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Sample records for genetic sexing strains

  1. Development of a genetic sexing strain in Bactrocera carambolae (Diptera: Tephritidae) by introgression of sex sorting components from B. dorsalis, Salaya1 strain

    Science.gov (United States)

    2014-01-01

    Background The carambola fruit fly, Bactrocera carambolae Drew & Hancock is a high profile key pest that is widely distributed in the southwestern ASEAN region. In addition, it has trans-continentally invaded Suriname, where it has been expanding east and southward since 1975. This fruit fly belongs to Bactrocera dorsalis species complex. The development and application of a genetic sexing strain (Salaya1) of B. dorsalis sensu stricto (s.s.) (Hendel) for the sterile insect technique (SIT) has improved the fruit fly control. However, matings between B. dorsalis s.s. and B. carambolae are incompatible, which hinder the application of the Salaya1 strain to control the carambola fruit fly. To solve this problem, we introduced genetic sexing components from the Salaya1 strain into the B. carambolae genome by interspecific hybridization. Results Morphological characteristics, mating competitiveness, male pheromone profiles, and genetic relationships revealed consistencies that helped to distinguish Salaya1 and B. carambolae strains. A Y-autosome translocation linking the dominant wild-type allele of white pupae gene and a free autosome carrying a recessive white pupae homologue from the Salaya1 strain were introgressed into the gene pool of B. carambolae. A panel of Y-pseudo-linked microsatellite loci of the Salaya1 strain served as markers for the introgression experiments. This resulted in a newly derived genetic sexing strain called Salaya5, with morphological characteristics corresponding to B. carambolae. The rectal gland pheromone profile of Salaya5 males also contained a distinctive component of B. carambolae. Microsatellite DNA analyses confirmed the close genetic relationships between the Salaya5 strain and wild B. carambolae populations. Further experiments showed that the sterile males of Salaya5 can compete with wild males for mating with wild females in field cage conditions. Conclusions Introgression of sex sorting components from the Salaya1 strain to a

  2. Development, genetic and cytogenetic analyses of genetic sexing strains of the Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae).

    Science.gov (United States)

    Zepeda-Cisneros, Cristina Silvia; Meza Hernández, José Salvador; García-Martínez, Víctor; Ibañez-Palacios, Jorge; Zacharopoulou, Antigone; Franz, Gerald

    2014-01-01

    Anastrepha ludens is among the pests that have a major impact on México's economy because it attacks fruits as citrus and mangoes. The Mexican Federal government uses integrated pest management to control A. ludens through the Programa Nacional Moscas de la Fruta [National Fruit Fly Program, SAGARPA-SENASICA]. One of the main components of this program is the sterile insect technique (SIT), which is used to control field populations of the pest by releasing sterile flies. To increase the efficiency of this technique, we have developed a genetic sexing strain (GSS) in which the sexing mechanism is based on a pupal colour dimorphism (brown-black) and is the result of a reciprocal translocation between the Y chromosome and the autosome bearing the black pupae (bp) locus. Ten strains producing wild-type (brown pupae) males and mutant (black pupae) females were isolated. Subsequent evaluations for several generations were performed in most of these strains. The translocation strain named Tapachula-7 showed minimal effect on survival and the best genetic stability of all ten strains. Genetic and cytogenetic analyses were performed using mitotic and polytene chromosomes and we succeeded to characterize the chromosomal structure of this reciprocal translocation and map the autosome breakpoint, despite the fact that the Y chromosome is not visible in polytene nuclei following standard staining. We show that mitotic and polytene chromosomes can be used in cytogenetic analyses towards the development of genetic control methods in this pest species. The present work is the first report of the construction of GSS of Anastrepha ludens, with potential use in a future Moscafrut operational program.

  3. Cryopreservation of Embryos of the Mediterranean Fruit Fly Ceratitis capitata Vienna 8 Genetic Sexing Strain.

    Science.gov (United States)

    Augustinos, Antonios A; Rajamohan, Arun; Kyritsis, Georgios A; Zacharopoulou, Antigone; Haq, Ihsan Ul; Targovska, Asya; Caceres, Carlos; Bourtzis, Kostas; Abd-Alla, Adly M M

    2016-01-01

    The Mediterranean fruit fly, Ceratitis capitata, is one of the most serious pests of fruit crops world-wide. During the last decades, area-wide pest management (AW-IPM) approaches with a sterile insect technique (SIT) component have been used to control populations of this pest in an effective and environment-friendly manner. The development of genetic sexing strains (GSS), such as the Vienna 8 strain, has been played a major role in increasing the efficacy and reducing the cost of SIT programs. However, mass rearing, extensive inbreeding, possible bottleneck phenomena and hitch-hiking effects might pose major risks for deterioration and loss of important genetic characteristics of domesticated insect. In the present study, we present a modified procedure to cryopreserve the embryos of the medfly Vienna 8 GSS based on vitrification and used this strain as insect model to assess the impact of the cryopreservation process on the genetic structure of the cryopreserved insects. Forty-eight hours old embryos, incubated at 24°C, were found to be the most suitable developmental stage for cryopreservation treatment for high production of acceptable hatch rate (38%). Our data suggest the absence of any negative impact of the cryopreservation process on egg hatch rate, pupation rates, adult emergence rates and stability of the temperature sensitive lethal (tsl) character on two established cryopreserved lines (flies emerged from cryopreserved embryos), named V8-118 and V8-228. Taken together, our study provides an optimized procedure to cryopreserve the medfly Vienna 8 GSS and documents the absence of any negative impact on the genetic structure and quality of the strain. Benefits and sceneries for utilization of this technology to support operational SIT projects are discussed in this paper.

  4. Cryopreservation of Embryos of the Mediterranean Fruit Fly Ceratitis capitata Vienna 8 Genetic Sexing Strain

    Science.gov (United States)

    Augustinos, Antonios A.; Rajamohan, Arun; Kyritsis, Georgios A.; Zacharopoulou, Antigone; Haq, Ihsan ul; Targovska, Asya; Caceres, Carlos; Bourtzis, Kostas; Abd-Alla, Adly M. M.

    2016-01-01

    The Mediterranean fruit fly, Ceratitis capitata, is one of the most serious pests of fruit crops world-wide. During the last decades, area-wide pest management (AW-IPM) approaches with a sterile insect technique (SIT) component have been used to control populations of this pest in an effective and environment-friendly manner. The development of genetic sexing strains (GSS), such as the Vienna 8 strain, has been played a major role in increasing the efficacy and reducing the cost of SIT programs. However, mass rearing, extensive inbreeding, possible bottleneck phenomena and hitch-hiking effects might pose major risks for deterioration and loss of important genetic characteristics of domesticated insect. In the present study, we present a modified procedure to cryopreserve the embryos of the medfly Vienna 8 GSS based on vitrification and used this strain as insect model to assess the impact of the cryopreservation process on the genetic structure of the cryopreserved insects. Forty-eight hours old embryos, incubated at 24°C, were found to be the most suitable developmental stage for cryopreservation treatment for high production of acceptable hatch rate (38%). Our data suggest the absence of any negative impact of the cryopreservation process on egg hatch rate, pupation rates, adult emergence rates and stability of the temperature sensitive lethal (tsl) character on two established cryopreserved lines (flies emerged from cryopreserved embryos), named V8-118 and V8-228. Taken together, our study provides an optimized procedure to cryopreserve the medfly Vienna 8 GSS and documents the absence of any negative impact on the genetic structure and quality of the strain. Benefits and sceneries for utilization of this technology to support operational SIT projects are discussed in this paper. PMID:27537351

  5. Mass Rearing of Temperature Sensitive Genetic Sexing Strains in the Mediterranean Fruit Fly (Ceratitis Capitata)

    Energy Technology Data Exchange (ETDEWEB)

    Caceres, C. [FAO/IAEA Agriculture and Biotechnology Laboratory, Entomology Unit, A-2444 Seibersdorf (Austria)]. E-mail: c.caceres@iaea.org

    2002-09-15

    Genetic sexing strains (GSS) based on the temperature sensitive lethal(tsl) mutation are being used to produce sterile male medflies for large scale sterile insect technique (SIT) programmes for this pest. The use of male-only strains increases the overall efficiency of the technique. Currently more than 1.4 billion sterile male-only pupae are produced per week in different facilities around the world. Due to the mutations used to construct these strains, that is, translocations and selectable markers, they require different and more careful mass rearing procedures than do bisexual strains (BSS). The basic rearing technology has been developed and can be used to produce only males on a predictable basis to a level of 99.9% accuracy. If specific rearing procedures are followed, then tsl-based GSS has a rearing efficiency that is equal to that of a BSS and it is already know that males produced by the tsl-based GSS are of equal quality to males produced by BSS. Based on current rearing technology the cost of production of male pupae is about the same for both types of strain. This is due to the large colony that is required for the tsl-based GSS. This paper discusses the considerations that need to be taken into account during mass rearing of GSS and identifies the most efficient production processes that are currently available. (author)

  6. Tapachula-7, a new genetic sexing strain of the Mexican fruit fly (Diptera: Tephritidae): sexual compatibility and competitiveness.

    Science.gov (United States)

    Orozco, Dina; Meza, J Salvador; Zepeda, Silvia; Solís, Eduardo; Quintero-Fong, J Luis

    2013-04-01

    A new genetic sexing strain of the Mexican fruit fly, Anastrepha ludens (Loew), was evaluated in tests of sexual behavior to determine its possible application using the sterile insect technique. Tests in field cages measuring time to sexual maturity, compatibility with wild flies, and competitiveness were compared between the genetic sexing strain, Tapachula-7, and the mass-reared standard bisexual strain. The results indicated that the onset of sexual maturity was similar for both laboratory strains. Males from the Tapachula-7 strain do not differ from the standard bisexual strain in compatibility and competitiveness with wild insects. The results indicate that the release of Tapachula-7 males in the field would be viable in programs that use the sterile insect technique for the control of the Mexican fruit fly.

  7. Effect of Genetic Strain and Sex on Water Absorption and Water-To-Protein Ratio in Chicken Meat

    Directory of Open Access Journals (Sweden)

    MJGS Ferrari

    Full Text Available ABSTRACT The objectives of the present study were to evaluate the water and protein contents and the water-to-protein ratio of chicken parts before and after the pre-chilling process, to compare these results with the values officially recommended by the Brazilian Ministry of Agriculture, and to evaluate the effect of genetic strain and sex on these parameters. Water (% and protein (% contents, and water-to-protein ratio (WPR of boneless and skinless breast (FILLETS and breast with bone and skin (BREAST were determined before (BPC and after (APC carcass pre-chilling. A total of 585 samples were evaluated: 221 fillets/male, 216 breasts/male, 76 fillets/female, and 72 fillets/female of four different broilers strains were evaluated before (BPC and after (APC samples. Water and protein contents and water-to-protein ratio were determined according to the Brazilian legislation. Results showed that there were no significant differences between genetic strains (p<0.05 neither in samples collected before or after the chiller. There were no statistical differences in the parameters studied among genetic strains. However, a high percentage of male breast samples presented water level and water-to-protein ratio above the official limits already before pre-chilling.

  8. Selection by mating competitiveness improves the performance of Anastrepha ludens males of the genetic sexing strain Tapachula-7.

    Science.gov (United States)

    Quintero-Fong, L; Toledo, J; Ruiz, L; Rendón, P; Orozco-Dávila, D; Cruz, L; Liedo, P

    2016-10-01

    The sexual performance of Anastrepha ludens males of the Tapachula-7 genetic sexing strain, produced via selection based on mating success, was compared with that of males produced without selection in competition with wild males. Mating competition, development time, survival, mass-rearing quality parameters and pheromone production were compared. The results showed that selection based on mating competitiveness significantly improved the sexual performance of offspring. Development time, survival of larvae, pupae and adults, and weights of larvae and pupae increased with each selection cycle. Differences in the relative quantity of the pheromone compounds (Z)-3-nonenol and anastrephin were observed when comparing the parental males with the F4 and wild males. The implications of this colony management method on the sterile insect technique are discussed.

  9. Sterile medfly males of the tsl Vienna 8 genetic sexing strain display improved mating performance with ginger root oil

    Energy Technology Data Exchange (ETDEWEB)

    Paranhos, Beatriz Jordao; Alves, Renata Morelli, E-mail: bjordao@cpatsa.embrapa.b [EMBRAPA Semi-Arido, Petrolina, PE (Brazil); McInnis, Donald [U.S. Department of Agriculture (USDA/ARS/PBARC), Honolulu, HI (United States). Agricultural Research Service. Pacific Basin Agricultural Research Center; Uramoto, Keiko [Universidade de Sao Paulo (USP), SP (Brazil); Damasceno, Itala; Malavasi, Aldo [Biofabrica Moscamed Brasil, Juazeiro, BA (Brazil); Goncalves, Nilmara [Valexport, Petrolina, PE (Brazil); Costa, Maria de Lourdes; Walder, Julio [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Nascimento, Antonio [EMBRAPA Mandioca e Fruticultura, Cruz das Almas, BA (Brazil)

    2006-07-01

    A key point of the sterile insect technique applied to the medfly, Ceratitis capitata, is that the sterile males produced in the laboratory should have at least a minimal sexual compatibility with wild females. Among several genetic sexing tsl (Temperature Sensitive Lethal) strains of C. capitata mass-reared around the world, the Biofabrica Moscamed Brasil has chosen the most recent mass produced tsl strain, Vienna 8 (V8), which has been evaluated in the San Francisco River Valley, Brazil, since April, 2005. The tests were accomplished in field cages, with different treatments for V8 males, sterile or fertile, exposed to the aroma of ginger root oil (GRO) or not, versus wild males and females. Males of one strain (V8 or wild) were painted white on the thorax the day before the mating tests. All the insects were virgin, and early in the morning (7-8 A.M.) males were released inside the field cages, 10 min. before females. Mating pairs were collected in glass vials, until early afternoon. From this raw data, both the type of male mating and the time in copula were recorded for each pair. Then, the total percentage of mated females, the RSI (Relative Sterility Index), and Fried's competitiveness values (C), were calculated for each field cage. The percentage of females mated was statistically higher to sterile males exposed to GRO than to non exposed to GRO. Time in copula was significantly higher for wild flies than for laboratory flies, except for the case of fertile V8 males exposed to GRO x wild females. The RSI and C values were significantly higher for V8 males (irradiated and fertile) treated with GRO than for V8 males not treated with GRO. The results indicate that there is adequate sexual compatibility between sterile males of the tsl Vienna 8 strain and wild C. capitata females from the San Francisco River Valley, Brazil. Also, the radiation dose of 95 Gy, used to sterilize the males, did not affect their sexual activity. Ginger root oil acted as a

  10. Sex Determination, Sex Ratios, and Genetic Conflict

    NARCIS (Netherlands)

    Werren, John H.; Beukeboom, Leo W.

    1998-01-01

    Genetic mechanisms of sex determination are unexpectedly diverse and change rapidly during evolution. We review the role of genetic conflict as the driving force behind this diversity and turnover. Genetic conflict occurs when different components of a genetic system are subject to selection in

  11. Sex Determination, Sex Ratios, and Genetic Conflict

    NARCIS (Netherlands)

    Werren, John H.; Beukeboom, Leo W.

    1998-01-01

    Genetic mechanisms of sex determination are unexpectedly diverse and change rapidly during evolution. We review the role of genetic conflict as the driving force behind this diversity and turnover. Genetic conflict occurs when different components of a genetic system are subject to selection in oppo

  12. Comparison of Anastrepha ludens (Diptera: Tephritidae) Bisexual and Genetic Sexing (Tapachula-7) Strains: Effect of Hypoxia, Fly Density, Chilling Period, and Food Type on Fly Quality.

    Science.gov (United States)

    Arredondo, José; Ruiz, Lía; Hernández, Emilio; Montoya, Pablo; Díaz-Fleischer, Francisco

    2016-04-01

    The use of genetic sexing strain (GSS) insects in the sterile insect technique (SIT) makes necessary the revision of quality parameters of some stressful steps used during the packing process for aerial release because of possible differences in tolerance between fly strains. Here, we determined the effect of three periods of hypoxia (12, 24, and 36 h at pupal stage), three cage densities (1.0, 1.3, and 1.5 flies/cm2), two different foods (protein/sugar (1/24) and Mubarqui), and three chilling times (20 min [control], 90, and 180 min) on the quality parameters of flies of two Anastrepha ludens (Loew) strains (bisexual and GSS Tapachula-7). In general, the response to stressful conditions of both fly strains was qualitatively equivalent but quantitatively different, as flies of both strains responded equally to the stressful factors; however, flies of Tapachula-7 exhibited lower quality parameters than the control flies. Thus, hypoxia affected the flying ability but not the emergence or longevity of flies. The food type affected the adult weight; protein/sugar produced heavier flies that also survived longer and had a greater mating propensity. Flies under the lowest density were better fliers that those at the other two densities. Increasing chilling time reduced flight ability but not longevity or mating propensity. The implications of these findings for the use of A. ludens GSS in SIT programs are discussed herein.

  13. Wild sex in zebrafish: loss of the natural sex determinant in domesticated strains.

    Science.gov (United States)

    Wilson, Catherine A; High, Samantha K; McCluskey, Braedan M; Amores, Angel; Yan, Yi-lin; Titus, Tom A; Anderson, Jennifer L; Batzel, Peter; Carvan, Michael J; Schartl, Manfred; Postlethwait, John H

    2014-11-01

    Sex determination can be robustly genetic, strongly environmental, or genetic subject to environmental perturbation. The genetic basis of sex determination is unknown for zebrafish (Danio rerio), a model for development and human health. We used RAD-tag population genomics to identify sex-linked polymorphisms. After verifying this "RAD-sex" method on medaka (Oryzias latipes), we studied two domesticated zebrafish strains (AB and TU), two natural laboratory strains (WIK and EKW), and two recent isolates from nature (NA and CB). All four natural strains had a single sex-linked region at the right tip of chromosome 4, enabling sex genotyping by PCR. Genotypes for the single nucleotide polymorphism (SNP) with the strongest statistical association to sex suggested that wild zebrafish have WZ/ZZ sex chromosomes. In natural strains, "male genotypes" became males and some "female genotypes" also became males, suggesting that the environment or genetic background can cause female-to-male sex reversal. Surprisingly, TU and AB lacked detectable sex-linked loci. Phylogenomics rooted on D. nigrofasciatus verified that all strains are monophyletic. Because AB and TU branched as a monophyletic clade, we could not rule out shared loss of the wild sex locus in a common ancestor despite their independent domestication. Mitochondrial DNA sequences showed that investigated strains represent only one of the three identified zebrafish haplogroups. Results suggest that zebrafish in nature possess a WZ/ZZ sex-determination mechanism with a major determinant lying near the right telomere of chromosome 4 that was modified during domestication. Strains providing the zebrafish reference genome lack key components of the natural sex-determination system but may have evolved variant sex-determining mechanisms during two decades in laboratory culture.

  14. Evaluation of Quality Production Parameters and Mating Behavior of Novel Genetic Sexing Strains of the Mediterranean Fruit Fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae).

    Science.gov (United States)

    Rempoulakis, Polychronis; Taret, Gustavo; Haq, Ihsan Ul; Wornayporn, Viwat; Ahmad, Sohel; Sto Tomas, Ulysses; Dammalage, Thilakasiri; Gembinsky, Keke; Franz, Gerald; Cáceres, Carlos; Vreysen, Marc J B

    2016-01-01

    The Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the most important pest of fruits and vegetables in tropical and subtropical countries. The sterile insect technique (SIT) as a component of area-wide integrated pest management (AW-IPM) approaches is being used for the successful management of this pest. VIENNA 8 is a genetic sexing strain (GSS) that has a white pupae (wp) and temperature sensitive lethal (tsl) mutation, the latter killing all female embryos when eggs are exposed to high temperatures (34°C). The use of this GSS permits production and the release of only males which has increased the cost effectiveness of the SIT several fold for this pest. An efficient method of identification of recaptured sterile males can further increase the cost effectiveness of the SIT for this pest. Therefore, VIENNA 8-Sergeant2 (Sr2) strain and the transgenic strain VIENNA 8-1260 having visible markers were constructed. All three strains were evaluated for egg production, egg hatch, and egg sterility parameters under semi mass-rearing conditions and mating competitiveness in field cages. VIENNA 8-1260 females produced significantly fewer eggs as compared with the two other strains, which produced similar numbers of eggs. However, egg hatch of all strains was similar. Egg hatch of eggs produced by untreated females that had mated with adult males that had been irradiated with 100 Gy as pupae 2 days before emergence, was different for the three strains, i.e., egg hatch of 0.63%, 0.77%, 0.89% for VIENNA 8, VIENNA 8-1260, and VIENNA 8-Sr2, respectively. Differences in male mating competitiveness of the three strains against wild-type males were gradually reduced with successive generations under semi mass-rearing conditions. However, VIENNA 8 males adapted faster to laboratory conditions as compared with VIENNA 8-Sr2 and VIENNA 8-1260 males with respect to mating competitiveness. VIENNA 8 males of the F10 generation were equally

  15. Evaluation of Quality Production Parameters and Mating Behavior of Novel Genetic Sexing Strains of the Mediterranean Fruit Fly Ceratitis capitata (Wiedemann (Diptera: Tephritidae.

    Directory of Open Access Journals (Sweden)

    Polychronis Rempoulakis

    Full Text Available The Mediterranean fruit fly Ceratitis capitata (Wiedemann (Diptera: Tephritidae is one of the most important pest of fruits and vegetables in tropical and subtropical countries. The sterile insect technique (SIT as a component of area-wide integrated pest management (AW-IPM approaches is being used for the successful management of this pest. VIENNA 8 is a genetic sexing strain (GSS that has a white pupae (wp and temperature sensitive lethal (tsl mutation, the latter killing all female embryos when eggs are exposed to high temperatures (34°C. The use of this GSS permits production and the release of only males which has increased the cost effectiveness of the SIT several fold for this pest. An efficient method of identification of recaptured sterile males can further increase the cost effectiveness of the SIT for this pest. Therefore, VIENNA 8-Sergeant2 (Sr2 strain and the transgenic strain VIENNA 8-1260 having visible markers were constructed. All three strains were evaluated for egg production, egg hatch, and egg sterility parameters under semi mass-rearing conditions and mating competitiveness in field cages. VIENNA 8-1260 females produced significantly fewer eggs as compared with the two other strains, which produced similar numbers of eggs. However, egg hatch of all strains was similar. Egg hatch of eggs produced by untreated females that had mated with adult males that had been irradiated with 100 Gy as pupae 2 days before emergence, was different for the three strains, i.e., egg hatch of 0.63%, 0.77%, 0.89% for VIENNA 8, VIENNA 8-1260, and VIENNA 8-Sr2, respectively. Differences in male mating competitiveness of the three strains against wild-type males were gradually reduced with successive generations under semi mass-rearing conditions. However, VIENNA 8 males adapted faster to laboratory conditions as compared with VIENNA 8-Sr2 and VIENNA 8-1260 males with respect to mating competitiveness. VIENNA 8 males of the F10 generation were

  16. Testing an aging gene in long-lived Drosophila strains: increased longevity depends on sex and genetic background

    National Research Council Canada - National Science Library

    Spencer, Christine C; Howell, Christine E; Wright, Amber R; Promislow, Daniel E. L

    2003-01-01

    .... Typically, long-lived mutants are identified in relatively short-lived genetic backgrounds, and their effects are rarely tested in genetic backgrounds other than the one in which they were isolated or derived...

  17. Novel PCR assay for determining the genetic sex of mice.

    Science.gov (United States)

    McFarlane, L; Truong, V; Palmer, J S; Wilhelm, D

    2013-01-01

    A number of studies require the determination of the genetic sex of mouse embryos before sexual differentiation and/or of mutant mice that display partial or complete sex reversal. The majority of current methods for sexing by PCR involve multiplexing of 2 primer pairs. We have developed a novel sexing PCR using a single primer pair that amplifies fragments from the X and the Y chromosome with a clear size difference between the respective amplicons. This assay provides a rapid and reliable method to identify the genetic sex of mice across different mouse strains.

  18. Sex reduces genetic variation: a multidisciplinary review.

    Science.gov (United States)

    Gorelick, Root; Heng, Henry H Q

    2011-04-01

    For over a century, the paradigm has been that sex invariably increases genetic variation, despite many renowned biologists asserting that sex decreases most genetic variation. Sex is usually perceived as the source of additive genetic variance that drives eukaryotic evolution vis-à-vis adaptation and Fisher's fundamental theorem. However, evidence for sex decreasing genetic variation appears in ecology, paleontology, population genetics, and cancer biology. The common thread among many of these disciplines is that sex acts like a coarse filter, weeding out major changes, such as chromosomal rearrangements (that are almost always deleterious), but letting minor variation, such as changes at the nucleotide or gene level (that are often neutral), flow through the sexual sieve. Sex acts as a constraint on genomic and epigenetic variation, thereby limiting adaptive evolution. The diverse reasons for sex reducing genetic variation (especially at the genome level) and slowing down evolution may provide a sufficient benefit to offset the famed costs of sex. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  19. Genetic architecture and the evolution of sex.

    Science.gov (United States)

    Lohaus, Rolf; Burch, Christina L; Azevedo, Ricardo B R

    2010-01-01

    Theoretical investigations of the advantages of sex have tended to treat the genetic architecture of organisms as static and have not considered that genetic architecture might coevolve with reproductive mode. As a result, some potential advantages of sex may have been missed. Using a gene network model, we recently showed that recombination imposes selection for robustness to mutation and that negative epistasis can evolve as a by-product of this selection. These results motivated a detailed exploration of the mutational deterministic hypothesis, a hypothesis in which the advantage of sex depends critically on epistasis. We found that sexual populations do evolve higher mean fitness and lower genetic load than asexual populations at equilibrium, and, under moderate stabilizing selection and large population size, these equilibrium sexual populations resist invasion by asexuals. However, we found no evidence that these long- and short-term advantages to sex were explained by the negative epistasis that evolved in our experiments. The long-term advantage of sex was that sexual populations evolved a lower deleterious mutation rate, but this property was not sufficient to account for the ability of sexual populations to resist invasion by asexuals. The ability to resist asexual invasion was acquired simultaneously with an increase in recombinational robustness that minimized the cost of sex. These observations provide the first direct evidence that sexual reproduction does indeed select for conditions that favor its own maintenance. Furthermore, our results highlight the importance of considering a dynamic view of the genetic architecture to understand the evolution of sex and recombination.

  20. Demographic and genetic consequences of disturbed sex determination.

    OpenAIRE

    Wedekind, C

    2017-01-01

    During sex determination, genetic and/or environmental factors determine the cascade of processes of gonad development. Many organisms, therefore, have a developmental window in which their sex determination can be sensitive to, for example, unusual temperatures or chemical pollutants. Disturbed environments can distort population sex ratios and may even cause sex reversal in species with genetic sex determination. The resulting genotype-phenotype mismatches can have long-lasting effects on p...

  1. Effects of Sex, Strain, and Energy Intake on Hallmarks of Aging in Mice

    DEFF Research Database (Denmark)

    Mitchell, Sarah J.; Madrigal-Matute, Julio; Scheibye-Knudsen, Morten

    2016-01-01

    Calorie restriction (CR) is the most robust non-genetic intervention to delay aging. However, there are a number of emerging experimental variables that alter CR responses. We investigated the role of sex, strain, and level of CR on health and survival in mice. CR did not always correlate...

  2. Visibility and Persistence of Marker Dyes and Effect on the Quality and Mating Competitiveness of Mass-Reared Flies (Diptera: Tephritidae): Anastrepha obliqua and Bisexual and Genetic Sexing (Tapachula-7) Strains of A. ludens.

    Science.gov (United States)

    Arredondo, José; Ruiz, Lia; López, Gladis; Díaz-Fleischer, Francisco

    2017-08-01

    Fluorescent dyes are commonly used in the sterile insect technique (SIT) for marking insects for a proper identification after recapture. However, the quality of the mark must be balanced against insect performance, because dyes can negatively affect some parameters of insect performance and reduce their effectiveness in control with the SIT. We determined the visibility and persistence and the effect of dyes on the quality of Anastrepha obliqua (Macquart) and Anastrepha ludens (Loew) (bisexual and genetic sexing strains) by testing four concentrations of a dye (Day-Glo) from 0 to 2.5 g dye/kg of pupae. Visibility and persistence of the mark were positively affected by dose and negatively affected by the length of time the samples were kept in a solution of 75% alcohol. However, upon dissection, even the lowest dose of dye was visible under a fluorescence microscope. Between dyed and undyed pupae (control), no significant differences were observed in rates of emergence, fliers and flight ability, and survival in two tests, with water and without food and without water and food, at any of the concentrations tested. Furthermore, no significant difference in mating competitiveness was detected between control pupae and those dyed at 1.0 and 2.5 g dye/kg pupae. We discuss our results with the possibility of reducing the dose of dye in these three flies, because the heads are large enough to capture sufficient particles to permit identification with the current methods of detection. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. [Elucidation of key genes in sex determination in genetics teaching].

    Science.gov (United States)

    Li, Meng; He, Zhumei

    2014-06-01

    Sex is an important and complex feature of organisms, which is controlled by the genetic and environmental factors. The genetic factors, i.e., genes, are vital in sex determination. However, not all the related genes play the same roles, and some key genes play a vital role in the sex determination and differentiation. With the development of the modern genetics, a great progress on the key genes has been made in sex determination. In this review, we summarize the mechanism of sex determination and the strategy of how to study the key genes in sex determination. It will help us to understand the mechanism of sex determination better in the teaching of genetics.

  4. Genetic characterization of measles vaccine strains.

    Science.gov (United States)

    Bankamp, Bettina; Takeda, Makoto; Zhang, Yan; Xu, Wenbo; Rota, Paul A

    2011-07-01

    The complete genomic sequences of 9 measles vaccine strains were compared with the sequence of the Edmonston wild-type virus. AIK-C, Moraten, Rubeovax, Schwarz, and Zagreb are vaccine strains of the Edmonston lineage, whereas CAM-70, Changchun-47, Leningrad-4 and Shanghai-191 were derived from 4 different wild-type isolates. Nucleotide substitutions were found in the noncoding regions of the genomes as well as in all coding regions, leading to deduced amino acid substitutions in all 8 viral proteins. Although the precise mechanisms involved in the attenuation of individual measles vaccines remain to be elucidated, in vitro assays of viral protein functions and recombinant viruses with defined genetic modifications have been used to characterize the differences between vaccine and wild-type strains. Although almost every protein contributes to an attenuated phenotype, substitutions affecting host cell tropism, virus assembly, and the ability to inhibit cellular antiviral defense mechanisms play an especially important role in attenuation.

  5. Sex without sex chromosomes: genetic architecture of multiple loci independently segregating to determine sex ratios in the copepod Tigriopus californicus.

    Science.gov (United States)

    Alexander, H J; Richardson, J M L; Edmands, S; Anholt, B R

    2015-12-01

    Sex-determining systems are remarkably diverse and may evolve rapidly. Polygenic sex-determination systems are predicted to be transient and evolutionarily unstable, yet examples have been reported across a range of taxa. Here, we provide the first direct evidence of polygenic sex determination in Tigriopus californicus, a harpacticoid copepod with no heteromorphic sex chromosomes. Using genetically distinct inbred lines selected for male- and female-biased clutches, we generated a genetic map with 39 SNPs across 12 chromosomes. Quantitative trait locus mapping of sex ratio phenotype (the proportion of male offspring produced by an F2 female) in four F2 families revealed six independently segregating quantitative trait loci on five separate chromosomes, explaining 19% of the variation in sex ratios. The sex ratio phenotype varied among loci across chromosomes in both direction and magnitude, with the strongest phenotypic effects on chromosome 10 moderated to some degree by loci on four other chromosomes. For a given locus, sex ratio phenotype varied in magnitude for individuals derived from different dam lines. These data, together with the environmental factors known to contribute to sex determination, characterize the underlying complexity and potential lability of sex determination, and confirm the polygenic architecture of sex determination in T. californicus.

  6. Sex differences in genetic architecture of complex phenotypes?

    Directory of Open Access Journals (Sweden)

    Jacqueline M Vink

    Full Text Available We examined sex differences in familial resemblance for a broad range of behavioral, psychiatric and health related phenotypes (122 complex traits in children and adults. There is a renewed interest in the importance of genotype by sex interaction in, for example, genome-wide association (GWA studies of complex phenotypes. If different genes play a role across sex, GWA studies should consider the effect of genetic variants separately in men and women, which affects statistical power. Twin and family studies offer an opportunity to compare resemblance between opposite-sex family members to the resemblance between same-sex relatives, thereby presenting a test of quantitative and qualitative sex differences in the genetic architecture of complex traits. We analyzed data on lifestyle, personality, psychiatric disorder, health, growth, development and metabolic traits in dizygotic (DZ same-sex and opposite-sex twins, as these siblings are perfectly matched for age and prenatal exposures. Sample size varied from slightly over 300 subjects for measures of brain function such as EEG power to over 30,000 subjects for childhood psychopathology and birth weight. For most phenotypes, sample sizes were large, with an average sample size of 9027 individuals. By testing whether the resemblance in DZ opposite-sex pairs is the same as in DZ same-sex pairs, we obtain evidence for genetic qualitative sex-differences in the genetic architecture of complex traits for 4% of phenotypes. We conclude that for most traits that were examined, the current evidence is that same the genes are operating in men and women.

  7. Evolutionary genetics: sex happens in Giardia.

    Science.gov (United States)

    Logsdon, John M

    2008-01-22

    Previous analyses of the Giardia genome exposed numerous genes required for meiosis, suggesting that sexual reproduction is occurring in this early-diverging eukaryote. A new study now uncovers direct genetic evidence for recombination in Giardia populations.

  8. Exacerbation of autoimmune neuroinflammation by dietary sodium is genetically controlled and sex specific.

    Science.gov (United States)

    Krementsov, Dimitry N; Case, Laure K; Hickey, William F; Teuscher, Cory

    2015-08-01

    Multiple sclerosis (MS) is a debilitating autoimmune neuroinflammatory disease influenced by genetics and the environment. MS incidence in female subjects has approximately tripled in the last century, suggesting a sex-specific environmental influence. Recent animal and human studies have implicated dietary sodium as a risk factor in MS, whereby high sodium augmented the generation of T helper (Th) 17 cells and exacerbated experimental autoimmune encephalomyelitis (EAE), the principal model of MS. However, whether dietary sodium interacts with sex or genetics remains unknown. Here, we show that high dietary sodium exacerbates EAE in a strain- and sex-specific fashion. In C57BL6/J mice, exposure to a high-salt diet exacerbated disease in both sexes, while in SJL/JCrHsd mice, it did so only in females. In further support of a genetic component, we found that sodium failed to modify EAE course in C57BL6/J mice carrying a 129/Sv-derived interval on chromosome 17. Furthermore, we found that the high-sodium diet did not augment Th17 or Th1 responses, but it did result in increased blood-brain barrier permeability and brain pathology. Our results demonstrate that the effects of dietary sodium on autoimmune neuroinflammation are sex specific, genetically controlled, and CNS mediated.

  9. The genetic sex-determination system predicts adult sex ratios in tetrapods.

    Science.gov (United States)

    Pipoly, Ivett; Bókony, Veronika; Kirkpatrick, Mark; Donald, Paul F; Székely, Tamás; Liker, András

    2015-11-05

    The adult sex ratio (ASR) has critical effects on behaviour, ecology and population dynamics, but the causes of variation in ASRs are unclear. Here we assess whether the type of genetic sex determination influences the ASR using data from 344 species in 117 families of tetrapods. We show that taxa with female heterogamety have a significantly more male-biased ASR (proportion of males: 0.55 ± 0.01 (mean ± s.e.m.)) than taxa with male heterogamety (0.43 ± 0.01). The genetic sex-determination system explains 24% of interspecific variation in ASRs in amphibians and 36% in reptiles. We consider several genetic factors that could contribute to this pattern, including meiotic drive and sex-linked deleterious mutations, but further work is needed to quantify their effects. Regardless of the mechanism, the effects of the genetic sex-determination system on the adult sex ratio are likely to have profound effects on the demography and social behaviour of tetrapods.

  10. Mating competitiveness of sterile genetic sexing strain males (GAMA) under laboratory and semi-field conditions: Steps towards the use of the Sterile Insect Technique to control the major malaria vector Anopheles arabiensis in South Africa.

    Science.gov (United States)

    Munhenga, Givemore; Brooke, Basil D; Gilles, Jeremie R L; Slabbert, Kobus; Kemp, Alan; Dandalo, Leonard C; Wood, Oliver R; Lobb, Leanne N; Govender, Danny; Renke, Marius; Koekemoer, Lizette L

    2016-03-02

    Anopheles arabiensis Patton is primarily responsible for malaria transmission in South Africa after successful suppression of other major vector species using indoor spraying of residual insecticides. Control of An. arabiensis using current insecticide based approaches is proving difficult owing to the development of insecticide resistance, and variable feeding and resting behaviours. The use of the sterile insect technique as an area-wide integrated pest management system to supplement the control of An. arabiensis was proposed for South Africa and is currently under investigation. The success of this technique is dependent on the ability of laboratory-reared sterile males to compete with wild males for mates. As part of the research and development of the SIT technique for use against An. arabiensis in South Africa, radio-sensitivity and mating competitiveness of a local An. arabiensis sexing strain were assessed. The optimal irradiation dose inducing male sterility without compromising mating vigour was tested using Cobalt 60 irradiation doses ranging from 70-100 Gy. Relative mating competitiveness of sterile laboratory-reared males (GAMA strain) compared to fertile wild-type males (AMAL strain) for virgin wild-type females (AMAL) was investigated under laboratory and semi-field conditions using large outdoor cages. Three different sterile male to fertile male to wild-type female ratios were evaluated [1:1:1, 5:1:1 and 10:1:1 (sterile males: fertile, wild-type males: fertile, wild-type females)]. Irradiation at the doses tested did not affect adult emergence but had a moderate effect on adult survivorship and mating vigour. A dose of 75 Gy was selected for the competitiveness assays. Mating competitiveness experiments showed that irradiated GAMA male mosquitoes are a third as competitive as their fertile AMAL counterparts under semi-field conditions. However, they were not as competitive under laboratory conditions. An inundative ratio of 10:1 induced the

  11. Genetic architecture of sex determination in fish: applications to sex ratio control in aquaculture

    Science.gov (United States)

    Martínez, Paulino; Viñas, Ana M.; Sánchez, Laura; Díaz, Noelia; Ribas, Laia; Piferrer, Francesc

    2014-01-01

    Controlling the sex ratio is essential in finfish farming. A balanced sex ratio is usually good for broodstock management, since it enables to develop appropriate breeding schemes. However, in some species the production of monosex populations is desirable because the existence of sexual dimorphism, primarily in growth or first time of sexual maturation, but also in color or shape, can render one sex more valuable. The knowledge of the genetic architecture of sex determination (SD) is convenient for controlling sex ratio and for the implementation of breeding programs. Unlike mammals and birds, which show highly conserved master genes that control a conserved genetic network responsible for gonad differentiation (GD), a huge diversity of SD mechanisms has been reported in fish. Despite theory predictions, more than one gene is in many cases involved in fish SD and genetic differences have been observed in the GD network. Environmental factors also play a relevant role and epigenetic mechanisms are becoming increasingly recognized for the establishment and maintenance of the GD pathways. Although major genetic factors are frequently involved in fish SD, these observations strongly suggest that SD in this group resembles a complex trait. Accordingly, the application of quantitative genetics combined with genomic tools is desirable to address its study and in fact, when applied, it has frequently demonstrated a multigene trait interacting with environmental factors in model and cultured fish species. This scenario has notable implications for aquaculture and, depending upon the species, from chromosome manipulation or environmental control techniques up to classical selection or marker assisted selection programs, are being applied. In this review, we selected four relevant species or fish groups to illustrate this diversity and hence the technologies that can be used by the industry for the control of sex ratio: turbot and European sea bass, two reference species of

  12. Genetic architecture of sex determination in fish: Applications to sex ratio control in aquaculture

    Directory of Open Access Journals (Sweden)

    Paulino eMartínez

    2014-09-01

    Full Text Available Controlling the sex ratio is essential in finfish farming. A balanced sex ratio is usually good for broodstock management, since it enables to develop appropriate breeding schemes. However, in some species the production of monosex populations is desirable because the existence of sexual dimorphism, primarily in growth or first time of sexual maturation, but also in color or shape, can render one sex more valuable. The knowledge of the genetic architecture of sex determination (SD is convenient for controlling sex ratio and for the implementation of breeding programs. Unlike mammals and birds, which show highly conserved master genes that control a conserved genetic network responsible for gonad differentiation (GD, a huge diversity of SD mechanisms has been reported in fish. Despite theory predictions, more than one gene is in many cases involved in fish SD and genetic differences have been observed in the GD network. Environmental factors also play a relevant role and epigenetic mechanisms are becoming increasingly recognized for the establishment and maintenance of the GD pathways. Although major genetic factors are frequently involved in fish SD, these observations strongly suggest that SD in this group resembles a complex trait. Accordingly, the application of quantitative genetics combined with genomic tools is desirable to address its study and in fact, when applied, it has frequently demonstrated a multigene trait interacting with environmental factors in model and cultured fish species. This scenario has notable implications for aquaculture and, depending upon the species, from chromosome manipulation or environmental control techniques up to classical selection or marker assisted selection programs, are being applied. In this review, we selected four relevant species or fish groups to illustrate this diversity and hence the technologies that can be used by the industry for the control of sex ratio: turbot and European sea bass, two

  13. Genetic architecture of sex determination in fish: applications to sex ratio control in aquaculture.

    Science.gov (United States)

    Martínez, Paulino; Viñas, Ana M; Sánchez, Laura; Díaz, Noelia; Ribas, Laia; Piferrer, Francesc

    2014-01-01

    Controlling the sex ratio is essential in finfish farming. A balanced sex ratio is usually good for broodstock management, since it enables to develop appropriate breeding schemes. However, in some species the production of monosex populations is desirable because the existence of sexual dimorphism, primarily in growth or first time of sexual maturation, but also in color or shape, can render one sex more valuable. The knowledge of the genetic architecture of sex determination (SD) is convenient for controlling sex ratio and for the implementation of breeding programs. Unlike mammals and birds, which show highly conserved master genes that control a conserved genetic network responsible for gonad differentiation (GD), a huge diversity of SD mechanisms has been reported in fish. Despite theory predictions, more than one gene is in many cases involved in fish SD and genetic differences have been observed in the GD network. Environmental factors also play a relevant role and epigenetic mechanisms are becoming increasingly recognized for the establishment and maintenance of the GD pathways. Although major genetic factors are frequently involved in fish SD, these observations strongly suggest that SD in this group resembles a complex trait. Accordingly, the application of quantitative genetics combined with genomic tools is desirable to address its study and in fact, when applied, it has frequently demonstrated a multigene trait interacting with environmental factors in model and cultured fish species. This scenario has notable implications for aquaculture and, depending upon the species, from chromosome manipulation or environmental control techniques up to classical selection or marker assisted selection programs, are being applied. In this review, we selected four relevant species or fish groups to illustrate this diversity and hence the technologies that can be used by the industry for the control of sex ratio: turbot and European sea bass, two reference species of

  14. Genetic study of Kelp"901"strain

    Institute of Scientific and Technical Information of China (English)

    XIA Peng; WANG Xiuliang; LI Xiaojie; ZHAO Yushan; YAO Lin; DUAN Delin

    2005-01-01

    Based on DNA extraction and optimization of random amplified reaction (RAPD) to the gametophytes and sporophytes of Kelp"901"strain,genetic study on variation was conducted to its parents and offsprings of F6,F7,F8,and F9 generation.RAPD results have shown that among 30 selected primers for gametophytes,297 loci ranging from 200 to 3 000 bp were obtained in the average of 9.9 loci for each primer.This indicated a high polymorphic rate with RAPD detection.UPGMA(unweighted pair-group method arithmetic average)analysis showed that each male and female gametophyte of a generation could be clustered into one pair separately.The genetic distances of the Kelp 901 generation were 0.321 2-0.476 7,and the maximum was between F7and F8 (0.476 7).Identityanalysis showed that F6 generation was more close to the female parent(0.659 3),and F7 generation was more close to the male parent(0.578 8).To the sporophytes study in 24 selected primers for RAPD amplification,191 loci ranging from 230-2 800 bp were obtained,in the average to each primer of 8.0 loci.The heterozygosity to six populations were male parent(0.223 9),female parent(0.107 2),F6(0.216 4),F7(0.228 6),F8 (0.229 6)and F9 (0.317 2).The nearest genetic distance was 0.083 5(F8,F9).Total heterozygosity (HT)ofF6,F7,F8and F9 generations was 0.318 6,the average heterozygosity(Hs) for F6,F7,F8 and F9 generations was 0.248 0,and deduced coefficient of population differentiation (Gst) was 22.2%.Six sequence characterized amplified regions (SCAR) were preliminary screened through RAPD analysis.It needed to be verified in detail as they are significant for molecular marker assistance in breeding and selecting Laminaria.

