring studies in the Rio Formoso estuarine. (author)

  10. The negative role of turbulence in estuarine mass transport

    Science.gov (United States)

    Nunes Vaz, Richard A.; Lennon, Geoffrey W.; de Silva Samarasinghe, Jayantha R.

    1989-04-01

    It is competition between the various stratifying and mixing influences which determines the character of stratification in an estuary. Borrowing concepts which have been successfully applied to the discussion of stratification in shelf seas, a quantitative basis for determining the potential energy associated with vertical structure in estuaries is derived. The formulation, along similar lines to that of Bowden (1981), provides a simple but comprehensive method of incorporating many relevant stratifying and mixing influences in a given problem, and is also shown to be capable of rearrangement into forms akin to the estuarine Richardson number which is commonly found in discussions of estuarine statification. The paper argues, based on a survey of the literature, that in wide, relatively well-mixed estuaries, the greatest longitudinal mass flux occurs at times when stratification is most developed, that is, when the turbulent kinetic energy in the water column is at a minimum. Modulation of turbulence, principally at various tidal frequencies, causes a pulsing of the mass flux in which the contribution of each pulse increases non-linearly as the period of the modulation increases. Some, possibly significant, changes to the state of stratification and to the corresponding mass transport may occur in association with slack water periods. However, the spring-neap cycle is proposed to have a far greater influence on stratification, mass transport and the long-term mass balance in estuaries, and recent observational studies lend support to this position.

  11. Metal Bioaccumulation by Estuarine Food Webs in New England, USA

    Directory of Open Access Journals (Sweden)

    Celia Y. Chen

    2016-06-01

    Full Text Available Evaluating the degree of metal exposure and bioaccumulation in estuarine organisms is important for understanding the fate of metals in estuarine food webs. We investigated the bioaccumulation of Hg, methylmercury (MeHg, Cd, Se, Pb, and As in common intertidal organisms across a watershed urbanization gradient of coastal marsh sites in New England to relate metal exposure and bioaccumulation in fauna to both chemical and ecological factors. In sediments, we measured metal and metalloid concentrations, total organic carbon (TOC and SEM-AVS (Simultaneously extracted metal-acid volatile sulfides. In five different functional feeding groups of biota, we measured metal concentrations and delta 15N and delta 13C signatures. Concentrations of Hg and Se in biota for all sites were always greater than sediment concentrations whereas Pb in biota was always lower. There were positive relationships between biota Hg concentrations and sediment concentrations, and between biota MeHg concentrations and both pelagic feeding mode and trophic level. Bioavailability of all metals measured as SEM-AVS or Benthic-Sediment Accumulation Factor was lower in more contaminated sites, likely due to biogeochemical factors related to higher levels of sulfides and organic carbon in the sediments. Our study demonstrates that for most metals and metalloids, bioaccumulation is metal specific and not directly related to sediment concentrations or measures of bioavailability such as AVS-SEM.

  12. Geochronology of the Rio Formoso estuarine by 210Pb

    International Nuclear Information System (INIS)

    Arruda, Gilberto N.; Lyra, Denilson T.; Melo, Julyanne T.B.; Farias, Emerson E.G.; Franca, Elvis J.; Santos, Thiago O.; Souza Neto, Joao A.

    2015-01-01

    Uranium series disequilibrium is useful for dating methods, in which profile sediments can be considered as historical records of anthropogenic events regarding the distribution and impacts of chemical substances on the environment. In this study, 2 deep sediment profiles (about 1 m) were collected, layered at each 3 cm, oven-dried and homogenized. The radiochemical separation of 210 Pb consisted of using hydrobromic acid and an ion exchange resin (DOWEX) for precipitating 210 Pb in the form of lead chromate. After 10 days, the radioactivity was therefore measured by means of the low level gas flow proportional counter, model S5-XLB, from Canberra. Sedimentation rate were obtained by CIC (Constant Initial Concentration) model assumes a constant sedimentation rate throughout the period over which unsupported 210 Pb is measurable. Some sediment profiles were not dated since the percentage of sand was quite high in top layers or a high percentage of organic matter and water in excess were observed in the all sediment samples. 210 Pb geochronology was successfully applied to age nine sediment profiles, in which higher sedimentation rates were observed in the middle portion of the estuarine probably related to shrimp farming impacts. By using geochronology, the detection of human impacts on chemical element distribution could be enhanced in the case of environmental monitoring studies in the Rio Formoso estuarine. (author)