  15. A predictive relationship between population and genetic sex ratios in clonal species

    Science.gov (United States)

    McLetchie, D. Nicholas; García-Ramos, Gisela

    2017-04-01

    Sexual reproduction depends on mate availability that is reflected by local sex ratios. In species where both sexes can clonally expand, the population sex ratio describes the proportion of males, including clonally derived individuals (ramets) in addition to sexually produced individuals (genets). In contrast to population sex ratio that accounts for the overall abundance of the sexes, the genetic sex ratio reflects the relative abundance of genetically unique mates, which is critical in predicting effective population size but is difficult to estimate in the field. While an intuitive positive relationship between population (ramet) sex ratio and genetic (genet) sex ratio is expected, an explicit relationship is unknown. In this study, we determined a mathematical expression in the form of a hyperbola that encompasses a linear to a nonlinear positive relationship between ramet and genet sex ratios. As expected when both sexes clonally have equal number of ramets per genet both sex ratios are identical, and thus ramet sex ratio becomes a linear function of genet sex ratio. Conversely, if sex differences in ramet number occur, this mathematical relationship becomes nonlinear and a discrepancy between the sex ratios amplifies from extreme sex ratios values towards intermediate values. We evaluated our predictions with empirical data that simultaneously quantified ramet and genet sex ratios in populations of several species. We found that the data support the predicted positive nonlinear relationship, indicating sex differences in ramet number across populations. However, some data may also fit the null model, which suggests that sex differences in ramet number were not extensive, or the number of populations was too small to capture the curvature of the nonlinear relationship. Data with lack of fit suggest the presence of factors capable of weakening the positive relationship between the sex ratios. Advantages of this model include predicting genet sex ratio using

  16. Sex specific gene regulation and expression QTLs in mouse macrophages from a strain intercross.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Bhasin

    Full Text Available BACKGROUND: A powerful way to identify genes for complex traits it to combine genetic and genomic methods. Many trait quantitative trait loci (QTLs for complex traits are sex specific, but the reason for this is not well understood. METHODOLOGY/PRINCIPAL FINDINGS: RNA was prepared from bone marrow derived macrophages of 93 female and 114 male F(2 mice derived from a strain intercross between apoE-deficient mice on the AKR and DBA/2 genetic backgrounds, and was subjected to transcriptome profiling using microarrays. A high density genome scan was performed using a mouse SNP chip, and expression QTLs (eQTLs were located for expressed transcripts. Using suggestive and significant LOD score cutoffs of 3.0 and 4.3, respectively, thousands of eQTLs in the female and male cohorts were identified. At the suggestive LOD threshold the majority of the eQTLs were trans eQTLs, mapping unlinked to the position of the gene. Cis eQTLs, which mapped to the location of the gene, had much higher LOD scores than trans eQTLs, indicating their more direct effect on gene expression. The majority of cis eQTLs were common to both males and females, but only approximately 1% of the trans eQTLs were shared by both sexes. At the significant LOD threshold, the majority of eQTLs were cis eQTLs, which were mostly sex-shared, while the trans eQTLs were overwhelmingly sex-specific. Pooling the male and female data, 31% of expressed transcripts were expressed at different levels in males vs. females after correction for multiple testing. CONCLUSIONS/SIGNIFICANCE: These studies demonstrate a large sex effect on gene expression and trans regulation, under conditions where male and female derived cells were cultured ex vivo and thus without the influence of endogenous sex steroids. These data suggest that eQTL data from male and female mice should be analyzed separately, as many effects, such as trans regulation are sex specific.

  17. Genetic sex separation of the malaria vector, Anopheles arabiensis, by exposing eggs to dieldrin.

    Science.gov (United States)

    Yamada, Hanano; Benedict, Mark Q; Malcolm, Colin A; Oliva, Clelia F; Soliban, Sharon M; Gilles, Jeremie R L

    2012-06-19

    The sterile insect technique (SIT) has been used with success for suppressing or eliminating important insect pests of agricultural or veterinary importance. In order to develop SIT for mosquitoes, female elimination prior to release is essential as they are the disease-transmitting sex. A genetic sexing strain (GSS) of Anopheles arabiensis was created based on resistance to dieldrin, and methods of sex separation at the egg stage were developed. The use of this strain for SIT will require sexually sterile males: useful radiation doses for this purpose were determined for pupae and adults. For the creation of the sexing strain, dieldrin-resistant males were irradiated with 40 Gy using a 60Co source and were subsequently crossed to homozygous susceptible virgin females. Individual families were screened for semi-sterility and for male resistance to dieldrin. For sex separation, eggs of a resulting GSS, ANO IPCL1, were exposed to varying concentrations of dieldrin for different durations. Percent hatch, larval survival, and male and female emergence were recorded. Radiation induced sterility was determined following adult and pupa exposure to gamma rays at 0-105 Gy. Mortality induced by dieldrin treatment, and levels of sterility post radiation were investigated. ANO IPCL1 contains a complex chromosome aberration that pseudo-links the male-determining Y chromosome and dieldrin resistance, conferring high natural semi-sterility. Exposure of eggs to 2, 3, and 4 ppm dieldrin solutions resulted in complete female elimination without a significant decrease of male emergence compared to the controls. A dose of 75 Gy reduced the fertility to 3.8 and 6.9% when males were irradiated as pupae or adults respectively, but the proportions of progeny of these males reaching adulthood were 0.6 and 1.5% respectively The GSS ANO IPCL1 was shown to be a suitable strain for further testing for SIT though high semi-sterility is a disadvantage for mass rearing.

  18. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria

    OpenAIRE

    Merilä Juha; Miura Ikuo; Matsuba Chikako

    2008-01-01

    Abstract Background Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria) do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determinat...

  19. Variation, sex, and social cooperation: molecular population genetics of the social amoeba Dictyostelium discoideum.

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    Jonathan M Flowers

    2010-07-01

    Full Text Available Dictyostelium discoideum is a eukaryotic microbial model system for multicellular development, cell-cell signaling, and social behavior. Key models of social evolution require an understanding of genetic relationships between individuals across the genome or possibly at specific genes, but the nature of variation within D. discoideum is largely unknown. We re-sequenced 137 gene fragments in wild North American strains of D. discoideum and examined the levels and patterns of nucleotide variation in this social microbial species. We observe surprisingly low levels of nucleotide variation in D. discoideum across these strains, with a mean nucleotide diversity (pi of 0.08%, and no strong population stratification among North American strains. We also do not find any clear relationship between nucleotide divergence between strains and levels of social dominance and kin discrimination. Kin discrimination experiments, however, show that strains collected from the same location show greater ability to distinguish self from non-self than do strains from different geographic areas. This suggests that a greater ability to recognize self versus non-self may arise among strains that are more likely to encounter each other in nature, which would lead to preferential formation of fruiting bodies with clonemates and may prevent the evolution of cheating behaviors within D. discoideum populations. Finally, despite the fact that sex has rarely been observed in this species, we document a rapid decay of linkage disequilibrium between SNPs, the presence of recombinant genotypes among natural strains, and high estimates of the population recombination parameter rho. The SNP data indicate that recombination is widespread within D. discoideum and that sex as a form of social interaction is likely to be an important aspect of the life cycle.

  20. Genetic Analysis of Haploids from Industrial Strains of Baker's Yeast.

    Science.gov (United States)

    Oda, Y; Ouchi, K

    1989-07-01

    Strains of baker's yeast conventionally used by the baking industry in Japan were tested for the ability to sporulate and produce viable haploid spores. Three isolates which possessed the properties of baker's yeasts were obtained from single spores. Each strain was a haploid, and one of these strains, YOY34, was characterized. YOY34 fermented maltose and sucrose, but did not utilize galactose, unlike its parental strain. Genetic analysis showed that YOY34 carried two MAL genes, one functional and one cryptic; two SUC genes; and one defective gal gene. The genotype of YOY34 was identified as MATalpha MAL1 MAL3g SUC2 SUC4 gall. The MAL1 gene from this haploid was constitutively expressed, was dominant over other wild-type MAL tester genes, and gave a weak sucrose fermentation. YOY34 was suitable for both bakery products, like conventional baker's yeasts, and for genetic analysis, like laboratory strains.

  1. Evolutionary implications of mitochondrial genetic variation: mitochondrial genetic effects on OXPHOS respiration and mitochondrial quantity change with age and sex in fruit flies.

    Science.gov (United States)

    Wolff, J N; Pichaud, N; Camus, M F; Côté, G; Blier, P U; Dowling, D K

    2016-04-01

    The ancient acquisition of the mitochondrion into the ancestor of modern-day eukaryotes is thought to have been pivotal in facilitating the evolution of complex life. Mitochondria retain their own diminutive genome, with mitochondrial genes encoding core subunits involved in oxidative phosphorylation. Traditionally, it was assumed that there was little scope for genetic variation to accumulate and be maintained within the mitochondrial genome. However, in the past decade, mitochondrial genetic variation has been routinely tied to the expression of life-history traits such as fertility, development and longevity. To examine whether these broad-scale effects on life-history trait expression might ultimately find their root in mitochondrially mediated effects on core bioenergetic function, we measured the effects of genetic variation across twelve different mitochondrial haplotypes on respiratory capacity and mitochondrial quantity in the fruit fly, Drosophila melanogaster. We used strains of flies that differed only in their mitochondrial haplotype, and tested each sex separately at two different adult ages. Mitochondrial haplotypes affected both respiratory capacity and mitochondrial quantity. However, these effects were highly context-dependent, with the genetic effects contingent on both the sex and the age of the flies. These sex- and age-specific genetic effects are likely to resonate across the entire organismal life-history, providing insights into how mitochondrial genetic variation may contribute to sex-specific trajectories of life-history evolution.

  2. High genetic variability of HIV-1 in female sex workers from Argentina

    Directory of Open Access Journals (Sweden)

    Carr Jean K

    2007-08-01

    Full Text Available Abstract Background A cross-sectional study on 625 Female Sex Workers (FSWs was conducted between 2000 and 2002 in 6 cities in Argentina. This study describes the genetic diversity and the resistance profile of the HIV-infected subjects. Results Seventeen samples from HIV positive FSWs were genotyped by env HMA, showing the presence of 9 subtype F, 6 subtype B and 2 subtype C. Sequence analysis of the protease/RT region on 16 of these showed that 10 were BF recombinants, three were subtype B, two were subtype C, and one sample presented a dual infection with subtype B and a BF recombinant. Full-length genomes of five of the protease/RT BF recombinants were also sequenced, showing that three of them were CRF12_BF. One FSW had a dual HIV-1 infection with subtype B and a BF recombinant. The B sections of the BF recombinant clustered closely with the pure B sequence isolated from the same patient. Major resistance mutations to antiretroviral drugs were found in 3 of 16 (18.8% strains. Conclusion The genetic diversity of HIV strains among FSWs in Argentina was extensive; about three-quarters of the samples were infected with diverse BF recombinants, near twenty percent had primary ART resistance and one sample presented a dual infection. Heterosexual transmission of genetically diverse, drug resistant strains among FSWs and their clients represents an important and underestimated threat, in Argentina.

  3. Genetic Characterization of Bacillus anthracis 17 JB strain

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    Sakineh Seyed-Mohamadi

    2015-11-01

    Full Text Available Background and Objectives: Bacillus anthracis is one of the most homogenous bacteria ever described. Bacillus anthracis 17JB is a laboratory strain. It is broadly used as a challenge strain in guinea pigs for potency test of anthrax vaccine.Material and Methods: This work describes genetic characterization of B. anthracis 17 JB strain using the SNPs and MLVA genotyping.Results and Conclusion: In SNPs typing, the originally French 17JB strain represented the A. Br. 008/009 subgroup. In Levy's genotyping method, 843, 451 and 864 bp long fragments were identified at AA03, AJ03 and AA07 loci, respectively. In the vaccine manufacturer perspective these findings are much valuable on their own account, but similar research is required to extend molecular knowledge of B. anthracis epidemiology in Persia.Keywords: Bacillus anthracis 17JB, Genetic characterization, SNPs typing

  4. Field Performance of a Genetically Engineered Strain of Pink Bollworm

    Science.gov (United States)

    Simmons, Gregory S.; McKemey, Andrew R.; Morrison, Neil I.; O'Connell, Sinead; Tabashnik, Bruce E.; Claus, John; Fu, Guoliang; Tang, Guolei; Sledge, Mickey; Walker, Adam S.; Phillips, Caroline E.; Miller, Ernie D.; Rose, Robert I.; Staten, Robert T.; Donnelly, Christl A.; Alphey, Luke

    2011-01-01

    Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT) – mass-release of sterile insects to mate with, and thereby control, their wild counterparts – has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field – ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area – were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests. PMID:21931649

  5. Field performance of a genetically engineered strain of pink bollworm.

    Directory of Open Access Journals (Sweden)

    Gregory S Simmons

    Full Text Available Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT--mass-release of sterile insects to mate with, and thereby control, their wild counterparts--has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field--ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area--were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests.

  6. Strains and stressors: an analysis of touchscreen learning in genetically diverse mouse strains.

    Directory of Open Access Journals (Sweden)

    Carolyn Graybeal

    Full Text Available Touchscreen-based systems are growing in popularity as a tractable, translational approach for studying learning and cognition in rodents. However, while mouse strains are well known to differ in learning across various settings, performance variation between strains in touchscreen learning has not been well described. The selection of appropriate genetic strains and backgrounds is critical to the design of touchscreen-based studies and provides a basis for elucidating genetic factors moderating behavior. Here we provide a quantitative foundation for visual discrimination and reversal learning using touchscreen assays across a total of 35 genotypes. We found significant differences in operant performance and learning, including faster reversal learning in DBA/2J compared to C57BL/6J mice. We then assessed DBA/2J and C57BL/6J for differential sensitivity to an environmental insult by testing for alterations in reversal learning following exposure to repeated swim stress. Stress facilitated reversal learning (selectively during the late stage of reversal in C57BL/6J, but did not affect learning in DBA/2J. To dissect genetic factors underlying these differences, we phenotyped a family of 27 BXD strains generated by crossing C57BL/6J and DBA/2J. There was marked variation in discrimination, reversal and extinction learning across the BXD strains, suggesting this task may be useful for identifying underlying genetic differences. Moreover, different measures of touchscreen learning were only modestly correlated in the BXD strains, indicating that these processes are comparatively independent at both genetic and phenotypic levels. Finally, we examined the behavioral structure of learning via principal component analysis of the current data, plus an archival dataset, totaling 765 mice. This revealed 5 independent factors suggestive of "reversal learning," "motivation-related late reversal learning," "discrimination learning," "speed to respond," and

  7. Strains and stressors: an analysis of touchscreen learning in genetically diverse mouse strains.

    Science.gov (United States)

    Graybeal, Carolyn; Bachu, Munisa; Mozhui, Khyobeni; Saksida, Lisa M; Bussey, Timothy J; Sagalyn, Erica; Williams, Robert W; Holmes, Andrew

    2014-01-01

    Touchscreen-based systems are growing in popularity as a tractable, translational approach for studying learning and cognition in rodents. However, while mouse strains are well known to differ in learning across various settings, performance variation between strains in touchscreen learning has not been well described. The selection of appropriate genetic strains and backgrounds is critical to the design of touchscreen-based studies and provides a basis for elucidating genetic factors moderating behavior. Here we provide a quantitative foundation for visual discrimination and reversal learning using touchscreen assays across a total of 35 genotypes. We found significant differences in operant performance and learning, including faster reversal learning in DBA/2J compared to C57BL/6J mice. We then assessed DBA/2J and C57BL/6J for differential sensitivity to an environmental insult by testing for alterations in reversal learning following exposure to repeated swim stress. Stress facilitated reversal learning (selectively during the late stage of reversal) in C57BL/6J, but did not affect learning in DBA/2J. To dissect genetic factors underlying these differences, we phenotyped a family of 27 BXD strains generated by crossing C57BL/6J and DBA/2J. There was marked variation in discrimination, reversal and extinction learning across the BXD strains, suggesting this task may be useful for identifying underlying genetic differences. Moreover, different measures of touchscreen learning were only modestly correlated in the BXD strains, indicating that these processes are comparatively independent at both genetic and phenotypic levels. Finally, we examined the behavioral structure of learning via principal component analysis of the current data, plus an archival dataset, totaling 765 mice. This revealed 5 independent factors suggestive of "reversal learning," "motivation-related late reversal learning," "discrimination learning," "speed to respond," and "motivation during

  8. Detected microsatellite polymorphisms in genetically altered inbred mouse strains.

    Science.gov (United States)

    Du, Xiaoyan; Cui, Jing; Wang, Chao; Huo, Xueyun; Lu, Jing; Li, Yichen; Chen, Zhenwen

    2013-08-01

    Microsatellites are 50-200 repetitive DNA sequences composed of 1- to 6-base-pair-long reiterative motifs within the genome. They are vulnerable to DNA modifications, such as recombination and/or integration, and are recognized as "sentinel" DNA. Our previous report indicated that the genotypes of the microsatellite loci could change from mono- to poly-morphisms (CMP) in gene knockout (KO) mice, implying that genetic modification induces microsatellite mutation. However, it is still unclear whether the random insertion of DNA fragments into mice genomes produced via transgene (Tg) or N-ethyl-N-nitrosourea (ENU) would also result in microsatellite mutations or microsatellite loci genotypes changes. This study was designed to find possible clues to answer this question. In brief, 198 microsatellite loci that were distributed among almost all of the chromosomes (except for the Y) were examined through polymerase chain reaction to screen possible CMPs in six Tg strains. First, for each strain, the microsatellite sequences of all loci were compared between Tg and the corresponding background strain to exclude genetic interference. Simultaneously, to exclude spontaneous mutation-related CMPs that might exist in the examined six strains, mice from five spontaneously mutated inbred strains were used as the negative controls. Additionally, the sequences of all loci in these spontaneous mutated mice were compared to corresponding genetic background controls. The results showed that 40 of the 198 (20.2%) loci were identified as having CMPs in the examined Tg mice strains. The CMP genotypes were either homozygous or heterozygous compared to the background controls. Next, we applied the 40 CMP positive loci in ENU-mutated mice and their corresponding background controls. After that, a general comparison of CMPs that exist among Tg, ENU-treated and KO mouse strains was performed. The results indicated that four (D11mit258, D13mit3, D14mit102 and DXmit172) of the 40 (10%) CMP

  9. Physiologic and genetic characterization of Bacillus sphaericus native strains

    Directory of Open Access Journals (Sweden)

    Jenny Dussen Garzón

    2012-06-01

    Full Text Available Eighteen pathogenic native strains of Bacillus sphaericus that were pathogens to mosquito larvae were isolated from different Colombia regions. The objective of this study was to evaluate at physiological and molecular level pathogenic strains and to compare them with the reference 2362 one. Cellular growth, sporulation percentage, pathogenic activity against third instar larvae of Culex quinquejasciaius, the presence of toxigenic proteins, the size of native plasmids and the genetic polymorphism among pathogenic and non pathogenic isolations was evaluated. The evaluated strains of Bs presented a latency stage ranging from 2 to 3 h and one logarithmic phase of 7 h; the sporulation in BHI was lower than 1% to 40 h of incubation, in NYSM medium was obtained ten times more production of biomass and spores, 26% of the population showed sporulation percentage higher than 90%; the isolations were classified in three groups of pathogenicity with [Formula] and [Formula]. Punctual mutations on the genes which encoding for native toxins were detected and was found a exclusive protein of 30 kDa in pathogenic native strains. The isolations of Bs presented a plasmid of 118Kb that was not related to the toxicity; pathogenic strains are a homogenous group with a similarity between 90 to 100%, whereas non-pathogenic ones are genetically heterogeneous group and conform a cluster aside. The native strains have a great potential in biological control of mosquito larvae that transmitting diseases such as dengue, malaria, encephalitis and filariasis among others.

  10. The effect of sex-biased dispersal on opposite-sexed spatial genetic structure and inbreeding risk.

    Science.gov (United States)

    Blyton, Michaela D J; Banks, Sam C; Peakall, Rod

    2015-04-01

    Natal sex-biased dispersal has long been thought to reduce the risk of inbreeding by spatially separating opposite-sexed kin. Yet, comprehensive and quantitative evaluations of this hypothesis are lacking. In this study, we quantified the effectiveness of sex-biased dispersal as an inbreeding avoidance strategy by combining spatially explicit simulations and empirical data. We quantified the extent of kin clustering by measuring the degree of spatial autocorrelation among opposite-sexed individuals (FM structure). This allowed us to systematically explore how the extent of sex-biased dispersal, generational overlap, and mate searching distance, influenced both kin clustering, and the resulting inbreeding in the absence of complementary inbreeding avoidance strategies. Simulations revealed that when sex-biased dispersal was limited, positive FM genetic structure developed quickly and increased as the mate searching distance decreased or as generational overlap increased. Interestingly, complete long-range sex-biased dispersal did not prevent the development of FM genetic structure when generations overlapped. We found a very strong correlation between FM genetic structure and both FIS under random mating, and pedigree-based measures of inbreeding. Thus, we show that the detection of FM genetic structure can be a strong indicator of inbreeding risk. Empirical data for two species with different life history strategies yielded patterns congruent with our simulations. Our study illustrates a new application of spatial genetic autocorrelation analysis that offers a framework for quantifying the risk of inbreeding that is easily extendable to other species. Furthermore, our findings provide other researchers with a context for interpreting observed patterns of opposite-sexed spatial genetic structure.

  11. Genetic mapping of sex determination in a wild strawberry, Fragaria virginiana, reveals earliest form of sex chromosome.

    Science.gov (United States)

    Spigler, R B; Lewers, K S; Main, D S; Ashman, T-L

    2008-12-01

    The evolution of separate sexes (dioecy) from hermaphroditism is one of the major evolutionary transitions in plants, and this transition can be accompanied by the development of sex chromosomes. Studies in species with intermediate sexual systems are providing unprecedented insight into the initial stages of sex chromosome evolution. Here, we describe the genetic mechanism of sex determination in the octoploid, subdioecious wild strawberry, Fragaria virginiana Mill., based on a whole-genome simple sequence repeat (SSR)-based genetic map and on mapping sex determination as two qualitative traits, male and female function. The resultant total map length is 2373 cM and includes 212 markers on 42 linkage groups (mean marker spacing: 14 cM). We estimated that approximately 70 and 90% of the total F. virginiana genetic map resides within 10 and 20 cM of a marker on this map, respectively. Both sex expression traits mapped to the same linkage group, separated by approximately 6 cM, along with two SSR markers. Together, our phenotypic and genetic mapping results support a model of gender determination in subdioecious F. virginiana with at least two linked loci (or gene regions) with major effects. Reconstruction of parental genotypes at these loci reveals that both female and hermaphrodite heterogamety exist in this species. Evidence of recombination between the sex-determining loci, an important hallmark of incipient sex chromosomes, suggest that F. virginiana is an example of the youngest sex chromosome in plants and thus a novel model system for the study of sex chromosome evolution.

  12. Genetic divergence and the genetic architecture of complex traits in chromosome substitution strains of mice

    Directory of Open Access Journals (Sweden)

    Spiezio Sabrina H

    2012-05-01

    Full Text Available Abstract Background The genetic architecture of complex traits strongly influences the consequences of inherited mutations, genetic engineering, environmental and genetic perturbations, and natural and artificial selection. But because most studies are under-powered, the picture of complex traits is often incomplete. Chromosome substitution strains (CSSs are a unique paradigm for these genome surveys because they enable statistically independent, powerful tests for the phenotypic effects of each chromosome on a uniform inbred genetic background. A previous CSS survey in mice and rats revealed many complex trait genes (QTLs, large phenotypic effects, extensive epistasis, as well as systems properties such as strongly directional phenotypic changes and genetically-determined limits on the range of phenotypic variation. However, the unusually close genetic relation between the CSS progenitor strains in that study raised questions about the impact of genetic divergence: would greater divergence between progenitor strains, with the corresponding changes in gene regulation and protein function, lead to significantly more distinctive phenotypic features, or alternatively would epistasis and systems constraints, which are pervasive in CSSs, limit the range of phenotypic variation regardless of the extent of DNA sequence variation? Results We analyzed results for an extensive survey of traits in two new panels of CSSs where the donor strains were derived from inbred strains with more distant origins and discovered a strong similarity in genetic and systems properties among the three CSS panels, regardless of divergence time. Conclusion Our results argue that DNA sequence differences between host and donor strains did not substantially affect the architecture of complex traits, and suggest instead that strong epistasis buffered the phenotypic effects of genetic divergence, thereby constraining the range of phenotypic variation.

  13. Genetic Characterization of Bacillus anthracis 17 JB strain.

    Science.gov (United States)

    Seyed-Mohamadi, Sakineh; Moradi Bidhendi, Soheila; Tadayon, Keyvan; Ghaderi, Rainak

    2015-06-01

    Bacillus anthracis is one of the most homogenous bacteria ever described. Some level of diversity. Bacillus anthracis 17JB is a laboratory strain It is broadly used as a challenge strain in guinea pigs for potency test of anthrax vaccine. This work describes genetic characterization of B. anthracis 17 JB strain using the SNPs and MLVA genotyping. In SNPs typing, the originally French 17JB strain represented the A.Br. 008/009 subgroup. In Levy's genotyping method, 843, 451 and 864 bp long fragments were identified at AA03, AJ03 and AA07 loci, respectively. In the vaccine manufacturer perspective these findings are much valuable on their own account, but similar research is required to extend molecular knowledge of B. anthracis epidemiology in Persia.

  14. Strain gage selection in loads equations using a genetic algorithm

    Science.gov (United States)

    1994-01-01

    Traditionally, structural loads are measured using strain gages. A loads calibration test must be done before loads can be accurately measured. In one measurement method, a series of point loads is applied to the structure, and loads equations are derived via the least squares curve fitting algorithm using the strain gage responses to the applied point loads. However, many research structures are highly instrumented with strain gages, and the number and selection of gages used in a loads equation can be problematic. This paper presents an improved technique using a genetic algorithm to choose the strain gages used in the loads equations. Also presented are a comparison of the genetic algorithm performance with the current T-value technique and a variant known as the Best Step-down technique. Examples are shown using aerospace vehicle wings of high and low aspect ratio. In addition, a significant limitation in the current methods is revealed. The genetic algorithm arrived at a comparable or superior set of gages with significantly less human effort, and could be applied in instances when the current methods could not.

  15. Genetic characterization of type A enterotoxigenic Clostridium perfringens strains.

    Directory of Open Access Journals (Sweden)

    Agi Deguchi

    Full Text Available Clostridium perfringens type A, is both a ubiquitous environmental bacterium and a major cause of human gastrointestinal disease, which usually involves strains producing C. perfringens enterotoxin (CPE. The gene (cpe encoding this toxin can be carried on the chromosome or a large plasmid. Interestingly, strains carrying cpe on the chromosome and strains carrying cpe on a plasmid often exhibit different biological characteristics, such as resistance properties against heat. In this study, we investigated the genetic properties of C. perfringens by PCR-surveying 21 housekeeping genes and genes on representative plasmids and then confirmed those results by Southern blot assay (SB of five genes. Furthermore, sequencing analysis of eight housekeeping genes and multilocus sequence typing (MLST analysis were also performed. Fifty-eight C. perfringens strains were examined, including isolates from: food poisoning cases, human gastrointestinal disease cases, foods in Japan or the USA, or feces of healthy humans. In the PCR survey, eight of eleven housekeeping genes amplified positive reactions in all strains tested. However, by PCR survey and SB assay, one representative virulence gene, pfoA, was not detected in any strains carrying cpe on the chromosome. Genes involved in conjugative transfer of the cpe plasmid were also absent from almost all chromosomal cpe strains. MLST showed that, regardless of their geographic origin, date of isolation, or isolation source, chromosomal cpe isolates, i assemble into one definitive cluster ii lack pfoA and iii lack a plasmid related to the cpe plasmid. Similarly, independent of their origin, strains carrying a cpe plasmid also appear to be related, but are more variable than chromosomal cpe strains, possibly because of the instability of cpe-borne plasmid(s and/or the conjugative transfer of cpe-plasmid(s into unrelated C. perfringens strains.

  16. Genetic mapping of social interaction behavior in B6/MSM consomic mouse strains.

    Science.gov (United States)

    Takahashi, Aki; Tomihara, Kazuya; Shiroishi, Toshihiko; Koide, Tsuyoshi

    2010-05-01

    Genetic studies are indispensable for understanding the mechanisms by which individuals develop differences in social behavior. We report genetic mapping of social interaction behavior using inter-subspecific consomic strains established from MSM/Ms (MSM) and C57BL/6J (B6) mice. Two animals of the same strain and sex, aged 10 weeks, were introduced into a novel open-field for 10 min. Social contact was detected by an automated system when the distance between the centers of the two animals became less than approximately 12 cm. In addition, detailed behavioral observations were made of the males. The wild-derived mouse strain MSM showed significantly longer social contact as compared to B6. Analysis of the consomic panel identified two chromosomes (Chr 6 and Chr 17) with quantitative trait loci (QTL) responsible for lengthened social contact in MSM mice and two chromosomes (Chr 9 and Chr X) with QTL that inhibited social contact. Detailed behavioral analysis of males identified four additional chromosomes associated with social interaction behavior. B6 mice that contained Chr 13 from MSM showed more genital grooming and following than the parental B6 strain, whereas the presence of Chr 8 and Chr 12 from MSM resulted in a reduction of those behaviors. Longer social sniffing was observed in Chr 4 consomic strain than in B6 mice. Although the frequency was low, aggressive behavior was observed in a few pairs from consomic strains for Chrs 4, 13, 15 and 17, as well as from MSM. The social interaction test has been used as a model to measure anxiety, but genetic correlation analysis suggested that social interaction involves different aspects of anxiety than are measured by open-field test.

  17. Cell Factory Stability and Genetic Circuits for Improved Strain Development

    DEFF Research Database (Denmark)

    Rugbjerg, Peter

    Development of new chemical-­‐producing microbial cell factories is an iterative trial-­and-­error process, and to screen candidate cells at high throughput, genetic biosensor systems are appealing. Each biosensor has distinct biological parameters, making modular tuning networks attractive....... However, all synthetic gene systems -­ including the target metabolic pathways themselves -­ represent a possible fitness burden to the cell and thus constitute a threat to strain stability. In this thesis, several studies served to develop genetic systems for optimizing cell factory development...... factories in future....

  18. Sex differences in genetic and environmental risk factors for irrational fears and phobias.

    Science.gov (United States)

    Kendler, K S; Jacobson, K C; Myers, J; Prescott, C A

    2002-02-01

    For irrational fears and their associated phobias, epidemiological studies suggest sex differences in prevalence and twin studies report significant genetic effects. How does sex impact on the familial transmission of liability to fears and phobias? In personal interviews with over 3000 complete pairs (of whom 1058 were opposite-sex dizygotic pairs), ascertained from a population-based registry, we assessed the lifetime prevalence of five phobias and their associated irrational fears analysed using a multiple threshold model. Twin resemblance was assessed by polychoric correlations and biometrical model-fitting incorporating sex-specific effects. For agoraphobia, situational and blood/injury fear/phobia, the best fit model suggested equal heritability in males and females and genetic correlations between the sexes of less than +0.50. For animal fear/phobias by contrast, the best fit model suggested equal heritability in males and females and a genetic correlation of unity. No evidence was found for an impact of family environment on liability to these fears or phobias. For social phobias, twin resemblance in males was explained by genetic factors and in females by familial-environmental factors. The impact of sex on genetic risk may differ meaningfully across phobia subtypes. Sex-specific genetic risk factors may exist for agoraphobia, social, situational and blood-injury phobias but not for animal fear/phobia. These results should be interpreted in the context of the limited power of twin studies, even with large sample sizes, to resolve sex-specific genetic effects.

  19. Genetic variation in virulence among chalkbrood strains infecting honeybees.

    Directory of Open Access Journals (Sweden)

    Svjetlana Vojvodic

    Full Text Available Ascosphaera apis causes chalkbrood in honeybees, a chronic disease that reduces the number of viable offspring in the nest. Although lethal for larvae, the disease normally has relatively low virulence at the colony level. A recent study showed that there is genetic variation for host susceptibility, but whether Ascosphaera apis strains differ in virulence is unknown. We exploited a recently modified in vitro rearing technique to infect honeybee larvae from three colonies with naturally mated queens under strictly controlled laboratory conditions, using four strains from two distinct A. apis clades. We found that both strain and colony of larval origin affected mortality rates. The strains from one clade caused 12-14% mortality while those from the other clade induced 71-92% mortality. Larvae from one colony showed significantly higher susceptibility to chalkbrood infection than larvae from the other two colonies, confirming the existence of genetic variation in susceptibility across colonies. Our results are consistent with antagonistic coevolution between a specialized fungal pathogen and its host, and suggest that beekeeping industries would benefit from more systematic monitoring of this chronic stress factor of their colonies.

  20. Genetics and genomics of ovarian sex cord-stromal tumors.

    Science.gov (United States)

    Fuller, P J; Leung, D; Chu, S

    2017-02-01

    Ovarian sex cord-stromal tumors (SCST) represent approximately 8% of malignant ovarian tumors. The most common are granulosa cell tumors (GCT) which account for approximately 90% of malignant SCST. Recent studies have unraveled the key genomic and genetic events contributing to their pathogenesis. SCST are found in the hereditary syndromes: Peutz-Jeghers syndrome, Ollier disease and Maffucci syndrome, and DICER1 syndrome. Genomic studies have largely been limited to GCT where a number of recurring chromosomal abnormalities (monsomy and trisomy) have been identified although their contribution to pathogenesis remains unclear. In addition to the recurrent DICER1 mutations reported in non-hereditary cases of Sertoli cell and Sertoli-Leydig cell tumors, recurrent somatic mutations in both the juvenile (j) and adult (a) forms of GCT have been reported. Approximately 30% of jGCT contain a somatic mutation, the gsp oncogene, while a further 60% have an activating mutation in the AKT gene. In the case of aGCT, a well characterized mutation in the FOXL2 transcription factor (FOXL2 C134W) is found in almost all cases, which arguably defines the disease, although the molecular events that determine the stage, behavior and prognosis of aGCT remain to be determined. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Children with sex chromosome trisomies: parental disclosure of genetic status.

    Science.gov (United States)

    Gratton, Nikki C; Myring, Jessica; Middlemiss, Prisca; Shears, Deborah; Wellesley, Diana; Wynn, Sarah; Bishop, Dorothy Vm; Scerif, Gaia

    2016-05-01

    Sex chromosome trisomies (SCTs) are frequently diagnosed, both prenatally and postnatally, but the highly variable childhood outcomes can leave parents at a loss on whether, when and how to disclose genetic status. In two complementary studies, we detail current parental practices, with a view to informing parents and their clinicians. Study 1 surveyed detailed qualitative data from focus groups of parents and affected young people with either Trisomy X or XYY (N=34 families). These data suggested that decisions to disclose were principally affected by the child's level of cognitive, social and emotional functioning. Parents reported that they were more likely to disclose when a child was experiencing difficulties. In Study 2, standardised data on cognitive, social and emotional outcomes in 126 children with an SCT and 63 sibling controls highlighted results that converged with Study 1: logistic regression analyses revealed that children with the lowest levels of functioning were more likely to know about their SCT than those children functioning at a higher level. These effects were also reflected in the likelihood of parents to disclose to unaffected siblings, schools and general practitioners. In contrast, specific trisomy type and the professional category of the clinician providing the original diagnosis did not affect likelihood of disclosure. Our study emphasises the complex weighing up of costs and benefits that parents engage in when deciding whether to disclose a diagnosis.

  2. Genetic characterisation of four strains of Nile tilapia (Oreochromie Niloticus L.) using microsatellite markers

    NARCIS (Netherlands)

    Rutten, M.J.M.; Komen, J.; Deerenberg, R.M.; Siwek-Gapinska, M.Z.; Bovenhuis, H.

    2004-01-01

    Four domesticated strains of Nile tilapia (Oreochromis niloticus L.) were genetically characterized using 14 microsatellite markers and 64 animals per strain. Two strains, Chitralada (AIT) and International Development Research Centers (IDRC) were obtained from the AIT institute, Bangkok, Thailand.

  3. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria.

    Science.gov (United States)

    Matsuba, Chikako; Miura, Ikuo; Merilä, Juha

    2008-01-08

    Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria) do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species. A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population. These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals - for which there is earlier evidence from this species - are frequently occurring.

  4. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria

    Directory of Open Access Journals (Sweden)

    Merilä Juha

    2008-01-01

    Full Text Available Abstract Background Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species. Results A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population. Conclusion These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals – for which there is earlier evidence from this species – are frequently occurring.

  5. The Effect of Ivermectin in Seven Strains of Aedes aegypti (Diptera: Culicidae) Including a Genetically Diverse Laboratory Strain and Three Permethrin Resistant Strains

    OpenAIRE

    Deus, K. M.; Saavedra-rodriguez, K.; Butters, M. P.; Black, W C; Foy, B.D.

    2012-01-01

    Seven different strains of Aedes aegypti (L.), including a genetically diverse laboratory strain, three laboratory-selected permethrin-resistant strains, a standard reference strain, and two recently colonized strains were fed on human blood containing various concentrations of ivermectin. Ivermectin reduced adult survival, fecundity, and hatch rate of eggs laid by ivermectin-treated adults in all seven strains. The LC50 of ivermectin for adults and the concentration that prevented 50% of egg...

  6. Magnetic resonance imaging detects significant sex differences in human myocardial strain

    Directory of Open Access Journals (Sweden)

    Reynolds Lina M

    2011-08-01

    Full Text Available Abstract Background The pathophysiology responsible for the significant outcome disparities between men and women with cardiac disease is largely unknown. Further investigation into basic cardiac physiological differences between the sexes is needed. This study utilized magnetic resonance imaging (MRI-based multiparametric strain analysis to search for sex-based differences in regional myocardial contractile function. Methods End-systolic strain (circumferential, longitudinal, and radial was interpolated from MRI-based radiofrequency tissue tagging grid point displacements in each of 60 normal adult volunteers (32 females. Results The average global left ventricular (LV strain among normal female volunteers (n = 32 was significantly larger in absolute value (functionally better than in normal male volunteers (n = 28 in both the circumferential direction (Male/Female = -0.19 ± 0.02 vs. -0.21 ± 0.02; p = 0.025 and longitudinal direction (Male/Female = -0.14 ± 0.03 vs. -0.16 ± 0.02; p = 0.007. Conclusions The finding of significantly larger circumferential and longitudinal LV strain among normal female volunteers suggests that baseline contractile differences between the sexes may contribute to the well-recognized divergence in cardiovascular disease outcomes. Further work is needed in order to determine the pathologic changes that occur in LV strain between women and men with the onset of cardiovascular disease.

  7. Isolation and characterization of a bacterial strain that efficiently degrades sex steroid hormones

    Institute of Scientific and Technical Information of China (English)

    JI Shulan; LIU Zhipei; LIU Zhipeng; REN Haiyan

    2007-01-01

    A bacterial strain,ZY3,growing on sex steroid hormones as the sole source of carbon and energy was isolated from the sewage treatment plant of a prophylactic steroids factory.ZY3 degrades the 3-methoxy-17β-hyclroxy-1,3,5(10),8(9)-δ-4-estren (MHE).This strain was preliminarily identified as Raoultella sp.ZY3 according to its morphology and its 16S rRNA gene sequence.During the experimental period (72 h),the optimum temperature,pH and 3-MHE concentration for the degradation of hydride by the strain ZY3 were 35℃,10 and 10 mg/L,respectively.The degradation rate of the sex steroid hormones increased to 87% and 85% after the addition of maltose and peptone,respectively.

  8. Sex-specific and strain-dependent effects of early life adversity on behavioral and epigenetic outcomes

    Directory of Open Access Journals (Sweden)

    Marija eKundakovic

    2013-08-01

    Full Text Available Early life adversity can have a significant long-term impact with implications for the emergence of psychopathology. Disruption to mother-infant interactions is a form of early life adversity that may, in particular, have profound programming effects on the developing brain. However, despite converging evidence from human and animal studies, the precise mechanistic pathways underlying adversity-associated neurobehavioral changes has yet to be elucidated. One approach to the study of mechanism is exploration of epigenetic changes associated with early life experience. In the current study, we examined the effects of postnatal maternal separation in mice and assessed the behavioral, brain gene expression, and epigenetic effects of this manipulation in offspring. Importantly, we included two different mouse strains (B6 and Balb/c and both male and female offspring to determine strain- and/or sex-associated differential response to maternal separation. We found both strain-specific and sex-dependent effects of maternal separation in early adolescent offspring on measures on open-field exploration, sucrose preference, and social behavior. Analyses of cortical and hippocampal mRNA levels of the glucocorticoid receptor (Nr3c1 and brain-derived neurotrophic factor (Bdnf genes revealed decreased hippocampal Bdnf expression in maternally-separated B6 females and increased cortical Bdnf expression in maternally separated male and female Balb/c offspring. Analyses of Nr3c1and Bdnf (IV and IX CpG methylation indicated increased hippocampal Nr3c1 methylation in maternally separated B6 males and increased hippocampal Bdnf IX methylation in male and female maternally separated Balb/c mice. Overall, though effect sizes were modest, these findings suggest a complex interaction between early life adversity, genetic background, and sex in the determination of neurobehavioral and epigenetic outcomes that may account for differential vulnerability to later life

  9. Sex differences in the genetic risk for schizophrenia: history of the evidence for sex-specific and sex-dependent effects.

    Science.gov (United States)

    Goldstein, Jill M; Cherkerzian, Sara; Tsuang, Ming T; Petryshen, Tracey L

    2013-10-01

    Although there is a long history to examinations of sex differences in the familial (and specifically, genetic) transmission of schizophrenia, there have been few investigators who have systematically and rigorously studied this issue. This is true even in light of population and clinical studies identifying significant sex differences in incidence, expression, neuroanatomic and functional brain abnormalities, and course of schizophrenia. This review highlights the history of work in this arena from studies of family transmission patterns, linkage and twin studies to the current molecular genetic strategies of large genome-wide association studies. Taken as a whole, the evidence supports the presence of genetic risks of which some are sex-specific (i.e., presence in one sex and not the other) or sex-dependent (i.e., quantitative differences in risk between the sexes). Thus, a concerted effort to systematically investigate these questions is warranted and, as we argue here, necessary in order to fully understand the etiology of schizophrenia. © 2013 Wiley Periodicals, Inc.

  10. Sex Education and Intellectual Disability: Practices and Insight from Pediatric Genetic Counselors.

    Science.gov (United States)

    Murphy, Carly; Lincoln, Sharyn; Meredith, Stephanie; Cross, Elizabeth M; Rintell, David

    2016-06-01

    Intellectual disability (ID) with or without other anomalies is a common referral for genetic counseling. Sessions may include discussions of reproductive implications and other issues related to sex education. Patients with ID regularly meet barriers when trying to obtain sex education due to the misperceptions of others as being either asexual or that such education would promote inappropriate sexual behavior. In this pilot study, we surveyed genetic counselors to explore their experiences with being asked to provide sex education counseling and their comfort in doing so for patients with ID ages 9-17. Results were analyzed from 38 respondents. Caregivers and patients most frequently requested information on puberty, sex abuse prevention, and reproductive health. Genetic counselors were most comfortable when they could provide sex education counseling within the context of a particular condition or constellation of features. They were least comfortable when they lacked familiarity with the patient, caregiver, or the family's culture. The most frequently cited barriers that prevented genetic counselors from providing sex education counseling were lack of time, lack of training, the patient's ID being too profound, and a belief that genetic counselors should not be responsible for providing sex education counseling. While many respondents reported that providing sex education counseling is not considered within the scope of a genetic counselor's practice, they also noted that patients' families initiate discussions for which counselors should be prepared. Respondents indicated that resource guides specifically designed for use by genetic counselors would be beneficial to their practice. Genetic counselors have the opportunity to embrace the role of advocate and broach the issue of sexual health with caregivers and patients by directing them toward educational resources, if not providing sex education directly to effectively serve the needs of patients and

  11. Effect of sex, age, and breed on genetic recombination features in cattle

    Science.gov (United States)

    Meiotic recombination is a fundamental biological process which generates genetic diversity, affects fertility, and influences evolvability. Here we investigate the roles of sex, age, and breed in cattle recombination features, including recombination rate, location and crossover interference. Usin...

  12. Genetic Characterization of Four Strains Borrelia Burgdorferi Isolated in China

    Institute of Scientific and Technical Information of China (English)

    曾霞; 王树声; 张涛; 毕胜利; 周永东

    2004-01-01

    To study the genetic characterization of four strains of Borrelia burgdorferi isolated in China. PCR technique was used to amplify the 5S-23S rRNA intergenic spacer DNA from the whole cellular DNA of isolated GXLD-4, 9, 18 and Chang 14, and then the amplified products were cloned into plasmid pGEM-T Easy and sequenced. It was found that the 5S-23S rRNA intergenic spacer DNA of the four isolates was 242 bp, revealing the nucleotide sequence identity of more than 99%. The four isolates had higher sequence identify with Borrelia valaisiana than with other genetic groups. These four isolates most likely belong to Borrelia valaisiana genomic group.

  13. Exploring Contemporary Issues in Genetics & Society: Karyotyping, Biological Sex, & Gender

    Science.gov (United States)

    Brown, Julie C.

    2013-01-01

    In this two-part activity, high school biology students examine human karyotyping, sex-chromosome-linked disorders, and the relationship between biological sex and gender. Through interactive simulations and a structured discussion lab, students create a human karyotype and diagnose chromosomal disorders in hypothetical patients, as well as…

  14. Mutation in a sex-determinig gene in rainbow trout: detection and genetic analysis

    OpenAIRE

    2002-01-01

    In rainbow trout (Oncorhynchus mykiss), the acknowledged sex-determining system is genetic sex determination (GSD) with female homogamety (_XX-_XY). Subsequently, mitotic gynogens are all expected to be females. Unexpected maleness was fortuitously observed in a mitotic gynogenetic family of rainbow trout (13 males out of 27). An equal ratio of males and females suggested the possible segregation of some Mendelian sex-influencing factor. In order to perform a comprehensive analysis of the inh...