  13. Effects of fire management on the richness and abundance of central North American grassland land snail faunas

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    Nekola, J. C.

    2002-01-01

    Full Text Available The land snail faunas from 72 upland and lowland grassland sites from central North America were analyzed. Sixteen of these had been exposed to fire management within the last 15 years, while the remainder had not. A total of 91,074 individuals in 72 different species were observed. Richness was reduced by approximately 30% on burned sites, while abundance was reduced by 50-90%. One-way ANOVA of all sites (using management type as the independent variable, a full 2-way ANOVA (using management and grassland type of all sites, and a 2-way ANOVA limited to 26 sites paired according to their habitat type and geographic location, demonstrated in all cases a highly significant (up to p < 0.0005 reduction in richness and abundance on fire managed sites. Contingency table analysis of individual species demonstrated that 44% experienced a significant reduction in abundance on fire-managed sites. Only six species positively responded to fire. Comparisons of fire response to the general ecological preferences of these species demonstrated that fully 72% of turf-specialists were negatively impacted by fire, while 67% of duff-specialists demonstrated no significant response. These differences were highly significant (p = 0.0006. Thus, frequent use of fire management represents a significant threat to the health and diversity of North American grassland land snail communities. Protecting this fauna will require the preservation of site organic litter layers, which will require the increase of fire return intervals to 15+ years in conjunction with use of more diversified methods to remove woody and invasive plants.

  14. Snail intermediate host/Schistosoma haematobium relationships from three transmission sites in Benin (West Africa).

    Science.gov (United States)

    Ibikounlé, Moudachirou; Mouahid, Gabriel; Mintsa Nguema, Rodrigue; Sakiti, Nestor; Massougbodji, Achille; Moné, Hélène

    2013-01-01

    The relationships between three strains of Schistosoma haematobium (Doh, Sô-Tchanhoué and Toho-Todougba; from Benin, West Africa) and their snail hosts were assessed by measurement of several life-history traits, including the infection rate; pre-patent period; cercarial production of each parasite strain; and growth, fecundity and survival of the host snails. Adaptations to its local snail host was found for the Toho-Todougba strain and included a short pre-patent period, a long patent period and production of more cercariae in its local snail host. In contrast, the life-history traits of the Doh and Sô-Tchanhoué strains indicated non-local adaptations, as some sympatric host-parasite combinations were not compatible, the highest infection rates occurred in the allopatric snail Bulinus wrighti, and the duration of cercarial production was short because of the high level of mortality of the snails. Furthermore, snail reproduction ceased following infection by each of the three parasite strains, and the life-history traits were not influenced by the miracidial dose.

  15. Kinetic and dynamic aspects of soil-plant-snail transfer of cadmium in the field

    Energy Technology Data Exchange (ETDEWEB)

    Gimbert, Frederic [University of Franche-Comte, Department of Environmental Biology, EA 3184 MR UsC INRA, Place Leclerc, 25030 Besancon Cedex (France); Mench, Michel [UMR BIOGECO INRA 1202, Ecology of Communities, University Bordeaux 1, Avenue des Facultes, 33405 Talence (France); Coeurdassier, Michael; Badot, Pierre-Marie [University of Franche-Comte, Department of Environmental Biology, EA 3184 MR UsC INRA, Place Leclerc, 25030 Besancon Cedex (France); Vaufleury, Annette de [University of Franche-Comte, Department of Environmental Biology, EA 3184 MR UsC INRA, Place Leclerc, 25030 Besancon Cedex (France)], E-mail: annette.devaufleury@univ-fcomte.fr