  15. Patterns and mechanisms of evolutionary transitions between genetic sex-determining systems

    NARCIS (Netherlands)

    van Doorn, G. Sander

    2014-01-01

    The diversity and patchy phylogenetic distribution of genetic sex-determining mechanisms observed in some taxa is thought to have arisen by the addition, modification, or replacement of regulators at the upstream end of the sex-determining pathway. Here, I review the various evolutionary forces acti

  16. Sex change and effective population size: implications for population genetic studies in marine fish.

    Science.gov (United States)

    Coscia, I; Chopelet, J; Waples, R S; Mann, B Q; Mariani, S

    2016-10-01

    Large variance in reproductive success is the primary factor that reduces effective population size (Ne) in natural populations. In sequentially hermaphroditic (sex-changing) fish, the sex ratio is typically skewed and biased towards the 'first' sex, while reproductive success increases considerably after sex change. Therefore, sex-changing fish populations are theoretically expected to have lower Ne than gonochorists (separate sexes), assuming all other parameters are essentially equal. In this study, we estimate Ne from genetic data collected from two ecologically similar species living along the eastern coast of South Africa: one gonochoristic, the 'santer' sea bream Cheimerius nufar, and one protogynous (female-first) sex changer, the 'slinger' sea bream Chrysoblephus puniceus. For both species, no evidence of genetic structuring, nor significant variation in genetic diversity, was found in the study area. Estimates of contemporary Ne were significantly lower in the protogynous species, but the same pattern was not apparent over historical timescales. Overall, our results show that sequential hermaphroditism may affect Ne differently over varying time frames, and that demographic signatures inferred from genetic markers with different inheritance modes also need to be interpreted cautiously, in relation to sex-changing life histories.

  17. Genetics of sex determination in the haplodiploid wasp Nasonia vitripennis (Hymenoptera: Chalcidoidea)

    Indian Academy of Sciences (India)

    Leo W. Beukeboom; Louis Van De Zande

    2010-09-01

    The parasitoid wasp Nasonia vitripennis reproduces by haplodiploidy; males are haploid and females are diploid. Sex determination in Nasonia is not governed by complementary alleles at one or more sex loci. As in most other insects, the sex-determining pathway consists of the basal switch doublesex that is sex-specifically regulated by transformer. Analysis of a polyploid and a mutant gynandromorphic strain, suggested a parent-specific effect (imprinting) on sex determination in Nasonia. Zygotic activity of transformer is autoregulated and depends on a combination of maternal provision of tra mRNA and a paternal genome set. This constitutes a novel way of transformer control in insect sex determination implying maternal imprinting. The nature of the maternal imprint is not yet known and it remains to be determined how broadly the Nasonia sex-determining mechanism applies to other haplodiploids.

  18. Variation in the production and distribution of substituted benzoquinone compounds among genetic strains of the confused flour beetle, Tribolium confusum.

    Science.gov (United States)

    Yezerski, A; Gilmor, T P; Stevens, L

    2000-01-01

    Insects often produce chemicals, such as defensive compounds, whose quantity and distribution can affect their fitness. For evolution to produce adaptations, chemical production must be genetically variable. Here we report the results of a study using high-performance liquid chromatography to quantify two important chemical secretions of the flour beetle Tribolium confusum, methyl-1, 4-benzoquinone (MBQ) and ethyl-1,4-benzoquinone (EBQ). Our results show a distinct difference in the production of the compounds among four genetically distinct strains of T. confusum (b-+, b-I, b-IV, b-Pakistan) with an unusually high amount measured for the b-Pakistan strain. By measuring internal and external benzoquinone levels separately, we were also able to detect differences in production and distribution of the compounds between the strains. Some strains secrete more of the chemicals, whereas other strains appear to sequester the compounds within their bodies. The sexes also differ in total quinone production as well as in their internal to external benzoquinone ratios, suggesting the trait is sex influenced. Finally, a consistent correlation in the amounts of MBQ to EBQ in individual beetles suggests that the substituted benzoquinones share a common precursor or pathway.

  19. Immortalized Rat Astrocyte Strain Genetically Modified by Rat Preprogalanin Gene

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To construct an immortalized rat astrocyte strain genetically modified by rat preprogalanin gene (IAST/GAL) and detect its galanin (GAL) expression and secretion, a cDNA fragment of rat GAL in plasmid of pBS KS(+)-GAL was inserted into eukaryotic expression vector pcDNA3.1(+) by DNA recombinant technology, then the restriction enzyme digestion and DNA sequencing were carried out to evaluate the recombinant. The pcDNA3.1 (+)-GAL and pcDNA3.1 (+) construct were transfected into immortalized rat astrocyte strain (IAST) by lipofectamine and the population of cells which stably integrated the construct was selected with 600 μg/mL G418. Individual clones were screened and expanded into clonal cell strains. Detection of Neo gene was used to validate the success of the transfection. Immunocytochemical staining, RT-PCR and radioimmunoassay were used to detect the expression and secretion level of GAL. The recombinant had been successfully constructed by restriction enzyme digestion and DNA sequencing. Detection of Neo gene showed that the pcDNA3.1 (+)-GAL and pcDNA3.1 (+) have been successfully transfected into IAST. After selection by using G418, IAST/GAL and IAST/Neo cell strains were obtained.IAST/GAL, IAST/Neo and IAST were immunostained positively for GAL, but the GAL average optical density of IAST/GAL was significantly higher than that of IAST/Neo and IAST (P<0.01). The level of GAL mRNA expression and the supernatant concentration of GAL in cultured IAST/GAL were significantly higher than those of IAST and IAST/Neo (P<0.01), but no significant differences were found between the IAST and IAST/Neo (P>0.05). It was concluded that IAST/GAL strain was constructed successfully and it might provide a basis for the further study of pain therapy.

  20. Towards mosquito sterile insect technique programmes: exploring genetic, molecular, mechanical and behavioural methods of sex separation in mosquitoes.

    Science.gov (United States)

    Gilles, Jeremie R L; Schetelig, Marc F; Scolari, Francesca; Marec, František; Capurro, Margareth L; Franz, Gerald; Bourtzis, Kostas

    2014-04-01

    When considering a mosquito release programme, one of the first issues to be addressed is how to eliminate/separate the females. The greatest number of options might eventually be available for those who can use transgenic mosquitoes, but the inherent characteristics of the target species may also provide possibilities for interim measures until more efficient methods can be developed. Differences in intrinsic size, in behaviour and in development rate between females and males are often available and useful for sexing. Efficient species-specific systems for eliminating females at the embryo stage have been developed, but most have since been discarded due to lack of use. Ideal systems specifically kill female embryos using some treatment that can be manipulated during production. Such killing systems are far more efficient than using intrinsic sexual differences, but they systems require selectable genetic markers and sex-linkage created by rare random chromosomal rearrangements. While intrinsic sexual differences should not be considered as long-term candidates for the development of robust and efficient sexing approaches, in the absence of these, the accessibility and integration of less efficient systems can provide a stop-gap measure that allows rapid start up with a minimum of investment. The International Atomic Energy Agency is funding over a 5 year period (2013-2018) a new Coordinated Research Project on "Exploring Genetic, Molecular, Mechanical and Behavioural Methods of Sex Separation in Mosquitoes" to network researchers and to address the critical need of genetic sexing strains for the implementation of the sterile insect technique (using radiation-sterilised or transgenic male mosquitoes) and for insect incompatibility technique programmes against disease-transmitting mosquitoes. Copyright © 2013 International Atomic Energy Agency. Published by Elsevier B.V. All rights reserved.

  1. Clinical applications of fetal sex determination in maternal blood in a preimplantation genetic diagnosis centre.

    Science.gov (United States)

    Tachdjian, Gérard; Frydman, Nelly; Audibert, Franciois; Ray, Pierre; Kerbrat, Violaine; Ernault, Pauline; Frydman, René; Costa, Jean-Marc

    2002-08-01

    Couples with a risk of transmitting X-linked diseases who are included in a preimplantation genetic diagnosis (PGD) programme need early and rapid fetal sex determination in two situations. The first situation is for the control of embryo sexing after PGD and the second situation is for those couples having a spontaneous pregnancy before the start of their PGD cycle. Among invasive techniques, chorionic villus sampling is the earliest procedure for fetal sex determination and molecular analysis of X-linked genetic disorders during the first trimester but it is associated with a risk of fetal loss. Non-invasive procedures such as ultrasound examination allow reliable fetal sex determination only during the second trimester. Reliable fetal sex determination can now be realised by using SRY gene amplification in maternal blood. We report the use of fetal sex determination from maternal serum as a diagnostic tool for the control of embryo sexing (two cases) and to manage spontaneous pregnancies in couples included in a PGD programme for X-linked diseases (five cases). Fetal sex determination using SRY gene amplification in maternal serum were in complete concordance with fetal sex observed by cytogenetic analysis or ultrasound examination and at birth. This novel strategy allowed the PGD results to be controlled precociously and avoided the performance of invasive procedures in four cases of female fetus. This rapid fetal sex determination during the first trimester provides advantages to both clinicians and patients in a PGD centre.

  2. Genetic susceptibility to dental caries differs between the sexes: a family-based study.

    Science.gov (United States)

    Shaffer, John R; Wang, Xiaojing; McNeil, Daniel W; Weyant, Robert J; Crout, Richard; Marazita, Mary L

    2015-01-01

    Many of the factors affecting susceptibility to dental caries are likely influenced by genetics. In fact, genetics accounts for up to 65% of inter-individual variation in dental caries experience. Sex differences in dental caries experience have been widely reported, with females usually exhibiting a higher prevalence and severity of disease across all ages. The cause for this sex bias is currently uncertain, although it may be partly due to the differential effects of genetic factors between the sexes: gene-by-sex interactions. In this family based study (N = 2,663; 740 families; ages 1-93 years), we assessed dental caries via intra-oral examination and generated six indices of caries experience (DMFS, dfs, and indices of both pit-and-fissure surface caries and smooth surface caries in both primary and permanent dentitions). We used likelihood-based methods to model the variance in caries experience conditional on the expected genetic sharing among relatives in our sample. This modeling framework allowed us to test two lines of evidence for gene-by-sex interactions: (1) whether the magnitude of the cumulative effect of genes differs between the sexes, and (2) whether different genes are involved. We observed significant evidence of gene-by-sex interactions for caries experience in both the primary and permanent dentitions. In the primary dentition, the magnitude of the effect of genes was greater in males than females. In the permanent dentition, different genes may play important roles in each of the sexes. Overall, this study provides the first direct evidence that sex differences in dental caries experiences may be explained, in part, by gene-by-sex interactions.

  3. Infection of Tribolium beetles with a tapeworm: variation in susceptibility within and between beetle species and among genetic strains.

    Science.gov (United States)

    Yan, G; Norman, S

    1995-02-01

    Host susceptibility and resistance to parasites are often hypothesized to be genetically variable traits. We tested 2 species of Tribolium flour beetles for among-strain variation in susceptibility to the rat tapeworm Hymenolepis diminuta. Twelve genetic strains of Tribolium confusum and 11 strains of Tribolium castaneum were examined. We found T. castaneum was more susceptible to the tapeworm than T. confusum. There was significant among-strain and between-sex variation for both beetle species in infection intensity and prevalence. Among-vial variation was marginally significant. These results add to evidence that host susceptibility to a parasite is a genetically variable trait. We view these results as important findings for understanding natural selection on host-parasite interactions. Traits that are genetically variable can respond to natural selection. Thus, if a beetle's susceptibility to the tapeworm is correlated with fitness and heritable, susceptibility can evolve. Susceptibility is likely to be pleiotropic and have important consequences on issues ranging from parasite transmission to host species interactions and community structure.

  4. Environmental versus genetic sex determination: a possible factor in dinosaur extinction?

    Science.gov (United States)

    Miller, David; Summers, Jonathan; Silber, Sherman

    2004-04-01

    This study examined the possibility that genetically based sex-determination mechanisms have evolved to ensure a balanced male/female ratio and that this temperature-independent checkpoint might have been unavailable to long-extinct reptiles, notably the dinosaurs. A review of the literature on molecular and phylogenetic relationships between modes of reproduction and sex determination in extant animals was conducted. Mammals, birds, all snakes and most lizards, amphibians, and some gonochoristic fish use specific sex-determining chromosomes or genes (genetic sex determination, GSD). Some reptiles, however, including all crocodilians studied to date, many turtle and tortoise species, and some lizards, use environmental or temperature-dependent sex determination (TSD). We show that various modes of GSD have evolved many times, independently in different orders. Animals using TSD would be at risk of rapid reproductive failure due to a skewed sex ratio favoring males in response to sustained environmental temperature change and favoring the selection of sex-determining genes. The disadvantage to the evolving male sex-determining chromosome, however, is its decay due to nonrecombination and the subsequent loss of spermatogenesis genes. Global temperature change can skew the sex ratio of TSD animals and might have played a significant role in the demise of long-extinct species, notably the dinosaurs, particularly if the temperature change resulted in a preponderance of males. Current global warming also represents a risk for extant TSD species.

  5. The genetic basis for mating-induced sex differences in starvation resistance in Drosophila melanogaster.

    Science.gov (United States)

    Jang, Taehwan; Lee, Kwang Pum

    2015-11-01

    Multiple genetic and environmental factors interact to influence starvation resistance, which is an important determinant of fitness in many organisms, including Drosophila melanogaster. Recent studies have revealed that mating can alter starvation resistance in female D. melanogaster, but little is known about the behavioral and physiological mechanisms underlying such mating-mediated changes in starvation resistance. In the present study, we first investigated whether the effect of mating on starvation resistance is sex-specific in D. melanogaster. As indicated by a significant sex×mating status interaction, mating increased starvation resistance in females but not in males. In female D. melanogaster, post-mating increase in starvation resistance was mainly attributed to increases in food intake and in the level of lipid storage relative to lean body weight. We then performed quantitative genetic analysis to estimate the proportion of the total phenotypic variance attributable to genetic differences (i.e., heritability) for starvation resistance in mated male and female D. melanogaster. The narrow-sense heritability (h(2)) of starvation resistance was 0.235 and 0.155 for males and females, respectively. Mated females were more resistant to starvation than males in all genotypes, but the degree of such sexual dimorphism varied substantially among genotypes, as indicated by a significant sex×genotype interaction for starvation resistance. Cross-sex genetic correlation was greater than 0 but less than l for starvation resistance, implying that the genetic architecture of this trait was partially shared between the two sexes. For both sexes, starvation resistance was positively correlated with longevity and lipid storage at genetic level. The present study suggests that sex differences in starvation resistance depend on mating status and have a genetic basis in D. melanogaster. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Sex Modifies Genetic Effects on Residual Variance in Urinary Calcium Excretion in Rat (Rattus norvegicus)

    OpenAIRE

    Perry, Guy M. L.; Nehrke, Keith W.; Bushinsky, David A; Reid, Robert; Lewandowski, Krista L.; Hueber, Paul; Scheinman, Steven J.

    2012-01-01

    Conventional genetics assumes common variance among alleles or genetic groups. However, evidence from vertebrate and invertebrate models suggests that residual genotypic variance may itself be under partial genetic control. Such a phenomenon would have great significance: high-variability alleles might confound the detection of “classically” acting genes or scatter predicted evolutionary outcomes among unpredicted trajectories. Of the few works on this phenomenon, many implicate sex in some a...

  7. Production of WTC.ZI-zi rat congenic strain and its pathological and genetic analyses.

    Science.gov (United States)

    Kuramoto, T; Yamasaki, K; Kondo, A; Nakajima, K; Yamada, M; Serikawa, T

    1998-04-01

    A new rat congenic strain, WTC.ZI-zi, was produced after eleven generations of backcrossing between ZI strain as a donor strain and WTC strain as an inbred partner. WTC.ZI-zi/zi homozygous rats generally exhibit more conspicuous body tremor and much earlier occurrence of flaccid paresis than the original ZI strain. The average life span of the congenic strain is approximately nine months, which is also much shorter than that of the original ZI strain. Pathological analysis of the central nervous system of the congenic strain revealed more aggravated vacuolation and hypomyelination than in the original ZI strain. Establishment of the genetic profile with microsatellite markers showed that the congenic strain was genetically almost identical to the WTC strain except for a small chromosome segment bearing the zitter gene. Analysis of markers in this region implied that the length of the donor segment was approximately 13.4 centimorgans which corresponded to 0.65% of the total genome. Thus, these results suggested that expressional alterations of zitter gene were due to replacement of the genetic background from the original ZI strain to the WTC strain. Furthermore, the WTC.ZI-zi congenic strain could provide a refined tool for the analysis of zitter mutation, because the congenic strain has a strict control strain, WTC, and the length of the donor chromosome is genetically defined.

  8. Genetic gain in dairy cattle populations is increased using sexed semen in commercial herds

    DEFF Research Database (Denmark)

    Sørensen, Morten Kargo; Andersen, Jakob Voergaard; Pedersen, Louise Dybdahl

    2011-01-01

    with 100 cows each. Each year 50 young bulls (YB), 10 active sires and 215 BD were selected on best linear unbiased prediction estimated breeding values by truncation selection across the simulated population, and the YB were tested within the population. Use of sexed semen alone gave a positive increase......Using stochastic simulation, the effect of using sexed semen to cow dams (CD) in a dairy cattle breeding scheme, with or without use of multiple ovulation and embryo transfer (MOET) to bull dams (BD), on annual genetic gain at the population level was examined. Three levels of sexed semen were...... combined with three levels of MOET: no sexed semen, sexed semen to the best CD and sexed semen to all heifers, combined with no MOET, MOET on all BD and MOET randomly on 20% of the BD. In total, nine scenarios were compared. The simulated population was monitored for 30 years and included 450 herds...

  9. Genetic Diversity Among Botulinum Neurotoxin Producing Clostridial Strains

    Energy Technology Data Exchange (ETDEWEB)

    Hill, K K; Smith, T J; Helma, C H; Ticknor, L O; Foley, B T; Svennson, R T; Brown, J L; Johnson, E A; Smith, L A; Okinaka, R T; Jackson, P J; Marks, J D

    2006-07-06

    Clostridium botulinum is a taxonomic designation for many diverse anaerobic spore forming rod-shaped bacteria which have the common property of producing botulinum neurotoxins (BoNTs). The BoNTs are exoneurotoxins that can cause severe paralysis and even death in humans and various other animal species. A collection of 174 C. botulinum strains were examined by amplified fragment length polymorphism (AFLP) analysis and by sequencing of the 16S rRNA gene and BoNT genes to examine genetic diversity within this species. This collection contained representatives of each of the seven different serotypes of botulinum neurotoxins (BoNT A-G). Analysis of the16S rRNA sequences confirmed earlier reports of at least four distinct genomic backgrounds (Groups I-IV) each of which has independently acquired one or more BoNT serotypes through horizontal gene transfer. AFLP analysis provided higher resolution, and can be used to further subdivide the four groups into sub-groups. Sequencing of the BoNT genes from serotypes A, B and E in multiple strains confirmed significant sequence variation within each serotype. Four distinct lineages within each of the BoNT A and B serotypes, and five distinct lineages of serotype E strains were identified. The nucleotide sequences of the seven serotypes of BoNT were compared and show varying degrees of interrelatedness and recombination as has been previously noted for the NTNH gene which is linked to BoNT. These analyses contribute to the understanding of the evolution and phylogeny within this species and assist in the development of improved diagnostics and therapeutics for treatment of botulism.

  10. Genetic sex determination in Astatotilapia calliptera, a prototype species for the Lake Malawi cichlid radiation

    Science.gov (United States)

    Peterson, Erin N.; Cline, Maggie E.; Moore, Emily C.; Roberts, Natalie B.; Roberts, Reade B.

    2017-06-01

    East African cichlids display extensive variation in sex determination systems. The species Astatotilapia calliptera is one of the few cichlids that reside both in Lake Malawi and in surrounding waterways. A. calliptera is of interest in evolutionary studies as a putative immediate outgroup species for the Lake Malawi species flock and possibly as a prototype ancestor-like species for the radiation. Here, we use linkage mapping to test association of sex in A. calliptera with loci that have been previously associated with genetic sex determination in East African cichlid species. We identify a male heterogametic XY system segregating at linkage group (LG) 7 in an A. calliptera line that originated from Lake Malawi, at a locus previously shown to act as an XY sex determination system in multiple species of Lake Malawi cichlids. Significant association of genetic markers and sex produce a broad genetic interval of approximately 26 megabases (Mb) using the Nile tilapia genome to orient markers; however, we note that the marker with the strongest association with sex is near a gene that acts as a master sex determiner in other fish species. We demonstrate that alleles of the marker are perfectly associated with sex in Metriaclima mbenjii, a species from the rock-dwelling clade of Lake Malawi. While we do not rule out the possibility of other sex determination loci in A. calliptera, this study provides a foundation for fine mapping of the cichlid sex determination gene on LG7 and evolutionary context regarding the origin and persistence of the LG7 XY across diverse, rapidly evolving lineages.

  11. Sex-, age- and strain-related quantities of muscalure on the cuticula of the housefly (Musca domestica)

    NARCIS (Netherlands)

    Noorman, N; denOtter, CJ; Sommeijer, MJ; Francke, PJ

    1997-01-01

    Muscalure, (Z)-9-tricosene, is the major component of the cuticular contact sex pheromone of female houseflies, Musca domestica. By means of gas chromatography the relative amounts of muscalure were determined on female and male houseflies of different sex, age and strain. Females and males of mixed

  12. Scientific Opinion on Lipase from a Genetically Modified Strain of Aspergillus oryzae (strain NZYM-FL

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-07-01

    Full Text Available The food enzyme considered in this opinion is a lipase (triacylglycerol lipase; EC 3.1.1.3 produced with a genetically modified strain of Aspergillus oryzae. The genetic modifications do not raise safety concern. The food enzyme contains neither the production organism nor recombinant DNA. The lipase is intended to be used in a number of food manufacturing processes, such as oils, fats and eggs processing. The dietary exposure was assessed on the basis of data retrieved from the EFSA Comprehensive European Food Consumption Database. The food enzyme did not induce gene mutations in bacteria nor chromosome aberrations in human lymphocytes. Therefore, there is no concern with respect to genotoxicity. The systemic toxicity was assessed by means of a 90-day subchronic oral toxicity study in rodents. A No Observed Adverse Effect Level was derived, which compared with the dietary exposure results in a sufficiently high Margin of Exposure. The allergenicity was evaluated by searching for similarity of the amino acid sequence to those of known allergens. The Panel considered that the likelihood of food allergic reactions to the enzyme is low and therefore does not raise safety concern. Based on the genetic modifications performed, the manufacturing process, the compositional and biochemical data provided and the toxicological studies, this food enzyme does not raise safety concern under the intended conditions of use.

  13. Scientific Opinion on Lipase from a Genetically Modified Strain of Aspergillus oryzae (strain NZYM-LH

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-07-01

    Full Text Available The food enzyme considered in this opinion is a lipase (triacylglycerol lipase; EC 3.1.1.3 produced with a genetically modified strain of Aspergillus oryzae. The genetic modifications do not raise safety concern. The food enzyme contains neither the production organism nor recombinant DNA. The lipase is intended to be used in a number of food manufacturing processes, such as in baking and other cereal-based processes. The dietary exposure was assessed on the basis of data retrieved from the EFSA Comprehensive European Food Consumption Database. The food enzyme did not induce gene mutations in bacteria nor micronuclei in human peripheral blood lymphocytes. Therefore, there is no concern with respect to genotoxicity. The systemic toxicity was assessed by means of a 90-day subchronic oral toxicity study in rodents. A No Observed Adverse Effect Level was derived, which compared with the dietary exposure results in a sufficiently high Margin of Exposure. The allergenicity was evaluated by searching for similarity of the amino acid sequence to those of known allergens. The Panel considered that the likelihood of food allergic reactions to the enzyme is low and therefore does not raise safety concern. Based on the genetic modifications performed, the manufacturing process, the compositional and biochemical data provided and the toxicological studies, this food enzyme does not raise safety concern under the intended conditions of use.

  14. Genetic engineering of industrial Saccharomyces cerevisiae strains using a selection/counter-selection approach.

    Science.gov (United States)

    Kutyna, Dariusz R; Cordente, Antonio G; Varela, Cristian

    2014-01-01

    Gene modification of laboratory yeast strains is currently a very straightforward task thanks to the availability of the entire yeast genome sequence and the high frequency with which yeast can incorporate exogenous DNA into its genome. Unfortunately, laboratory strains do not perform well in industrial settings, indicating the need for strategies to modify industrial strains to enable strain development for industrial applications. Here we describe approaches we have used to genetically modify industrial strains used in winemaking.

  15. Microbe inhibition by Tribolium flour beetles varies with beetle species, strain, sex, and microbe group.

    Science.gov (United States)

    Prendeville, Holly R; Stevens, Lori

    2002-06-01

    Tribolium flour beetles produce defensive compounds, including quinones, putatively aimed at deterring predators and inhibiting microbes. Here we examine how effective the defensive secretions of Tribolium confusum and T. castaneum are at inhibiting growth of various microbes and how this varies with species, geographic strain, and sex of the beetles. We explore differences at both the kingdom and species level of common flour microbes in their susceptibility to defensive compounds. Beetle species and strains vary in their ability to inhibit microbial growth. In addition, microbes vary in their sensitivity to the beetles' defense compounds. The capability to suppress microbial growth is likely under stabilizing selection with optimum quinone production varying among populations and may be dependent on several environmental factors including temperature, humidity, and predators.

  16. Differences in Common Genetic Predisposition to Ischemic Stroke by Age and Sex.

    Science.gov (United States)

    Traylor, Matthew; Rutten-Jacobs, Loes C A; Holliday, Elizabeth G; Malik, Rainer; Sudlow, Cathie; Rothwell, Peter M; Maguire, Jane M; Koblar, Simon A; Bevan, Steve; Boncoraglio, Giorgio; Dichgans, Martin; Levi, Chris; Lewis, Cathryn M; Markus, Hugh S

    2015-11-01

    Evidence from epidemiological studies points to differences in factors predisposing to stroke by age and sex. Whether these arise because of different genetic influences remained untested. Here, we use data from 4 genome-wide association data sets to study the relationship between genetic influence on stroke with both age and sex. Using genomic-relatedness-matrix restricted maximum likelihood methods, we performed 4 analyses: (1) we calculated the genetic correlation between groups divided by age and (2) by sex, (3) we calculated the heritability of age-at-stroke-onset, and (4) we evaluated the evidence that heritability of stroke is greater in women than in men. We found that genetic factors influence age at stroke onset (h2 [SE]=18.0 [6.8]; P=0.0038), with a trend toward a stronger influence in women (women: h2 [SE]=21.6 [3.5]; Men: h2 [SE]=13.9 [2.8]). Although a moderate proportion of genetic factors was shared between sexes (rG [SE]=0.68 [0.16]) and between younger and older cases (rG [SE]=0.70 [0.17]), there was evidence to suggest that there are genetic susceptibility factors that are specific to sex (P=0.037) and to younger or older groups (P=0.056), particularly for women (P=0.0068). Finally, we found a trend toward higher heritability of stroke in women although this was not significantly greater than in men (P=0.084). Our results indicate that there are genetic factors that are either unique to or have a different effect between younger and older age groups and between women and men. Performing large, well-powered genome-wide association study analyses in these groups is likely to uncover further associations. © 2015 The Authors.

  17. Inbreeding Ratio and Genetic Relationships among Strains of the Western Clawed Frog, Xenopus tropicalis.

    Directory of Open Access Journals (Sweden)

    Takeshi Igawa

    Full Text Available The Western clawed frog, Xenopus tropicalis, is a highly promising model amphibian, especially in developmental and physiological research, and as a tool for understanding disease. It was originally found in the West African rainforest belt, and was introduced to the research community in the 1990s. The major strains thus far known include the Nigerian and Ivory Coast strains. However, due to its short history as an experimental animal, the genetic relationship among the various strains has not yet been clarified, and establishment of inbred strains has not yet been achieved. Since 2003 the Institute for Amphibian Biology (IAB, Hiroshima University has maintained stocks of multiple X. tropicalis strains and conducted consecutive breeding as part of the National BioResource Project. In the present study we investigated the inbreeding ratio and genetic relationship of four inbred strains at IAB, as well as stocks from other institutions, using highly polymorphic microsatellite markers and mitochondrial haplotypes. Our results show successive reduction of heterozygosity in the genome of the IAB inbred strains. The Ivory Coast strains clearly differed from the Nigerian strains genetically, and three subgroups were identified within both the Nigerian and Ivory Coast strains. It is noteworthy that the Ivory Coast strains have an evolutionary divergent genetic background. Our results serve as a guide for the most effective use of X. tropicalis strains, and the long-term maintenance of multiple strains will contribute to further research efforts.

  18. Solving ethanol production problems with genetically modified yeast strains

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    A. Abreu-Cavalheiro

    2013-09-01

    Full Text Available The current world demand for bioethanol is increasing as a consequence of low fossil fuel availability and a growing number of ethanol/gasoline flex-fuel cars. In addition, countries in several parts of the world have agreed to reduce carbon dioxide emissions, and the use of ethanol as a fuel (which produces fewer pollutants than petroleum products has been considered to be a good alternative to petroleum products. The ethanol that is produced in Brazil from the first-generation process is optimized and can be accomplished at low cost. However, because of the large volume of ethanol that is produced and traded each year, any small improvement in the process could represent a savings of billions dollars. Several Brazilian research programs are investing in sugarcane improvement, but little attention has been given to the improvement of yeast strains that participate in the first-generation process at present. The Brazilian ethanol production process uses sugarcane as a carbon source for the yeast Saccharomyces cerevisiae. Yeast is then grown at a high cellular density and high temperatures in large-capacity open tanks with cells recycle. All of these culture conditions compel the yeast to cope with several types of stress. Among the main stressors are high temperatures and high ethanol concentrations inside the fermentation tanks during alcohol production. Moreover, the competition between the desired yeast strains, which are inoculated at the beginning of the process, with contaminants such as wild type yeasts and bacteria, requires acid treatment to successfully recycle the cells. This review is focused on describing the problems and stressors within the Brazilian ethanol production system. It also highlights some genetic modifications that can help to circumvent these difficulties in yeast.

  19. Genomic landscapes of endogenous retroviruses unveil intricate genetics of conventional and genetically-engineered laboratory mouse strains.

    Science.gov (United States)

    Lee, Kang-Hoon; Lim, Debora; Chiu, Sophia; Greenhalgh, David; Cho, Kiho

    2016-04-01

    Laboratory strains of mice, both conventional and genetically engineered, have been introduced as critical components of a broad range of studies investigating normal and disease biology. Currently, the genetic identity of laboratory mice is primarily confirmed by surveying polymorphisms in selected sets of "conventional" genes and/or microsatellites in the absence of a single completely sequenced mouse genome. First, we examined variations in the genomic landscapes of transposable repetitive elements, named the TREome, in conventional and genetically engineered mouse strains using murine leukemia virus-type endogenous retroviruses (MLV-ERVs) as a probe. A survey of the genomes from 56 conventional strains revealed strain-specific TREome landscapes, and certain families (e.g., C57BL) of strains were discernible with defined patterns. Interestingly, the TREome landscapes of C3H/HeJ (toll-like receptor-4 [TLR4] mutant) inbred mice were different from its control C3H/HeOuJ (TLR4 wild-type) strain. In addition, a CD14 knock-out strain had a distinct TREome landscape compared to its control/backcross C57BL/6J strain. Second, an examination of superantigen (SAg, a "TREome gene") coding sequences of mouse mammary tumor virus-type ERVs in the genomes of the 46 conventional strains revealed a high diversity, suggesting a potential role of SAgs in strain-specific immune phenotypes. The findings from this study indicate that unexplored and intricate genomic variations exist in laboratory mouse strains, both conventional and genetically engineered. The TREome-based high-resolution genetics surveillance system for laboratory mice would contribute to efficient study design with quality control and accurate data interpretation. This genetics system can be easily adapted to other species ranging from plants to humans.

  20. Host Genetic Variations and Sex Differences Potentiate Predisposition, Severity, and Outcomes of Group A Streptococcus-Mediated Necrotizing Soft Tissue Infections

    Science.gov (United States)

    Mukundan, Santhosh; Alagarsamy, Jeyashree; Laturnus, Donna

    2015-01-01

    Host genetic variations play an important role in several pathogenic diseases, and we previously provided strong evidence that these genetic variations contribute significantly to differences in susceptibility and clinical outcomes of invasive group A Streptococcus (GAS) patients, including sepsis and necrotizing soft tissue infections (NSTIs). The goal of the present study was to investigate how genetic variations and sex differences among four commonly used mouse strains contribute to variation in severity, manifestations, and outcomes of NSTIs. DBA/2J mice were more susceptible to NSTIs than C57BL/6J, BALB/c, and CD-1 mice, as exhibited by significantly greater bacteremia, excessive dissemination to the spleen, and significantly higher mortality. Differences in the sex of the mice also contributed to differences in disease severity and outcomes: DBA/2J female mice were relatively resistant compared to their male counterparts. However, DBA/2J mice exhibited minimal weight loss and developed smaller lesions than did the aforementioned strains. Moreover, at 48 h after infection, compared with C57BL/6J mice, DBA/2J mice had increased bacteremia, excessive dissemination to the spleen, and excessive concentrations of inflammatory cytokines and chemokines. These results indicate that variations in the host genetic context as well as sex play a dominant role in determining the severity of and susceptibility to GAS NSTIs. PMID:26573737

  1. The effect of ivermectin in seven strains of Aedes aegypti (Diptera: Culicidae) including a genetically diverse laboratory strain and three permethrin resistant strains.

    Science.gov (United States)

    Deus, K M; Saavedra-Rodriguez, K; Butters, M P; Black, W C; Foy, B D

    2012-03-01

    Seven different strains of Aedes aegypti (L.), including a genetically diverse laboratory strain, three laboratory-selected permethrin-resistant strains, a standard reference strain, and two recently colonized strains were fed on human blood containing various concentrations of ivermectin. Ivermectin reduced adult survival, fecundity, and hatch rate of eggs laid by ivermectin-treated adults in all seven strains. The LC50 of ivermectin for adults and the concentration that prevented 50% of eggs from hatching was calculated for all strains. Considerable variation in adult survival after an ivermectin-bloodmeal occurred among strains, and all three permethrin-resistant strains were significantly less susceptible to ivermectin than the standard reference strain. The hatch rate after an ivermectin bloodmeal was less variable among strains, and only one of the permethrin-resistant strains differed significantly from the standard reference strain. Our studies suggest that ivermectin induces adult mortality and decreases the hatch rate of eggs through different mechanisms. A correlation analysis of log-transformed LC50 among strains suggests that permethrin and ivermectin cross-resistance may occur.

  2. Genetics of dioecy and causal sex chromosomes in plants

    Indian Academy of Sciences (India)

    Sushil Kumar; Renu Kumari; Vishakha Sharma

    2014-04-01

    Dioecy (separate male and female individuals) ensures outcrossing and is more prevalent in animals than in plants. Although it is common in bryophytes and gymnosperms, only 5% of angiosperms are dioecious. In dioecious higher plants, flowers borne on male and female individuals are, respectively deficient in functional gynoecium and androecium. Dioecy is inherited via three sex chromosome systems: XX/XY, XX/X0 and WZ/ZZ, such that XX or WZ is female and XY, X0 or ZZ are males. The XX/XY system generates the rarer XX/X0 andWZ/ZZ systems. An autosome pair begets XY chromosomes. A recessive loss-of-androecium mutation (ana) creates X chromosome and a dominant gynoecium-suppressing (GYS) mutation creates Y chromosome. The ana/ANA and gys/GYS loci are in the sex-determining region (SDR) of the XY pair. Accumulation of inversions, deleterious mutations and repeat elements, especially transposons, in the SDR of Y suppresses recombination between X and Y in SDR, making Y labile and increasingly degenerate and heteromorphic from X. Continued recombination between X and Y in their pseudoautosomal region located at the ends of chromosomal arms allows survival of the degenerated Y and of the species. Dioecy is presumably a component of the evolutionary cycle for the origin of new species. Inbred hermaphrodite species assume dioecy. Later they suffer degenerate-Y-led population regression. Cross-hybridization between such extinguishing species and heterologous species, followed by genome duplication of segregants from hybrids, give rise to new species.

  3. Sexes suffer from suboptimal lifespan because of genetic conflict in a seed beetle.

    Science.gov (United States)

    Berg, Elena C; Maklakov, Alexei A

    2012-10-22

    Males and females have different routes to successful reproduction, resulting in sex differences in lifespan and age-specific allocation of reproductive effort. The trade-off between current and future reproduction is often resolved differently by males and females, and both sexes can be constrained in their ability to reach their sex-specific optima owing to intralocus sexual conflict. Such genetic antagonism may have profound implications for evolution, but its role in ageing and lifespan remains unresolved. We provide direct experimental evidence that males live longer and females live shorter than necessary to maximize their relative fitness in Callosobruchus maculatus seed beetles. Using artificial selection in a genetically heterogeneous population, we created replicate long-life lines where males lived on average 27 per cent longer than in short-life lines. As predicted by theory, subsequent assays revealed that upward selection on male lifespan decreased relative male fitness but increased relative female fitness compared with downward selection. Thus, we demonstrate that lifespan-extending genes can help one sex while harming the other. Our results show that sexual antagonism constrains adaptive life-history evolution, support a novel way of maintaining genetic variation for lifespan and argue for better integration of sex effects into applied research programmes aimed at lifespan extension.

  4. Multiple across-strain and within-strain QTLs suggest highly complex genetic architecture for hypoxia tolerance in channel catfish.

    Science.gov (United States)

    Wang, Xiaozhu; Liu, Shikai; Jiang, Chen; Geng, Xin; Zhou, Tao; Li, Ning; Bao, Lisui; Li, Yun; Yao, Jun; Yang, Yujia; Zhong, Xiaoxiao; Jin, Yulin; Dunham, Rex; Liu, Zhanjiang

    2017-02-01

    The ability to survive hypoxic conditions is important for various organisms, especially for aquatic animals. Teleost fish, representing more than 50 % of vertebrate species, are extremely efficient in utilizing low levels of dissolved oxygen in water. However, huge variations exist among various taxa of fish in their ability to tolerate hypoxia. In aquaculture, hypoxia tolerance is among the most important traits because hypoxia can cause major economic losses. Genetic enhancement for hypoxia tolerance in catfish is of great interest, but little was done with analysis of the genetic architecture of hypoxia tolerance. The objective of this study was to conduct a genome-wide association study to identify QTLs for hypoxia tolerance using the catfish 250K SNP array with channel catfish families from six strains. Multiple significant and suggestive QTLs were identified across and within strains. One significant QTL and four suggestive QTLs were identified across strains. Six significant QTLs and many suggestive QTLs were identified within strains. There were rare overlaps among the QTLs identified within the six strains, suggesting a complex genetic architecture of hypoxia tolerance. Overall, within-strain QTLs explained larger proportion of phenotypic variation than across-strain QTLs. Many of genes within these identified QTLs have known functions for regulation of oxygen metabolism and involvement in hypoxia responses. Pathway analysis indicated that most of these genes were involved in MAPK or PI3K/AKT/mTOR signaling pathways that were known to be important for hypoxia-mediated angiogenesis, cell proliferation, apoptosis and survival.

  5. Genetically-Improved Tilapia Strains in Africa: Potential Benefits and Negative Impacts

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    Yaw B. Ansah

    2014-06-01

    Full Text Available Two genetically improved tilapia strains (GIFT and Akosombo have been created with Oreochromis niloticus (Nile tilapia, which is native to Africa. In particular, GIFT has been shown to be significantly superior to local African tilapia strains in terms of growth rate. While development economists see the potential for food security and poverty reduction in Africa from culture of these new strains of tilapia, conservationists are wary of potential ecological and genetic impacts on receiving ecosystems and native stocks of tilapia. This study reviews the history of the GIFT technology, and identifies potential environmental and genetic risks of improved and farmed strains and tilapia in general. We also estimate the potential economic gains from the introduction of genetically improved strains in Africa, using Ghana as a case country. Employing a combination of the Economic-Surplus model and Monte Carlo simulation, we found the mean net present value (NPV of the introduction of the GIFT strain in Ghana to be approximately 1% of the country’s gross domestic product. Sensitivity analysis indicated that the difference in growth or yield between the GIFT and locally-available strains has the largest effect on mean NPV. We conclude that improvements in management practices and infrastructure could increase the yield and profitability of the local strains even if genetically-improved strains are not introduced. These improvements also will ensure the realization of the full potential of introduced strains.

  6. Sex- and strain-specific expression and vomeronasal activity of mouse ESP family peptides.

    Science.gov (United States)

    Kimoto, Hiroko; Sato, Koji; Nodari, Francesco; Haga, Sachiko; Holy, Timothy E; Touhara, Kazushige

    2007-11-06

    Male mice secrete exocrine-gland-secreting peptide 1 (ESP1) from the extraorbital lacrimal gland into tear fluid [1]. Other mice detect ESP1 through sensory neurons in the vomeronasal organ (VNO), a secondary olfactory system that senses pheromonal information, including sex, strain, and species. ESP1 is now known to be a member of a multigene family that encodes peptides of various lengths. We herein performed genomic and expression analyses of the ESP family. The ESP family consists of 38 members in mice and 10 members in rat but is absent from the human genome, suggesting rapid molecular evolution. In addition to the male-specific ESP1, we discovered one, which we designated ESP36, that, in adult BALB/c mice, is expressed only in the female extraorbital lacrimal gland. The sexually dimorphic expression is ensured by the release of testosterone after puberty. However, we observed dramatic differences in the expression levels of ESPs between strains. Finally, all ESPs elicited an electrical response in the vomeronasal epithelium but not in the main olfactory epithelium. Multielectrode recording of VNO activity demonstrated that ESP1 induces action potentials in vomeronasal neurons, leading to an increase in the spike firing rate, and that ESP1 is recognized by narrowly tuned vomeronasal sensory neurons. Sexual dimorphism and strain differences of ESPs and their reception in the VNO suggest that the ESP family can convey information about sex and individual identity via the vomeronasal system. The chemosensation of this nonvolatile peptide family by direct contact appears to be one of strategies for sociosexual communication in rodent species.

  7. Sex differences in genetic and environmental influences on educational attainment and income.

    Science.gov (United States)

    Orstavik, Ragnhild E; Czajkowski, Nikolai; Røysamb, Espen; Knudsen, Gun Peggy; Tambs, Kristian; Reichborn-Kjennerud, Ted

    2014-12-01

    In many Western countries, women now reach educational levels comparable to men, although their income remains considerably lower. For the past decades, it has become increasingly clear that these measures of socio-economic status are influenced by genetic as well as environmental factors. Less is known about the relationship between education and income, and sex differences. The aim of this study was to explore genetic and environmental factors influencing education and income in a large cohort of young Norwegian twins, with special emphasis on gender differences. National register data on educational level and income were obtained for 7,710 twins (aged 29-41 years). Bivariate Cholesky models were applied to estimate qualitative and quantitative gender differences in genetic and environmental influences, the relative contribution of genetic and environmental factors to the correlation between education and income, and genetic correlations within and between sexes and phenotypes. The phenotypic correlation between educational level and income was 0.34 (0.32-0.39) for men and 0.45 (0.43-0.48) for women. An ACE model with both qualitative and quantitative sex differences fitted the data best. The genetic correlation between men and women (rg) was 0.66 (0.22-1.00) for educational attainment and 0.38 (0.01-0.75) for income, and between the two phenotypes 0.31 (0.08-0.52) for men and 0.72 (0.64-0.85) for women. Our results imply that, in relatively egalitarian societies with state-supported access to higher education and political awareness of gender equality, genetic factors may play an important role in explaining sex differences in the relationship between education and income.

  8. A set of haploid strains available for genetic studies of Saccharomyces cerevisiae flor yeasts.

    Science.gov (United States)

    Coi, Anna Lisa; Legras, Jean-Luc; Zara, Giacomo; Dequin, Sylvie; Budroni, Marilena

    2016-09-01

    Flor yeasts of Saccharomyces cerevisiae have been extensively studied for biofilm formation, however the lack of specific haploid model strains has limited the application of genetic approaches such as gene knockout, allelic replacement and Quantitative Trait Locus mapping for the deciphering of the molecular basis of velum formation under biological ageing. The aim of this work was to construct a set of flor isogenic haploid strains easy to manipulate genetically. The analysis of the allelic variations at 12 minisatellite loci of 174 Saccharomyces cerevisiae strains allowed identifying three flor parental strains with different phylogenic positions. These strains were characterized for sporulation efficiency, growth on galactose, adherence to polystyrene, agar invasion, growth on wine and ability to develop a biofilm. Interestingly, the inability to grow on galactose was found associated with a frameshift in GAL4 gene that seems peculiar of flor strains. From these wild flor strains, isogenic haploid strains were constructed by deleting HO gene with a loxP-KanMX-loxP cassette followed by the removal of the kanamycin cassette. Haploid strains obtained were characterized for their phenotypic and genetic properties and compared with the parental strains. Preliminary results showed that the haploid strains represent new tools for genetic studies and breeding programs on biofilm formation.

  9. Genetic relationships among strains of the Aspergillus niger aggregate

    Directory of Open Access Journals (Sweden)

    Lara Munique Ferracin

    2009-11-01

    Full Text Available We analyzed the genetic relationships between 51 fungal isolates previously identified as A. niger aggregate, obtained from dried fruit samples from worldwide origin and 7 A. tubingensis obtained from Brazilian coffee beans samples. Greater fungal diversity was found in black sultanas. Aspergillus niger sensu stricto was the most prevalent species. It was found in all fruit substrates of all geographical origins. Based on Random Amplification of Polymorphic DNA (RAPD and β-tubulin sequences data two groups of A. niger were found. In spite of the small number of isolates from Group IV an association between extrolite patterns and molecular clustering is speculated. A. tubingensis were the second most frequent species and this species were clearly subdivided into two groups. The finding of two groups for A. tubingensis strains could not yet explain the contradictions found in the literature about the capability this species for ochratoxin production, because both of them were formed by only non-ochratoxin-producing strains.Neste trabalho foi analisada a relação genética entre 51 isolados obtidos de amostras de frutas secas provenientes de diferentes regiões do previamente identificados como pertencentes ao agregado A. niger e 7 isolados de Aspergillus tubingensis obtidos de amostras de café do Brasil. Maior diversidade fúngica foi encontrada em uvas passas escuras. Aspergillus niger sensu stricto foi a espécie mais frequente. Esta espécie foi encontrada em todos os substratos e origens geográficas analisadas. Baseando-se nos dados de Polimorfismo de DNA Amplificado ao Acaso (RAPD e sequências de nucleotídeos do gene da β-tubulina, dois grupos de A. niger foram observados. Apesar do pequeno número de isolados do grupo IV uma associação entre padrão de extrólitos e agrupamento molecular foi encontrada. A. tubingensis foi a segunda espécie mais frequente e foi claramente subdivida em dois grupos. Como os grupos de A. tubingensis s

  10. Genetic diversity in strains of Helicobacter pylori from India and their relatedness to strains from other parts of the world.

    Science.gov (United States)

    Kumar, Sushil; Kumar, Ashok; Dixit, Vinod Kumar

    2011-01-01

    Helicobacter pylori is predominantly transmitted within families and infection occurs mostly in early childhood, frequently leading to persistent infection lifelong. In the present study, genetic diversity of Helicobacter pylori among North and South Indian isolates was evaluated. 16S rDNA, cagA, vacA and iceA genes were amplified followed by sequencing of respective amplicons for diversity analysis. Result of PCR assay showed that status of pathogenicity genes varied among strains from Varanasi and Hyderabad. Phylogenetic analysis based on 16S rDNA sequences showed clustering of Hyderabad and Varanasi strains in separate groups, pointing to significant diversity. Additionally, phylogenetic analysis revealed that most of the Varanasi strains shared homology with the strains from Taiwan except for two isolates which matched with an isolate from Brazil. On the other hand majority of the Hyderabad strains showed relatedness with strains from Brazil except one which showed homology with one strain from Taiwan. In conclusion our results show that genetic diversity among H. pylori isolates is widely prevalent regardless of the region from which they are isolated. More interestingly, phylogenetic analysis suggests that the Indian strains of H. pylori show close homology to those from Taiwan and/or Brazil. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Controversies of Sex Re-assignment in Genetic Males with Congenital Inadequacy of the Penis.

    Science.gov (United States)

    Raveenthiran, Venkatachalam

    2017-07-08

    Sex assignment in 46XY genetic male children with congenital inadequacy of the penis (CIP) is controversial. Traditionally, children with penile length less than 2 cm at birth are considered unsuitable to be raised as males. They are typically re-assigned to female-sex and feminizing genitoplasty is usually done in infancy. However, the concept of cerebral androgen imprinting has caused paradigm shift in the philosophy of sex re-assignment. Masculinization of the brain, rather than length of the penis, is the modern criterion of sex re-assignment in CIP. This review summarizes the current understanding of the complex issue. In 46XY children with CIP, male-sex assignment appears appropriate in non-hormonal conditions such as idiopathic micropenis, aphallia and exstrophy. Female-sex re-assignment appears acceptable in complete androgen insensitivity (CAIS), while partial androgen insensitivity syndrome (PAIS) patients are highly dissatisfied with the assignment of either sex. Children with 5-alpha reductase deficiency are likely to have spontaneous penile lengthening at puberty. Hence, they are better raised as males. Although female assignment is common in pure gonadal dysgenesis, long-term results are not known to justify the decision.

  12. Genetic Diversity of Tick-Borne Rickettsial Pathogens; Insights Gained from Distant Strains

    Directory of Open Access Journals (Sweden)

    Sebastián Aguilar Pierlé

    2014-01-01

    Full Text Available The ability to capture genetic variation with unprecedented resolution improves our understanding of bacterial populations and their ability to cause disease. The goal of the pathogenomics era is to define genetic diversity that results in disease. Despite the economic losses caused by vector-borne bacteria in the Order Rickettsiales, little is known about the genetic variants responsible for observed phenotypes. The tick-transmitted rickettsial pathogen Anaplasma marginale infects cattle in tropical and subtropical regions worldwide, including Australia. Genomic analysis of North American A. marginale strains reveals a closed core genome defined by high levels of Single Nucleotide Polymorphisms (SNPs. Here we report the first genome sequences and comparative analysis for Australian strains that differ in virulence and transmissibility. A list of genetic differences that segregate with phenotype was evaluated for the ability to distinguish the attenuated strain from virulent field strains. Phylogenetic analyses of the Australian strains revealed a marked evolutionary distance from all previously sequenced strains. SNP analysis showed a strikingly reduced genetic diversity between these strains, with the smallest number of SNPs detected between any two A. marginale strains. The low diversity between these phenotypically distinct bacteria presents a unique opportunity to identify the genetic determinants of virulence and transmission.

  13. Genetic basis for nitrate resistance in Desulfovibrio strains

    Directory of Open Access Journals (Sweden)

    Hannah eKorte

    2014-04-01

    Full Text Available Nitrate is an inhibitor of sulfate-reducing bacteria (SRB. In petroleum production sites, amendments of nitrate and nitrite are used to prevent SRB production of sulfide that causes souring of oil wells. A better understanding of nitrate stress responses in the model SRB, Desulfovibrio vulgaris Hildenborough and Desulfovibrio alaskensis G20, will strengthen predictions of environmental outcomes. Nitrate inhibition of SRB has historically been considered to result from the generation of small amounts of nitrite, to which SRB are quite sensitive. Here we explored the possibility that nitrate might inhibit SRB by a mechanism other than through nitrite inhibition. We found that nitrate-stressed D. vulgaris cultures grown in lactate-sulfate conditions eventually grew in the presence of high concentrations of nitrate, and their resistance continued through several subcultures. Nitrate consumption was not detected over the course of the experiment, suggesting adaptation to nitrate. With high-throughput genetic approaches employing TnLE-seq for D. vulgaris and a pooled mutant library of D. alaskensis, we determined the fitness of many transposon mutants of both organisms in nitrate stress conditions. We found that several mutants, including homologs present in both strains, had a greatly increased ability to grow in the presence of nitrate but not nitrite. The mutated genes conferring nitrate resistance included the gene encoding the putative Rex transcriptional regulator (DVU0916/Dde_2702, as well as a cluster of genes (DVU0251-DVU0245/Dde_0597-Dde_0605 that is poorly annotated. Follow-up studies with individual D. vulgaris transposon and deletion mutants confirmed high-throughput results. We conclude that, in D. vulgaris and D. alaskensis, nitrate resistance in wild-type cultures is likely conferred by spontaneous mutations. Furthermore, the mechanisms that confer nitrate resistance may be different from those that confer nitrite resistance.

  14. Sex-specific genetic diversity is shaped by cultural factors in Inner Asian human populations.

    Science.gov (United States)

    Marchi, Nina; Hegay, Tatyana; Mennecier, Philippe; Georges, Myriam; Laurent, Romain; Whitten, Mark; Endicott, Philipp; Aldashev, Almaz; Dorzhu, Choduraa; Nasyrova, Firuza; Chichlo, Boris; Ségurel, Laure; Heyer, Evelyne

    2017-04-01

    Sex-specific genetic structures have been previously documented worldwide in humans, even though causal factors have not always clearly been identified. In this study, we investigated the impact of ethnicity, geography and social organization on the sex-specific genetic structure in Inner Asia. Furthermore, we explored the process of ethnogenesis in multiple ethnic groups. We sampled DNA in Central and Northern Asia from 39 populations of Indo-Iranian and Turkic-Mongolic native speakers. We focused on genetic data of the Y chromosome and mitochondrial DNA. First, we compared the frequencies of haplogroups to South European and East Asian populations. Then, we investigated the genetic differentiation for eight Y-STRs and the HVS1 region, and tested for the effect of geography and ethnicity on such patterns. Finally, we reconstructed the male demographic history, inferred split times and effective population sizes of different ethnic groups. Based on the haplogroup data, we observed that the Indo-Iranian- and Turkic-Mongolic-speaking populations have distinct genetic backgrounds. However, each population showed consistent mtDNA and Y chromosome haplogroups patterns. As expected in patrilocal populations, we found that the Y-STRs were more structured than the HVS1. While ethnicity strongly influenced the genetic diversity on the Y chromosome, geography better explained that of the mtDNA. Furthermore, when looking at various ethnic groups, we systematically found a genetic split time older than historical records, suggesting a cultural rather than biological process of ethnogenesis. This study highlights that, in Inner Asia, specific cultural behaviors, especially patrilineality and patrilocality, leave a detectable signature on the sex-specific genetic structure. © 2017 Wiley Periodicals, Inc.

  15. Autism risk assessment in siblings of affected children using sex-specific genetic scores

    Directory of Open Access Journals (Sweden)

    Carayol Jerome

    2011-10-01

    Full Text Available Abstract Background The inheritance pattern in most cases of autism is complex. The risk of autism is increased in siblings of children with autism and previous studies have indicated that the level of risk can be further identified by the accumulation of multiple susceptibility single nucleotide polymorphisms (SNPs allowing for the identification of a higher-risk subgroup among siblings. As a result of the sex difference in the prevalence of autism, we explored the potential for identifying sex-specific autism susceptibility SNPs in siblings of children with autism and the ability to develop a sex-specific risk assessment genetic scoring system. Methods SNPs were chosen from genes known to be associated with autism. These markers were evaluated using an exploratory sample of 480 families from the Autism Genetic Resource Exchange (AGRE repository. A reproducibility index (RI was proposed and calculated in all children with autism and in males and females separately. Differing genetic scoring models were then constructed to develop a sex-specific genetic score model designed to identify individuals with a higher risk of autism. The ability of the genetic scores to identify high-risk children was then evaluated and replicated in an independent sample of 351 affected and 90 unaffected siblings from families with at least 1 child with autism. Results We identified three risk SNPs that had a high RI in males, two SNPs with a high RI in females, and three SNPs with a high RI in both sexes. Using these results, genetic scoring models for males and females were developed which demonstrated a significant association with autism (P = 2.2 × 10-6 and 1.9 × 10-5, respectively. Conclusions Our results demonstrate that individual susceptibility associated SNPs for autism may have important differential sex effects. We also show that a sex-specific risk score based on the presence of multiple susceptibility associated SNPs allow for the identification of

  16. Scientific Opinion on Lipase from a Genetically Modified Strain of Aspergillus oryzae (strain NZYM-FL)

    OpenAIRE

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF)

    2014-01-01

    The food enzyme considered in this opinion is a lipase (triacylglycerol lipase; EC 3.1.1.3) produced with a genetically modified strain of Aspergillus oryzae. The genetic modifications do not raise safety concern. The food enzyme contains neither the production organism nor recombinant DNA. The lipase is intended to be used in a number of food manufacturing processes, such as oils, fats and eggs processing. The dietary exposure was assessed on the basis of data retrieved from the EFSA Compreh...

  17. Sex determination of superorder Neognathae (class Aves by molecular genetics methods

    Directory of Open Access Journals (Sweden)

    Michal Gábor

    2014-05-01

    Full Text Available The aim of this study was optimization molecular genetic method for sex determination of superorder Neognathae from class Aves. Molecular-genetic methods was based on the amplification of a chromo-helicase DNA binding 1 (CHD gene region, which is located in both sex chromozomes Z and W. Genomic DNA was isolated from whole blood and feathers by using commercial column kit QIAamp DNA Mini kit. The intron regions of CHDW and CHDZ genes were amplified by sex specific primers P2 and P8. The PCR method used in this study was based on two differences between CHDW and CHDZ genes. One of them is restriction site for endonuclease HaeIII located only in CHDZ and the second is the lenght polymorphism between CHDW and CHDZ where for the males was detected one band and for the females were detected two bands in 3 % agarose gel. These molecular-genetics methods were successfully used for sex determination in 36 species from superorder Neognathae.

  18. Sex differentiation disorders (SDD) prenatal sonographic diagnosis, genetic and hormonal work-up.

    Science.gov (United States)

    Katorza, Eldad; Pinhas-Hamiel, Orit; Mazkereth, Ram; Gilboa, Yinon; Achiron, Reuven

    2009-09-01

    Gender is determined by the genetic, gonadal and hormonal/ phenotypic sex. Genetic sex is determined at conception. The establishment of the gonadal sex (ovary/testis) and the phenotypic sex (external and internal genitalia) is a complicated multistep process which is determined during fetal life mainly during the first trimester. Recently more genes have been found to be involved in this process. Prenatal diagnosis of fetal gender can be made using ultrasound technology, genetic and hormonal examinations. Nowadays using a vaginal and abdominal transducer for US examination recognition of external and internal genitalia of both genders is possible. The determination of gender during fetal life is important not only as a matter of curiosity; in some cases of ambiguity (for example congenital adrenal hyperplasia) prenatal treatment can change the natural history of the disease. Prenatal diagnosis can also subtype the ambiguity, and its severity can be established. In this review we describe our experience in prenatal diagnosis and establishment of the fetal gender, the subtypes of ambiguity and our suggestion for the process of diagnostic work-up.

  19. Geographic, genetic and life-history variability in a sex-changing fish

    Directory of Open Access Journals (Sweden)

    Chiara Benvenuto

    2015-11-01

    Full Text Available Sequential hermaphroditism, commonly referred to as sex change or sex reversal, is a striking phenomenon in mating-system evolution and the most remarkable example of sexual plasticity. Among vertebrates, it is specific to teleosts. Some fish species reproduce initially as females and then change into males (protogynous hermaphrodites or vice versa (protandrous hermaphrodites. The white sea bream, Diplodus sargus, exhibits a high degree of sexual plasticity: populations have been reported to be gonochoristic, protandrous or digynic (with primary females, derived from intersexual juveniles, and secondary females, derived from males. We analysed populations collected from eight different locations across the species distribution range (between the Mediterranean and the North-Eastern Atlantic. These populations are characterized by different degrees of connectivity, spatial demographics and life histories. Using individual-based analyses, we linked the genetic structure of each specimen with environmental heterogeneity, life-history traits and reproductive modes. Our aim is to gather a better understanding of the variation in reproductive life-history strategies in this sexually plastic species. Diplodus sargus is a valuable candidate organism to investigate sequential hermaphroditism and it also has a commercial value. The application of population genetics tools against the background of life-history theory can bring valuable insights for the management of marine resources. The geographical patterns of sex change (and of age- and size-at-sex change linked with population genetics can be pivotal for both theoretical investigations and conservation and management plans in marine areas.

  20. Dosage Effects of Fadrozole on Growth and Development of Sex-Reversed Genetic Female Chickens

    Institute of Scientific and Technical Information of China (English)

    YANG Xiu-rong; JIANG He-sheng; ZHENG Jiang-xia; QU Lu-jiang; CHEN Si-rui; LI Jun-ying; XU Gui-yun; YANG Ning

    2013-01-01

    Fadrozole, an aromatase inhibitor, can masculinize genetic female chickens and high-dose decreases the hatchability. Therefore, it is important to study the growth and development of sex-reversed females after hatch. Chick embryos from a population of CAU3 egg-type were treated with different concentrations of Fadrozole prior to the sexual differentiation at E3.0 (st18). At hatch, the phenotypic sex and genetic sex were identified by vent sexing and genetic diagnosis with CHD1, respectively. Body weight and shank length of sex reversal were tested at 8 and 20 wk, respectively. Testicular development, oviduct and ovarian degeneration were observed and serum concentration of estradiol and testosterone were tested with radioimmunoassay (RIA) at 30 wk. The results showed that body weight and shank length of sex-reversed females were not significantly different between low-dose groups (0.1, 0.3, and 0.5 mg for F1, F2, and F3, respectively) and high-dose groups (1.0 and 1.3 mg for F4 and F5, respectively) (P>0.05). Left and right testes or ovotestes in F2, F3, F4, and F5 groups were heavier than that of in F1 group (P<0.05). While the gonad weight of treatment groups were less than that in male control (P<0.05), oviduct weight in F2, F3, F4, and F5 groups were significant differences compared with female control and F1 group (P<0.05). Egg number from onset of laying egg to 30 wk in F4 and F5 groups were less than in female control, F1 and F2 groups (P<0.05). Serum testosterone level in F5 group was significant higher compared with female control, F1, F2, F3, and F4 groups (P<0.05), but significant lower compared with male control (P<0.05). While concentration of serum estradiol in F5 group was significant lower compared with female control, F1, F2, and F4 groups (P<0.05). In conclusion, the concentration of Fadrozole do not affect postnatal growth of sex-reversed female chicken and the degree of sex-reversed females elevate with the increase of Fadrozole concentration at

  1. Comparative genetic mapping points to different sex chromosomes in sibling species of wild strawberry (Fragaria).

    Science.gov (United States)

    Goldberg, Margot T; Spigler, Rachel B; Ashman, Tia-Lynn

    2010-12-01

    Separate sexes have evolved repeatedly from hermaphroditic ancestors in flowering plants, and thus select taxa can provide unparalleled insight into the evolutionary dynamics of sex chromosomes that are thought to be shared by plants and animals alike. Here we ask whether two octoploid sibling species of wild strawberry--one almost exclusively dioecious (males and females), Fragaria chiloensis, and one subdioecious (males, females, and hermaphrodites), F. virginiana--share the same sex-determining chromosome. We created a genetic map of the sex chromosome and its homeologs in F. chiloensis and assessed macrosynteny between it and published maps of the proto-sex chromosome of F. virginiana and the homeologous autosome of hermaphroditic diploid species. Segregation of male and female function in our F. chiloensis mapping population confirmed that linkage and dominance relations are similar to those in F. virginiana. However, identification of the molecular markers most tightly linked to the sex-determining locus in the two octoploid species shows that, in both, this region maps to homeologues of chromosome 6 in diploid congeners, but is located at opposite ends of their respective chromosomes.

  2. Genetic modifiers and subtypes in schizophrenia: investigations of age at onset, severity, sex and family history.

    Science.gov (United States)

    Bergen, Sarah E; O'Dushlaine, Colm T; Lee, Phil H; Fanous, Ayman H; Ruderfer, Douglas M; Ripke, Stephan; Sullivan, Patrick F; Smoller, Jordan W; Purcell, Shaun M; Corvin, Aiden

    2014-04-01

    Schizophrenia is a genetically and clinically heterogeneous disorder. Genetic risk factors for the disorder may differ between the sexes or between multiply affected families compared to cases with no family history. Additionally, limited data support a genetic basis for variation in onset and severity, but specific loci have not been identified. We performed genome-wide association studies (GWAS) examining genetic influences on age at onset (AAO) and illness severity as well as specific risk by sex or family history status using up to 2762 cases and 3187 controls from the International Schizophrenia Consortium (ISC). Subjects with a family history of schizophrenia demonstrated a slightly lower average AAO that was not significant following multiple testing correction (p=.048), but no differences in illness severity were observed by family history status (p=.51). Consistent with prior reports, we observed earlier AAO (p=.005) and a more severe course of illness for men (p=.002). Family history positive analyses showed the greatest association with KIF5C (p=1.96×10(-8)), however, genetic risk burden overall does not differ by family history. Separate association analyses for males and females revealed no significant sex-specific associations. The top GWAS hit for AAO was near the olfactory receptor gene OR2K2 (p=1.52×10(-7)). Analyses of illness severity (episodic vs. continuous) implicated variation in ST18 (p=8.24×10(-7)). These results confirm recognized demographic relationships but do not support a simplified genetic architecture for schizophrenia subtypes based on these variables. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The large X-effect on secondary sexual characters and the genetics of variation in sex comb tooth number in Drosophila subobscura.

    Science.gov (United States)

    Mittleman, Briana E; Manzano-Winkler, Brenda; Hall, Julianne B; Korunes, Katharine L; Noor, Mohamed A F

    2017-01-01

    Genetic studies of secondary sexual traits provide insights into whether and how selection drove their divergence among populations, and these studies often focus on the fraction of variation attributable to genes on the X-chromosome. However, such studies may sometimes misinterpret the amount of variation attributable to the X-chromosome if using only simple reciprocal F1 crosses, or they may presume sexual selection has affected the observed phenotypic variation. We examined the genetics of a secondary sexual trait, male sex comb size, in Drosophila subobscura. This species bears unusually large sex combs for its species group, and therefore, this trait may be a good candidate for having been affected by natural or sexual selection. We observed significant heritable variation in number of teeth of the distal sex comb across strains. While reciprocal F1 crosses seemed to implicate a disproportionate X-chromosome effect, further examination in the F2 progeny showed that transgressive autosomal effects inflated the estimate of variation associated with the X-chromosome in the F1. Instead, the X-chromosome appears to confer the smallest contribution of all major chromosomes to the observed phenotypic variation. Further, we failed to detect effects on copulation latency or duration associated with the observed phenotypic variation. Overall, this study presents an examination of the genetics underlying segregating phenotypic variation within species and illustrates two common pitfalls associated with some past studies of the genetic basis of secondary sexual traits.

  4. Heritability and cross-sex genetic correlations of early-life circulating testosterone levels in a wild mammal.

    Science.gov (United States)

    Pavitt, Alyson T; Walling, Craig A; Pemberton, Josephine M; Kruuk, Loeske E B

    2014-11-01

    Testosterone is an important hormone that has been shown to have sex-specific links to fitness in numerous species. Although testosterone concentrations vary substantially between individuals in a population, little is known about its heritable genetic basis or between-sex genetic correlations that determine its evolutionary potential. We found circulating neonatal testosterone levels to be both heritable (0.160 ± 0.064 s.e.) and correlated between the sexes (0.942 ± 0.648 s.e.) in wild red deer calves (Cervus elaphus). This may have important evolutionary implications if, as in adults, the sexes have divergent optima for circulating testosterone levels.

  5. The effects of stress and sex on selection, genetic covariance, and the evolutionary response.

    Science.gov (United States)

    Holman, L; Jacomb, F

    2017-08-01

    The capacity of a population to adapt to selection (evolvability) depends on whether the structure of genetic variation permits the evolution of fitter trait combinations. Selection, genetic variance and genetic covariance can change under environmental stress, and males and females are not genetically independent, yet the combined effects of stress and dioecy on evolvability are not well understood. Here, we estimate selection, genetic (co)variance and evolvability in both sexes of Tribolium castaneum flour beetles under stressful and benign conditions, using a half-sib breeding design. Although stress uncovered substantial latent heritability, stress also affected genetic covariance, such that evolvability remained low under stress. Sexual selection on males and natural selection on females favoured a similar phenotype, and there was positive intersex genetic covariance. Consequently, sexual selection on males augmented adaptation in females, and intralocus sexual conflict was weak or absent. This study highlights that increased heritability does not necessarily increase evolvability, suggests that selection can deplete genetic variance for multivariate trait combinations with strong effects on fitness, and tests the recent hypothesis that sexual conflict is weaker in stressful or novel environments. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  6. Understanding sex determination in the mouse: genetics, epigenetics and the story of mutual antagonisms

    Indian Academy of Sciences (India)

    Andy Greenfield

    2015-12-01

    Recent years have seen a rapid growth in mouse genetics resources that support research into fundamental mechanisms in organogenesis, including those controlling mammalian sex determinations. Numerous mouse mutants have shed light on molecular pathways of cell fate specification during gonadogenesis and the `decision' as to whether testis or ovary development is achieved. These studies indicate substantial genetic complexity, characterized by redundancy, feedback loops, mutual antagonism between testis-determining and ovary-determining gene regulatory networks and a degree of plasticity in the fully differentiated state of the adult gonad that was not appreciated until conditional loss-of-function studies were performed. One challenge now is to understand how controlled epigenomic changes effect the now familiar sexually dimorphic transcriptomic profiles of the male and female gonads, firstly during primary sex determination, but also in the adult gonad, thereby regulating cellular behaviour during morphogenesis and maintaining the differentiated state.

  7. Genetic architecture of isolation between two species of Silene with sex chromosomes and Haldane's rule.

    Science.gov (United States)

    Demuth, Jeffery P; Flanagan, Rebecca J; Delph, Lynda F

    2014-02-01

    Examination of the genetic architecture of hybrid breakdown can provide insight into the genetic mechanisms of commonly observed isolating phenomena such as Haldane's rule. We used line-cross analysis to dissect the genetic architecture of divergence between two plant species that exhibit Haldane's rule for male sterility and rarity, Silene latifolia and Silene diclinis. We made 15 types of crosses, including reciprocal F1, F2, backcrosses, and later-generation crosses, grew the seeds to flowering, and measured the number of viable ovules, proportion of viable pollen, and sex ratio. Typically, Haldane's rule for male rarity in XY animal hybrids is explained by interactions involving recessive X-linked alleles that are deleterious when hemizygous (dominance theory), whereas sterility is explained by rapid evolution of spermatogenesis genes (faster-male evolution). In contrast, we found that the genetic mechanisms underlying Haldane's rule between the two Silene species did not follow these conventions. Dominance theory was sufficient to explain male sterility, but male rarity likely involved faster-male evolution. We also found an effect of the neo-sex chromosomes of S. diclinis on the extreme rarity of some hybrid males. Our findings suggest that the genetic architecture of Haldane's rule in dioecious plants may differ from those commonly found in animals.

  8. Genetic variations among Mycoplasma bovis strains isolated from Danish cattle

    DEFF Research Database (Denmark)

    Kusiluka, L.J.M.; Kokotovic, Branko; Ojeniyi, B.

    2000-01-01

    strain of M. bovis (PG45(T)) were assayed for variations in the BglII and MfeI restriction sites in the chromosomal DNA by using the amplified fragment length polymorphism (AFLP) fingerprinting technique. The obtained genomic fingerprints consisted of 62-68 AFLP fragments in the size range of 50-500 bp....... Among the analyzed strains, 18 different AFLP profiles were detected. The similarity between individual fingerprints, calculated by Dice similarity coefficient, ranged from 0.9 to 1.0. Twenty-five strains, including 23 which were isolated during two outbreaks of M. bovis-induced mastitis which occurred...

  9. Caregiving strain and estimated risk for stroke and coronary heart disease among spouse caregivers: differential effects by race and sex.

    Science.gov (United States)

    Haley, William E; Roth, David L; Howard, George; Safford, Monika M

    2010-02-01

    Psychosocial stress has been widely studied as a risk factor for stroke and coronary heart disease (CHD) but little is known about the differential effects of stress on stroke and CHD risk by race and sex. Caregiving for a disabled spouse has been associated with increased mortality and CHD risk, but the association of caregiving strain with stroke and CHD risk across race and sex is unknown. Participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study who were providing in-home caregiving to a disabled spouse reported on caregiving strain (high, some, or none), depressive symptoms, social network, education, and age. Caregiving strain groups were compared on the Framingham Stroke Risk Score (N=716) and Framingham CHD Risk Score (N=607), which estimate the projected 10-year risk of incident stroke and ischemic heart disease, respectively. High caregiving strain was associated with a 23% higher covariate-adjusted estimated stroke risk (11.06% for caregivers with no strain versus 13.62% risk for high-strain caregivers). This association was stronger in men, particularly African American men with high caregiving strain (26.95% estimated 10-year stroke risk). Caregiving strain was not associated with CHD risk scores. Caregiving strain is significantly associated with higher estimated stroke risk with greatest effects for men, particularly African American men, providing caregiving to their wives. Male spouse caregivers may need special caregiving support. Prospective longitudinal studies should examine how sex and race may moderate the impact of stress on stroke and CHD risk.

  10. Insomnia, sleep quality, pain, and somatic symptoms: sex differences and shared genetic components.

    Science.gov (United States)

    Zhang, Jihui; Lam, Siu-Ping; Li, S X; Tang, N L; Yu, M W M; Li, A M; Wing, Yun-Kwok

    2012-03-01

    This study investigated the sex differences, and the shared genetic and environmental factors underlying the associations of sleep disturbances (insomnia and sleep quality) with pain and somatic symptoms in both adolescents and middle-aged adults. We recruited 259 adolescents (69 with current insomnia) and their parents (256 middle-aged adults, 78 with current insomnia). Insomnia severity and sleep quality were measured by the Insomnia Severity Inventory (ISI) and Pittsburgh Sleep Quality Index (PSQI), respectively. Pain and somatic symptoms were measured by the Somatic Symptom Inventory and Visual Analogue Scale for overall pain. Subjects with insomnia scored higher on all measures of pain and somatic symptoms than non-insomnia patients, in both adolescents and adults (Ppain and somatic measures were associated with ISI and PSQI scores after controlling for age, sex, depressive and anxiety symptoms. There was an interaction effect between insomnia and female sex on pain and somatic symptoms (PPain and somatic symptoms ran in family with moderate heritability (range h(2)=0.15-0.42). The phenotypic associations of ISI and PSQI with pain and somatic measures were both contributed by genetic (range p(G)=0.41-0.96) and environmental (range p(E)=0.27-0.40) factors with a major genetic contribution. In summary, insomnia and poor sleep quality are closely associated with pain and somatic symptoms. Insomnia seems to modulate the sex differences in pain and somatic symptoms, especially in the adult population. A shared genetic predisposition might underlie the associations of insomnia and sleep quality with pain and somatic symptoms.

  11. Genetic analysis of Streptococcus agalactiae strains isolated from neonates and their mothers.

    NARCIS (Netherlands)

    Melchers, W.J.G.; Bakkers, J.M.J.E.; Toonen, M.; Kuppeveld, F.J.M. van; Trijbels-Smeulders, M.J.A.M.; Hoogkamp-Korstanje, J.A.A.

    2003-01-01

    Streptococcus agalactiae or group B streptococcus (GBS) is the most common cause of neonatal sepsis and meningitis in neonates. One of the major questions is whether the GBS strains able to cause neonatal invasive disease have peculiar genetic features. A collection of S. agalactiae strains, isolate

  12. Isolation and molecular genetic characterization of a yeast strain ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... Key words: Yeast, PAHs pollutant, 26S rRNA gene. INTRODUCTION. Polycyclic .... sole source of carbon and energy. Although all the strains .... Calculated mass balance of PAHs in liqued culture (n = 3). PAH. No. of rings.

  13. Pathogenicity of three genetically diverse strains of PRRSV Type 1 in specific pathogen free pigs.

    Science.gov (United States)

    Stadejek, Tomasz; Larsen, Lars E; Podgórska, Katarzyna; Bøtner, Anette; Botti, Sara; Dolka, Izabella; Fabisiak, Michał; Heegaard, Peter M H; Hjulsager, Charlotte K; Huć, Tomasz; Kvisgaard, Lise K; Sapierzyński, Rafał; Nielsen, Jens

    2017-05-16

    Studies from Eastern European countries proved that porcine reproductive and respiratory syndrome virus Type 1 (PRRSV-1) harbours high genetic diversity and that genetically divergent subtypes 2-4 circulate in this area. In the present study, we compared the pathogenicity of two different PRRSV-1 subtype 2 strains and a strain representing PRRSV-1 subtype 1. Four groups of 8-week-old specific pathogen free pigs were either infected with subtype 2 strain ILI6, subtype 2 strain or BOR59, subtype 1 strain 18794, or mock inoculated. The most pronounced clinical signs were observed in pigs infected with BOR59. Pigs from both subtype 2 strain infected groups exhibited significantly elevated mean body temperatures on DPI 2 compared to the other two groups, the difference remaining significant up to DPI 13 for the BOR59 group, only. The pigs in the latter group also displayed significantly highest levels of early viremia together with the most rapid APP response. Overall, the results indicated that BOR59 strain can be considered a highly pathogenic strain, similarly to subtype 3 strains Lena and SU1-bel, while the virulence of the other subtype 2 strain ILI6 was intermediate between BOR59 and subtype 1 strain. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Development and application of genetically uniform strains of common carp (Cyprinus carpio L.)

    NARCIS (Netherlands)

    Bongers, A.B.J.

    1997-01-01

    In this thesis, the development of genetically uniform strains of common carp, Cyprinus carpio L. is described. As in research on mammals, the use of genetically uniform fish could increase the quality (replicability, reproducability and repeatability) of experiments. Inbreeding was done by gynogene

  15. Sex determination of Pohnpei Micronesian kingfishers using morphological and molecular genetic techniques

    Science.gov (United States)

    Kesler, Dylan C.; Lopes, I.F.; Haig, Susan M.

    2006-01-01

    Conservation-oriented studies of Micronesian Kingfishers (Todiramphus cinnamominus) have been hindered by a lack of basic natural history information, despite the status of the Guam subspecies (T. c. cinnamominus) as one of the most endangered species in the world. We used tissue samples and morphometric measures from museum specimens and wild-captured Pohnpei Micronesian Kingfishers (T. c. reichenbachii) to develop methods for sex determination. We present a modified molecular protocol and a discriminant function that yields the probability that a particular individual is male or female. Our results revealed that females were significantly larger than males, and the discriminant function correctly predicted sex in 73% (30/41) of the individuals. The sex of 86% (18/21) of individuals was correctly assigned when a moderate reliability threshold was set. Sex determination using molecular genetic techniques was more reliable than methods based on morphology. Our results will facilitate recovery efforts for the critically endangered Guam Micronesian Kingfisher and provide a basis for sex determination in the 11 other endangered congeners in the Pacific Basin.

  16. A CRISPR-Cas9 sex-ratio distortion system for genetic control.

    Science.gov (United States)

    Galizi, Roberto; Hammond, Andrew; Kyrou, Kyros; Taxiarchi, Chrysanthi; Bernardini, Federica; O'Loughlin, Samantha M; Papathanos, Philippos-Aris; Nolan, Tony; Windbichler, Nikolai; Crisanti, Andrea

    2016-08-03

    Genetic control aims to reduce the ability of insect pest populations to cause harm via the release of modified insects. One strategy is to bias the reproductive sex ratio towards males so that a population decreases in size or is eliminated altogether due to a lack of females. We have shown previously that sex ratio distortion can be generated synthetically in the main human malaria vector Anopheles gambiae, by selectively destroying the X-chromosome during spermatogenesis, through the activity of a naturally-occurring endonuclease that targets a repetitive rDNA sequence highly-conserved in a wide range of organisms. Here we describe a CRISPR-Cas9 sex distortion system that targets ribosomal sequences restricted to the member species of the Anopheles gambiae complex. Expression of Cas9 during spermatogenesis resulted in RNA-guided shredding of the X-chromosome during male meiosis and produced extreme male bias among progeny in the absence of any significant reduction in fertility. The flexibility of CRISPR-Cas9 combined with the availability of genomic data for a range of insects renders this strategy broadly applicable for the species-specific control of any pest or vector species with an XY sex-determination system by targeting sequences exclusive to the female sex chromosome.

  17. Genetic differences between Tunisian camel and sheep strains of the cestode Echinococcus granulosus revealed by SSCP

    Directory of Open Access Journals (Sweden)

    Oudni-M’rad M.

    2006-06-01

    Full Text Available Ovine and dromedary Echinococcus granulosus isolates from Tunisia were identified as G1 and G6 strains based on polymorphism of the mitochondrial cytochrome C oxydase CO1. Single strand conformation polymorphism (SSCP was used in order to examine the genetic variation within and between Tunisian G1 and G6 strains and to estimate the extent of selfing. The dromedary isolates are genetically distinct from sheep isolates (high value of genetic variation between populations: Fst = 0.46. No significant deficiency in heterozygotes was found in sheep isolates, whereas heterozygote deficiency (suggesting selfing was found in a limited number of camel isolates.

  18. [Contribution of genotyping for fetal sex determination in maternal serum for preimplantation genetic diagnosis of X-linked diseases].

    Science.gov (United States)

    Tachdjian, G; Costa, J M; Frydman, N; Ray, P; Le Dû, A; Kerbrat, V; Ernault, P; Frydman, R

    2003-12-01

    Couples with a risk of transmitting X-linked diseases included in a preimplantation genetic diagnosis (PGD) center need early and rapid fetal sex determination during pregnancy in two situations. The first situation corresponds to control of embryo sexing after PGD, the second one being that of couples in PGD program having a spontaneous pregnancy. Determination of fetal sex can be achieved by karyotyping using invasive procedures such as chorionic villus sampling (CVS), amniocentesis or cordocentesis and by non-invasive procedures such as ultrasound (US) examination. CVS is the earliest invasive procedure for fetal sex determination and molecular analysis of X-linked genetic disorders during the first trimester but it is associated with a risk of fetal loss. US allows reliable fetal sex determination only during the second trimester. Recently, reliable non-invasive fetal sex determination was realized by using SRY gene amplification in maternal serum. We report the prospective use of fetal sex determination in maternal serum in our PGD center. Management of pregnancies was performed using this non-invasive procedure in four cases of embryo sexing control and nine cases of spontaneous pregnancies in couples included in PGD program for X-linked diseases. Fetal sex results using SRY gene amplification on maternal serum were in complete concordance with fetal sex observed by cytogenetic analysis or US examination, as well as at birth. This new strategy allowed rapid sex determination during the first trimester and permitted to avoid performing invasive procedures in nine pregnancies.

  19. Mitochondrial DNA paradox: sex-specific genetic structure in a marine mussel--despite maternal inheritance and passive dispersal

    National Research Council Canada - National Science Library

    Teske, Peter R; Papadopoulos, Isabelle; Barker, Nigel P; McQuaid, Christopher D

    2012-01-01

    When genetic structure is identified using mitochondrial DNA (mtDNA), but no structure is identified using biparentally-inherited nuclear DNA, the discordance is often attributed to differences in dispersal potential between the sexes...

  20. Genetic and virulence variability among Erwinia tracheiphila strains recovered from different cucurbit hosts.

    Science.gov (United States)

    Rojas, E Saalau; Dixon, P M; Batzer, J C; Gleason, M L

    2013-09-01

    The causal agent of cucurbit bacterial wilt, Erwinia tracheiphila, has a wide host range in the family Cucurbitaceae, including economically important crops such as muskmelon (Cucumis melo), cucumber (C. sativus), and squash (Cucurbita spp.). Genetic variability of 69 E. tracheiphila strains was investigated by repetitive-element polymerase chain reaction (rep-PCR) using BOXA1R and ERIC1-2 primers. Fingerprint profiles revealed significant variability associated with crop host; strains isolated from Cucumis spp. were clearly distinguishable from Cucurbita spp.-isolated strains regardless of geographic origin. Twelve E. tracheiphila strains isolated from muskmelon, cucumber, or summer squash were inoculated onto muskmelon and summer squash seedlings, followed by incubation in a growth chamber. Wilt symptoms were assessed over 3 weeks, strains were reisolated, and rep-PCR profiles were compared with the inoculated strains. Wilting occurred significantly faster when seedlings were inoculated with strains that originated from the same crop host genus (P<0.001). In the first run of the experiment, cucumber and muskmelon strains caused wilting on muskmelon seedlings at a median of 7.8 and 5.6 days after inoculation (dai), respectively. Summer squash seedlings wilted 18.0, 15.7, and 5.7 dai when inoculated with muskmelon-, cucumber-, and squash-origin strains, respectively. In a second run of the experiment, cucumber and muskmelon strains caused wilting on muskmelon at 7.0 and 6.9 dai, respectively, whereas summer squash seedlings wilted at 23.6, 29.0 and 9.0 dai when inoculated with muskmelon-, cucumber-, and squash-origin strains, respectively. Our results provide the first evidence of genetic diversity within E. tracheiphila and suggest that strain specificity is associated with plant host. This advance is a first step toward understanding the genetic and population structure of E. tracheiphila.

  1. Genetic Diversity Among Botulinum Neurotoxin-Producing Clostridial Strains

    Science.gov (United States)

    2007-02-01

    fragment length polymorphism analysis of Norwegian Bacillus cereus and Bacillus thuringiensis soil isolates. Appl. Environ. Microbiol. 67:4863–4873...isolation and purification. Individual bacterial colonies of each of the C. botulinum strains were removed from anaerobic CDC blood agar plates and

  2. Genetic Analysis of Wild-type Hepatitis A Virus Strains

    Institute of Scientific and Technical Information of China (English)

    ChenYong; MaoJiang-sen; HongYan; YangLian-hua; LingZhi-qiang; YuWei-qun

    2005-01-01

    To clarify the distribution of hepatitis A virus (HAV)genotype in geographical regions of China.Methods Seventeen representative HAV strains were isolated from the stool or serum of hepatitis A patients in different geographical regions.Viral RNA was recovered from stool or serum by proteinase K digestion and phenol-chloroform extraction,followed by ethanol precipitation prior to reverse transcription and polymerase chain reaction(RT-PCR)amplification.The nucleotide sequences of VP1/2A junction region were tested by using a direct sequencing technique.Results A pairwise comparison of sequences within 168 bases at the VP1/2A junction revealed that all the sequences clustered within genotype I.About 53% of strains clustered in genotype IB,with less than 6% variability;while the others clustered in genotype IA,with less than 5.3% variability Sequence hore ology between genotype IA and IB varied from 88.7% to 92.3%. Conclusion Epidemic or sporadic HAV strains in China may belong to HAV genotype IA or IB, Epidemiologically related strains may be identical or closely related in sequence.

  3. Metabolic alterations in genetically selected Drosophila strains with different longevities.

    Science.gov (United States)

    Buck, S A; Arking, R

    2001-10-01

    Sometime ago we obtained biomarker data suggesting that the earliest determining event in the expression of the extended longevity phenotype in our selected strains of Drosophila took place early in adult life at about 5-7 days of age. In a later series of experiments we documented that our La and Lb long lived strains underwent a specific up-regulation of the antioxidant defense system (ADS) genes and enzymes. This led to a reduction in oxidative damage and an extended longevity. In the current work, we assayed the activity of 17 metabolically important enzymes in 5-7 day old flies of 13 strains variously selected for different longevities. We conclude that the two sets of replicated long-lived strains have an altered metabolic pattern (relative to normal-lived animals) which is consistent with an increased flux through the pentose shunt and an enhanced NADP+ reducing system to support the increased activity of the ADS enzymes. This result can be interpreted as a shift of energy expenditure from reproduction to somatic maintenance. We conclude that theories based on differential energy allocations appear to empirically explain, at least in part, the mechanisms underlying the transformation of a normal longevity phenotype to an extended longevity phenotype.

  4. A test of genetic models for the evolutionary maintenance of same-sex sexual behaviour.

    Science.gov (United States)

    Hoskins, Jessica L; Ritchie, Michael G; Bailey, Nathan W

    2015-06-22

    The evolutionary maintenance of same-sex sexual behaviour (SSB) has received increasing attention because it is perceived to be an evolutionary paradox. The genetic basis of SSB is almost wholly unknown in non-human animals, though this is key to understanding its persistence. Recent theoretical work has yielded broadly applicable predictions centred on two genetic models for SSB: overdominance and sexual antagonism. Using Drosophila melanogaster, we assayed natural genetic variation for male SSB and empirically tested predictions about the mode of inheritance and fitness consequences of alleles influencing its expression. We screened 50 inbred lines derived from a wild population for male-male courtship and copulation behaviour, and examined crosses between the lines for evidence of overdominance and antagonistic fecundity selection. Consistent variation among lines revealed heritable genetic variation for SSB, but the nature of the genetic variation was complex. Phenotypic and fitness variation was consistent with expectations under overdominance, although predictions of the sexual antagonism model were also supported. We found an unexpected and strong paternal effect on the expression of SSB, suggesting possible Y-linkage of the trait. Our results inform evolutionary genetic mechanisms that might maintain low but persistently observed levels of male SSB in D. melanogaster, but highlight a need for broader taxonomic representation in studies of its evolutionary causes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  5. Differences in Brazilian strains of Schistosoma mansoni evaluated by means of morphometric analysis of cercariae of both sexes

    Directory of Open Access Journals (Sweden)

    Machado-Silva José Roberto

    2000-01-01

    Full Text Available Morphometrics of Brazilian strains (BH, SJ and CMO of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS, considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05 than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment.