    2008-04-15

    The proper use of bioaccumulation in the assessment of environmental quality involves accounting for chemical fluxes in organisms. Cadmium (Cd) accumulation kinetics in a soil-plant-snail food chain were therefore investigated in the field under different soil contamination (from 0 to 40 mg kg{sup -1}), soil pH (6 and 7) and season. Allowing for an accurate and sensitive assessment of Cd transfer to snails, toxicokinetics appears an interesting tool in the improvement of risk assessment procedures and a way to quantify metal bioavailability for a defined target. On the basis of uptake fluxes, snails proved to be sensitive enough to distinguish moderate soil contaminations. The soil pH did not appear, in the range studied, as a modulating parameter of the Cd transfer from soil to snail whereas the season, by influencing the snail mass, may modify the internal concentrations. The present data specifying a time integrated assessment of environmental factors on metal bioavailability and transfer to terrestrial snails should ensure their rational use in environmental biomonitoring. - Toxicokinetics and uptake fluxes can be used to describe the environment contamination by Cd, its bioavailability and transfer to Helix aspersa snails in the field.

  16. Three Strigeid cercariae from Littorina littorea snail, Qarun Lake, Fayoum, Egypt

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    Fayez A. Bakry

    2018-03-01

    Full Text Available Aim: The present study aims to focus on the role of common marine snails (Littorina littorea as a vector for some trematode parasites. Materials and Methods: A total of 327 marine water L. littorea snails were collected during the summer of 2016 from a Qarun lake in the EL-Fayoum Governorate, Egypt. The snails were investigated for infection by trematode parthenitae through induction of cercarial shedding by exposure to light and crushing the snails. The species were stored in Search Laboratory of Zoology Department, Faculty of Science, Fayoum University. Results: Three species of Strigeid littorina cercaria were identified from the infected snails. They are described here and they identified in relation to close-up morphological features and linked to its snail hosts. They give the following names: Cercaria strigeid littorina type 1, C. strigeid littorina type 2, and C. strigeid littorina type 3. The incidence of infection by these cercariae was 33%, 25.7%, and 2.4%, respectively. Conclusion: This study is clarifying the importance of this marine snail as intermediate hosts for new trematode species.

  17. Allelic variation in a single genomic region alters the microbiome of the snail Biomphalaria glabrata.

    Science.gov (United States)

    Allan, Euan R O; Tennessen, Jacob A; Sharpton, Thomas J; Blouin, Michael S

    2018-03-16

    Freshwater snails are the intermediate hosts for numerous parasitic worms which can have negative consequences for human health and agriculture. Understanding the transmission of these diseases requires a more complete characterization of the immunobiology of snail hosts. This includes the characterization of its microbiome and genetic factors which may interact with this important commensal community. Allelic variation in the Guadeloupe Resistance Complex (GRC) genomic region of Guadeloupean Biomphalaria glabrata influences their susceptibility to schistosome infection, and may have other roles in the snail immune response. In the present study, we examined whether a snail's GRC genotype has a role in shaping the bacterial diversity and composition present on or in whole snails. We show that the GRC haplotype, including the resistant genotype, has a significant effect on the diversity of bacterial species present in or on whole snails, including the relative abundances of Gemmatimonas aurantiaca and Micavibrio aeruginosavorus. These findings support the hypothesis that the GRC region is likely involved in pathways that can modify the microbial community of these snails, and may have more immune roles in B. glabrata than originally believed. This is also one of few examples in which allelic variation at a particular locus has been shown to affect the microbiome in any species.