  6. Development and use of genetically uniform strains of common carp in experimental animal research.

    Science.gov (United States)

    Bongers, A B; Sukkel, M; Gort, G; Komen, J; Richter, C J

    1998-10-01

    Fish are widely used in numerous fields of basic and applied research. Currently, they are the third laboratory animal group in numbers, and will become increasingly important. Common carp is a major species in both aquaculture and research. Inbred strains of carp by gynogenetic (only female inheritance) and androgenetic (only male inheritance) reproduction techniques were developed at our university. With these methods, homozygous animals are produced in one generation and we present the production of homozygous inbred and F1 hybrid strains of common carp. As in mammalian research, using genetically well defined fish is a methodological necessity since in outbred stocks: (1) repeatability between experiments is low, (2) high levels of inbreeding may have accumulated and (3) high intrastrain variability might obscure treatment effects. Within inbred strains, the variation is reduced and as a result, less animals (compared to outbreds) are necessary to obtain statistically significant results. We illustrate this with experimental data from an F1 hybrid and partly outbred strain of common carp, both subjected to an antibiotic treatment resulting in reduced gonadal growth. Results obtained from a single inbred strain should be generalized with the use of a panel of inbred strains. We show that optimal allocation of animals between and within inbred strains depends on the ratio (variation between strains): (variation within strains). When selecting a panel of inbred strains, attention has to be paid to genetic relations between strains to avoid testing within a limited genetic range. It should be considered that in inbred strains, (genic) dominance and interaction effects are absent, due to the absence of heterozygous genotypes. In general, variation within inbred strains will be reduced for traits with a high degree of genetic determination. However, in inbred strains of carp produced by gynogenesis or androgenesis, the chromosome manipulation treatment induces

  7. Allopatric speciation in ticks: genetic and reproductive divergence between geographic strains of Rhipicephalus (Boophilus microplus

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    Jongejan Frans

    2009-02-01

    Full Text Available Abstract Background The cattle tick, Rhipicephalus (Boophilus microplus, economically impact cattle industry in tropical and subtropical regions of the world. The morphological and genetic differences among R. microplus strains have been documented in the literature, suggesting that biogeographical and ecological separation may have resulted in boophilid ticks from America/Africa and those from Australia being different species. To test the hypothesis of the presence of different boophilid species, herein we performed a series of experiments to characterize the reproductive performance of crosses between R. microplus from Australia, Africa and America and the genetic diversity of strains from Australia, Asia, Africa and America. Results The results showed that the crosses between Australian and Argentinean or Mozambican strains of boophilid ticks are infertile while crosses between Argentinean and Mozambican strains are fertile. These results showed that tick strains from Africa (Mozambique and America (Argentina are the same species, while ticks from Australia may actually represent a separate species. The genetic analysis of mitochondrial 12S and 16S rDNA and microsatellite loci were not conclusive when taken separately, but provided evidence that Australian tick strains were genetically different from Asian, African and American strains. Conclusion The results reported herein support the hypothesis that at least two different species share the name R. microplus. These species could be redefined as R. microplus (Canestrini, 1887 (for American and African strains and probably the old R. australis Fuller, 1899 (for Australian strains, which needs to be redescribed. However, experiments with a larger number of tick strains from different geographic locations are needed to corroborate these results.

  8. Genetic Relatedness among Hepatitis A Virus Strains Associated with Food-Borne Outbreaks

    Science.gov (United States)

    Vaughan, Gilberto; Xia, Guoliang; Forbi, Joseph C.; Purdy, Michael A.; Rossi, Lívia Maria Gonçalves; Spradling, Philip R.; Khudyakov, Yury E.

    2013-01-01

    The genetic characterization of hepatitis A virus (HAV) strains is commonly accomplished by sequencing subgenomic regions, such as the VP1/P2B junction. HAV genome is not extensively variable, thus presenting opportunity for sharing sequences of subgenomic regions among genetically unrelated isolates. The degree of misrepresentation of phylogenetic relationships by subgenomic regions is especially important for tracking transmissions. Here, we analyzed whole-genome (WG) sequences of 101 HAV strains identified from 4 major multi-state, food-borne outbreaks of hepatitis A in the Unites States and from 14 non-outbreak-related HAV strains that shared identical VP1/P2B sequences with the outbreak strains. Although HAV strains with an identical VP1/P2B sequence were specific to each outbreak, WG were different, with genetic diversity reaching 0.31% (mean 0.09%). Evaluation of different subgenomic regions did not identify any other section of the HAV genome that could accurately represent phylogenetic relationships observed using WG sequences. The identification of 2–3 dominant HAV strains in 3 out of 4 outbreaks indicates contamination of the implicated food items with a heterogeneous HAV population. However, analysis of intra-host HAV variants from eight patients involved in one outbreak showed that only a single sequence variant established infection in each patient. Four non-outbreak strains were found closely related to strains from 2 outbreaks, whereas ten were genetically different from the outbreak strains. Thus, accurate tracking of HAV strains can be accomplished using HAV WG sequences, while short subgenomic regions are useful for identification of transmissions only among cases with known epidemiological association. PMID:24223112

  9. Performance of a Genetically Modified Strain of the Mediterranean Fruit Fly (Diptera: Tephritidae) for Area-Wide Integrated Pest Management With the Sterile Insect Technique.

    Science.gov (United States)

    Ramírez-Santos, Edwin M; Rendón, Pedro; Ruiz-Montoya, Lorena; Toledo, Jorge; Liedo, Pablo

    2016-12-23

    The genetically modified strain of Ceratitis capitata (Wiedemann) VIENNA 8 1260 has two morphological markers that exhibit fluorescence in body and sperm. To assess the feasibility of its use in area-wide integrated pest management (AW-IPM) programs using the sterile insect technique, its rearing performance and quality control profile under small, medium, and large scales was evaluated, as well as in field cages. The VIENNA 8 1260 strain had a lower yield than the control strains, VIENNA 8 with D53 inversion (VIENNA 8) and without D53 inversion (VIENNA 8 D53-). At mass-rearing scale, yield gradually increased in three generations without reaching the control strain values. The VIENNA 8 1260 strain was stable in the genetic sexing mechanism (>99.9%) and expression of fluorescence (100%). In field cages, the VIENNA 8 1260 males reduced the mating potential of wild males in the same magnitude as the VIENNA 8, when evaluated in independent cage tests. However, the relative sterility index and the strain male relative performance index of VIENNA 8 1260 males were significantly lower than those of the VIENNA 8. There were no significant differences in longevity of these strains. The potential application of the VIENNA 8 1260 in AW-IPM programs is further discussed.

  10. Comparison of morphological and molecular genetic sex-typing on mediaeval human skeletal remains☆

    Science.gov (United States)

    Bauer, Christiane Maria; Niederstätter, Harald; McGlynn, George; Stadler, Harald; Parson, Walther

    2013-01-01

    Archaeological excavations conducted at an early mediaeval cemetery in Volders (Tyrol, Austria) produced 141 complete skeletal remains dated between the 5th/6th and 12th/13th centuries. These skeletons represent one of the largest historical series of human remains ever discovered in the East Alpine region. Little historical information is available for this region and time period. The good state of preservation of these bioarchaeological finds offered the opportunity of performing molecular genetic investigations. Adequate DNA extraction methods were tested in the attempt to obtain as high DNA yields as possible for further analyses. Molecular genetic sex-typing using a dedicated PCR multiplex (“Genderplex”) gave interpretable results in 88 remains, 78 of which had previously been sexed based on morphological features. We observed a discrepancy in sex determination between the two methods in 21 cases. An unbiased follow-up morphological examination of these finds showed congruence with the DNA results in all but five samples. PMID:23941903

  11. Genetic relationships among strains of the Aspergillus niger aggregate

    DEFF Research Database (Denmark)

    Ferracin, L.M.; Frisvad, Jens Christian; Taniwaki, M.H.

    2009-01-01

    We analyzed the genetic relationships between 51 fungal isolates previously identified as A. niger aggregate, obtained from dried fruit samples from worldwide origin and 7 A. tubingensis obtained from Brazilian coffee beans samples. Greater fungal diversity was found in black sultanas. Aspergillus...

  12. Genetic variation of Border disease virus species strains

    Directory of Open Access Journals (Sweden)

    Massimo Giangaspero

    2011-12-01

    Full Text Available The 5´-untranslated region of Pestivirus strains isolated from domestic and wild animals were analysed to determine their taxonomic status according to nucleotide changes in the secondary genomic structure using the palindromic nucleotide substitutions (PNS method. A total of 131 isolates out of 536 Pestivirus strains evaluated, were clustered as Border disease virus (BDV species. The BDV strains were further divided into at least 8 genotypes or subspecies. Thirty-two isolates from small ruminants suffering from clinical symptoms of Border disease were clustered into bovine viral diarrhoea virus 1 (BVDV-1, BVDV-2 and classical swine fever (hog cholera virus species and also into the tentative BDV-2 species. Since the definition of an infectious disease is based primarily on a specific causative pathogen and taking into account the heterogeneity of the genus Pestivirus, clinical cases should be named according to the laboratory results. The PNS procedure could be useful for laboratory diagnosis of Border disease in domestic and wild ruminants.

  13. Genetic mapping of sex determination in a wild strawberry, Fragaria virginiana reveals earliest form of sex chromosome

    Science.gov (United States)

    The evolution of separate sexes (dioecy) from hermaphroditism is one of the major evolutionary transitions in plants and this transition can be accompanied by the development of sex chromosomes. However, we are now just beginning to gain insight into the initial stages of sex chromosome evolution vi...

  14. Molecular Identification and Genetic Characterization of Macrophomina phaseolina Strains Causing Pathogenicity on Sunflower and Chickpea

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    Ali N. Khan

    2017-07-01

    Full Text Available Macrophomina phaseolina is the most devastating pathogen which causes charcoal rot and root rot diseases in various economically important crops. Three strains M. phaseolina 1156, M. phaseolina 1160, and M. phaseolina PCMC/F1 were tested for their virulence on sunflower (Helianthus annuus L. and chickpea (Cicer arietinum L.. The strains showed high virulence on both hosts with a disease score of 2 on chickpea and sunflower. The strains also increased the hydrogen per oxide (H2O2 content by 1.4- to 1.6-fold in root as well as shoot of chickpea and sunflower. A significant increase in antioxidant enzymes was observed in fungal infected plants which indicated prevalence of oxidative stress during pathogen propagation. The M. phaseolina strains also produced hydrolytic enzymes such as lipase, amylase, and protease with solubilization zone of 5–43 mm, 5–45 mm, and 12–35 mm, respectively. The M. phaseolina strains were identified by 18S rRNA and analyzed for genetic diversity by using random amplified polymorphic DNA (RAPD markers. The findings based on RAPD markers and 18S rRNA sequence analysis clearly indicate genetic variation among the strains collected from different hosts. The genetically diverse strains were found to be pathogenic to sunflower and chickpea.

  15. Molecular Identification and Genetic Characterization of Macrophomina phaseolina Strains Causing Pathogenicity on Sunflower and Chickpea.

    Science.gov (United States)

    Khan, Ali N; Shair, Faluk; Malik, Kamran; Hayat, Zafar; Khan, Muhammad Ayub; Hafeez, Fauzia Yusuf; Hassan, Muhammad Nadeem

    2017-01-01

    Macrophomina phaseolina is the most devastating pathogen which causes charcoal rot and root rot diseases in various economically important crops. Three strains M. phaseolina 1156, M. phaseolina 1160, and M. phaseolina PCMC/F1 were tested for their virulence on sunflower (Helianthus annuus L.) and chickpea (Cicer arietinum L.). The strains showed high virulence on both hosts with a disease score of 2 on chickpea and sunflower. The strains also increased the hydrogen per oxide (H2O2) content by 1.4- to 1.6-fold in root as well as shoot of chickpea and sunflower. A significant increase in antioxidant enzymes was observed in fungal infected plants which indicated prevalence of oxidative stress during pathogen propagation. The M. phaseolina strains also produced hydrolytic enzymes such as lipase, amylase, and protease with solubilization zone of 5-43 mm, 5-45 mm, and 12-35 mm, respectively. The M. phaseolina strains were identified by 18S rRNA and analyzed for genetic diversity by using random amplified polymorphic DNA (RAPD) markers. The findings based on RAPD markers and 18S rRNA sequence analysis clearly indicate genetic variation among the strains collected from different hosts. The genetically diverse strains were found to be pathogenic to sunflower and chickpea.

  16. Interspecific sex in grass smuts and the genetic diversity of their pheromone-receptor system.

    Directory of Open Access Journals (Sweden)

    Ronny Kellner

    2011-12-01

    Full Text Available The grass smuts comprise a speciose group of biotrophic plant parasites, so-called Ustilaginaceae, which are specifically adapted to hosts of sweet grasses, the Poaceae family. Mating takes a central role in their life cycle, as it initiates parasitism by a morphological and physiological transition from saprobic yeast cells to pathogenic filaments. As in other fungi, sexual identity is determined by specific genomic regions encoding allelic variants of a pheromone-receptor (PR system and heterodimerising transcription factors. Both operate in a biphasic mating process that starts with PR-triggered recognition, directed growth of conjugation hyphae, and plasmogamy of compatible mating partners. So far, studies on the PR system of grass smuts revealed diverse interspecific compatibility and mating type determination. However, many questions concerning the specificity and evolutionary origin of the PR system remain unanswered. Combining comparative genetics and biological approaches, we report on the specificity of the PR system and its genetic diversity in 10 species spanning about 100 million years of mating type evolution. We show that three highly syntenic PR alleles are prevalent among members of the Ustilaginaceae, favouring a triallelic determination as the plesiomorphic characteristic of this group. Furthermore, the analysis of PR loci revealed increased genetic diversity of single PR locus genes compared to genes of flanking regions. Performing interspecies sex tests, we detected a high potential for hybridisation that is directly linked to pheromone signalling as known from intraspecies sex. Although the PR system seems to be optimised for intraspecific compatibility, the observed functional plasticity of the PR system increases the potential for interspecific sex, which might allow the hybrid-based genesis of newly combined host specificities.

  17. Multi-trophic consequences of plant genetic variation in sex and growth.

    Science.gov (United States)

    Abdala-Roberts, Luis; Pratt, Jessica D; Pratt, Riley; Schreck, Tadj K; Hanna, Victoria; Mooney, Kailen A

    2016-03-01

    There is growing evidence for the influence of plant intraspecific variation on associated multi-trophic communities, but the traits driving such effects are largely unknown. We conducted a field experiment with selected genetic lines of the dioecious shrub Baceharis salicifolia to investigate the effects of plant growth rate (two-fold variation) and gender (males vs. females of the same growth rate) on above- and belowground insect and fungal associates. We documented variation in associate density to test for effects occurring through plant-based habitat quality (controlling for effects of plant size) as well as variation in associate abundance to test for effects occurring through both habitat quality and abundance (including effects of plant size). Whereas the dietary specialist aphid Uroleucon macaolai was unaffected by plant sex and growth rate, the generalist aphid Aphis gossypii and its tending ants (Linepithema humile) had higher abundances and densities on male (vs. female) plants, suggesting males provide greater habitat quality. In contrast, Aphis and ant abundance and density were unaffected by plant growth rate, while Aphis parasitoids were unaffected by either plant sex or growth rate. Arbuscular mycorrhizal fungi had higher abundance and density (both marginally significant) on females (vs. males), suggesting females provide greater habitat quality, but lower abundances (marginally significant) and higher densities on slow- (vs. fast-) growing genotypes, suggesting slow-growing genotypes provided lower resource abundance but greater habitat quality. Overall, plant sex and growth rate effects on associates acted independently (i.e., no interactive effects), and these effects were of a greater magnitude than those coming from other axes of plant genetic variation. These findings thus demonstrate that plant genetic effects on associated communities may be driven by a small number of trait-specific mechanisms.

  18. Production of functionalized polyhydroxyalkanoates by genetically modified Methylobacterium extorquens strains

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    Miguez Carlos B

    2010-09-01

    Full Text Available Abstract Background Methylotrophic (methanol-utilizing bacteria offer great potential as cell factories in the production of numerous products from biomass-derived methanol. Bio-methanol is essentially a non-food substrate, an advantage over sugar-utilizing cell factories. Low-value products as well as fine chemicals and advanced materials are envisageable from methanol. For example, several methylotrophic bacteria, including Methylobacterium extorquens, can produce large quantities of the biodegradable polyester polyhydroxybutyric acid (PHB, the best known polyhydroxyalkanoate (PHA. With the purpose of producing second-generation PHAs with increased value, we have explored the feasibility of using M. extorquens for producing functionalized PHAs containing C-C double bonds, thus, making them amenable to future chemical/biochemical modifications for high value applications. Results Our proprietary M. extorquens ATCC 55366 was found unable to yield functionalized PHAs when fed methanol and selected unsaturated carboxylic acids as secondary substrates. However, cloning of either the phaC1 or the phaC2 gene from P. fluorescens GK13, using an inducible and regulated expression system based on cumate as inducer (the cumate switch, yielded recombinant M. extorquens strains capable of incorporating modest quantities of C-C double bonds into PHA, starting from either C6= and/or C8=. The two recombinant strains gave poor results with C11=. The strain containing the phaC2 gene was better at using C8= and at incorporating C-C double bonds into PHA. Solvent fractioning indicated that the produced polymers were PHA blends that consequently originated from independent actions of the native and the recombinant PHA synthases. Conclusions This work constitutes an example of metabolic engineering applied to the construction of a methanol-utilizing bacterium capable of producing functionalized PHAs containing C-C double bonds. In this regard, the PhaC2 synthase

  19. Winning the genetic lottery: biasing birth sex ratio results in more grandchildren.

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    Collette M Thogerson

    Full Text Available Population dynamics predicts that on average parents should invest equally in male and female offspring; similarly, the physiology of mammalian sex determination is supposedly stochastic, producing equal numbers of sons and daughters. However, a high quality parent can maximize fitness by biasing their birth sex ratio (SR to the sex with the greatest potential to disproportionately outperform peers. All SR manipulation theories share a fundamental prediction: grandparents who bias birth SR should produce more grandoffspring via the favored sex. The celebrated examples of biased birth SRs in nature consistent with SR manipulation theories provide compelling circumstantial evidence. However, this prediction has never been directly tested in mammals, primarily because the complete three-generation pedigrees needed to test whether individual favored offspring produce more grandoffspring for the biasing grandparent are essentially impossible to obtain in nature. Three-generation pedigrees were constructed using 90 years of captive breeding records from 198 mammalian species. Male and female grandparents consistently biased their birth SR toward the sex that maximized second-generation success. The most strongly male-biased granddams and grandsires produced respectively 29% and 25% more grandoffspring than non-skewing conspecifics. The sons of the most male-biasing granddams were 2.7 times as fecund as those of granddams with a 50∶50 bias (similar results are seen in grandsires. Daughters of the strongest female-biasing granddams were 1.2 times as fecund as those of non-biasing females (this effect is not seen in grandsires. To our knowledge, these results are the first formal test of the hypothesis that birth SR manipulation is adaptive in mammals in terms of grandchildren produced, showing that SR manipulation can explain biased birth SR in general across mammalian species. These findings also have practical implications: parental control of birth

  20. Genetic organisation, mobility and predicted functions of genes on integrated, mobile genetic elements in sequenced strains of Clostridium difficile.

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    Michael S M Brouwer

    Full Text Available BACKGROUND: Clostridium difficile is the leading cause of hospital-associated diarrhoea in the US and Europe. Recently the incidence of C. difficile-associated disease has risen dramatically and concomitantly with the emergence of 'hypervirulent' strains associated with more severe disease and increased mortality. C. difficile contains numerous mobile genetic elements, resulting in the potential for a highly plastic genome. In the first sequenced strain, 630, there is one proven conjugative transposon (CTn, Tn5397, and six putative CTns (CTn1, CTn2 and CTn4-7, of which, CTn4 and CTn5 were capable of excision. In the second sequenced strain, R20291, two further CTns were described. RESULTS: CTn1, CTn2 CTn4, CTn5 and CTn7 were shown to excise from the genome of strain 630 and transfer to strain CD37. A putative CTn from R20291, misleadingly termed a phage island previously, was shown to excise and to contain three putative mobilisable transposons, one of which was capable of excision. In silico probing of C. difficile genome sequences with recombinase gene fragments identified new putative conjugative and mobilisable transposons related to the elements in strains 630 and R20291. CTn5-like elements were described occupying different insertion sites in different strains, CTn1-like elements that have lost the ability to excise in some ribotype 027 strains were described and one strain was shown to contain CTn5-like and CTn7-like elements arranged in tandem. Additionally, using bioinformatics, we updated previous gene annotations and predicted novel functions for the accessory gene products on these new elements. CONCLUSIONS: The genomes of the C. difficile strains examined contain highly related CTns suggesting recent horizontal gene transfer. Several elements were capable of excision and conjugative transfer. The presence of antibiotic resistance genes and genes predicted to promote adaptation to the intestinal environment suggests that CTns play a

  1. A whole-genome microarray reveals genetic diversity among Helicobacter pylori strains

    OpenAIRE

    Salama, Nina; Guillemin, Karen; McDaniel, Timothy K.; Sherlock, Gavin; Tompkins, Lucy; Falkow, Stanley

    2000-01-01

    Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolate...

  2. Cryptic sex-ratio bias provides indirect genetic benefits despite sexual conflict.

    Science.gov (United States)

    Cox, Robert M; Calsbeek, Ryan

    2010-04-02

    When selection favors sexual dimorphism, high-fitness parents often produce low-fitness progeny of the opposite sex. This sexual conflict is thought to overwhelm the genetic benefits of mate choice because preferred males incur a cost through the production of low-fitness daughters. We provide a counterpoint in a lizard (Anolis sagrei) that exhibits sexual conflict over body size. By using mate-choice experiments, we show that female brown anoles produce more sons than daughters via large sires but more daughters than sons via small sires. Measures of progeny fitness in the wild suggest that maximal fitness payoffs can be achieved by shifting offspring production from daughters to sons as sire size increases. These results illustrate how the resolution of sexual conflict can restore the genetic benefits of mate choice.

  3. Genetic variation in strains of zebrafish (Danio rerio) and the implications for ecotoxicology studies.

    Science.gov (United States)

    Coe, T S; Hamilton, P B; Griffiths, A M; Hodgson, D J; Wahab, M A; Tyler, C R

    2009-01-01

    There is substantial evidence that genetic variation, at both the level of the individual and population, has a significant effect on behaviour, fitness and response to toxicants. Using DNA microsatellites, we examined the genetic variation in samples of several commonly used laboratory strains of zebrafish, Danio rerio, a model species in toxicological studies. We compared the genetic variation to that found in a sample of wild fish from Bangladesh. Our findings show that the wild fish were significantly more variable than the laboratory strains for several measures of genetic variability, including allelic richness and expected heterozygosity. This lack of variation should be given due consideration for any study which attempts to extrapolate the results of ecotoxicological laboratory tests to wild populations.

  4. Population genetic evidence for sex-specific dispersal in an inbred social spider.

    Science.gov (United States)

    Smith, Deborah R; Su, Yong-Chao; Berger-Tal, Reut; Lubin, Yael

    2016-08-01

    Dispersal in most group-living species ensures gene flow among groups, but in cooperative social spiders, juvenile dispersal is suppressed and colonies are highly inbred. It has been suggested that such inbred sociality is advantageous in the short term, but likely to lead to extinction or reduced speciation rates in the long run. In this situation, very low levels of dispersal and gene flow among colonies may have unusually important impacts on fitness and persistence of social spiders. We investigated sex-specific differences in dispersal and gene flow among colonies, as reflected in the genetic structure within colonies and populations of the African social spider Stegodyphus dumicola Pocock, 1898 (Eresidae). We used DNA fingerprinting and mtDNA sequence data along with spatial mapping of colonies to compare male and female patterns of relatedness within and among colonies at three study sites. Samples were collected during and shortly after the mating season to detect sex-specific dispersal. Distribution of mtDNA haplotypes was consistent with proliferation of social nests by budding and medium- to long-distance dispersal by ballooning females. Analysis of molecular variance and spatial autocorrelation analyses of AFLPs showed high levels of genetic similarity within colonies, and STRUCTURE analyses revealed that the number of source populations contributing to colonies ranged from one to three. We also showed significant evidence of male dispersal among colonies at one site. These results support the hypothesis that in social spiders, genetic cohesion among populations is maintained by long-distance dispersal of female colony founders. Genetic diversity within colonies is maintained by colony initiation by multiple dispersing females, and adult male dispersal over short distances. Male dispersal may be particularly important in maintaining gene flow among colonies in local populations.

  5. Low cross-sex genetic correlation in carotenoid-based plumage traits in the blue tit nestlings (Cyanistes caeruleus.

    Directory of Open Access Journals (Sweden)

    Szymon M Drobniak

    Full Text Available In some bird species, both adult and juvenile individuals are often brightly coloured. It has been commonly assumed that identical plumage colouration present in both sexes results from strong intersexual genetic correlations in colour-related traits. Here, we aimed at testing this hypothesis in juvenile individuals and looked at genetic parameters describing carotenoid-based colouration of blue tit nestlings in a wild population. To separate genetic and environmental sources of phenotypic variation we performed a cross-fostering experiment. Our analyses confirmed the existence of sexual dichromatism in blue tit nestlings and revealed a significant, although low, genetic component of carotenoid-based colouration. However, genetic effects are expressed differently across sexes as indicated by low cross-sex genetic correlations (rmf. Thus our results do not support the prediction of generally high rmf and suggest that intersexual constraints on the evolution of colouration traits may be weaker than expected. We hypothesise that observed patterns of genetic correlations result from sex-specific selective pressures acting on nestling plumage colouration.

  6. Genetic Architecture of Atherosclerosis in Mice: A Systems Genetics Analysis of Common Inbred Strains.

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    Brian J Bennett

    2015-12-01

    Full Text Available Common forms of atherosclerosis involve multiple genetic and environmental factors. While human genome-wide association studies have identified numerous loci contributing to coronary artery disease and its risk factors, these studies are unable to control environmental factors or examine detailed molecular traits in relevant tissues. We now report a study of natural variations contributing to atherosclerosis and related traits in over 100 inbred strains of mice from the Hybrid Mouse Diversity Panel (HMDP. The mice were made hyperlipidemic by transgenic expression of human apolipoprotein E-Leiden (APOE-Leiden and human cholesteryl ester transfer protein (CETP. The mice were examined for lesion size and morphology as well as plasma lipid, insulin and glucose levels, and blood cell profiles. A subset of mice was studied for plasma levels of metabolites and cytokines. We also measured global transcript levels in aorta and liver. Finally, the uptake of acetylated LDL by macrophages from HMDP mice was quantitatively examined. Loci contributing to the traits were mapped using association analysis, and relationships among traits were examined using correlation and statistical modeling. A number of conclusions emerged. First, relationships among atherosclerosis and the risk factors in mice resemble those found in humans. Second, a number of trait-loci were identified, including some overlapping with previous human and mouse studies. Third, gene expression data enabled enrichment analysis of pathways contributing to atherosclerosis and prioritization of candidate genes at associated loci in both mice and humans. Fourth, the data provided a number of mechanistic inferences; for example, we detected no association between macrophage uptake of acetylated LDL and atherosclerosis. Fifth, broad sense heritability for atherosclerosis was much larger than narrow sense heritability, indicating an important role for gene-by-gene interactions. Sixth, stepwise linear

  7. Genetic diversity among major endemic strains of Leptospira interrogans in China

    Directory of Open Access Journals (Sweden)

    Zhang Zhi-Ming

    2007-07-01

    Full Text Available Abstract Background Leptospirosis is a world-widely distributed zoonosis. Humans become infected via exposure to pathogenic Leptospira spp. from contaminated water or soil. The availability of genomic sequences of Leptospira interrogans serovar Lai and serovar Copenhageni opened up opportunities to identify genetic diversity among different pathogenic strains of L. interrogans representing various kinds of serotypes (serogroups and serovars. Results Comparative genomic hybridization (CGH analysis was used to compare the gene content of L. interrogans serovar Lai strain Lai with that of other 10 L. interrogans strains prevailed in China and one identified from Brazil using a microarray spotted with 3,528 protein coding sequences (CDSs of strain Lai. The cutoff ratio of sample/reference (S/R hybridization for detecting the absence of genes from one tested strain was set by comparing the ratio of S/R hybridization and the in silico sequence similarities of strain Lai and serovar Copenhageni strain Fiocruz L1-130. Among the 11 strains tested, 275 CDSs were found absent from at least one strain. The common backbone of the L. interrogans genome was estimated to contain about 2,917 CDSs. The genes encoding fundamental cellular functions such as translation, energy production and conversion were conserved. While strain-specific genes include those that encode proteins related to either cell surface structures or carbohydrate transport and metabolism. We also found two genomic islands (GIs in strain Lai containing genes divergently absent in other strains. Because genes encoding proteins with potential pathogenic functions are located within GIs, these elements might contribute to the variations in disease manifestation. Differences in genes involved in O-antigen biosynthesis were also identified for strains belonging to different serogroups, which offers an opportunity for future development of genomic typing tools for serological classification

  8. Genetic factors control nicotine self-administration in isogenic adolescent rat strains.

    Directory of Open Access Journals (Sweden)

    Hao Chen

    Full Text Available Adult cigarette smokers usually become dependent on cigarettes during adolescence. Despite recent advances in addiction genetics, little data delineates the genetic factors that account for the vulnerability of humans to smoke tobacco. We studied the operant nicotine self-administration (SA behavior of six inbred strains of adolescent male rats (Fisher 344, Brown Norway, Dark Agouti, Spontaneous Hypertensive Rat, Wistar Kyoto and Lewis and six selected F1 hybrids. All rats were trained to press a lever to obtain food starting on postnatal day (PN 32, and then nicotine (0.03 mg/kg/infusion, i.v. reinforcement was made available on PN41-42 (10 consecutive daily 2 h sessions. Of the 12 isogenic strains, Fisher rats self-administered the fewest nicotine infusions (1.45 ± 0.36/d during the last 3 d, while Lewis rats took the most nicotine (13.0 ± 1.4/d. These strains sorted into high, intermediate and low self-administration groups in 2, 2, and 8 strains, respectively. The influence of heredity on nicotine SA (0.64 is similar to that reported for humans. Therefore, this panel of isogenic rat strains effectively models the overall impact of genetics on the vulnerability to acquire nicotine-reinforced behavior during adolescence. Separate groups of rats responded for food starting on PN41. The correlation between nicotine and food reward was not significant. Hence, the genetic control of the motivation to obtain nicotine is distinctly different from food reward, indicating the specificity of the underlying genetic mechanisms. Lastly, the behavior of F1 hybrids was not predicted from the additive behavior of the parental strains, indicating the impact of significant gene-gene interactions on the susceptibility to nicotine reward. Taken together, the behavioral characteristics of this model indicate its strong potential to identify specific genes mediating the human vulnerability to smoke cigarettes.

  9. Structure and genetic content of the megaplasmids of neurotoxigenic clostridium butyricum type E strains from Italy.

    Science.gov (United States)

    Iacobino, Angelo; Scalfaro, Concetta; Franciosa, Giovanna

    2013-01-01

    We determined the genetic maps of the megaplasmids of six neutoroxigenic Clostridium butyricum type E strains from Italy using molecular and bioinformatics techniques. The megaplasmids are circular, not linear as we had previously proposed. The differently-sized megaplasmids share a genetic region that includes structural, metabolic and regulatory genes. In addition, we found that a 168 kb genetic region is present only in the larger megaplasmids of two tested strains, whereas it is absent from the smaller megaplasmids of the four remaining strains. The genetic region unique to the larger megaplasmids contains, among other features, a locus for clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR associated (cas) genes, i.e. a bacterial adaptive immune system providing sequence-specific protection from invading genetic elements. Some CRISPR spacer sequences of the neurotoxigenic C. butyricum type E strains showed homology to prophage, phage and plasmid sequences from closely related clostridia species or from distant species, all sharing the intestinal habitat, suggesting that the CRISPR locus might be involved in the microorganism adaptation to the human or animal intestinal environment. Besides, we report here that each of four distinct CRISPR spacers partially matched DNA sequences of different prophages and phages, at identical nucleotide locations. This suggests that, at least in neurotoxigenic C. butyricum type E, the CRISPR locus is potentially able to recognize the same conserved DNA sequence of different invading genetic elements, besides targeting sequences unique to previously encountered invading DNA, as currently predicted for a CRISPR locus. Thus, the results of this study introduce the possibility that CRISPR loci can provide resistance to a wider range of invading DNA elements than previously appreciated. Whether it is more advantageous for the peculiar neurotoxigenic C. butyricum type E strains to maintain or to lose the

  10. Structure and genetic content of the megaplasmids of neurotoxigenic clostridium butyricum type E strains from Italy.

    Directory of Open Access Journals (Sweden)

    Angelo Iacobino

    Full Text Available We determined the genetic maps of the megaplasmids of six neutoroxigenic Clostridium butyricum type E strains from Italy using molecular and bioinformatics techniques. The megaplasmids are circular, not linear as we had previously proposed. The differently-sized megaplasmids share a genetic region that includes structural, metabolic and regulatory genes. In addition, we found that a 168 kb genetic region is present only in the larger megaplasmids of two tested strains, whereas it is absent from the smaller megaplasmids of the four remaining strains. The genetic region unique to the larger megaplasmids contains, among other features, a locus for clustered regularly interspaced short palindromic repeats (CRISPR and CRISPR associated (cas genes, i.e. a bacterial adaptive immune system providing sequence-specific protection from invading genetic elements. Some CRISPR spacer sequences of the neurotoxigenic C. butyricum type E strains showed homology to prophage, phage and plasmid sequences from closely related clostridia species or from distant species, all sharing the intestinal habitat, suggesting that the CRISPR locus might be involved in the microorganism adaptation to the human or animal intestinal environment. Besides, we report here that each of four distinct CRISPR spacers partially matched DNA sequences of different prophages and phages, at identical nucleotide locations. This suggests that, at least in neurotoxigenic C. butyricum type E, the CRISPR locus is potentially able to recognize the same conserved DNA sequence of different invading genetic elements, besides targeting sequences unique to previously encountered invading DNA, as currently predicted for a CRISPR locus. Thus, the results of this study introduce the possibility that CRISPR loci can provide resistance to a wider range of invading DNA elements than previously appreciated. Whether it is more advantageous for the peculiar neurotoxigenic C. butyricum type E strains to maintain

  11. High-density linkage maps fail to detect any genetic component to sex determination in a Rana temporaria family.

    Science.gov (United States)

    Brelsford, A; Rodrigues, N; Perrin, N

    2016-01-01

    Sex chromosome differentiation in Rana temporaria varies strikingly among populations or families: whereas some males display well-differentiated Y haplotypes at microsatellite markers on linkage group 2 (LG2), others are genetically undistinguishable from females. We analysed with RADseq markers one family from a Swiss lowland population with no differentiated sex chromosomes, and where sibship analyses had failed to detect any association between the phenotypic sex of progeny and parental haplotypes. Offspring were reared in a common tank in outdoor conditions and sexed at the froglet stage. We could map a total of 2177 SNPs (1123 in the mother, 1054 in the father), recovering in both adults 13 linkage groups (= chromosome pairs) that were strongly syntenic to Xenopus tropicalis despite > 200 My divergence. Sexes differed strikingly in the localization of crossovers, which were uniformly distributed in the female but limited to chromosome ends in the male. None of the 2177 markers showed significant association with offspring sex. Considering the very high power of our analysis, we conclude that sex determination was not genetic in this family; which factors determined sex remain to be investigated.

  12. Toxin production in a rare and genetically remote cluster of strains of the Bacillus cereus group

    Directory of Open Access Journals (Sweden)

    Granum Per

    2007-05-01

    Full Text Available Abstract Background Three enterotoxins are implicated in diarrhoeal food poisoning due to Bacillus cereus: Haemolysin BL (Hbl, Non-haemolytic enterotoxin (Nhe, and Cytotoxin K (CytK. Toxin gene profiling and assays for detection of toxin-producing stains have been used in attempts to evaluate the enterotoxic potential of B. cereus group strains. B. cereus strain NVH 391/98, isolated from a case of fatal enteritis, was genetically remote from other B. cereus group strains. This strain lacked the genes encoding Hbl and Nhe, but contains CytK-1. The high virulence of this strain is thought to be due to the greater cytotoxic activity of CytK-1 compared to CytK-2, and to a high level of cytK expression. To date, only three strains containing cytK-1 have been identified; B. cereus strains NVH 391/98, NVH 883/00, and INRA AF2. Results A novel gene variant encoding Nhe was identified in these three strains, which had an average of 80% identity in protein sequence with previously identified Nhe toxins. While culture supernatants containing CytK and Nhe from NVH 391/98 and INRA AF2 were highly cytotoxic, NVH 883/00 expressed little or no CytK and Nhe and was non-cytotoxic. Comparative sequence and expression studies indicated that neither the PlcR/PapR quorum sensing system, nor theYvrGH and YvfTU two-component systems, were responsible for the observed difference in toxin production. Additionally, phylogenetic analysis of 13 genes showed that NVH 391/98, NVH 883/00, and INRA AF2 comprise a novel cluster of strains genetically distant from other B. cereus group strains. Conclusion Due to its divergent sequence, the novel nhe operon had previously not been detected in NVH 391/98 using PCR and several monoclonal antibodies. Thus, toxigenic profiling based on the original nhe sequence will fail to detect the toxin in this group of strains. The observation that strain NVH 883/00 carries cytK-1 but is non-cytotoxic indicates that the detection of this gene

  13. Mitochondrial DNA paradox: sex-specific genetic structure in a marine mussel – despite maternal inheritance and passive dispersal

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    Teske Peter R

    2012-06-01

    Full Text Available Abstract Background When genetic structure is identified using mitochondrial DNA (mtDNA, but no structure is identified using biparentally-inherited nuclear DNA, the discordance is often attributed to differences in dispersal potential between the sexes. Results We sampled the intertidal rocky shore mussel Perna perna in a South African bay and along the nearby open coast, and sequenced maternally-inherited mtDNA (there is no evidence for paternally-inherited mtDNA in this species and a biparentally-inherited marker. By treating males and females as different populations, we identified significant genetic structure on the basis of mtDNA data in the females only. Conclusions This is the first study to report sex-specific differences in genetic structure based on matrilineally-inherited mtDNA in a passively dispersing species that lacks social structure or sexual dimorphism. The observed pattern most likely stems from females being more vulnerable to selection in habitats from which they did not originate, which also manifests itself in a male-biased sex ratio. Our results have three important implications for the interpretation of population genetic data. First, even when mtDNA is inherited exclusively in the female line, it also contains information about males. For that reason, using it to identify sex-specific differences in genetic structure by contrasting it with biparentally-inherited markers is problematic. Second, the fact that sex-specific differences were found in a passively dispersing species in which sex-biased dispersal is unlikely highlights the fact that significant genetic structure is not necessarily a function of low dispersal potential or physical barriers. Third, even though mtDNA is typically used to study historical demographic processes, it also contains information about contemporary processes. Higher survival rates of males in non-native habitats can erase the genetic structure present in their mothers within a single

  14. Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae) and of its Rickettsia Endosymbiont, and Associated Sex-Ratio Differences.

    Science.gov (United States)

    Nugnes, Francesco; Gebiola, Marco; Monti, Maurilia Maria; Gualtieri, Liberata; Giorgini, Massimo; Wang, Jianguo; Bernardo, Umberto

    2015-01-01

    The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed.

  15. Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae) and of its Rickettsia Endosymbiont, and Associated Sex-Ratio Differences

    Science.gov (United States)

    Nugnes, Francesco; Gebiola, Marco; Monti, Maurilia Maria; Gualtieri, Liberata; Giorgini, Massimo; Wang, Jianguo; Bernardo, Umberto

    2015-01-01

    The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed. PMID:25970681

  16. Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae and of its Rickettsia Endosymbiont, and Associated Sex-Ratio Differences.

    Directory of Open Access Journals (Sweden)

    Francesco Nugnes

    Full Text Available The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed.

  17. [Retrotransposon MDG4 and its role in genetic instability of a mutator strain of Drosophila melanogaster].

    Science.gov (United States)

    Liubomirskaia, N V; Kim, A I; Il'in, Iu V

    2003-02-01

    This article summarizes the results of a ten-year study of genetic instability of a mutator strain of Drosophila melanogaster caused by transposition of the gypsy retrotransposon. The results of other authors working with an analogous system are analyzed. Possible mechanisms are suggested for the interaction of gypsy with the cell gene flamenco that participates in transposition control of this mobile element.

  18. Application of reverse genetics for producing attenuated vaccine strains against highly pathogenic avian influenza viruses.

    Science.gov (United States)

    Uchida, Yuko; Takemae, Nobuhiro; Saito, Takehiko

    2014-08-01

    In this study, reverse genetics was applied to produce vaccine candidate strains against highly pathogenic avian influenza viruses (HPAIVs) of the H5N1 subtype. The H5 subtype vaccine strains were generated by a reverse genetics method in a biosafety level 2 facility. The strain contained the HA gene from the H5N1 subtype HPAIV attenuated by genetic modification at the cleavage site, the NA gene derived from the H5N1 subtype HPAI or the H5N3 subtype of avian influenza virus and internal genes from A/Puerto Rico/8/34. Vaccination with an inactivated recombinant virus with oil-emulsion completely protected chickens from a homologous viral challenge with a 640 HAU or 3,200 HAU/vaccination dose. Vaccination with a higher dose of antigen, 3,200 HAU, was effective at increasing survival and efficiently reduced viral shedding even when challenged by a virus of a different HA clade. The feasibility of differentiation of infected from vaccinated animals (DIVA) was demonstrated against a challenge with H5N1 HPAIVs when the recombinant H5N3 subtype viruses were used as the antigens of the vaccine. Our study demonstrated that the use of reverse genetics would be an option to promptly produce an inactivated vaccine with better matching of antigenicity to a circulating strain.

  19. Markerless Escherichia coli rrn Deletion Strains for Genetic Determination of Ribosomal Binding Sites

    DEFF Research Database (Denmark)

    Quan, Selwyn; Skovgaard, Ole; McLaughlin, Robert E

    2015-01-01

    Single-copy rrn strains facilitate genetic ribosomal studies in Escherichia coli. Consecutive markerless deletion of rrn operons resulted in slower growth upon inactivation of the fourth copy, which was reversed by supplying transfer RNA genes encoded in rrn operons in trans. Removal of the sixth...

  20. A genetic method for sex identification of raccoons (Procyon lotor) with using the ZFX and ZFY genes.

    Science.gov (United States)

    Okuyama, Minami W; Shimozuru, Michito; Tsubota, Toshio

    2014-05-01

    A genetic method for sex determination in raccoons was developed based on nucleotide differences of the zinc finger protein genes ZFX and ZFY. Four novel internal primers specific for ZFX or ZFY were designed. PCR amplification using two primer sets followed by agarose gel electrophoresis enabled sex determination. 141-bp and 447-bp bands were in both sex, and 346-bp band was specific only in male with primer set I. 345-bp and 447-bp bands were in both sex, and 141-bp band was specific only in male with primer set II, which could distinguish raccoon's electrophoresis pattern from three native carnivores in Hokkaido. This method will be useful for conservation genetics studies or biological analyses of raccoons.

  1. Children with severe early childhood caries: streptococci genetic strains within carious and white spot lesions

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    Kenneth Gilbert

    2014-10-01

    Full Text Available Background and objectives: Mutans streptococci (MS are one of the major microbiological determinants of dental caries. The objectives of this study are to identify distinct MS and non-MS streptococci strains that are located at carious sites and non-carious enamel surfaces in children with severe early childhood caries (S-ECC, and assess if cariogenic MS and non-cariogenic streptococci might independently exist as primary bacterial strains on distinct sites within the dentition of individual children. Design: Dental plaque from children (N=20; aged 3–6 with S-ECC was collected from carious lesions (CLs, white spot lesions (WSLs and non-carious enamel surfaces. Streptococcal isolates (N=10–20 from each site were subjected to polymerase chain reaction (PCR to identify MS, and arbitrarily primed-PCR for assignment of genetic strains. Primary strains were identified as ≥50% of the total isolates surveyed at any site. In several cases, strains were characterized for acidurity using ATP-driven bioluminescence and subjected to PCR-determination of potential MS virulence products. Identification of non-MS was determined by 16S rRNA gene sequencing. Results: Sixty-four independent MS or non-MS streptococcal strains were identified. All children contained 1–6 strains. In many patients (N=11, single primary MS strains were identified throughout the dentition. In other patients (N=4, primary MS strains were identified within CLs that were distinct from primary strains found on enamel. Streptococcus gordonii strains were identified as primary strains on enamel or WSLs in four children, and in general were less aciduric than MS strains. Conclusions: Many children with S-ECC contained only a single primary MS strain that was present in both carious and non-carious sites. In some cases, MS and non-cariogenic S. gordonii strains were found to independently exist as dominant strains at different locations within the dentition of individual children, and

  2. Children with severe early childhood caries: streptococci genetic strains within carious and white spot lesions.

    Science.gov (United States)

    Gilbert, Kenneth; Joseph, Raphael; Vo, Alex; Patel, Trusha; Chaudhry, Samiya; Nguyen, Uyen; Trevor, Amy; Robinson, Erica; Campbell, Margaret; McLennan, John; Houran, Farielle; Wong, Tristan; Flann, Kendra; Wages, Melissa; Palmer, Elizabeth A; Peterson, John; Engle, John; Maier, Tom; Machida, Curtis A

    2014-01-01

    Mutans streptococci (MS) are one of the major microbiological determinants of dental caries. The objectives of this study are to identify distinct MS and non-MS streptococci strains that are located at carious sites and non-carious enamel surfaces in children with severe early childhood caries (S-ECC), and assess if cariogenic MS and non-cariogenic streptococci might independently exist as primary bacterial strains on distinct sites within the dentition of individual children. Dental plaque from children (N=20; aged 3-6) with S-ECC was collected from carious lesions (CLs), white spot lesions (WSLs) and non-carious enamel surfaces. Streptococcal isolates (N=10-20) from each site were subjected to polymerase chain reaction (PCR) to identify MS, and arbitrarily primed-PCR for assignment of genetic strains. Primary strains were identified as ≥50% of the total isolates surveyed at any site. In several cases, strains were characterized for acidurity using ATP-driven bioluminescence and subjected to PCR-determination of potential MS virulence products. Identification of non-MS was determined by 16S rRNA gene sequencing. Sixty-four independent MS or non-MS streptococcal strains were identified. All children contained 1-6 strains. In many patients (N=11), single primary MS strains were identified throughout the dentition. In other patients (N=4), primary MS strains were identified within CLs that were distinct from primary strains found on enamel. Streptococcus gordonii strains were identified as primary strains on enamel or WSLs in four children, and in general were less aciduric than MS strains. Many children with S-ECC contained only a single primary MS strain that was present in both carious and non-carious sites. In some cases, MS and non-cariogenic S. gordonii strains were found to independently exist as dominant strains at different locations within the dentition of individual children, and the aciduric potential of these strains may influence susceptibility in the

  3. A molecular genetic study of natural strains of Saccharomyces isolated from Asturian cider fermentations.

    Science.gov (United States)

    Suárez Valles, B; Pando Bedriñana, R; González García, A; Querol Simón, A

    2007-10-01

    To analyse the genetic diversity and the dynamics of Saccharomyces strains in spontaneous fermentation in ciders. The effect of the cellar, harvest and cider-making technology were evaluated. The ecology of spontaneous cider fermentations in the same cellar (Asturias) was studied for two consecutive harvests (2000 and 2001) by using mtDNA restriction analysis. Our results showed that there was a succession of genetically different strains of Saccharomyces during cider production. In general, strains of Saccharomyces bayanus species predominated at the early fermentation steps (begining and/or tumultuous fermentations), while Saccharomyces cerevisiae yeasts were the most abundant at the end of the fermentation. Five S. bayanus strains (patterns III, VII, VIII, XV and XVII) were present at significant frequencies in all the experimental tanks during the two consecutive years. The results of the cluster analysis (unweighted pair group method using average linkage) showed higher similarities for the patterns III, XV, VII and VIII. Therefore, these strains should be considered associated with the microbiota of this cellar. A high polymorphism within populations of Saccharomyces was found throughout the different stages of Asturian production of cider. In all the cider fermentations, a variable number of S. bayanus and S. cerevisiae strains was always present. Our results indicate, over the period of time studied, the existence of the natural microbiota in the cellar. This study has allowed us to gain a better understanding of the role of wild Saccharomyces yeast in Asturian cider fermentations.

  4. Trichophyton tonsurans strains from Brazil: phenotypic heterogeneity, genetic homology, and detection of virulence genes.

    Science.gov (United States)

    Sidrim, José Julio Costa; Rocha, Marcos Fábio Gadelha; Leite, João Jaime Giffoni; Maranhão, Fernanda Cristina de Albuquerque; Lima, Rita Amanda Chaves; Castelo-Branco, Débora de Souza Collares Maia; Bandeira, Tereza de Jesus Pinheiro Gomes; Cordeiro, Rossana de Aguiar; Brilhante, Raimunda Sâmia Nogueira

    2013-11-01

    The objective of this study was to establish the phenotypical and molecular patterns of clinical isolates of Trichophyton tonsurans circulating in the state of Ceará, northeastern Brazil. For this purpose, 25 T. tonsurans strains isolated from independent cases of tinea capitis in children were phenotypically evaluated regarding their macro- and micro-morphological characteristics, vitamin requirements, urease production, and antifungal susceptibility. The molecular characterization was carried out with random amplified polymorphic DNA molecular markers and M13 fingerprinting. The presence of the genes CarbM14, Sub2, CER, URE, ASP, PBL, and LAC, which encode enzymes related to fungal virulence, was also evaluated. Finally, melanin production was assessed through specific staining. The data obtained demonstrated that these T. tonsurans strains have considerable phenotypical variation, although they showed a low degree of genetic polymorphism according to the markers used. The genes CarbM14, Sub2, CER, and URE were detected in all the analyzed strains. The gene LAC was also identified in all the strains, and melanin synthesis was phenotypically confirmed. The strains were susceptible to antifungals, especially itraconazole (GM = 0.06 μg/mL) and ketoconazole (GM = 0.24 μg/mL). Therefore, T. tonsurans strains can present great phenotypical heterogeneity, even in genetically similar isolates. Moreover, the presence of the LAC gene indicates the possible participation of melanin in the pathogenesis of these dermatophytes.

  5. Genetic Diversity and Global Distribution of Citrus tristeza virus (CTV) Strains

    Institute of Scientific and Technical Information of China (English)

    Wu Xiao-yun; Cheng Xiao-fei; Luo Lu; Wu Xiao-xia

    2012-01-01

    Citrus tristeza virus (CTV), the most devastating viral pathogen in citrus, causes tremendous economic losses to citrus industry worldwide. The CTV isolates exhibit variable pathogenicities on their hosts indicating a mixed population of the CTV in nature. Several fragments within the CTV genome have been used for studying the genetic diversity of the CTV, however, the best region for rapid the CTV strain differentiation is still absent at present. In present study, a systemic analysis was carried out to evaluate the best region within the CTV genome for rapid CTV strain differentiation. Results of our study showed that the major coat protein (CP) coding region was the best region for this purpose. Using pair-wise distance frequency distribution plot, a reasonable genetic distance cut-off value was set for the CTV CP gene for the CTV strain differentiation. Using this criterion, eight CTV strains, including seven well characterized and a new strain, were successfully differentiated using 537 CTV isolates reported from 38 countries. The global strain distribution pattern was then determined and discussed. Our results also provided a new insight into the evolution and spreading of the virus, as well as the information for developing proper disease management strategy.

  6. Genetic diversity of Ehrlichia canis strains from naturally infected dogs in Rio de Janeiro, Brazil.

    Science.gov (United States)

    Ferreira, Renata Fernandes; Cerqueira, Aloysio de Mello Figueiredo; Castro, Tatiana Xavier de; Ferreira, Eliane de Oliveira; Neves, Felipe Piedade Gonçalves; Barbosa, André Victor; Macieira, Daniel de Barros; Almosny, Nádia Regina Pereira

    2014-01-01

    The aim of this study was to characterize Ehrlichia canis strains from naturally infected dogs in Rio de Janeiro, Brazil. In addition, all the clinical and hematological findings observed in these dogs were reported. PCR targeting the 16S rRNA gene was used for diagnostic purposes, and the TRP19 and TRP36 genes were sequenced to evaluate the genetic diversity. Fifteen samples were positive for E. canis. The polymerase chain reaction for the TRP19 gene resulted in 11 amplicons (11/15), which were cloned into the pGEM-T easy vector for sequencing. The complete sequence of TRP19 gene was compared to those in the GenBank, revealing high identicalness. Phylogenetic analysis on the TRP36 gene sequences demonstrated two distinct strains from two dogs, named 56C and 70C. The 56C strain was grouped with the strain Cuiaba 16, which is a hybrid strain formed by Brazilian and US genogroups; and the 70C strain was grouped with other strains of the US genogroup, thus suggesting that there are at least two genogroups of E. canis in Rio de Janeiro (US and Brazilian). Those animals, in which the 70C and 56C strains were isolated, showed distinct clinical and hematological manifestations of the disease. The appearance of different genotypes may express new phenotypes, thus resulting in different forms of presentation of the disease and making its diagnosis more complex.

  7. Pain modality- and sex-specific effects of COMT genetic functional variants.

    Science.gov (United States)

    Belfer, Inna; Segall, Samantha K; Lariviere, William R; Smith, Shad B; Dai, Feng; Slade, Gary D; Rashid, Naim U; Mogil, Jeffrey S; Campbell, Claudia M; Edwards, Robert R; Liu, Qian; Bair, Eric; Maixner, William; Diatchenko, Luda

    2013-08-01

    The enzyme catechol-O-methyltransferase (COMT) metabolizes catecholamine neurotransmitters involved in a number of physiological functions, including pain perception. Both human and mouse COMT genes possess functional polymorphisms contributing to interindividual variability in pain phenotypes such as sensitivity to noxious stimuli, severity of clinical pain, and response to pain treatment. In this study, we found that the effects of Comt functional variation in mice are modality specific. Spontaneous inflammatory nociception and thermal nociception behaviors were correlated the most with the presence of the B2 SINE transposon insertion residing in the 3'UTR mRNA region. Similarly, in humans, COMT functional haplotypes were associated with thermal pain perception and with capsaicin-induced pain. Furthermore, COMT genetic variations contributed to pain behaviors in mice and pain ratings in humans in a sex-specific manner. The ancestral Comt variant, without a B2 SINE insertion, was more strongly associated with sensitivity to capsaicin in female vs male mice. In humans, the haplotype coding for low COMT activity increased capsaicin-induced pain perception in women, but not men. These findings reemphasize the fundamental contribution of COMT to pain processes, and provide a fine-grained resolution of this contribution at the genetic level that can be used to guide future studies in the area of pain genetics.

  8. Genetic diversity of environmental Vibrio cholerae O1 strains isolated in Northern Vietnam.

    Science.gov (United States)

    Takemura, Taichiro; Murase, Kazunori; Maruyama, Fumito; Tran, Thi Luong; Ota, Atsushi; Nakagawa, Ichiro; Nguyen, Dong Tu; Ngo, Tu Cuong; Nguyen, Thi Hang; Tokizawa, Asako; Morita, Masatomo; Ohnishi, Makoto; Nguyen, Binh Minh; Yamashiro, Tetsu

    2017-10-01

    Cholera epidemics have been recorded periodically in Vietnam during the seventh cholera pandemic. Since cholera is a water-borne disease, systematic monitoring of environmental waters for Vibrio cholerae presence is important for predicting and preventing cholera epidemics. We conducted monitoring, isolation, and genetic characterization of V. cholerae strains in Nam Dinh province of Northern Vietnam from Jul 2013 to Feb 2015. In this study, four V. cholerae O1 strains were detected and isolated from 110 analyzed water samples (3.6%); however, none of them carried the cholera toxin gene, ctxA, in their genomes. Whole genome sequencing and phylogenetic analysis revealed that the four O1 isolates were separated into two independent clusters, and one of them diverged from a common ancestor with pandemic strains. The analysis of pathogenicity islands (CTX prophage, VPI-I, VPI-II, VSP-I, and VSP-II) indicated that one strain (VNND_2014Jun_6SS) harbored an unknown prophage-like sequence with high homology to vibriophage KSF-1 phi and VCY phi, identified from Bangladesh and the USA, respectively, while the other three strains carried tcpA gene with a distinct sequence demonstrating a separate clonal lineage. These results suggest that the aquatic environment can harbor highly divergent V. cholera strains and serve as a reservoir for multiple V. cholerae virulence-associated genes which may be exchanged via mobile genetic elements. Therefore, continuous monitoring and genetic characterization of V. cholerae strains in the environment should contribute to the early detection of the sources of infection and prevention of cholera outbreaks as well as to understanding the natural ecology and evolution of V. cholerae. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Genetic diversity and transmission characteristics of Beijing family strains of Mycobacterium tuberculosis in Peru.

    Directory of Open Access Journals (Sweden)

    Tomotada Iwamoto

    Full Text Available Beijing family strains of Mycobacterium tuberculosis have attracted worldwide attention because of their wide geographical distribution and global emergence. Peru, which has a historical relationship with East Asia, is considered to be a hotspot for Beijing family strains in South America. We aimed to unveil the genetic diversity and transmission characteristics of the Beijing strains in Peru. A total of 200 Beijing family strains were identified from 2140 M. tuberculosis isolates obtained in Lima, Peru, between December 2008 and January 2010. Of them, 198 strains were classified into sublineages, on the basis of 10 sets of single nucleotide polymorphisms (SNPs. They were also subjected to variable number tandem-repeat (VNTR typing using an international standard set of 15 loci (15-MIRU-VNTR plus 9 additional loci optimized for Beijing strains. An additional 70 Beijing family strains, isolated between 1999 and 2006 in Lima, were also analyzed in order to make a longitudinal comparison. The Beijing family was the third largest spoligotyping clade in Peru. Its population structure, by SNP typing, was characterized by a high frequency of Sequence Type 10 (ST10, which belongs to a modern subfamily of Beijing strains (178/198, 89.9%. Twelve strains belonged to the ancient subfamily (ST3 [n=3], ST25 [n=1], ST19 [n=8]. Overall, the polymorphic information content for each of the 24 loci values was low. The 24 loci VNTR showed a high clustering rate (80.3% and a high recent transmission index (RTI(n-1=0.707. These strongly suggest the active and on-going transmission of Beijing family strains in the survey area. Notably, 1 VNTR genotype was found to account for 43.9% of the strains. Comparisons with data from East Asia suggested the genotype emerged as a uniquely endemic clone in Peru. A longitudinal comparison revealed the genotype was present in Lima by 1999.

  10. Susceptibility of carnivore hosts to strains of canine distemper virus from distinct genetic lineages.

    Science.gov (United States)

    Nikolin, Veljko M; Wibbelt, Gudrun; Michler, Frank-Uwe F; Wolf, Peter; East, Marion L

    2012-04-23

    Using the complete haemagglutinin (HA) gene and partial phosphoprotein (P) gene we investigated the genotype of canine distemper virus (CDV) strains recovered from two wildlife species in Mecklenburg-Vorpommern, Germany. Phylogenetic analyses demonstrated significant differences between the strains from raccoons Procyon lotor (family Procyonidae) obtained in 2007 and strains from red foxes Vulpes vulpes (family Canidae) obtained in 2008. The raccoon strains belonged to the CDV European wildlife lineage whereas the red fox strains belonged to the CDV Europe lineage. We combined our genetic sequence data with published data from 138 CDV stains worldwide to investigate the proposed importance of amino acid substitutions in the SLAM binding region of the CDV HA protein at position 530 (G/E to R/D/N) and 549 (Y to H) to the spread of domestic dog-adapted CDV strains to other carnivores. We found no evidence that amino acid 530 was strongly affected by host species. Rather, site 530 was conserved within CDV lineages, regardless of host species. Contrary to expectation, strains from non-dog hosts did not exhibit a bias towards the predicted substitution Y549H. Wild canid hosts were more frequently infected by strains with 549Y, a pattern similar to domestic dogs. Non-canid strains showed no significant bias towards either H or Y at site 549, although there was a trend towards 549H. Significant differences between the prevalence of 549Y and 549H in wild canid strains and non-canid strains suggests a degree of virus adaptation to these categories of host.

  11. Sex-differential genetic effect of phosphodiesterase 4D (PDE4D on carotid atherosclerosis

    Directory of Open Access Journals (Sweden)

    Guo Yuh-Cherng

    2010-06-01

    Full Text Available Abstract Background The phosphodiesterase 4D (PDE4D gene was reported as a susceptibility gene to stroke. The genetic effect might be attributed to its role in modulating the atherogenic process in the carotid arteries. Using carotid intima-media thickness (IMT and plaque index as phenotypes, the present study sought to determine the influence of this gene on subclinical atherosclerosis. Methods Carotid ultrasonography was performed on 1013 stroke-free subjects who participated in the health screening programs (age 52.6 ± 12.2; 47.6% men. Genotype distribution was compared among the high-risk (plaque index ≥ 4, low-risk (index = 1-3, and reference (index = 0 groups. We analyzed continuous IMT data and further dichotomized IMT data using mean plus one standard deviation as the cutoff level. Because the plaque prevalence and IMT values displayed a notable difference between men and women, we carried out sex-specific analyses in addition to analyzing the overall data. Rs702553 at the PDE4D gene was selected because it conferred a risk for young stroke in our previous report. Previous young stroke data (190 cases and 211 controls with an additional 532 control subjects without ultrasonic data were shown as a cross-validation for the genetic effect. Results In the overall analyses, the rare homozygote of rs702553 led to an OR of 3.1 (p = 0.034 for a plaque index ≥ 4. When subjects were stratified by sex, the genetic effect was only evident in men but not in women. Comparing male subjects with plaque index ≥ 4 and those with plaque index = 0, the TT genotype was over-represented (27.6% vs. 13.4%, p = 0.008. For dichotomized IMT data in men, the TT genotype had an OR of 2.1 (p = 0.032 for a thicker IMT at the common carotid artery compared with the (AA + AT genotypes. In women, neither IMT nor plaque index was associated with rs702553. Similarly, SNP rs702553 was only significant in young stroke men (OR = 1.8, p = 0.025 but not in women (p = 0

  12. [A molecular-and-genetic analysis of species and strain diversity of bifidobacteria in early childhood].

    Science.gov (United States)

    Shkoporov, A N; Kafarskaia, L I; Afanas'ev, S S; Smeianov, V V; Kirillov, M Iu; Postnikova, E A; Maksimov, F E; Khokhlova, E V; Efimov, B A

    2006-01-01

    The species and strain composition of bifidobacteria in 29 children both sexes, aged 8 to 16 months, was studied. Species-specific primers and PCR were used to determine to which species the predominant strains of bifidobacteria, isolated from feces by cultural methods, belonged. Bifidobacteria were found in 28 (96.5%) children; their number was 10.2 +/- 0.7 ECU per a gram of the material. B. longum and B. bifidum were frequent (71.4 and 53.5%, respectively). The level of quantitative detection used in the study also allowed revealing of B. catenulatum (17.9%) and B. breve (14.4%). A high titer of B. dentium was found in one case (3.6%). B. adolescentis and B. angulatum were not found in any patient. The average number of species found in one child was 1.7 +/- 0.7. RAPD-PCR and investigation of plasmid profile were used to determine possible belonging of the isolates to different strains. The average number of strains per one sample was 2.3 +/- 1.2. Nine unique plasmid bifidobacterial strains were isolated from 7 children. In 3 children the intestinal tract was found to be colonized by both plasmid and non-plasmid-carrying strains of one bifidobacterial species.

  13. Genetic studies on sex determination and colouration in Nile tilapia (Oreochromis niloticus L.)

    Energy Technology Data Exchange (ETDEWEB)

    Karayuecel, I

    1999-05-01

    .6{+-}9.8% compared to the survival rates of 97.0{+-}0.9% and 97.3{+-}0.8% in controls and DES treated groups, respectively. YYRR males and YYRR neofemales were produced by integrating existing YYrr males and YYrr neofemales from the Egypt-Swansea-Philippine isolate and YYRR androgenetic males from the Stirling isolate with XXRR females and XYRR males of the Stirling isolate of Egyptian strain O. niloticus. In summary, this study provides valuable information regarding the colour and sex determination mechanisms of O. niloticus. The research in this thesis also demonstrated that both YY genotype and red coloration can be combined in a single strain in order to produce all male and stable red coloured O. niloticus. (author)

  14. Genetic and antigenic analysis of the G attachment protein of bovine respiratory syncytial virus strains

    DEFF Research Database (Denmark)

    Elvander, M.; Vilcek, S.; Baule, C.

    1998-01-01

    Antigenic and genetic studies of bovine respiratory syncytial virus (BRSV) were made on isolates obtained from three continents over 27 years. Antigenic variation between eight isolates was initially determined using protein G-specific monoclonal antibodies. Four distinct reaction patterns were...... of a 731 nucleotide fragment in the G protein gene. Nine of the BRSV strains were analysed by direct sequencing of RT-PCR amplicons whereas sequences of 18 BRSV and three human respiratory syncytial virus (HRSV) strains were obtained from GenBank. The analysis revealed similarities of 88-100% among BRSV...... strains and 38-41 % between BRSV and HRSV. A phylogenetic tree created for BRSV revealed two main branches, one of which divided into five further lineages, each representing a geographic cluster. A correlation was evident between the positions of some strains in the phylogenetic tree and their antigenic...

  15. Genetically Modified Vibrio harveyi Strains as Potential Bioindicators of Mutagenic Pollution of Marine Environments

    Science.gov (United States)

    Czyż, Agata; Jasiecki, Jacek; Bogdan, Adam; Szpilewska, Hanna; Węgrzyn, Grzegorz

    2000-01-01

    For biodetection of mutagenic pollution of marine environments, an organism naturally occurring in these habitats should be used. We found that marine bacterium Vibrio harveyi may be an appropriate bioindicator of mutagenic pollution. For positive selection of mutants, we developed a simple method for isolation of V. harveyi mutants resistant to neomycin. We constructed genetically modified V. harveyi strains that produce significantly more neomycin-resistant mutants upon treatment with low concentrations of mutagens than the wild-type counterpart. The sensitivity of the mutagenicity test with the V. harveyi strains is at least comparable to (if not higher than) that of the commonly used Ames test, which uses Salmonella enterica serovar Typhimurium strains. Therefore, we consider that the V. harveyi strains described in this report could be used as potential bioindicators of mutagenic pollution of marine environments. PMID:10653723

  16. Genetic analyses of the antibiotic resistance of Bifidobacterium bifidum strain Yakult YIT 4007.

    Science.gov (United States)

    Sato, Takashi; Iino, Tohru

    2010-02-28

    Bifidobacterium bifidum strain Yakult YIT 4007 (abbreviated as B. bifidum YIT 4007) is a commercial strain and resistant to erythromycin, neomycin, and streptomycin. Resistances to these antibiotics were endowed by sequential isolation of resistant mutants from its susceptible progenitor strain YIT 4001. Comparison of nucleotide sequences of various candidate genes of both strains led us to find that B. bifidum YIT 4007 had mutations on three copies of 23S ribosomal RNA genes, an 8 bp deletion of the rluD gene for pseudouridine synthase, and a mutation on the rpsL gene for ribosomal protein S12. The responsibility of these mutations to antibiotic resistances was supported by analyses of newly isolated mutants resistant to these antibiotics. The antibiotic resistances of B. bifidum YIT 4007 were evidently acquired by mutations of the structural genes on the chromosome and not associated with mobile genetic elements like insertion sequences, phages, and plasmids.

  17. Genetically modified Vibrio harveyi strains as potential bioindicators of mutagenic pollution of marine environments

    Energy Technology Data Exchange (ETDEWEB)

    Czyz, A.; Jasiecki, J.; Bogdan, A.; Szpilewska, H.; Wegrzyn, G.

    2000-02-01

    For biodetection of mutagenic pollution of marine environments, an organism naturally occurring in these habitats should be used. The authors found that marine bacterium Vibrio harveyi may be an appropriate bioindicator of mutagenic pollution. For positive selection of mutants, they developed a simple method for isolation of V. harveyi mutants resistant to neomycin. The authors constructed genetically modified V. harveyi strains that produce significantly more neomycin-resistant mutants upon treatment with low concentrations of mutagens than the wild-type counterpart. The sensitivity of the mutagenicity test with the V. harveyi strains is at least comparable to (if not higher than) that of the commonly used Ames test, which uses Salmonella enterica serovar Typhimurium strains. Therefore, the authors consider that the V. harveyi strains described in this report could be used as potential bioindicators of mutagenic pollution of marine environments.

  18. Unaltered membrane properties of arterial muscle in Dahl strain genetic hypertension.

    Science.gov (United States)

    Abel, P W; Trapani, A; Matsuki, N; Ingram, M J; Ingram, F D; Hermsmeyer, K

    1981-08-01

    To characterize membrane properties of arterial muscle from Dahl strain hypertensive rats, we measured caudal artery contractile sensitivity to norepinephrine and serotonin, membrane potential at 16 and 37 degrees C, and intracellular potassium, sodium, and chloride content. Dahl salt-resistant (R) strain fed low- or high-salt diets and Dahl salt-sensitive (S) strain fed a low-salt diet remained normotensive. The Dahl S strain on high-salt diets became hypertensive after 4 wk of high salt feeding. There was no significant difference in the norepinephrine or serotonin effective concentration (EC) EC50, EC10, or maximum response between the hypertensive and any of the three normotensive groups. Membrane potential measured at 37 and 16 degrees C and electron-probe analysis of intracellular potassium, sodium, and chloride concentration showed no significant differences between the four groups of animals. These results that arterial muscle membrane mechanisms are not altered in genetically hypertensive Dahl salt-sensitive rats.

  19. Genetic characterization of Zika virus strains: geographic expansion of the Asian lineage.

    Directory of Open Access Journals (Sweden)

    Andrew D Haddow

    Full Text Available Zika virus (ZIKV is a mosquito-borne flavivirus distributed throughout much of Africa and Asia. Infection with the virus may cause acute febrile illness that clinically resembles dengue fever. A recent study indicated the existence of three geographically distinct viral lineages; however this analysis utilized only a single viral gene. Although ZIKV has been known to circulate in both Africa and Asia since at least the 1950s, little is known about the genetic relationships between geographically distinct virus strains. Moreover, the geographic origin of the strains responsible for the epidemic that occurred on Yap Island, Federated States of Micronesia in 2007, and a 2010 pediatric case in Cambodia, has not been determined.To elucidate the genetic relationships of geographically distinct ZIKV strains and the origin of the strains responsible for the 2007 outbreak on Yap Island and a 2010 Cambodian pediatric case of ZIKV infection, the nucleotide sequences of the open reading frame of five isolates from Cambodia, Malaysia, Nigeria, Uganda, and Senegal collected between 1947 and 2010 were determined. Phylogenetic analyses of these and previously published ZIKV sequences revealed the existence of two main virus lineages (African and Asian and that the strain responsible for the Yap epidemic and the Cambodian case most likely originated in Southeast Asia. Examination of the nucleotide and amino acid sequence alignments revealed the loss of a potential glycosylation site in some of the virus strains, which may correlate with the passage history of the virus.The basal position of the ZIKV strain isolated in Malaysia in 1966 suggests that the recent outbreak in Micronesia was initiated by a strain from Southeast Asia. Because ZIKV infection in humans produces an illness clinically similar to dengue fever and many other tropical infectious diseases, it is likely greatly misdiagnosed and underreported.

  20. One group of genetically similar Listeria monocytogenes strains frequently dominates and persists in several fish slaughter- and smokehouses

    DEFF Research Database (Denmark)

    Wulff, Gitte; Gram, Lone; Ahrens, Peter;

    2006-01-01

    Contamination of foods with the human pathogen Listeria monocytogenes may occur during processing, and the purpose of this study was to determine whether genetically similar strains colonize different processing plants or whether specific persistent strains are unique to each processing plant. We...... smokehouses and two slaughterhouses and was predominant in three of these plants. A subset of 35 strains was also analyzed by amplified fragment length polymorphism typing, which confirmed the genetic similarity of the groups. Moreover, strains of the dominant RAPD type were indistinguishable from strains...... related may be especially adapted to colonizing the processing equipment or especially resistant to cleaning and disinfection....

  1. IMPACT OF GENETIC STRAIN ON BODY FAT LOSS, FOOD CONSUMPTION, METABOLISM, VENTILATION, AND MOTOR ACTIVITY IN FREE RUNNING FEMALE RATS

    Science.gov (United States)

    Physiologic data associated with different strains of common laboratory rat strains.This dataset is associated with the following publication:Gordon , C., P. Phillips , and A. Johnstone. Impact of Genetic Strain on Body Fat Loss, Food Consumption, Metabolism, Ventilation, and Motor Activity in Free Running Female Rats. PHYSIOLOGY AND BEHAVIOR. Elsevier Science Ltd, New York, NY, USA, 153: 56-63, (2016).

  2. Space mutagenesis of genetically engineered bacteria expressing recombinant human interferon α1b and screening of higher yielding strains.

    Science.gov (United States)

    Wang, Junfeng; Liu, Changting; Liu, Jinyi; Fang, Xiangqun; Xu, Chen; Guo, Yinghua; Chang, De; Su, Longxiang

    2014-03-01

    The aim of this study was to investigate the space mutagenesis of genetically engineered bacteria expressing recombinant human interferon α1b. The genetically engineered bacteria expressing the recombinant interferon α1b were sent into outer space on the Chinese Shenzhou VIII spacecraft. After the 17 day space flight, mutant strains that highly expressed the target gene were identified. After a series of screening of spaceflight-treated bacteria and the quantitative comparison of the mutant strains and original strain, we found five strains that showed a significantly higher production of target proteins, compared with the original strain. Our results support the notion that the outer space environment has unique effects on the mutation breeding of microorganisms, including genetically engineered strains. Mutant strains that highly express the target protein could be obtained through spaceflight-induced mutagenesis.

  3. Non-invasive genetic sampling for molecular sexing and microsatellite genotyping of hyacinth macaw (Anodorhynchus hyacinthinus

    Directory of Open Access Journals (Sweden)

    Flavia T. Presti

    2013-01-01

    Full Text Available Molted feather sampling is a useful tool for genetic analyses of endangered species, but it is often very laborious due to the low quality and quantity of the DNA obtained. In the present study we show the parts of feathers that resulted in better yield of DNA. In descending order these were: blood clot outside the umbilicus, umbilicus (without blood clot, tip, inner membrane, and small calamus. Compared to DNA extracted from blood samples, DNA extracted from feathers produced microsatellite alleles of poorer quality and had to be processed immediately after extraction. As expected due to the level of DNA degradation, molecular sexing protocols that result in shorter PCR products were more efficient.

  4. Non-invasive genetic sampling for molecular sexing and microsatellite genotyping of hyacinth macaw (Anodorhynchus hyacinthinus)

    Science.gov (United States)

    Presti, Flavia T.; Meyer, Janaína; Antas, Paulo T.Z.; Guedes, Neiva M.R.; Miyaki, Cristina Y.

    2013-01-01

    Molted feather sampling is a useful tool for genetic analyses of endangered species, but it is often very laborious due to the low quality and quantity of the DNA obtained. In the present study we show the parts of feathers that resulted in better yield of DNA. In descending order these were: blood clot outside the umbilicus, umbilicus (without blood clot), tip, inner membrane, and small calamus. Compared to DNA extracted from blood samples, DNA extracted from feathers produced microsatellite alleles of poorer quality and had to be processed immediately after extraction. As expected due to the level of DNA degradation, molecular sexing protocols that result in shorter PCR products were more efficient. PMID:23569419

  5. Application of a naturalistic psychogenic stressor in periadolescent mice: effect on serum corticosterone levels differs by strain but not sex

    Directory of Open Access Journals (Sweden)

    Klein Laura C

    2010-06-01

    Full Text Available Abstract Background As a first step in determining whether psychogenic stressors might be incorporated into periadolescent mouse models of stress, we evaluated whether a commonly used psychogenic stressor, exposure to red fox urine, alters serum corticosterone levels in periadolescent C57BL/6J and DBA/2J mice. Findings In a 1-day experiment, forty-eight 38-day-old C57BL/6J (N = 12 males; N = 12 females and DBA/2J (N = 12 males; N = 12 females mice were exposed to 10-min of red fox urine via cotton ball (N = 12 C57BL/6J mice; N = 12 DBA/2J mice or to a non-saturated cotton ball (N = 12 C57BL/6J mice; N = 12 DBA/2J mice. All mice were sacrificed 15-min after cotton ball exposure and serum was collected for corticosterone assessment. Overall, there was a main effect for strain such that C57BL/6J male and female mice displayed higher corticosterone levels than did male and female DBA/2J mice. There were no main effects for sex or odor exposure. However, there was a significant strain by odor exposure interaction, whereby, within odor-exposed mice, DBA/2J mice displayed lower corticosterone levels (ng/mL compared to C57BL/6J mice, regardless of sex. Further, among DBA/2J mice, predator odor exposure reduced corticosterone levels compared to no odor exposure. Conclusions Findings indicate that mouse strain, but not sex, may play an important role in the efficacy of a predator odor among periadolescent mice.

  6. Molecular variability and genetic relationship among Brazilian strains of the sugarcane smut fungus.

    Science.gov (United States)

    Benevenuto, Juliana; Longatto, Daniel P; Reis, Gislaine V; Mielnichuk, Natalia; Palhares, Alessandra C; Carvalho, Giselle; Saito, Suzane; Quecine, Maria C; Sanguino, Alvaro; Vieira, Maria Lucia C; Camargo, Luis Eduardo A; Creste, Silvana; Monteiro-Vitorello, Claudia B

    2016-12-01

    Sporisorium scitamineum is the fungus that causes sugarcane smut disease. Despite of the importance of sugarcane for Brazilian agribusiness and the persistence of the pathogen in most cropping areas, genetic variation studies are still missing for Brazilian isolates. In this study, sets of isolates were analyzed using two molecular markers (AFLP and telRFLP) and ITS sequencing. Twenty-two whips were collected from symptomatic plants in cultivated sugarcane fields of Brazil. A total of 41 haploid strains of compatible mating types were selected from individual teliospores and used for molecular genetic analyses. telRFLP and ITS analyses were expanded to six Argentine isolates, where the sugarcane smut was first recorded in America. Genetic relationship among strains suggests the human-mediated dispersal of S. scitamineum within the Brazilian territory and between the two neighboring countries. Two genetically distinct groups were defined by the combined analysis of AFLP and telRFLP. The opposite mating-type strains derived from single teliospores were clustered together into these main groups, but had not always identical haplotypes. telRFLP markers analyzed over two generations of selfing and controlled outcrossing confirmed the potential for emergence of new variants and occurrence of recombination, which are relevant events for evolution of virulence and environmental adaptation.

  7. Genetic diversity and C2-like subgenogroup strains of enterovirus 71, Taiwan, 2008

    Directory of Open Access Journals (Sweden)

    Yang Jyh-Yuan

    2010-10-01

    Full Text Available Abstract Background Human enterovirus 71 (EV-71 is known of having caused numerous outbreaks of hand-foot-mouth disease, and other clinical manifestations globally. In 2008, 989 EV-71 strains were isolated in Taiwan. Results In this study, the genetic and antigenic properties of these strains were analyzed and the genetic diversity of EV-71 subgenogroups surfacing in Taiwan was depicted, which includes 3 previously reported subgenogroups of C5, B5, and C4, and one C2-like subgenogroup. Based on the phylogenetic analyses using their complete genome nucleotide sequences and neutralization tests, the C2-like subgenogroup forms a genetically distinct cluster from other subgenogroups, and the antisera show a maximum of 128-fold decrease of neutralization titer against this subgenogroup. In addition, the subgenogroup C4 isolates of 2008 were found quite similar genetically to the Chinese strains that caused outbreaks in recent years and thus they should be carefully watched. Conclusions Other than to be the first report describing the existence of C2-like subgenogroup of EV-71 in Taiwan, this article also foresees a potential of subgenogroup C4 outbreaks in Taiwan in the near future.

  8. Influence of sex and genetic variability on expression of X-linked genes in human monocytes.

    Science.gov (United States)

    Castagné, Raphaële; Zeller, Tanja; Rotival, Maxime; Szymczak, Silke; Truong, Vinh; Schillert, Arne; Trégouët, David-Alexandre; Münzel, Thomas; Ziegler, Andreas; Cambien, François; Blankenberg, Stefan; Tiret, Laurence

    2011-11-01

    In humans, the fraction of X-linked genes with higher expression in females has been estimated to be 5% from microarray studies, a proportion lower than the 25% of genes thought to escape X inactivation. We analyzed 715 X-linked transcripts in circulating monocytes from 1,467 subjects and found an excess of female-biased transcripts on the X compared to autosomes (9.4% vs 5.5%, pgenes not previously known to escape inactivation, the most significant one was EFHC2 whose 20% of variability was explained by sex. We also investigated cis expression quantitative trait loci (eQTLs) by analyzing 15,703 X-linked SNPs. The frequency and magnitude of X-linked cis eQTLs were quite similar in males and females. Few genes exhibited a stronger genetic effect in females than in males (ARSD, DCX, POLA1 and ITM2A). These genes would deserve further investigation since they may contribute to sex pathophysiological differences.

  9. Suppression of initiation-negative strains of Escherichia coli by integration of the sex factor F.

    Science.gov (United States)

    Tresguerres, E F; Nandadasa, H G; Pritchard, R H

    1975-01-01

    Data are presented suggesting that the most critical factor determining whether an Hfr dnaAts strain can synthesize deoxyribonucleic acid and form colonies at temperatures that are nonpermissive for corresponding F- strains is neither the site of insertion of F nor the presence of additional mutations in the F particle or the chromosome; it is whether the particle is capable of autonomous replication at the temperature used. Consequently, suppression of the DnaA phenotype in Hfr strains occurs at 40 C but not, in most of them, at 42 C without the occurrence of additional mutations. The site of insertion of F may also be important since it is shown that in one Hfr dnaA strain partial suppression does occur at 42 C. In addition, it is shown that strains exhibiting suppression by integration of F at 40 C on minimal agar plates do not do so at this temperature on nutrient agar plates. PMID:1089635

  10. Genetic Characterization of Fowl Adenovirus Strains Isolated from Poultry in China.

    Science.gov (United States)

    Zhang, Hewei; Jin, Wenjie; Ding, Ke; Cheng, Xiangchao; Sun, Yaru; Wang, Jianke; Cheng, Shipeng; Wu, Hua; Zhang, Chunjie

    2017-09-01

    Fowl adenoviruses (FAdVs) infect chickens worldwide, resulting in global economic losses in the poultry industry. We examined the strains present in chickens in regions of China where infections are particularly prevalent. Fifteen FAdV strains were successfully isolated in the field. The L1 loop region of the hexon gene was sequenced to genetically identify the FAdV isolates. By comparing these sequences to adenovirus reference strain sequences using phylogenetics, 15 adenovirus strains were found to cluster into two distinct species. One cluster containing 12 strains belonged to the fowl adenoviruses C species and serotyped as FAdV-4. The other cluster containing three strains belonged to the fowl adenoviruses E species and serotyped as FAdV-10. To our knowledge, this is the first report of the existence of fowl adenoviruses E in China. Furthermore, at least two types of fowl adenovirus strains are predominant among poultry in China. Cumulatively, this study helps lays the groundwork for future research on the pathogenicity and potential treatment measures for FAdV infections in chickens.

  11. Genetic and Filogenetic Characterization of some Newcastle Strains Isolated from Poultry in Albania

    Directory of Open Access Journals (Sweden)

    MARSEL BORAKAJ

    2015-06-01

    Full Text Available Abstract section. In this study, we present the molecular characterization and phylogenetic analysis of three strains of NDV, isolated from the Tirana region in Albania during the 2011-2014 years. Three strains with number 28, 29 and 31, isolated from a different farm of poultry in Tirana Region (Rural flocks, which were diagnosed clinically with the ND. The Intracerebral Pathogenicity Index in SPF bird one day old was determined by doing the proteolytic sequencing at the cleavage, and specifying the aminoacid motif at proteolytic cleavage site. More over we performed BLAST search and phylogenetic analysis of obtained RNA sequences. All strains replicated well in the SPF –chicken emryo eggs. The isolates displayed an aminoacid motif at the proteolytic cleavage site at the Fusion (F protein with multiple basic amino acids as a well a Phenylalanine on position 117. For one isolate (28 numerous nucleotide positions had signals for at last two nucleotides, making it imposible to conclude on a specific sequence. The pathogenicity of all three isolates (28, 29 and 33, was assessed by the analysis of the F protein cleavage site and by standart ICPI. The ICPI (pathogenicity index of our strains varies from of 1.85, 2 and 1.75, respectively which according [19,7] are typical for velogenic strains of NDV. We found that two NDV strain has a most close genetic relationship with the Serbia 2007 NDV, having 98% similarity at nucleotide level.Velogenic viscerotropic strains are considered endemic in our country.

  12. Study of genetic factors and temperature influence on sex determination and differentiation in turbot

    OpenAIRE

    2016-01-01

    Sex, as intuitive and simple as it may seem to us, poses some of the most interesting and complex questions when studying life. Sex is an intrinsic characteristic of most eukaryote species which eventually has led to the appearance of two differentiated adult phenotypes or sexes, males and females. This distinction rules a huge part of our lives and is the origin of important evolutionary processes based on intra-sex competition or inter-sex conflict due to sexual antagonism. Furthermore, sex...

  13. Identification and genetic characterization of Clostridium botulinum serotype A strains from commercially pasteurized carrot juice.

    Science.gov (United States)

    Marshall, Kristin M; Nowaczyk, Louis; Raphael, Brian H; Skinner, Guy E; Rukma Reddy, N

    2014-12-01

    Clostridium botulinum is an important foodborne pathogen capable of forming heat resistant endospores and producing deadly botulinum neurotoxins (BoNTs). In 2006, C. botulinum was responsible for an international outbreak of botulism attributed to the consumption of commercially pasteurized carrot juice. The purpose of this study was to isolate and characterize strains of C. botulinum from the adulterated product. Carrot juice bottles retrieved from the manufacturing facility were analyzed for the presence of BoNT and BoNT-producing isolates using DIG-ELISA. Toxigenic isolates from the carrot juice were analyzed using pulsed-field gel electrophoresis (PFGE) and DNA microarray analysis to determine their genetic relatedness to the original outbreak strains CDC51348 and CDC51303. PFGE revealed that isolates CJ4-1 and CJ10-1 shared an identical pulsotype with strain CDC51303, whereas isolate CJ5-1 displayed a unique restriction banding pattern. DNA microarray analysis identified several phage related genes unique to strain CJ5-1, and Southern hybridization analysis of XhoI digested and nondigested DNA showed their chromosomal location, while a homolog to pCLI_A009 of plasmid pCLI of C. botulinum serotype Langeland F, was located on a small plasmid. The acquisition or loss of bacteriophages and other mobile genetic elements among C. botulinum strains has epidemiological and evolutionary implications.

  14. Characterization of Fusarium verticillioides strains isolated from maize in Italy: fumonisin production, pathogenicity and genetic variability.

    Science.gov (United States)

    Covarelli, Lorenzo; Stifano, Simonetta; Beccari, Giovanni; Raggi, Lorenzo; Lattanzio, Veronica Maria Teresa; Albertini, Emidio

    2012-08-01

    Fusarium verticillioides (teleomorph Gibberella moniliformis) is the main fungal agent of ear and kernel rot of maize (Zea mays L.) worldwide, including Italy. F.verticillioides is a highly toxigenic species since it is able to produce the carcinogenic mycotoxins fumonisins. In this study, 25 F. verticillioides strains, isolated from maize in different regions of Italy were analyzed for their ability to produce fumonisins, their pathogenicity and their genetic variability. A further referenced strain of G. moniliformis isolated from maize in USA was also used as outgroup. The fumonisins B₁, B₂, and B₃ were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pathogenicity tests were carried out by symptom observation and determination of growth parameters after inoculation of maize seeds, seedlings and wounded detached leaves. Total genomic DNA was used for Amplified Fragment Length Polymorphism (AFLP) analysis. About 20% of the analyzed strains were unable to produce fumonisins in in vitro experiments on inoculated maize flour, while, among fumonisin producers, a great variability was observed, with values ranging from 1 to 115 mg kg⁻¹. The different analyzed strains showed a wide range of pathogenicity in terms of effect on seed germination, seedling development and of symptoms produced on detached leaves, which were not correlated with the different in vitro fumonisin production. AFLP analysis indicated the presence of genetic diversity not only between the Italian strains and the American reference but also among the Italian isolates. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Sex differences in the genetic architecture of lifespan in a seed beetle: extreme inbreeding extends male lifespan

    Directory of Open Access Journals (Sweden)

    Maklakov Alexei A

    2009-02-01

    Full Text Available Abstract Background Sex differences in lifespan are ubiquitous throughout the animal kingdom but the causes underlying this phenomenon remain poorly understood. Several explanations based on asymmetrical inheritance patterns (sex chromosomes or mitochondrial DNA have been proposed, but these ideas have rarely been tested experimentally. Alternatively, sexual dimorphism in lifespan could result from sex-specific selection, caused by fundamental differences in how males and females optimize their fitness by allocating resources into current and future reproduction. Results Here we used sex-specific responses to inbreeding to study the genetic architecture of lifespan and mortality rates in Callosobruchus maculatus, a seed beetle that shows sexual dimorphism in lifespan. Two independent assays revealed opposing sex-specific responses to inbreeding. The combined data set showed that inbred males live longer than outbred males, while females show the opposite pattern. Both sexes suffered reduced fitness measured as lifetime reproductive success as a result of inbreeding. Conclusion No model based on asymmetrical inheritance can explain increased male lifespan in response to inbreeding. Our results are however compatible with models based on sex-specific selection on reproductive strategies. We therefore suggest that sex-specific differences in lifespan in this species primarily result from sexually divergent selection.

  16. Genetic and antigenic analysis of the G attachment protein of bovine respiratory syncytial virus strains

    DEFF Research Database (Denmark)

    Elvander, M.; Vilcek, S.; Baule, C.;

    1998-01-01

    Antigenic and genetic studies of bovine respiratory syncytial virus (BRSV) were made on isolates obtained from three continents over 27 years. Antigenic variation between eight isolates was initially determined using protein G-specific monoclonal antibodies. Four distinct reaction patterns were...... of a 731 nucleotide fragment in the G protein gene. Nine of the BRSV strains were analysed by direct sequencing of RT-PCR amplicons whereas sequences of 18 BRSV and three human respiratory syncytial virus (HRSV) strains were obtained from GenBank. The analysis revealed similarities of 88-100% among BRSV...

  17. Genetic diversity evaluation on Portuguese Leishmania infantum strains by multilocus microsatellite typing.

    Science.gov (United States)

    Cortes, Sofia; Maurício, Isabel L; Kuhls, Katrin; Nunes, Mónica; Lopes, Carla; Marcos, Marta; Cardoso, Luís; Schönian, Gabriele; Campino, Lenea

    2014-08-01

    Leishmania infantum is the main etiological agent of zoonotic visceral leishmaniasis in the Mediterranean region, including Portugal, but, given its low isoenzyme diversity in this country, the population structure is poorly known. A set of 14 polymorphic microsatellite markers was studied on 136 Portuguese Leishmania strains isolated from different hosts, geographic regions and different clinical forms. A total of 108 different genotypes were found, which is a degree of genetic diversity comparable to other regions, even within zymodeme MON-1. A single most common genotype was detected in 1:5 of all strains, which, with a greater number of multi-strain genotypes found in the Lisbon Metropolitan Region, particularly for human strains, was suggestive of the occurrence of clonal transmission. In addition, a high re-infection rate was found among HIV+ patients. Model based analysis by STRUCTURE uncovered two main populations (populations A and B, composed of MON-1 and non-MON-1 strains, respectively), with great genetic diversity between them, and two MON-1 sub-populations (A1 and A2). High inbreeding coefficients were found in these populations, although strains with mixed ancestry were identified, suggesting that recombination also plays a role in the epidemiology of this species in Portugal. Some but limited geographical differentiation was observed, with groups of strains from the same regions clustering together, particularly those from canine origin. Our results show that L. infantum isolates from Portugal present microsatellite diversity comparable to other regions and that different transmission models play a role in its epidemiology, from clonal transmission to recombination. In addition, although Portugal is a small country, mobility of people and animals is high and Leishmania can be probably easily disseminated between infected hosts throughout the country, two instances of seemingly local restricted transmission were identified.