  18. Biological control of snail hosts transmitting schistosomiasis by the water bug, Sphaerodema urinator.

    Science.gov (United States)

    Younes, Aly; El-Sherief, Hanaa; Gawish, Fathia; Mahmoud, Marwa

    2017-04-01

    The water bug, Sphaerodema urinator (Hemiptera : Belostomatidae), shares the same habitat of the freshwater snails in ponds, lakes, and streams. Studies conducted in lakes show that fish and crayfish predators play an important role in determining the abundance of freshwater snails. In contrast, shallow ponds and marches often lack fish and crayfish but have abundant insect predators. This study has been carried out to evaluate the predatory potential of S. urinator adult on two freshwater snails that serves as intermediate hosts of Schistosoma. Laboratory evaluation of predation by S. urinator on these intermediate hosts revealed that the adult bug could kill and consume the two intermediate hosts: Bulinus truncatus and Biomphalaria alexandrina. The number of snails consumed differed according to the snail type, size, and density. The times taken for searching and handling times were depending on the snail size, type, and vulnerability of the predator. The predation rate varied also with respect to snail type and density. Prey size is a major factor influencing predator preferences. This study indicated that the predator, S. urinator, may be a suitable bio-control agent in connection with Schistosoma intermediate hosts in the aquatic area.

  19. Utilization Of Golden Snail As Alternative Liquid Organic Fertilizer LOF On Paddy Farmers In Dairi Indonesia

    Directory of Open Access Journals (Sweden)

    Ameilia Zuliyanti Siregar

    2017-11-01

    Full Text Available Golden snail Pomaceae canaliculata is a pest of rice plants and used as a food source to be processed into satay seasoning spices biscuits pastry candy crackers animal feed and fertilizer. In Lae Parira village the golden snail is very diverse. Because of this reason the preliminary study and utilization of golden snail used for of liquid organic fertilizer called LOF or and microorganisms local MOL. The golden snail is obtained from a livestock that is still alive and then washed boiled and removed from its shell. The golden snail meat is cut into small pieces separated from the intestine and other visceral organs. Flesh of golden snail give coconut water dilute brown sugar EM4 and fermentation until 10-14 days. The use of mashed LOF can be sprayed on the surface of the soil or all parts of the plant. For fertilization in rice plants the recommended dose of 250 ml15 liters of water is sprayed on the rice age 10 days after planting and repeated again at interval distance of 15 days. Fertilization on the plant recommended 200ml 15 liters of water sprayed on leaves and soil 7 days after planting and repeated every 7 days. The golden snail is potensial used for fertilizer in paddy plantation environmentally.

  20. Comparative toxicity of Paraquat herbicide and some plant extracts in Lymnaea natalensis snails.

    Science.gov (United States)

    Bakry, Fayez A; Eleiwa, Mona E; Taha, Samir A; Ismil, Somya M

    2016-01-01

    Paraquat has been shown to be a highly toxic compound for humans and animals, and many cases of acute poisoning and death have been reported over the past few decades. The present study was undertaken to evaluate comprehensively herbicides (Paraquat) and some plant extracts to biochemical aspects of Lymnaea natalensis snails. It was found that the exposure of L. natalensis to Paraquat and plant extracts led to a significant reduction in the infectivity of Fasciola gigantica miracidia to the snail. The glucose level in hemolymph of exposed snails was elevated, while the glycogen showed a decrease in soft tissues when compared with the control group. In addition, the activity level of some enzymes representing glycolytic enzymes as hexokinase (HK), pyruvate kinase (PK), phosphofructokinase (PFK), lactate dehydrogenase (LDH), and glucose phosphate isomerase (GPI) in snail's tissues were reduced in response to the treatment. It was concluded that the pollution of the aquatic environment by herbicide would adversely affect the metabolism of the L. natalensis snails. Snails treated with Agave attenuate, Ammi visnaga, and Canna iridiflora plant had less toxic effect compared to snails treated with Paraquat. © The Author(s) 2013.