  18. Genetic Analysis of Vibrio parahaemolyticus O3:K6 Strains That Have Been Isolated in Mexico Since 1998

    Science.gov (United States)

    Licea-Navarro, Alexei Fedorovish; Revilla-Castellanos, Valeria Jeanette; Wong-Chang, Irma; González-Sánchez, Ricardo

    2017-01-01

    Vibrio parahaemolyticus is an important human pathogen that has been isolated worldwide from clinical cases, most of which have been associated with seafood consumption. Environmental and clinical toxigenic strains of V. parahaemolyticus that were isolated in Mexico from 1998 to 2012, including those from the only outbreak that has been reported in this country, were characterized genetically to assess the presence of the O3:K6 pandemic clone, and their genetic relationship to strains that are related to the pandemic clonal complex (CC3). Pathogenic tdh+ and tdh+/trh+ strains were analyzed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Also, the entire genome of a Mexican O3:K6 strain was sequenced. Most of the strains were tdh/ORF8-positive and corresponded to the O3:K6 serotype. By PFGE and MLST, there was very close genetic relationship between ORF8/O3:K6 strains, and very high genetic diversities from non-pandemic strains. The genetic relationship is very close among O3:K6 strains that were isolated in Mexico and sequences that were available for strains in the CC3, based on the PubMLST database. The whole-genome sequence of CICESE-170 strain had high similarity with that of the reference RIMD 2210633 strain, and harbored 7 pathogenicity islands, including the 4 that denote O3:K6 pandemic strains. These results indicate that pandemic strains that have been isolated in Mexico show very close genetic relationship among them and with those isolated worldwide. PMID:28099500

  19. Sex differences in the genetic architecture of lifespan in a seed beetle: extreme inbreeding extends male lifespan

    DEFF Research Database (Denmark)

    Bilde, T.; Maklakov, Alexei A.; Meisner, Katrine;

    2009-01-01

    -specific responses to inbreeding to study the genetic architecture of lifespan and mortality rates in Callosobruchus maculatus, a seed beetle that shows sexual dimorphism in lifespan. Two independent assays revealed opposing sex-specific responses to inbreeding. The combined data set showed that inbred males live...

  20. Genetic evidence that raised sex hormone binding globulin (SHBG) levels reduce the risk of type 2 diabetes

    DEFF Research Database (Denmark)

    Perry, John R B; Weedon, Michael N; Langenberg, Claudia;

    2010-01-01

    Epidemiological studies consistently show that circulating sex hormone binding globulin (SHBG) levels are lower in type 2 diabetes patients than non-diabetic individuals, but the causal nature of this association is controversial. Genetic studies can help dissect causal directions of epidemiologi...

  1. Genetic characterization of Vibrio vulnificus strains isolated from oyster samples in Mexico.

    Science.gov (United States)

    Guerrero, Abraham; Gómez Gil Rodríguez, Bruno; Wong-Chang, Irma; Lizárraga-Partida, Marcial Leonardo

    2015-01-01

    Vibrio vulnificus strains were isolated from oysters that were collected at the main seafood market in Mexico City. Strains were characterized with regard to vvhA, vcg genotype, PFGE, multilocus sequence typing (MLST), and rtxA1. Analyses included a comparison with rtxA1 reference sequences. Environmental (vcgE) and clinical (vcgC) genotypes were isolated at nearly equal percentages. PFGE had high heterogeneity, but the strains clustered by vcgE or vcgC genotype. Select housekeeping genes for MLST and primers that were designed for rtxA1 domains divided the strains into two clusters according to the E or C genotype. Reference rtxA1 sequences and those from this study were also clustered according to genotype. These results confirm that this genetic dimorphism is not limited to vcg genotyping, as other studies have reported. Some environmental C genotype strains had high similarity to reference strains, which have been reported to be virulent, indicating a potential risk for oyster consumers in Mexico City.

  2. Identification of Resistance to Wet Bubble Disease and Genetic Diversity in Wild and Cultivated Strains of Agaricus bisporus

    Directory of Open Access Journals (Sweden)

    Yongping Fu

    2016-09-01

    Full Text Available Outbreaks of wet bubble disease (WBD caused by Mycogone perniciosa are increasing across the world and seriously affecting the yield of Agaricus bisporus. However, highly WBD-resistant strains are rare. Here, we tested 28 A. bisporus strains for WBD resistance by inoculating M. perniciosa spore suspension on casing soil, and assessed genetic diversity of these strains using 17 new simple sequence repeat (SSR markers developed in this study. We found that 10 wild strains originating from the Tibetan Plateau in China were highly WBD-resistant strains, and 13 cultivated strains from six countries were highly susceptible strains. A total of 88 alleles were detected in these 28 strains, and the observed number of alleles per locus ranged from 2 to 8. Cluster and genetic structure analysis results revealed the wild resources from China have a relatively high level of genetic diversity and occur at low level of gene flow and introgression with cultivated strains. Moreover, the wild strains from China potentially have the consensus ancestral genotypes different from the cultivated strains and evolved independently. Therefore, the highly WBD-resistant wild strains from China and newly developed SSR markers could be used as novel sources for WBD-resistant breeding and quantitative trait locus (QTL mapping of WBD-resistant gene of A. bisporus.

  3. Identification of Resistance to Wet Bubble Disease and Genetic Diversity in Wild and Cultivated Strains of Agaricus bisporus

    Science.gov (United States)

    Fu, Yongping; Wang, Xinxin; Li, Dan; Liu, Yuan; Song, Bing; Zhang, Chunlan; Wang, Qi; Chen, Meiyuan; Zhang, Zhiwu; Li, Yu

    2016-01-01

    Outbreaks of wet bubble disease (WBD) caused by Mycogone perniciosa are increasing across the world and seriously affecting the yield of Agaricus bisporus. However, highly WBD-resistant strains are rare. Here, we tested 28 A. bisporus strains for WBD resistance by inoculating M. perniciosa spore suspension on casing soil, and assessed genetic diversity of these strains using 17 new simple sequence repeat (SSR) markers developed in this study. We found that 10 wild strains originating from the Tibetan Plateau in China were highly WBD-resistant strains, and 13 cultivated strains from six countries were highly susceptible strains. A total of 88 alleles were detected in these 28 strains, and the observed number of alleles per locus ranged from 2 to 8. Cluster and genetic structure analysis results revealed the wild resources from China have a relatively high level of genetic diversity and occur at low level of gene flow and introgression with cultivated strains. Moreover, the wild strains from China potentially have the consensus ancestral genotypes different from the cultivated strains and evolved independently. Therefore, the highly WBD-resistant wild strains from China and newly developed SSR markers could be used as novel sources for WBD-resistant breeding and quantitative trait locus (QTL) mapping of WBD-resistant gene of A. bisporus. PMID:27669211

  4. The common ecotoxicology laboratory strain of Hyalella azteca is genetically distinct from most wild strains sampled in eastern North America.

    Science.gov (United States)

    Major, Kaley; Soucek, David J; Giordano, Rosanna; Wetzel, Mark J; Soto-Adames, Felipe

    2013-11-01

    The amphipod Hyalella azteca is commonly used as a model for determining safe concentrations of contaminants in freshwaters. The authors sequenced the mitochondrial cytochrome c oxidase subunit I (COI) gene for representatives of 38 populations of this species complex from US and Canadian toxicology research laboratories and eastern North American field sites to determine their genetic relationships. With 1 exception, all US and Canadian laboratory cultures sampled were identified as conspecific. In 22 wild populations spanning 5 US states and 1 Canadian province, the commonly occurring laboratory species was found only in northern Florida, USA. Therefore, the diversity of the H. azteca species complex detected in the wild is not accurately represented in North American laboratories, questioning the reliability of H. azteca cultures currently in use to accurately predict the responses of wild populations in ecotoxicological assays. The authors also examined the utility of different COI nucleotide fragments presently in use to determine phylogenetic relationships in this group and concluded that saturation in DNA sequences leads to inconsistent relationships between clades. Amino acid sequences for COI were not saturated and may allow a more accurate phylogeny estimate. Hyalella azteca is crucial for developing water-quality regulations; therefore, laboratories should know and standardize the strain(s) they use to confidently compare toxicity tests across laboratories and determine whether they are an appropriate surrogate for their regions.

  5. Improving toxicity screening and drug development by using genetically defined strains.

    Science.gov (United States)

    Festing, Michael F W

    2010-01-01

    According to the US Food and Drugs Administration (Food and Drug Administration (2004) Challenge and opportunity on the critical path to new medical products.) "The inability to better assess and predict product safety leads to failures during clinical development and, occasionally, after marketing". This increases the cost of new drugs as clinical trials are even more expensive than pre-clinical testing.One relatively easy way of improving toxicity testing is to improve the design of animal experiments. A fundamental principle when designing an experiment is to control all variables except the one of interest: the treatment. Toxicologist and pharmacologists have widely ignored this principle by using genetically heterogeneous "outbred" rats and mice, increasing the chance of false-negative results. By using isogenic (inbred or F1 hybrid, see Note 1) rats and mice instead of outbred stocks the signal/noise ratio and the power of the experiments can be increased at little extra cost whilst using no more animals. Moreover, the power of the experiment can be further increased by using more than one strain, as this reduces the chance of selecting one which is resistant to the test chemical. This can also be done without increasing the total number of animals by using a factorial experimental design, e.g. if the ten outbred animals per treatment group in a 28-day toxicity test were replaced by two animals of each of five strains (still ten animals per treatment group) selected to be as genetically diverse as possible, this would increase the signal/noise ratio and power of the experiment. This would allow safety to be assessed using the most sensitive strain.Toxicologists should also consider making more use of the mouse instead of the rat. They are less costly to maintain, use less test substance, there are many inbred and genetically modified strains, and it is easier to identify gene loci controlling variation in response to xenobiotics in this species.We demonstrate

  6. Genetic manipulation of ligninolytic streptomyces and generation of improved lignin-to-chemical bioconversion strains

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, D.L.; Pettey, T.M.; Thede, B.M.; Deobald, L.A.

    1984-01-01

    Streptomyces viridosporus T7A, when used in solid-state fermentation, degrades lignin at high yields to a water-soluble modified polymer, acid precipitable polymeric lignin (APPL) that is useful as an antioxidant, surfactant, and potentially as a component of adhesives and resins. Enhanced strains generated from ultraviolet irradiation mutagenesis and protoplast fusion produced up to 90% more APPL from corn stover lignocellulose than did the wildtype, and they were stable and produced APPL at a faster rate and to a higher final yield than did parental strain T7A. APPLs produced by the wildtype and selected mutants were chemicaly similar polyphenols, but some catabolic enzymes of the genetically manipulated strains were produced in greater amounts.

  7. Environmental effects on sex differences in the genetic load for adult lifespan in a seed-feeding beetle.

    Science.gov (United States)

    Fox, C W; Stillwell, R C

    2009-07-01

    We have little understanding of how environmental conditions affect the expression of the genetic load for lifespan and adult mortality rates, or how this environmental dependence affect tests of models for the evolution of senescence. We use the seed-feeding beetle, Callosobruchus maculatus, as a model to explore how the inbreeding load (L) affecting adult lifespan varies with rearing conditions (diet and temperature), and how rearing conditions affect tests of the mutation accumulation model of senescence. When reared under benign conditions, there was a large sex difference in inbreeding depression (delta) and the inbreeding load (L=0.51-0.86 lethal equivalents per gamete for females L= approximately 0 for males). This sex difference in L was dependent on temperature, but not on rearing host or heat shock. At both high and low temperatures (relative to intermediate temperature) L increased for males, and L converged for the sexes at low temperature (L=0.26-0.53 for both sexes). Correlations were small for L between pairs of temperatures, indicating that the genes responsible for the inbreeding load differed between temperatures. In contrast to predictions of the mutation accumulation model of senescence, the age-specific inbreeding load for the adult mortality rate (L(u(t))) did not increase with age in any rearing environment. The genetic load underlying lifespan and adult mortality rates, and large sex differences in the genetic load, is highly dependent on environmental conditions. Estimating the genetic load in benign laboratory environments may be insufficient to predict the genetics underlying lifespan variation in nature where environmental variation is the norm.

  8. Construction of integrative plasmids suitable for genetic modification of industrial strains of Saccharomyces cerevisiae.

    Science.gov (United States)

    Leite, Fernanda Cristina Bezerra; Dos Anjos, Rute Salgues Gueiros; Basilio, Anna Carla Moreira; Leal, Guilherme Felipe Carvalho; Simões, Diogo Ardaillon; de Morais, Marcos A

    2013-01-01

    The development of efficient tools for genetic modification of industrial yeast strains is one of the challenges that face the use of recombinant cells in industrial processes. In this study, we examine how the construction of two complementary integrative vectors can fulfill the major requirements of industrial recombinant yeast strains: the use of lactose assimilation genes as a food-grade yeast selection marker, and a system of integration that does not leave hazardous genes in the host genome and involves minimal interference in the yeast physiology. The pFB plasmid set was constructed to co-integrate both LAC4-based and LAC12-based cassettes into the ribosomal DNA (rDNA) locus to allow yeast cells to be selected in lactose medium. This phenotype can also be used to trace the recombinant cells in the environment by simply being plated on X-gal medium. The excisable trait of the LAC12 marker allows the introduction of many different heterologous genes, and makes it possible to introduce a complete heterologous metabolic pathway. The cloned heterologous genes can be highly expressed under the strong and constitutive TPI1 gene promoter, which can be exchanged for easy digestion of enzymes if necessary. This platform was introduced into Saccharomyces cerevisiae JP1 industrial strain where a recombinant with high stability of markers was produced without any change in the yeast physiology. Thus, it proved to be an efficient tool for the genetic modification of industrial strains.

  9. Genetic variations alter physiological responses following heat stress in 2 strains of laying hens.

    Science.gov (United States)

    Felver-Gant, J N; Mack, L A; Dennis, R L; Eicher, S D; Cheng, H W

    2012-07-01

    Heat stress (HS) is a major problem experienced by the poultry industry during high-temperature conditions. The ability to manage the detrimental effects of HS can be attributed to multiple factors, including genetic background of flocks. The objective of the present study was to determine the genetic variation in HS effects on laying hens' physiological homeostasis. Ninety 28-wk-old White Leghorn hens of 2 strains were used: a commercial line of individually selected hens for high egg production, DeKalb XL (DXL), and a line of group-selected hens for high productivity and survivability, named kind gentle bird (KGB). Hens were randomly paired by strain and assigned to hot or control treatment for 14 d. Physical and physiological parameters were analyzed at d 8 and 14 posttreatment. Compared with controls, HS increased hen's core body temperature (P hens exposed to HS (P hens, KGB hens had higher heat shock protein 70 concentrations (P hens' liver weight decreased following HS, with less of a response in the KGB line (P hens due to genetic variations. These data provide evidence that is valuable for determining genetic interventions for laying hens under HS.

  10. Genetic analysis of an incomplete bio operon in a biotin auxotrophic strain of Bacillus subtilis natto OK2.

    Science.gov (United States)

    Sasaki, Mayumi; Kawamura, Fujio; Kurusu, Yasurou

    2004-03-01

    We describe the genetic analysis of the bio operon of the biotin auxotrophic Bacillus subtilis natto OK2 strain. The OK2 strain would only cross-feed with the Escherichia coli bioB mutant and also grew well in medium containing dethiobiotin. Sequencing analysis revealed two significant genetic alterations in the bioW and bioF genes within the bio operon of the OK2 strain. Complementation analysis with B. subtilis 168 bio mutants demonstrated that only the bioB gene could complement, but other bio operon genes could not. A bio(+) transformant, isolated from an OK2 strain, has biotin autotrophy.

  11. Genetic dissection of sex determinism, inflorescence morphology and downy mildew resistance in grapevine.

    Science.gov (United States)

    Marguerit, Elisa; Boury, Christophe; Manicki, Aurélie; Donnart, Martine; Butterlin, Gisèle; Némorin, Alice; Wiedemann-Merdinoglu, Sabine; Merdinoglu, Didier; Ollat, Nathalie; Decroocq, Stéphane

    2009-05-01

    A genetic linkage map of grapevine was constructed using a pseudo-testcross strategy based upon 138 individuals derived from a cross of Vitis vinifera Cabernet Sauvignon x Vitis riparia Gloire de Montpellier. A total of 212 DNA markers including 199 single sequence repeats (SSRs), 11 single strand conformation polymorphisms (SSCPs) and two morphological markers were mapped onto 19 linkage groups (LG) which covered 1,249 cM with an average of 6.7 cM between markers. The position of SSR loci in the maps presented here is consistent with the genome sequence. Quantitative traits loci (QTLs) for several traits of inflorescence and flower morphology, and downy mildew resistance were investigated. Two novel QTLs for downy mildew resistance were mapped on linkage groups 9 and 12, they explain 26.0-34.4 and 28.9-31.5% of total variance, respectively. QTLs for inflorescence morphology with a large effect (14-70% of total variance explained) were detected close to the Sex locus on LG 2. The gene of the enzyme 1-aminocyclopropane-1-carboxylic acid synthase, involved in melon male organ development and located in the confidence interval of all QTLs detected on the LG 2, could be considered as a putative candidate gene for the control of sexual traits in grapevine. Co-localisations were found between four QTLs, detected on linkage groups 1, 14, 17 and 18, and the position of the floral organ development genes GIBBERELLIN INSENSITIVE1, FRUITFULL, LEAFY and AGAMOUS. Our results demonstrate that the sex determinism locus also determines both flower and inflorescence morphological traits.

  12. Genetic diversity and genetic structure of different types of natural populations in Osmanthus fragrans Lour. and the relationships with sex ratio, population structure, and geographic isolation.

    Science.gov (United States)

    Hu, Shaoqing; Wu, Shuai; Wang, Yiguang; Zhao, Hongbo; Zhang, Yuanyan

    2014-01-01

    Osmanthus fragrans Lour., an evergreen small tree, has the rare sexual system of androdioecy (coexistence of males and hermaphrodites), once with wide-spread natural distribution in the areas of the South Yangzi river basin. However, due to excessive human utilization, natural distribution became fragmented and the number and size of natural populations reduced sharply. With four different types of natural populations from the same region as research object, we aim to provide a comparative analysis on the relationships among genetic diversity, sexual system, population structure and size, and geographic isolation by ISSR. In genetic parameters of N e , H e , and I, the LQGC population had the highest value and the LQZGQ population had the lowest value. These indicated that LQGC population showed the highest genetic diversity, followed by QDH and JN population, and LQZGQ population exhibited the lowest genetic diversity. Genetic diversity in populations is closely related to population structure, reproduction mode, and sex ratio. However, there seems to be no obvious correlation between genetic diversity and population size. The results of AMOVA showed that genetic variations mostly occurred within populations. It indicates that no significant genetic differentiation among populations occurs, and geographic isolation has no significant effect on genetic diversity.

  13. Genetic Diversity and Genetic Structure of Different Types of Natural Populations in Osmanthus fragrans Lour. and the Relationships with Sex Ratio, Population Structure, and Geographic Isolation

    Directory of Open Access Journals (Sweden)

    Shaoqing Hu

    2014-01-01

    Full Text Available Osmanthus fragrans Lour., an evergreen small tree, has the rare sexual system of androdioecy (coexistence of males and hermaphrodites, once with wide-spread natural distribution in the areas of the South Yangzi river basin. However, due to excessive human utilization, natural distribution became fragmented and the number and size of natural populations reduced sharply. With four different types of natural populations from the same region as research object, we aim to provide a comparative analysis on the relationships among genetic diversity, sexual system, population structure and size, and geographic isolation by ISSR. In genetic parameters of Ne, He, and I, the LQGC population had the highest value and the LQZGQ population had the lowest value. These indicated that LQGC population showed the highest genetic diversity, followed by QDH and JN population, and LQZGQ population exhibited the lowest genetic diversity. Genetic diversity in populations is closely related to population structure, reproduction mode, and sex ratio. However, there seems to be no obvious correlation between genetic diversity and population size. The results of AMOVA showed that genetic variations mostly occurred within populations. It indicates that no significant genetic differentiation among populations occurs, and geographic isolation has no significant effect on genetic diversity.

  14. Genetic diversity among Clostridium botulinum strains harboring bont/A2 and bont/A3 genes.

    Science.gov (United States)

    Lúquez, Carolina; Raphael, Brian H; Joseph, Lavin A; Meno, Sarah R; Fernández, Rafael A; Maslanka, Susan E

    2012-12-01

    Clostridium botulinum type A strains are known to be genetically diverse and widespread throughout the world. Genetic diversity studies have focused mainly on strains harboring one type A botulinum toxin gene, bont/A1, although all reported bont/A gene variants have been associated with botulism cases. Our study provides insight into the genetic diversity of C. botulinum type A strains, which contain bont/A2 (n = 42) and bont/A3 (n = 4) genes, isolated from diverse samples and geographic origins. Genetic diversity was assessed by using bont nucleotide sequencing, content analysis of the bont gene clusters, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Sequences of bont genes obtained in this study showed 99.9 to 100% identity with other bont/A2 or bont/A3 gene sequences available in public databases. The neurotoxin gene clusters of the subtype A2 and A3 strains analyzed in this study were similar in gene content. C. botulinum strains harboring bont/A2 and bont/A3 genes were divided into six and two MLST profiles, respectively. Four groups of strains shared a similarity of at least 95% by PFGE; the largest group included 21 out of 46 strains. The strains analyzed in this study showed relatively limited genetic diversity using either MLST or PFGE.

  15. Genetic Characterization of the Belgian Nephropathogenic Infectious Bronchitis Virus (NIBV Reference Strain B1648

    Directory of Open Access Journals (Sweden)

    Vishwanatha R.A.P. Reddy

    2015-08-01

    Full Text Available The virulent nephropathogenic infectious bronchitis virus (NIBV strain B1648 was first isolated in 1984, in Flanders, Belgium. Despite intensive vaccination, B1648 and its variants are still circulating in Europe and North Africa. Here, the full-length genome of this Belgian NIBV reference strain was determined by next generation sequencing (NGS to understand its evolutionary relationship with other IBV strains, and to identify possible genetic factors that may be associated with the nephropathogenicity. Thirteen open reading frames (ORFs were predicted in the B1648 strain (51UTR-1a-1b-S-3a-3b-E-M-4b-4c-5a-5b-N-6b-31UTR. ORFs 4b, 4c and 6b, which have been rarely reported in literature, were present in B1648 and most of the other IBV complete genomes. According to phylogenetic analysis of the full-length genome, replicase transcriptase complex, spike protein, partial S1 gene and M protein, B1648 strain clustered with the non-Massachusetts type strains NGA/A116E7/2006, UKr 27-11, QX-like ITA/90254/2005, QX-like CK/SWE/0658946/10, TN20/00, RF-27/99, RF/06/2007 and SLO/266/05. Based on the partial S1 fragment, B1648 clustered with the strains TN20/00, RF-27/99, RF/06/2007 and SLO/266/05 and, further designated as B1648 genotype. The full-length genome of B1648 shared the highest sequence homology with UKr 27-11, Gray, JMK, and NGA/A116E7/2006 (91.2% to 91.6% and was least related with the reference Beaudette and Massachusetts strains (89.7%. Nucleotide and amino acid sequence analyses indicated that B1648 strain may have played an important role in the evolution of IBV in Europe and North Africa. Further, the nephropathogenicity determinants might be located on the 1a, spike, M and accessory proteins (3a, 3b, 4b, 4c, 5a, 5b and 6b. Overall, strain B1648 is distinct from all the strains reported so far in Europe and other parts of the world.

  16. STABILITY IN REAL TIME OF SOME CRYOPRESERVED MICROBIAL STRAINS WITH REFERENCE TO GENETICALLY MODIFIED MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    DANIELA VINTILĂ

    2013-12-01

    Full Text Available The aim of this work is to analyze the viability of microorganisms from Collection of Industrial Microorganisms from Faculty of Animal Science and Biotechnology – Timisoara, during freezing and thawing as part of cryopreservation technique. The stability in real time of 19 strains cryopreserved in 16% glycerol was evaluated during a 6-months period. The strains studied were: Escherichia coli, Lactobacillus acidophilus, Rhizobium meliloti, Saccharomyces cerevisiae, Aspergillus oryzae, Aspergillus niger, Trichoderma viride, Bacillus globigii, Bacillus licheniformis, and 9 strains of Bacillus subtilis. The strains cryopreserved at -20oC and -70oC were activated using the fast thawing protocol. A better cell recovery was achieved with the -70oC protocol reaching an average viability for E. coli of 86,3%, comparing with 78,6% in -20oC protocol. The cell recovery percentages for the other strains were: 92,4% for L. acidophilus, 93,9% for A.niger, 89% for A. oryzae, 86,7% for T. viride, 94,2% for R. meliloti, 82,1% for S. cerevisiae, 89,9% for B. licheniformis. Regarding the viability of genetically modified microorganisms, the values shows a good recovering after freezing and thawing, even after 180 days of cryopreservation. With the -20oC protocol lower viability was observed due probably to the formation of eutectic mixtures and recrystalization processes.

  17. Correlated responses to clonal selection in populations of Daphnia pulicaria: mechanisms of genetic correlation and the creative power of sex.

    Science.gov (United States)

    Dudycha, Jeffry L; Snoke-Smith, Margaret; Alía, Ricardo

    2013-02-01

    Genetic correlations among traits alter evolutionary trajectories due to indirect selection. Pleiotropy, chance linkage, and selection can all lead to genetic correlations, but have different consequences for phenotypic evolution. We sought to assess the mechanisms contributing to correlations with size at maturity in the cyclic parthenogen Daphnia pulicaria. We selected on size in each of four populations that differ in the frequency of sex, and evaluated correlated responses in a life table. Size at advanced adulthood, reproductive output, and adult growth rate clearly showed greater responses in high-sex populations, with a similar pattern in neonate size and r. This pattern is expected only when trait correlations are favored by selection and the frequency of sex favors the creation and demographic expansion of highly fit clones. Juvenile growth and age at maturity did not diverge consistently. The inter-clutch interval appeared to respond more strongly in low-sex populations, but this was not statistically significant. Our data support the hypothesis that correlated selection is the strongest driver of genetic correlations, and suggest that in organisms with both sexual and asexual reproduction, adaptation can be enhanced by recombination.

  18. Nasal bone shape is under complex epistatic genetic control in mouse interspecific recombinant congenic strains.

    Directory of Open Access Journals (Sweden)

    Gaétan Burgio

    Full Text Available BACKGROUND: Genetic determinism of cranial morphology in the mouse is still largely unknown, despite the localization of putative QTLs and the identification of genes associated with Mendelian skull malformations. To approach the dissection of this multigenic control, we have used a set of interspecific recombinant congenic strains (IRCS produced between C57BL/6 and mice of the distant species Mus spretus (SEG/Pas. Each strain has inherited 1.3% of its genome from SEG/Pas under the form of few, small-sized, chromosomal segments. RESULTS: The shape of the nasal bone was studied using outline analysis combined with Fourier descriptors, and differential features were identified between IRCS BcG-66H and C57BL/6. An F2 cross between BcG-66H and C57BL/6 revealed that, out of the three SEG/Pas-derived chromosomal regions present in BcG-66H, two were involved. Segments on chromosomes 1 (∼32 Mb and 18 (∼13 Mb showed additive effect on nasal bone shape. The three chromosomal regions present in BcG-66H were isolated in congenic strains to study their individual effect. Epistatic interactions were assessed in bicongenic strains. CONCLUSIONS: Our results show that, besides a strong individual effect, the QTL on chromosome 1 interacts with genes on chromosomes 13 and 18. This study demonstrates that nasal bone shape is under complex genetic control but can be efficiently dissected in the mouse using appropriate genetic tools and shape descriptors.

  19. Ontogenesis of gonadal aromatase gene expression in atlantic silverside (Menidia menidia) populations with genetic and temperature-dependent sex determination.

    Science.gov (United States)

    Duffy, Tara A; Picha, Matthew E; Won, Eugene T; Borski, Russell J; McElroy, Anne E; Conover, David O

    2010-08-01

    Cytochrome P450 aromatase (P450arom), an enzyme that converts testosterone to 17beta-estradiol, is an important mediator of sex determination in teleosts with genetic sex determination (GSD) and temperature-dependent sex determination (TSD). We compared the ontogenetic expression of P450arom in two populations of Atlantic silversides, Menidia menidia, which exhibit TSD (South Carolina) or GSD (Nova Scotia, Canada) using quantitative, real-time polymerase chain reaction (qRT-PCR). Embryos and newly hatched larvae were reared at an intermediate sex ratio-producing temperature (21 degrees C), and older larvae and juveniles were reared at temperatures that feminize (15 degrees C) and masculinize (28 degrees C) to assess the temperature response of P450arom during development. Before sex determination, embryos and newly-hatched larvae displayed negligible P450arom expression, indicating minimal upregulation of this gene before sex determination. Gene expression increased in both populations during sex differentiation. Nova Scotia fish with GSD exhibited presumptive male- and female-like expression levels during early sex differentiation that were not influenced by temperature. South Carolina fish displayed low levels of expression at 28 degrees C with significantly heightened expression in some individuals at 15 degrees C, indicating that P450arom is temperature sensitive in the population with TSD. Populations also differed in the timing and maximal levels of P450arom expression, with fish from Nova Scotia exhibiting both the highest and earliest increase in expression in presumptive females. Our results support the hypothesis that P450arom is involved in female sex differentiation in this species, but is only responsive to temperature in M. menidia populations that exhibit TSD.

  20. Genetic basis of variations in nitrogen source utilization in four wine commercial yeast strains.

    Directory of Open Access Journals (Sweden)

    Alicia Gutiérrez

    Full Text Available The capacity of wine yeast to utilize the nitrogen available in grape must directly correlates with the fermentation and growth rates of all wine yeast fermentation stages and is, thus, of critical importance for wine production. Here we precisely quantified the ability of low complexity nitrogen compounds to support fast, efficient and rapidly initiated growth of four commercially important wine strains. Nitrogen substrate abundance in grape must failed to correlate with the rate or the efficiency of nitrogen source utilization, but well predicted lag phase length. Thus, human domestication of yeast for grape must growth has had, at the most, a marginal impact on wine yeast growth rates and efficiencies, but may have left a surprising imprint on the time required to adjust metabolism from non growth to growth. Wine yeast nitrogen source utilization deviated from that of the lab strain experimentation, but also varied between wine strains. Each wine yeast lineage harbored nitrogen source utilization defects that were private to that strain. By a massive hemizygote analysis, we traced the genetic basis of the most glaring of these defects, near inability of the PDM wine strain to utilize methionine, as consequence of mutations in its ARO8, ADE5,7 and VBA3 alleles. We also identified candidate causative mutations in these genes. The methionine defect of PDM is potentially very interesting as the strain can, in some circumstances, overproduce foul tasting H2S, a trait which likely stems from insufficient methionine catabolization. The poor adaptation of wine yeast to the grape must nitrogen environment, and the presence of defects in each lineage, open up wine strain optimization through biotechnological endeavors.

  1. Genetic diversity and population structure of food-borne Staphylococcus carnosus strains.

    Science.gov (United States)

    Bückle Née Müller, Anne; Kranz, Markus; Schmidt, Herbert; Weiss, Agnes

    2017-01-01

    The species Staphylococcus carnosus is a non-pathogenic representative of the coagulase negative staphylococci. Specific strains are applied as meat starter cultures. The species consists of two subspecies, S. carnosus ssp. carnosus and S. carnosus ssp. utilis. In order to place S. carnosus strains, characterized in former studies, in a genetic background that allows a typing of candidates for starter cultures, a Multilocus Sequence Typing (MLST) scheme was developed. Internal fragments of the genes tpiA, xprT, dat, gmk, glpK, narG, cstA, encoding triosephosphate isomerase, xanthine phosphoribosyltransferase, d-amino acid aminotransferase, guanylate kinase, glycerol kinase, the α-chain of the respiratory nitrate reductase, and a carbon starvation protein where chosen. Genes were selected based on their equal distribution in the genome, taxonomic value in subspecies differentiation and metabolic function. This MLST was applied to 44 S. carnosus strains, most of them previously analyzed for their suitability as starter cultures. The number of alleles varied between zero (tpiA) and five (cstA) and allowed the definition of nine sequence types (ST). ST1 was most abundant (18 strains), followed by ST2 (8) and ST4 (6). The nine STs confirmed a close relationship of all strains despite their isolation source and year, but lacked correlation with physiological activities relevant for starter cultures. The low amount of STs in the strain set lets us suggest that recombination between strains is rare. Thus, it is hypothesized that evolutionary events seem to be due to single point mutations rather than intrachromosomal recombination, and that the species possesses a clonal population structure. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Resistance Markers and Genetic Diversity in Acinetobacter baumannii Strains Recovered from Nosocomial Bloodstream Infections

    Directory of Open Access Journals (Sweden)

    Hanoch S. I. Martins

    2014-01-01

    Full Text Available In this study, phenotypic and genotypic methods were used to detect metallo-β-lactamases, cephalosporinases and oxacillinases and to assess genetic diversity among 64 multiresistant Acinetobacter baumannii strains recovered from blood cultures in five different hospitals in Brazil from December 2008 to June 2009. High rates of resistance to imipenem (93.75% and polymyxin B (39.06% were observed using the disk diffusion (DD method and by determining the minimum inhibitory concentration (MIC. Using the disk approximation method, thirty-nine strains (60.9% were phenotypically positive for class D enzymes, and 51 strains (79.6% were positive for cephalosporinase (AmpC. Using the E-test, 60 strains (93.75% were positive for metallo-β-lactamases (MβLs. All strains were positive for at least one of the 10 studied genes; 59 (92.1% contained blaVIM-1, 79.6% contained blaAmpC, 93.7% contained blaOXA23 and 84.3% contained blaOXA51. Enterobacteria Repetitive Intergenic Consensus (ERIC-PCR analysis revealed a predominance of certain clones that differed from each other. However, the same band pattern was observed in samples from the different hospitals studied, demonstrating correlation between the genotypic and phenotypic results. Thus, ERIC-PCR is an appropriate method for rapidly clustering genetically related isolates. These results suggest that defined clonal clusters are circulating within the studied hospitals. These results also show that the prevalence of MDR A. baumannii may vary among clones disseminated in specific hospitals, and they emphasize the importance of adhering to appropriate infection control measures.

  3. Population genetic structure of Helicobacter pylori strains from Portuguese-speaking countries.

    Science.gov (United States)

    Oleastro, Mónica; Rocha, Raquel; Vale, Filipa F

    2017-08-01

    The human gastric colonizer Helicobacter pylori is useful to track human migrations given the agreement between the bacterium phylogeographic distribution and human migrations. As Portugal was an African and Brazilian colonizer for over 400 years, we hypothesized that Portuguese isolates were likely genetically closer with those from countries colonized by Portuguese in the past. We aimed to characterize the population structure of several Portuguese-speaking countries, including Portugal, Brazil, Angola, and Cape Verde. We included strains isolated in Portugal from Portuguese and from former Portuguese colonies. These strains were typed by multilocus sequence typing (MLST) for seven housekeeping genes. We also retrieved from Multi Locus Sequence Typing Web site additional housekeeping gene sequences, namely from Angola and Brazil. We provided evidence that strains from Portuguese belong to hpEurope and that the introgression of hpEurope in non-European countries that speak Portuguese is low, except for Brazil and Cape Verde, where hpEurope accounted for one quarter and one half of the population, respectively. We found genetic similarity for all strains from Portuguese-speaking countries that belong to hpEurope population. Moreover, these strains showed a predominance of ancestral Europe 2 (AE2) over ancestral Europe 1 (AE1), followed by ancestral Africa 1. H. pylori is a useful marker even for relative recent human migration events and may become rapidly differentiated from founder populations. H. pylori from Portuguese-speaking countries assigned to hpEurope appears to be a hybrid population resulting from the admixture of AE1, AE2 and ancestral hpAfrica1. © 2017 John Wiley & Sons Ltd.

  4. 1 original article diverse genetic subtypes of hiv-1 among female sex ...

    African Journals Online (AJOL)

    boaz

    Keywords: Diverse, HIV, subtypes, Female Sex workers and Vaccine ..... social power to set the terms for sexual relationship. These women live in poverty and are often coerced to trade sex for support and may be forced into prostitution.

  5. Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene.

    Science.gov (United States)

    Oka, Tomoichiro; Saif, Linda J; Marthaler, Douglas; Esseili, Malak A; Meulia, Tea; Lin, Chun-Ming; Vlasova, Anastasia N; Jung, Kwonil; Zhang, Yan; Wang, Qiuhong

    2014-10-10

    The highly contagious and deadly porcine epidemic diarrhea virus (PEDV) first appeared in the US in April 2013. Since then the virus has spread rapidly nationwide and to Canada and Mexico causing high mortality among nursing piglets and significant economic losses. Currently there are no efficacious preventive measures or therapeutic tools to control PEDV in the US. The isolation of PEDV in cell culture is the first step toward the development of an attenuated vaccine, to study the biology of PEDV and to develop in vitro PEDV immunoassays, inactivation assays and screen for PEDV antivirals. In this study, nine of 88 US PEDV strains were isolated successfully on Vero cells with supplemental trypsin and subjected to genomic sequence analysis. They differed genetically mainly in the N-terminal S protein region as follows: (1) strains (n=7) similar to the highly virulent US PEDV strains; (2) one similar to the reportedly US S INDEL PEDV strain; and (3) one novel strain most closely related to highly virulent US PEDV strains, but with a large (197aa) deletion in the S protein. Representative strains of these three genetic groups were passaged serially and grew to titers of ∼5-6log10 plaque forming units/mL. To our knowledge, this is the first report of the isolation in cell culture of an S INDEL PEDV strain and a PEDV strain with a large (197aa) deletion in the S protein. We also designed primer sets to detect these genetically diverse US PEDV strains. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Sex-specific genetic admixture of Mestizos, Amerindian Kichwas, and Afro-Ecuadorans from Ecuador.

    Science.gov (United States)

    González-Andrade, Fabricio; Sánchez, Dora; González-Solórzano, Jorge; Gascón, Santiago; Martínez-Jarreta, Begoña

    2007-02-01

    Three main ethnic groups live in the South American country of Ecuador: Mestizos, Amerindian natives, and African-derived populations, or Afro-Ecuadorans. Mestizos and Afro-Ecuadorans can be considered trihybrid populations containing genes originating in the Americas, Europe, and Africa, as is the case with equivalent populations in other Latin American countries. The proportion and the dynamics of the admixture process remain unknown. However, a certain sex asymmetry of the admixture process can be expected for historical reasons. We typed 11 Y-chromosome short tandem repeats (STRs) in these three ethnic groups to provide adequate allele and haplotype frequencies for forensic genetic purposes and to quantify admixture proportions in male lineages. In addition, a data set of 15 autosomal STRs in the same samples were reanalyzed for the same purpose. Contributions to Mestizo Y chromosomes were estimated to be 70% European, 28% Amerindian, and 2% African, whereas in autosomes the contributions were 19%, 73%, and 8%, respectively, which underlines the sexual asymmetry in mating, with Europeans contributing mostly males. European Y-chromosome haplotypes in Mestizos were similar to those in Spain. Moreover, about 10% of European Y chromosomes were found in the Amerindian Kichwa. As for Afro-Ecuadorans, their contributions to the male line are 44% African, 31% European, and 15% Native American; the last value is the highest percentage reported so far for an African-derived American group. Autosomal admixture was estimated as 56% African, 16% European, and 28% Amerindian.

  7. Genetic correlation between rheumatoid arthritis and periodontal disease: the role of sex and IL-10.

    Science.gov (United States)

    Azzi, L; Rania, S; Spadari, F; Vinci, R; Manfredini, M; Croveri, F; Boggio, A; Tettamanti, L; Tagliabue, A; Silvestre-Rangil, J; Bellintani, C

    2017-01-01

    The chronic stimulation of the immune system due to the presence of bacterial antigens within periodontal tissues has been associated with several autoimmune diseases, like diabetes mellitus, infective endocarditis or cardiovascular atherosclerosis. The current study aims at evaluating the correlation between Rheumatoid Arthritis (RA) and Periodontal Disease (PD) with special attention to genetic polymorphisms in cytokine expression. A total number of 34 patients affected by RA were recruited. Each of them underwent haematochemical analysis and data were collected for Rheumatoid Factor (RF), Anti-Citrullinated Protein’s Antibody (CCP) and HLA-BDR1. DAS-28 questionnaire for disease activity was fulfilled by the rheumatologist, while a periodontal examination was carried out by the dental clinician and crevicular fluid samples were collected to evaluate the IL-6, IL-10 and VDR polymorphysms. A connection between CCP and IL-10 polymorphisms was found, with IL-10 expressing protecting tendency against periodontal disease when CCP are found in the bloodstream (p=0.0017). Finally, males mainly expressed IL-10 predisposing genes (p=0.046), while females showed a greater tendency to express RF (p=0.014) and CCP (p=0.050). This paper corroborates the idea of a correlation between sex, IL-10 polymorphisms and RA, which should be studied in depth, since recent papers have shown that IL-10 injected into joints seems to decrease inflammation.

  8. Population genetic structure, gene flow and sex-biased dispersal in frillneck lizards (Chlamydosaurus kingii).

    Science.gov (United States)

    Ujvari, Beata; Dowton, Mark; Madsen, Thomas

    2008-08-01

    By using both mitochondrial and nuclear multiloci markers, we explored population genetic structure, gene flow and sex-specific dispersal of frillneck lizards (Chlamydosaurus kingii) sampled at three locations, separated by 10 to 50 km, in a homogenous savannah woodland in tropical Australia. Apart from a recombinant lizard, the mitochondrial analyses revealed two nonoverlapping haplotypes/populations, while the nuclear markers showed that the frillneck lizards represented three separate clusters/populations. Due to the small population size of the mtDNA, fixation may occur via founder effects and/or drift. We therefore suggest that either of these two processes, or a combination of the two, are the most likely causes of the discordant results obtained from the mitochondrial and the nuclear markers. In contrast to the nonoverlapping mitochondrial haplotypes, in 12 out of 74 lizards, mixed nuclear genotypes were observed, hence revealing a limited nuclear gene flow. Although gene flow should ultimately result in a blending of the populations, we propose that the distinct nuclear population structure is maintained by frequent fires resulting in local bottlenecks, and concomitant spatial separation of the frillneck lizard populations. Limited mark-recapture data and the difference in distribution of the mitochondrial and nuclear markers suggest that the mixed nuclear genotypes were caused by juvenile male-biased dispersal.

  9. Genetics of sex determination in the haplodiploid wasp Nasonia vitripennis (Hymenoptera: Chalcidoidea)

    NARCIS (Netherlands)

    Beukeboom, Leo W.; van de Zande, Louis

    2010-01-01

    The parasitoid wasp Nasonia vitripennis reproduces by haplodiploidy; males are haploid and females are diploid. Sex determination in Nasonia is not governed by complementary alleles at one or more sex loci. As in most other insects, the sex-determining pathway consists of the basal switch doublesex

  10. Genetic and serological identification of three Vibrio parahaemolyticus strains as candidates for novel provisional O serotypes.

    Science.gov (United States)

    Guo, Xi; Liu, Bin; Chen, Min; Wang, Yuanyuan; Wang, Lu; Chen, Hongyou; Wang, Yao; Tu, Lihong; Zhang, Xi; Feng, Lu

    2017-03-20

    Vibrio parahaemolyticus is a Gram-negative, halophilic Vibrio that naturally inhabits marine and estuarine environments worldwide and has recently been recognized as one of the most important foodborne pathogens. To date, 13 O serotypes and 71 K serotypes of V. parahaemolyticus have been identified. However, untypeable V. parahaemolyticus strains are frequently found during routine detection, indicating that other forms of serotypes exist and suggesting the necessity for extension of the antigenic scheme. In this work, through the genetic analysis of the O serotype genetic determinants (OGDs) and the production of antisera and serological tests, we identified three novel O serotypes of V. parahaemolyticus. Further analyses showed that recombination and gene-set deletions/insertions within OGDs may play key roles in the generation of V. parahaemolyticus O serotype diversity. A PCR method was developed for the identification of these novel O serotypes, and specificity and sensitivity were evaluated. A double-blind test including 283 clinical isolates was performed, giving perfect correlation with the agglutination test results. Generally, our study expanded the O-antigenic scheme of V. parahaemolyticus from 13 to 16 and provided a tool with the potential for the detection and identification of V. parahaemolyticus strains (especially untypeable strains) isolated from both the clinic and the environment.

  11. Genetic Evaluation of E. coli Strains Isolated from Asymptomatic Children with Neurogenic Bladders

    Directory of Open Access Journals (Sweden)

    John Kryger

    2015-01-01

    Full Text Available This study was conducted to describe the genetic profiles of E. coli that colonize asymptomatic pediatric neurogenic bladders. E. coli was isolated from 25 of 80 urine samples. Patients were excluded if they presented with symptomatic urinary tract infection or received treatment with antibiotics in the preceding three months. Multiplex PCR was performed to determine E. coli phylotype (A, B1, B2, and D and the presence of seven pathogenicity islands (PAIs and 10 virulence factors (VFs. E. coli strains were predominantly of the B1 and B2 phylotype, with few strains in the A or D phylotype. The PAIs IV536, ICFT073, and IICFT073 had the highest prevalence: 76%, 64%, and 48%, respectively. The PAIs II536, IJ96, and IIJ96 were less prevalent: 28%, 20%, and 24%, respectively. The most prevalent VF was vat (40%, while the least prevalent VFs were sfa (8% and iha (12%. None of the strains carried the VF fyuA, which is very common in uropathogenic E. coli (UPEC. The genetic profiles of E. coli in this cohort seem to be more similar to UPEC than to commensal E. coli. However, they appear to have reduced virulence potential that allows them to colonize asymptomatically.

  12. Sex impact on the quality of fatty liver and its genetic determinism in mule ducks.

    Science.gov (United States)

    Marie-Etancelin, C; Retailleau, B; Alinier, A; Vitezica, Z G

    2015-09-01

    Recent changes to French regulations now allow farmers to produce "foie gras" from both male and female mule ducks. The aim of this study was to assess the quality of female fatty liver and to compare, from a phenotypic and genetic point of view, liver quality in males and females. A total of 914 mule ducks (591 males and 323 females), hatched in a single pedigree batch, were reared until 86 d of age and then force-fed for 12 d, before being slaughtered. Carcasses and livers were weighed and liver quality was assessed by grading the extent of liver veining and measuring the liver melting rate, either after sterilization of 60 g of liver or pasteurization of 180 g of liver. Sexual dimorphism was observed in favor of males, with a difference of approximately 10% in carcass and liver weights and up to 54% for the liver melting rate. Moreover, one-third of female livers showed moderate to high veining, whereas this was not the case for male livers. The fatty livers of female mule ducks are, therefore, of poorer quality and could not be transformed into a product with the appellation "100% fatty liver." According to sex and parental line, heritability values ranged from 0.12 ± 0.05 to 0.18 ± 0.07 for fatty liver weight and from 0.09 ± 0.05 to 0.18 ± 0.05 for the 2 melting rate traits. The genetic correlations between the fatty liver weight and both melting rates were high (greater than +0.80) in the Muscovy population, whereas in the Pekin population, the liver weight and melting rates were less strongly correlated (estimates ranging from +0.36 ± 0.30 to +0.45 ± 0.28). Selection for lower liver melting rates without reducing the liver weight would, therefore, be easier to achieve in the Pekin population. Finally, as the 2 melting rate measurements are highly correlated (0.91 and over 0.95 for phenotypic and genetic correlations, respectively), we suggest using the easiest method, that is, sterilization of 60 g of liver.

  13. Characterization and restriction analysis of the P sex factor and the cryptic plasmid of Vibrio cholerae strain V58.

    Science.gov (United States)

    Bartowsky, E J; Morelli, G; Kamke, M; Manning, P A

    1987-07-01

    The P plasmid of Vibrio cholerae is a derepressed sex factor restricted to V. cholerae and has been shown to express surface exclusion. We have isolated the plasmids of strain V58 and have found that in addition to P, two further cryptic plasmids are also present. P has a size of 68 kb as determined by both electron microscopy and restriction endonuclease analysis. These other plasmids are 34 and 4.7 kb in size. Restriction maps of P and the larger cryptic plasmid have been determined. It has been demonstrated that P differs from the standard Inc group test plasmids and also expresses a surface exclusion system. The ability of the type Inc plasmids to be transferred to V. cholerae by either liquid or filter matings and the stability of these plasmids in V. cholerae have also been examined.

  14. X-ray sensitivity of fifty-three human diploid fibroblast cell strains from patients with characterized genetic disorders

    Energy Technology Data Exchange (ETDEWEB)

    Weichselbaum, R.R.; Nove, J.; Little, J.B.

    1980-03-01

    The in vitro response of 53 human diploid fibroblast strains to x-irradiation was studied using a clonogenic survival assay. The strains, derived from patients with a variety of characterized clinical conditions, most with a genetic component, ranged in Do (a measure of the slope of the survival curve) from 43 to 168 rads. The mean Do's of six strains from normal individuals was 140 to 152 rads, with an overall range, based on the extremes of their standard errors, of 128 to 164 rads. Three-quarters of the strains studied fell within this range. Strains identified as sensitive came from patients with ataxia telangiectasia, progeria, the two genetic forms of retinoblastoma, and partial trisomy of chromosome 13. No marked radiosensitivity was found among strains derived from patients with a number of other conditions associated with a predisposition to malignancy.

  15. Efficacy of EGFR inhibition is modulated by model, sex, genetic background and diet: implications for preclinical cancer prevention and therapy trials.

    Directory of Open Access Journals (Sweden)

    Erica S Rinella

    Full Text Available Molecule-targeted therapies are being widely developed and deployed, but they are frequently less effective in clinical trials than predicted based upon preclinical studies. Frequently, only a single model or genetic background is utilized using diets that are not relevant to that consumed by most cancer patients, which may contribute to the lack of predictability of many preclinical therapeutic studies. Inhibition of epidermal growth factor receptor (EGFR in colorectal cancer was used to investigate potential causes for low predictive values of many preclinical studies. The efficacy of the small molecule EGFR inhibitor AG1478 was evaluated using two mouse models, Apc(Min/+ and azoxymethane (AOM, both sexes on three genetic backgrounds, C57BL/6J (B6 and A/J (A inbred strains and AB6F1 hybrids, and two diets, standard chow (STD or Western-style diet (WD. AG1478 has significant anti-tumor activity in the B6-Apc(Min/+ model with STD but only moderately on the WD and in the AOM model on an A background with a WD but not STD. On the F1 hybrid background AG1478 is effective in the Apc(Min/+ model with either STD or WD, but has only moderate efficacy in the AOM model with either diet. Sex differences were also observed. Unexpectedly, the level of liver EGFR phosphorylation inhibition by AG1478 was not positively correlated with inhibition of tumor growth in the AOM model. Model-dependent interactions between genetic background and diet can dramatically impact preclinical results, and indicate that low predictive values of preclinical studies can be attributed to study designs that do not account for the heterogeneous patient population or the diets they consume. Better-designed preclinical studies should lead to more accurate predictions of therapeutic response in the clinic.

  16. Population Genetic Structure of Listeria monocytogenes Strains as Determined by Pulsed-Field Gel Electrophoresis and Multilocus Sequence Typing

    DEFF Research Database (Denmark)

    Henri, Clémentine; Félix, Benjamin; Guillier, Laurent

    2016-01-01

    Listeria monocytogenes is a ubiquitous bacterium that may cause the foodborne illness listeriosis. Only a small amount of data about the population genetic structure of strains isolated from food is available. This study aimed to provide an accurate view of the L. monocytogenes food strain...

  17. Tick-Borne Transmission of Two Genetically Distinct Anaplasma marginale Strains following Superinfection of the Mammalian Reservoir Host

    Science.gov (United States)

    Strain superinfection affects the dynamics of epidemiological spread of pathogens through a host population. Superinfection has recently been shown to occur for genetically distinct strains of the tick-borne pathogen Anaplasma marginale that encode distinctly different surface protein variants. Supe...

  18. Experimental Infection of Calves by Two Genetically-Distinct Strains of Rift Valley Fever Virus

    Directory of Open Access Journals (Sweden)

    William C. Wilson

    2016-05-01

    Full Text Available Recent outbreaks of Rift Valley fever in ruminant livestock, characterized by mass abortion and high mortality rates in neonates, have raised international interest in improving vaccine control strategies. Previously, we developed a reliable challenge model for sheep that improves the evaluation of existing and novel vaccines in sheep. This sheep model demonstrated differences in the pathogenesis of Rift Valley fever virus (RVFV infection between two genetically-distinct wild-type strains of the virus, Saudi Arabia 2001 (SA01 and Kenya 2006 (Ken06. Here, we evaluated the pathogenicity of these two RVFV strains in mixed breed beef calves. There was a transient increase in rectal temperatures with both virus strains, but this clinical sign was less consistent than previously reported with sheep. Three of the five Ken06-infected animals had an early-onset viremia, one day post-infection (dpi, with viremia lasting at least three days. The same number of SA01-infected animals developed viremia at 2 dpi, but it only persisted through 3 dpi in one animal. The average virus titer for the SA01-infected calves was 1.6 logs less than for the Ken06-infected calves. Calves, inoculated with either strain, seroconverted by 5 dpi and showed time-dependent increases in their virus-neutralizing antibody titers. Consistent with the results obtained in the previous sheep study, elevated liver enzyme levels, more severe liver pathology and higher virus titers occurred with the Ken06 strain as compared to the SA01 strain. These results demonstrate the establishment of a virulent challenge model for vaccine evaluation in calves.

  19. Experimental Infection of Calves by Two Genetically-Distinct Strains of Rift Valley Fever Virus.

    Science.gov (United States)

    Wilson, William C; Davis, A Sally; Gaudreault, Natasha N; Faburay, Bonto; Trujillo, Jessie D; Shivanna, Vinay; Sunwoo, Sun Young; Balogh, Aaron; Endalew, Abaineh; Ma, Wenjun; Drolet, Barbara S; Ruder, Mark G; Morozov, Igor; McVey, D Scott; Richt, Juergen A

    2016-05-23

    Recent outbreaks of Rift Valley fever in ruminant livestock, characterized by mass abortion and high mortality rates in neonates, have raised international interest in improving vaccine control strategies. Previously, we developed a reliable challenge model for sheep that improves the evaluation of existing and novel vaccines in sheep. This sheep model demonstrated differences in the pathogenesis of Rift Valley fever virus (RVFV) infection between two genetically-distinct wild-type strains of the virus, Saudi Arabia 2001 (SA01) and Kenya 2006 (Ken06). Here, we evaluated the pathogenicity of these two RVFV strains in mixed breed beef calves. There was a transient increase in rectal temperatures with both virus strains, but this clinical sign was less consistent than previously reported with sheep. Three of the five Ken06-infected animals had an early-onset viremia, one day post-infection (dpi), with viremia lasting at least three days. The same number of SA01-infected animals developed viremia at 2 dpi, but it only persisted through 3 dpi in one animal. The average virus titer for the SA01-infected calves was 1.6 logs less than for the Ken06-infected calves. Calves, inoculated with either strain, seroconverted by 5 dpi and showed time-dependent increases in their virus-neutralizing antibody titers. Consistent with the results obtained in the previous sheep study, elevated liver enzyme levels, more severe liver pathology and higher virus titers occurred with the Ken06 strain as compared to the SA01 strain. These results demonstrate the establishment of a virulent challenge model for vaccine evaluation in calves.

  20. First isolation and genetic characterization of a Toxoplasma gondii strain from a symptomatic human case of congenital toxoplasmosis in Romania

    Science.gov (United States)

    Costache, Carmen Anca; Colosi, Horaţiu Alexandru; Blaga, Ligia; Györke, Adriana; Paştiu, Anamaria Ioana; Colosi, Ioana Alina; Ajzenberg, Daniel

    2013-01-01

    Very limited data exists on the genetic diversity of Toxoplasma gondii from Eastern Europe. We present the first Romanian case of symptomatic congenital toxoplasmosis in which the T. gondii strain was isolated after inoculation in mice of a cerebrospinal fluid sample from a living neonate. The T. gondii strain was genotyped with 15 microsatellite markers distributed on 10 of the 14 chromosomes of T. gondii. The strain had a type II genotype. PMID:23537840

  1. Ura- host strains for genetic manipulation and heterologous expression of Torulaspora delbrueckii.

    Science.gov (United States)

    Hernandez-Lopez, Maria Jose; Blasco, Amalia; Prieto, Jose Antonio; Randez-Gil, Francisca

    2003-09-01

    Recently, the industrial and academic interest in the yeast Torulaspora delbrueckii has increased notably due to its high resistance to several stresses. This characteristic has made of this organism a very attractive model to study the molecular basis of the stress response in yeast. However, very little is known about the physiology and genetics of this yeast, and the tools for its manipulation have not been developed. Here, we have generated Ura(-) strains of the baker's yeast T. delbrueckii IGC5323 by either 5-FOA-aided selection or transformation with a PCR-based disruption cassette, natMX4, which confers nourseothricin resistance. Furthermore, the mutant and disruptant strains were used as recipient of a plasmid containing the xlnB cDNA from Aspergillus nidulans. Our results indicate that Torulaspora transformants produce active recombinant protein at a similar level to that found for Saccharomyces.

  2. Origins of albino and hooded rats: implications from molecular genetic analysis across modern laboratory rat strains.

    Directory of Open Access Journals (Sweden)

    Takashi Kuramoto

    Full Text Available Albino and hooded (or piebald rats are one of the most frequently used laboratory animals for the past 150 years. Despite this fact, the origin of the albino mutation as well as the genetic basis of the hooded phenotype remained unclear. Recently, the albino mutation has been identified as the Arg299His missense mutation in the Tyrosinase gene and the hooded (H locus has been mapped to the ∼460-kb region in which only the Kit gene exists. Here, we surveyed 172 laboratory rat strains for the albino mutation and the hooded (h mutation that we identified by positional cloning approach to investigate possible genetic roots and relationships of albino and hooded rats. All of 117 existing laboratory albino rats shared the same albino missense mutation, indicating they had only one single ancestor. Genetic fine mapping followed by de novo sequencing of BAC inserts covering the H locus revealed that an endogenous retrovirus (ERV element was inserted into the first intron of the Kit gene where the hooded allele maps. A solitary long terminal repeat (LTR was found at the same position to the ERV insertion in another allele of the H locus, which causes the so called Irish (h(i phenotype. The ERV and the solitary LTR insertions were completely associated with the hooded and Irish coat patterns, respectively, across all colored rat strains examined. Interestingly, all 117 albino rat strains shared the ERV insertion without any exception, which strongly suggests that the albino mutation had originally occurred in hooded rats.

  3. Improving itaconic acid production through genetic engineering of an industrial Aspergillus terreus strain.

    Science.gov (United States)

    Huang, Xuenian; Lu, Xuefeng; Li, Yueming; Li, Xia; Li, Jian-Jun

    2014-08-11

    Itaconic acid, which has been declared to be one of the most promising and flexible building blocks, is currently used as monomer or co-monomer in the polymer industry, and produced commercially by Aspergillus terreus. However, the production level of itaconic acid hasn't been improved in the past 40 years, and mutagenesis is still the main strategy to improve itaconate productivity. The genetic engineering approach hasn't been applied in industrial A. terreus strains to increase itaconic acid production. In this study, the genes closely related to itaconic acid production, including cadA, mfsA, mttA, ATEG_09969, gpdA, ATEG_01954, acoA, mt-pfkA and citA, were identified and overexpressed in an industrial A. terreus strain respectively. Overexpression of the genes cadA (cis-aconitate decarboxylase) and mfsA (Major Facilitator Superfamily Transporter) enhanced the itaconate production level by 9.4% and 5.1% in shake flasks respectively. Overexpression of other genes showed varied effects on itaconate production. The titers of other organic acids were affected by the introduced genes to different extent. Itaconic acid production could be improved through genetic engineering of the industrially used A. terreus strain. We have identified some important genes such as cadA and mfsA, whose overexpression led to the increased itaconate productivity, and successfully developed a strategy to establish a highly efficient microbial cell factory for itaconate protuction. Our results will provide a guide for further enhancement of the itaconic acid production level through genetic engineering in future.

  4. Meningococcal genetic variation mechanisms viewed through comparative analysis of serogroup C strain FAM18.

    Directory of Open Access Journals (Sweden)

    Stephen D Bentley

    2007-02-01

    Full Text Available The bacterium Neisseria meningitidis is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. Occasionally strains can invade host tissues causing septicaemia and meningitis, making the bacterium a major cause of morbidity and mortality in both the developed and developing world. The species is known to be diverse in many ways, as a product of its natural transformability and of a range of recombination and mutation-based systems. Previous work on pathogenic Neisseria has identified several mechanisms for the generation of diversity of surface structures, including phase variation based on slippage-like mechanisms and sequence conversion of expressed genes using information from silent loci. Comparison of the genome sequences of two N. meningitidis strains, serogroup B MC58 and serogroup A Z2491, suggested further mechanisms of variation, including C-terminal exchange in specific genes and enhanced localised recombination and variation related to repeat arrays. We have sequenced the genome of N. meningitidis strain FAM18, a representative of the ST-11/ET-37 complex, providing the first genome sequence for the disease-causing serogroup C meningococci; it has 1,976 predicted genes, of which 60 do not have orthologues in the previously sequenced serogroup A or B strains. Through genome comparison with Z2491 and MC58 we have further characterised specific mechanisms of genetic variation in N. meningitidis, describing specialised loci for generation of cell surface protein variants and measuring the association between noncoding repeat arrays and sequence variation in flanking genes. Here we provide a detailed view of novel genetic diversification mechanisms in N. meningitidis. Our analysis provides evidence for the hypothesis that the noncoding repeat arrays in neisserial genomes (neisserial intergenic mosaic elements provide a crucial mechanism for the generation of surface antigen variants. Such variation will have an

  5. Genetic diversity among food-borne and waterborne norovirus strains causing outbreaks in Sweden.

    Science.gov (United States)

    Lysén, Maria; Thorhagen, Margareta; Brytting, Maria; Hjertqvist, Marika; Andersson, Yvonne; Hedlund, Kjell-Olof

    2009-08-01

    A total of 101 food-borne and waterborne outbreaks that were caused by norovirus and that resulted in more than 4,100 cases of illness were reported to the Swedish Institute for Infectious Disease Control from January 2002 to December 2006. Sequence and epidemiological data for isolates from 73 outbreaks were analyzed. In contrast to health care-related outbreaks, no clear seasonality could be observed. Sequence analysis showed a high degree of genetic variation among the noroviruses detected. Genogroup II (GII) viruses were detected in 70% of the outbreaks, and of those strains, strains of GII.4 were the most prevalent and were detected in 25% of all outbreaks. The GII.4 variants detected in global outbreaks in health care settings during 2002, 2004, and 2006 were also found in the food-borne outbreaks. GI strains totally dominated as the cause of water-related (drinking and recreational water) outbreaks and were found in 12 of 13 outbreaks. In 14 outbreaks, there were discrepancies among the polymerase and capsid genotype results. In four outbreaks, the polymerase of the recombinant GII.b virus occurred together with the GII.1 or GII.3 capsids, while the GII.7 polymerase occurred together with the GII.6 and GII.7 capsids. Mixed infections were observed in six outbreaks; four of these were due to contaminated water, and two were due to imported frozen berries. Contaminated food and water serve as important reservoirs for noroviruses. The high degree of genetic diversity found among norovirus strains causing food-borne and waterborne infections stresses the importance of the use of broad reaction detection methods when such outbreaks are investigated.

  6. Meningococcal genetic variation mechanisms viewed through comparative analysis of serogroup C strain FAM18.

    Directory of Open Access Journals (Sweden)

    Stephen D Bentley

    2007-02-01

    Full Text Available The bacterium Neisseria meningitidis is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. Occasionally strains can invade host tissues causing septicaemia and meningitis, making the bacterium a major cause of morbidity and mortality in both the developed and developing world. The species is known to be diverse in many ways, as a product of its natural transformability and of a range of recombination and mutation-based systems. Previous work on pathogenic Neisseria has identified several mechanisms for the generation of diversity of surface structures, including phase variation based on slippage-like mechanisms and sequence conversion of expressed genes using information from silent loci. Comparison of the genome sequences of two N. meningitidis strains, serogroup B MC58 and serogroup A Z2491, suggested further mechanisms of variation, including C-terminal exchange in specific genes and enhanced localised recombination and variation related to repeat arrays. We have sequenced the genome of N. meningitidis strain FAM18, a representative of the ST-11/ET-37 complex, providing the first genome sequence for the disease-causing serogroup C meningococci; it has 1,976 predicted genes, of which 60 do not have orthologues in the previously sequenced serogroup A or B strains. Through genome comparison with Z2491 and MC58 we have further characterised specific mechanisms of genetic variation in N. meningitidis, describing specialised loci for generation of cell surface protein variants and measuring the association between noncoding repeat arrays and sequence variation in flanking genes. Here we provide a detailed view of novel genetic diversification mechanisms in N. meningitidis. Our analysis provides evidence for the hypothesis that the noncoding repeat arrays in neisserial genomes (neisserial intergenic mosaic elements provide a crucial mechanism for the generation of surface antigen variants. Such variation will have an

  7. Microsatellites reveal the genetic structure of thelytokous strains of the migratory locust

    Institute of Scientific and Technical Information of China (English)

    ZHAO-QIAN TENG; LE KANG

    2007-01-01

    This study reports on two parthenogenetic strains of the migratory locust Locusta migratoria. The offspring of thelytokou females had a single fragment per microsatellite loci. All offspring of the parthenogenetic F1 females were genetically identical. These results further confirmed that restitution of the sister products of early cleavage mitoses and cell fusion might be the most likely diploidization mechanisms in the thelytokous locusts. Polymerase chain reaction amplification results demonstrated that thelytoky in the locust was not induced by Wolbachia bacteria. Apart from the low fitness gained in thelytokous females, large populations with migration and losing heterozygosity may be other reasons why regular parthenogenesis has not evolved in the locust.

  8. Complete genetic characterization of a Brazilian dengue virus type 3 strain isolated from a fatal outcome

    Directory of Open Access Journals (Sweden)

    Marize Pereira Miagostovich

    2006-05-01

    Full Text Available We have determined the complete nucleotide and the deduced amino acid sequences of Brazilian dengue virus type 3 (DENV-3 from a dengue case with fatal outcome, which occurred during an epidemic in the state of Rio de Janeiro, Brazil, in 2002. This constitutes the first complete genetic characterization of a Brazilian DENV-3 strain since its introduction into the country in 2001. DENV-3 was responsible for the most severe dengue epidemic in the state, based on the highest number of reported cases and on the severity of clinical manifestations and deaths reported.

  9. Sex-linked inheritance, genetic correlations and sexual dimorphism in three melanin-based colour traits in the barn owl.

    Science.gov (United States)

    Roulin, A; Jensen, H

    2015-03-01

    Theory states that genes on the sex chromosomes have stronger effects on sexual dimorphism than genes on the autosomes. Although empirical data are not necessarily consistent with this theory, this situation may prevail because the relative role of sex-linked and autosomally inherited genes on sexual dimorphism has rarely been evaluated. We estimated the quantitative genetics of three sexually dimorphic melanin-based traits in the barn owl (Tyto alba), in which females are on average darker reddish pheomelanic and display more and larger black eumelanic feather spots than males. The plumage traits with higher sex-linked inheritance showed lower heritability and genetic correlations, but contrary to prediction, these traits showed less pronounced sexual dimorphism. Strong offspring sexual dimorphism primarily resulted from daughters not expressing malelike melanin-based traits and from sons expressing femalelike traits to similar degrees as their sisters. We conclude that in the barn owl, polymorphism at autosomal genes rather than at sex-linked genes generate variation in sexual dimorphism in melanin-based traits.

  10. Electron microscopic, genetic and protein expression analyses of Helicobacter acinonychis strains from a Bengal tiger.

    Science.gov (United States)

    Tegtmeyer, Nicole; Rivas Traverso, Francisco; Rohde, Manfred; Oyarzabal, Omar A; Lehn, Norbert; Schneider-Brachert, Wulf; Ferrero, Richard L; Fox, James G; Berg, Douglas E; Backert, Steffen

    2013-01-01

    Colonization by Helicobacter species is commonly noted in many mammals. These infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. The aim of this study was to isolate and characterize putative novel Helicobacter spp. from Bengal tigers in Thailand. Morphological investigation (Gram-staining and electron microscopy) and genetic studies (16SrRNA, 23SrRNA, flagellin, urease and prophage gene analyses, RAPD DNA fingerprinting and restriction fragment polymorphisms) as well as Western blotting were used to characterize the isolated Helicobacters. Electron microscopy revealed spiral-shaped bacteria, which varied in length (2.5-6 µm) and contained up to four monopolar sheathed flagella. The 16SrRNA, 23SrRNA, sequencing and protein expression analyses identified novel H. acinonychis isolates closely related to H. pylori. These Asian isolates are genetically very similar to H. acinonychis strains of other big cats (cheetahs, lions, lion-tiger hybrid and other tigers) from North America and Europe, which is remarkable in the context of the great genetic diversity among worldwide H. pylori strains. We also found by immunoblotting that the Bengal tiger isolates express UreaseA/B, flagellin, BabA adhesin, neutrophil-activating protein NapA, HtrA protease, γ-glutamyl-transpeptidase GGT, Slt lytic transglycosylase and two DNA transfer relaxase orthologs that were known from H. pylori, but not the cag pathogenicity island, nor CagA, VacA, SabA, DupA or OipA proteins. These results give fresh insights into H. acinonychis genetics and the expression of potential pathogenicity-associated factors and their possible pathophysiological relevance in related gastric infections.

  11. Electron microscopic, genetic and protein expression analyses of Helicobacter acinonychis strains from a Bengal tiger.

    Directory of Open Access Journals (Sweden)

    Nicole Tegtmeyer

    Full Text Available Colonization by Helicobacter species is commonly noted in many mammals. These infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. The aim of this study was to isolate and characterize putative novel Helicobacter spp. from Bengal tigers in Thailand. Morphological investigation (Gram-staining and electron microscopy and genetic studies (16SrRNA, 23SrRNA, flagellin, urease and prophage gene analyses, RAPD DNA fingerprinting and restriction fragment polymorphisms as well as Western blotting were used to characterize the isolated Helicobacters. Electron microscopy revealed spiral-shaped bacteria, which varied in length (2.5-6 µm and contained up to four monopolar sheathed flagella. The 16SrRNA, 23SrRNA, sequencing and protein expression analyses identified novel H. acinonychis isolates closely related to H. pylori. These Asian isolates are genetically very similar to H. acinonychis strains of other big cats (cheetahs, lions, lion-tiger hybrid and other tigers from North America and Europe, which is remarkable in the context of the great genetic diversity among worldwide H. pylori strains. We also found by immunoblotting that the Bengal tiger isolates express UreaseA/B, flagellin, BabA adhesin, neutrophil-activating protein NapA, HtrA protease, γ-glutamyl-transpeptidase GGT, Slt lytic transglycosylase and two DNA transfer relaxase orthologs that were known from H. pylori, but not the cag pathogenicity island, nor CagA, VacA, SabA, DupA or OipA proteins. These results give fresh insights into H. acinonychis genetics and the expression of potential pathogenicity-associated factors and their possible pathophysiological relevance in related gastric infections.

  12. Fischer 344 and Lewis Rat Strains as a Model of Genetic Vulnerability to Drug Addiction.

    Science.gov (United States)

    Cadoni, Cristina

    2016-01-01

    Today it is well acknowledged that both nature and nurture play important roles in the genesis of psychopathologies, including drug addiction. Increasing evidence suggests that genetic factors contribute for at least 40-60% of the variation in liability to drug dependence. Human genetic studies suggest that multiple genes of small effect, rather than single genes, contribute to the genesis of behavioral psychopathologies. Therefore, the use of inbred rat strains might provide a valuable tool to identify differences, linked to genotype, important in liability to addiction and related disorders. In this regard, Lewis and Fischer 344 inbred rats have been proposed as a model of genetic vulnerability to drug addiction, given their innate differences in sensitivity to the reinforcing and rewarding effects of drugs of abuse, as well their different responsiveness to stressful stimuli. This review will provide evidence in support of this model for the study of the genetic influence on addiction vulnerability, with particular emphasis on differences in mesolimbic dopamine (DA) transmission, rewarding and emotional function. It will be highlighted that Lewis and Fischer 344 rats differ not only in several indices of DA transmission and adaptive changes following repeated drug exposure, but also in hypothalamic-pituitary-adrenal (HPA) axis responsiveness, influencing not only the ability of the individual to cope with stressful events, but also interfering with rewarding and motivational processes, given the influence of corticosteroids on dopamine neuron functionality. Further differences between the two strains, as impulsivity or anxiousness, might contribute to their different proneness to addiction, and likely these features might be linked to their different DA neurotransmission plasticity. Although differences in other neurotransmitter systems might deserve further investigation, results from the reviewed studies might open new vistas in understanding aberrant

  13. Fischer 344 and Lewis rat strains as a model of genetic vulnerability to drug addiction

    Directory of Open Access Journals (Sweden)

    Cristina eCadoni

    2016-02-01

    Full Text Available Today it is well acknowledged that both nature and nurture play important roles in the genesis of psychopathologies, including drug addiction. Increasing evidence suggests that genetic factors contribute for at least 40-60 % of the variation in liability to drug dependence. Human genetic studies suggest that multiple genes of small effect, rather than single genes, contribute to the genesis of behavioral psychopathologies. Therefore the use of inbred rat strains might provide a valuable tool to identify differences, linked to genotype, important in liability to addiction and related disorders. In this regard, Lewis and Fischer 344 inbred rats have been proposed as a model of genetic vulnerability to drug addiction, given their innate differences in sensitivity to the reinforcing and rewarding effects of drugs of abuse, as well their different responsiveness to stressful stimuli. This review will provide evidence in support of this model for the study of the genetic influence on addiction vulnerability, with particular emphasis to differences in mesolimbic dopamine (DA transmission, rewarding and emotional function. It will be highlighted that Lewis and Fischer 344 rats differ not only in several indices of DA transmission and adaptive changes following repeated drug exposure, but also in hypothalamic-pituitary-adrenal (HPA axis responsiveness, influencing not only the ability of the individual to cope with stressful events, but also interfering with rewarding and motivational processes, given the influence of corticosteroids on dopamine neurons functionality.Further differences between the two strains, as impulsivity or anxiousness, might contribute to their different proneness to addiction, and likely these features might be linked to their different DA neurotransmission plasticity. Although differences in other neurotransmitter systems might deserve further investigations, results from the reviewed studies might open new vistas in

  14. Prevalence and genetic diversity of Bartonella strains in rodents from northwestern Mexico.

    Science.gov (United States)

    Rubio, André V; Ávila-Flores, Rafael; Osikowicz, Lynn M; Bai, Ying; Suzán, Gerardo; Kosoy, Michael Y

    2014-12-01

    Bartonella infections were investigated in wild rodents from northwestern Chihuahua, Mexico. A total of 489 rodents belonging to 14 species were surveyed in four areas. Bartonella bacteria were cultured from 50.1% of rodent samples (245/489). Infection rates ranged from 0% to 83.3% per rodent species, with no significant difference between sites except for Cynomys ludovicianus. Phylogenetic analyses of the citrate synthase gene (gltA) of the Bartonella isolates revealed 23 genetic variants (15 novel and 8 previously described), clustering into five phylogroups. Three phylogroups were associated with Bartonella vinsonii subsp. vinsonii, B. vinsonii subsp. arupensis, and B. washoensis, respectively. The other two phylogroups were not genetically related to any known Bartonella species. The genetic variants and phylogenetic groups exhibited a high degree of host specificity, mainly at the genus and family levels. This is the first study that describes the genetic diversity of Bartonella strains in wild rodents from Mexico. Considering that some variants found in this study are associated with Bartonella species that have been reported as zoonotic, more investigations are needed to further understand the ecology of Bartonella species in Mexican wildlife and their implications for human health.

  15. Genetic parameters for resistance to the Salmonella abortusovis vaccinal strain Rv6 in sheep

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    Bouix Jacques

    2003-03-01

    Full Text Available Abstract An experimental population (1216 lambs from 30 sires of the Inra401 sheep was created in an Inra flock to allow QTL detection for susceptibility to Salmonella infection, wool and carcass traits. The Inra401 is a sheep composite line developed from two breeds: Berrichon du Cher and Romanov. At 113 days of age on average, the lambs were inoculated intravenously with 108 Salmonella abortusovis Rv6 (vaccinal strain. They were slaughtered 10 days after the inoculation. Several traits were measured at inoculation and/or slaughtering to estimate the genetic resistance of the lambs to Salmonella infection: specific IgM and IgG1 antibody titres, body weight loss, spleen and pre-scapular node weights and counts of viable Salmonella persisting in these organs. This paper presents a quantitative analysis of the genetic variability of the traits related to salmonellosis susceptibility. The heritabilities of the traits varied between 0.10 and 0.64 (significantly different from zero. Thus, in sheep as well as in other species, the determinism of resistance to Salmonella infection is under genetic control. Moreover, the correlations between the traits are in agreement with the known immune mechanisms. The genetic variability observed should help QTL detection.

  16. Sex-determining chromosomes and sexual dimorphism: insights from genetic mapping of sex expression in a natural hybrid Fragaria × ananassa subsp. cuneifolia.

    Science.gov (United States)

    Govindarajulu, R; Liston, A; Ashman, T-L

    2013-05-01

    We studied the natural hybrid (Fragaria × ananassa subsp. cuneifolia) between two sexually dimorphic octoploid strawberry species (Fragaria virginiana and Fragaria chiloensis) to gain insight into the dynamics of sex chromosomes and the genesis of sexual dimorphism. Male sterility is dominant in both the parental species and thus will be inherited maternally, but the chromosome that houses the sex-determining region differs. Thus, we asked whether (1) the cytotypic composition of hybrid populations represents one or both maternal species, (2) the sex-determining chromosome of the hybrid reflects the location of male sterility within the maternal donor species and (3) crosses from the hybrid species show less sexual dimorphism than the parental species. We found that F. × ananassa subsp. cuneifolia populations consisted of both parental cytotypes but one predominated within each population. Genetic linkage mapping of two crosses showed dominance of male sterility similar to the parental species, however, the map location of male sterility reflected the maternal donor in one cross, but not the other. Moreover, female function mapped to a single region in the first cross, but to two regions in the second cross. Aside from components of female function (fruit set and seed set), other traits that have been found to be significantly sexually dimorphic in the pure species were either not dimorphic or were dimorphic in the opposite direction to the parental species. These results suggest that hybrids experience some disruption of dimorphism in secondary sexual traits, as well as novel location and number of quantitative trait locus (QTL) affecting sex function.

  17. Associations of genetic lactase non-persistence and sex with bone loss in young adulthood.

    Science.gov (United States)

    Laaksonen, Marika M L; Impivaara, Olli; Sievänen, Harri; Viikari, Jorma S A; Lehtimäki, Terho J; Lamberg-Allardt, Christel J E; Kärkkäinen, Merja U M; Välimäki, Matti; Heikkinen, Jorma; Kröger, Liisa M; Kröger, Heikki P J; Jurvelin, Jukka S; Kähönen, Mika A P; Raitakari, Olli T

    2009-05-01

    Some studies have reported that after attainment of peak bone mass (PBM), slow bone loss may occur in both men and women; however, findings are inconsistent. Genetic factors play a significant role in bone loss, but the available evidence is conflicting. Genetic lactase non-persistence (lactase C/C(-13910) genotype) is suggested to increase risk for inadequate calcium intake predisposing to poorer bone health. We investigated whether this genotype is associated with PBM and bone loss in young Finnish adults. Subjects belong to the Cardiovascular Risk in Young Finns Study that is an ongoing multi-centre follow-up of atherosclerosis risk factors. From the original cohort, randomly selected subjects aged 20-29 participated in baseline bone mineral density (BMD) measurements (n=358), and in follow-up measurements 12 years later (n=157). Bone mineral content (BMC) and BMD at lumbar spine (LS) and femoral neck (FN) were measured at baseline and follow-up with dual energy X-ray absorptiometry (DXA). Lactase C/T(-13910) polymorphism was determined by PCR and allele-specific fluorogenic probes. Information on lifestyle was elicited with questionnaires. During the follow-up, bone loss at both bone sites was greater in males (LS BMD: -1.1%, FN BMD: -5.2%) than in females (LS BMD: +2.1%, FN BMD: -0.7%) (both bone sites p=0.001). Younger age predicted greater loss of FN BMC and BMD in females (p=0.013 and p=0.001, respectively). Increased calcium intake predicted FN BMD gain in both sexes (in females B=0.007 g/cm(2)/mg, p=0.002; in males B=0.006, p=0.045), and increased physical activity LS BMD gain in females (B=0.091 g/cm(2)/physical activity point, p=0.023). PBM did not differ between the lactase genotypes, but males with the CC(-13910) genotype seemed to be prone to greater bone loss during the follow-up (LS BMD: C/C vs. T/T p=0.081). In conclusion, bone loss in young adulthood was more common in males than in females and seemed to occur mainly at the femoral neck. Young

  18. Molecular typing of canine distemper virus strains reveals the presence of a new genetic variant in South America.

    Science.gov (United States)

    Sarute, Nicolás; Pérez, Ruben; Aldaz, Jaime; Alfieri, Amauri A; Alfieri, Alice F; Name, Daniela; Llanes, Jessika; Hernández, Martín; Francia, Lourdes; Panzera, Yanina

    2014-06-01

    Canine distemper virus (CDV, Paramyxoviridae, Morbillivirus) is the causative agent of a severe infectious disease affecting terrestrial and marine carnivores worldwide. Phylogenetic relationships and the genetic variability of the hemagglutinin (H) protein and the fusion protein signal-peptide (Fsp) allow for the classification of field strains into genetic lineages. Currently, there are nine CDV lineages worldwide, two of them co-circulating in South America. Using the Fsp-coding region, we analyzed the genetic variability of strains from Uruguay, Brazil, and Ecuador, and compared them with those described previously in South America and other geographical areas. The results revealed that the Brazilian and Uruguayan strains belong to the already described South America lineage (EU1/SA1), whereas the Ecuadorian strains cluster in a new clade, here named South America 3, which may represent the third CDV lineage described in South America.

  19. PERFORMA IKAN NILA (Oreochromis niloticus HASIL SEX REVERSAL, GENETICALLY MALE DAN YY PADA FASE PENDEDERAN PERTAMA

    Directory of Open Access Journals (Sweden)

    Odang Carman

    2016-11-01

    Full Text Available Penelitian ini dilakukan untuk mengkaji performa ikan nila hasil sex reversal (SRV, genetically male tilapia (GMT, dan YY pada fase pendederan pertama di akuarium. Benih ikan dipelihara selama 22 hari, dari umur 6 hari hingga 28 hari. Parameter yang diamati meliputi tingkat sintasan, persentase ikan jantan, laju pertumbuhan, dan biomassa. Hasil penelitian menunjukkan bahwa tingkat sintasan tidak berbeda (P>0,05 antar ketiga kelompok ikan dan kontrol (KN, berkisar antara 85,30%--86,20%. Persentase ikan jantan antara SRV (94,5% ± 1,32% vs. GMT (93,8% ± 1,25% dan GMT vs. YY (90,2% ± 1,83% tidak berbeda (P>0,05, sedangkan antara SRV lebih tinggi daripada YY (P0.05, ranged from 85.30%-86.20%. Percentage of male fish between SRV (94.5% ± 1.32% versus GMT (93.8% ± 1.25% and GMT versus YY (90.2% ± 1.83% were also similar (P>0.05, while SRV is higher than YY (P<0.05. Percentage of male fish in the three fish groups was higher than that of control (56.9% ± 3.62%. Growth of YY fish and GMT were higher compared to SRV and control fish (KN. The mean weight of YY fish at the end of the experiment reached 476 mg, GMT fish 447 mg, SRV fish 379 mg and control 342 mg. Biomass of YY, GMT and SRV fish were respectively higher by 41.3%, 32.9%, and 10.3% compared to control. With high performance and technical consideration in farm, GMT fish can be a potential alternative to be cultured in fish farm in order to increase aquaculture production of nile tilapia.

  20. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-22

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

  1. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

  2. Genome Analyses of Icelandic Strains of Sulfolobus islandicus, Model Organisms for Genetic and Virus-Host Interaction Studies

    DEFF Research Database (Denmark)

    Guo, Li; Brügger, Kim; Liu, Chao;

    2011-01-01

    The genomes of two Sulfolobus islandicus strains obtained from Icelandic solfataras were sequenced and analyzed. Strain REY15A is a host for a versatile genetic toolbox. It exhibits a genome of minimal size, is stable genetically, and is easy to grow and manipulate. Strain HVE10/4 shows a broad h...... conjugative plasmids, which have integrated at a few tRNA genes lacking introns. This provides a possible rationale for the presence of the introns.......The genomes of two Sulfolobus islandicus strains obtained from Icelandic solfataras were sequenced and analyzed. Strain REY15A is a host for a versatile genetic toolbox. It exhibits a genome of minimal size, is stable genetically, and is easy to grow and manipulate. Strain HVE10/4 shows a broad...... in gene content and gene order occur. These include gene clusters involved in specific metabolic pathways, multiple copies of VapBC antitoxin-toxin gene pairs, and in strain HVE10/4, a 50-kb region rich in glycosyl transferase genes. The variable region also contains most of the insertion sequence (IS...

  3. Variation and evolution of male sex combs in Drosophila: nature of selection response and theories of genetic variation for sexual traits.

    Science.gov (United States)

    Ahuja, Abha; Singh, Rama S

    2008-05-01

    We investigated the genetic architecture of variation in male sex comb bristle number, a rapidly evolving secondary sexual character of Drosophila. Twenty-four generations of divergent artificial selection for sex comb bristle number in a heterogeneous population of Drosophila melanogaster resulted in a significant response that was more pronounced in the direction of low bristle numbers. We observed a strong positive correlated response to selection in the corresponding female transverse bristle row. The correlated response in male abdominal and sternopleural bristle numbers, on the other hand, did not follow the same pattern as sex comb bristle number differences between selection lines. Relaxation-of-selection experiments along with mate choice and fecundity assays using the selection lines developed demonstrated the action of stabilizing selection on sex comb bristle number. Our results show (1) substantial genetic variation underlying sex comb bristle number variation; (2) a weak relationship between the sex comb and developmentally related, non-sex bristle systems; and (3) that sexual selection may be a driving force in sex comb evolution, indicating the potential of sex combs to diversify rapidly during population differentiation and speciation. We discuss the implications of these results for theories of genetic variation in display and nondisplay male sex traits.

  4. Media debates and 'ethical publicity' on social sex selection through preimplantation genetic diagnosis (PGD) technology in Australia.

    Science.gov (United States)

    Whittaker, Andrea

    2015-01-01

    This paper offers a critical discourse analysis of media debate over social sex selection in the Australian media from 2008 to 2014. This period coincides with a review of the National Health and Medical Research Council's Ethical Guidelines on the Use of Assisted Reproductive Technology in Clinical Practice and Research (2007), which underlie the regulation of assisted reproductive clinics and practice in Australia. I examine the discussion of the ethics of pre-implatation genetic diagnosis (PGD) within the media as 'ethical publicity' to the lay public. Sex selection through PGD is both exemplary of and interconnected with a range of debates in Australia about the legitimacy of certain reproductive choices and the extent to which procreative liberties should be restricted. Major themes emerging from media reports on PGD sex selection in Australia are described. These include: the spectre of science out of control; ramifications for the contestation over the public funding of abortion in Australia; private choices versus public authorities regulating reproduction; and the ethics of travelling overseas for the technology. It is concluded that within Australia, the issue of PGD sex selection is framed in terms of questions of individual freedom against the principle of sex discrimination - a principle enshrined in legislation - and a commitment to publically-funded medical care.

  5. Coalescent Times and Patterns of Genetic Diversity in Species with Facultative Sex: Effects of Gene Conversion, Population Structure, and Heterogeneity.

    Science.gov (United States)

    Hartfield, Matthew; Wright, Stephen I; Agrawal, Aneil F

    2016-01-01

    Many diploid organisms undergo facultative sexual reproduction. However, little is currently known concerning the distribution of neutral genetic variation among facultative sexual organisms except in very simple cases. Understanding this distribution is important when making inferences about rates of sexual reproduction, effective population size, and demographic history. Here we extend coalescent theory in diploids with facultative sex to consider gene conversion, selfing, population subdivision, and temporal and spatial heterogeneity in rates of sex. In addition to analytical results for two-sample coalescent times, we outline a coalescent algorithm that accommodates the complexities arising from partial sex; this algorithm can be used to generate multisample coalescent distributions. A key result is that when sex is rare, gene conversion becomes a significant force in reducing diversity within individuals. This can reduce genomic signatures of infrequent sex (i.e., elevated within-individual allelic sequence divergence) or entirely reverse the predicted patterns. These models offer improved methods for assessing null patterns of molecular variation in facultative sexual organisms.

  6. High genetic diversity in RdRp gene of Brazilian porcine sapovirus strains.

    Science.gov (United States)

    Barry, Aline F; Alfieri, Alice F; Alfieri, Amauri A

    2008-09-18

    Sapovirus is one genus within Caliciviridae family that causes diarrhea in humans and animals. Sapovirus (SaV) has been classified into seven genogroups (GI to GVII). The GIII, GVI, and GVII, which prototype is Cowden, JJ681, and K7/JP strains, respectively, infect pigs. The objective of this study was to characterize wild-type Brazilian SaV strains from piglet stool samples and determine SaV infection frequency, age distribution and association with diarrheic disease. Stool samples from 113 piglets up to 28-days-old were collected from 34 pig farms located in the States of Minas Gerais (MG), Mato Grosso do Sul (MS), Paraná (PR), Santa Catarina (SC), and Rio Grande do Sul (RS), during 2004 and 2005. The specimens were evaluated for enteric calicivirus by RT-PCR assay with primers p289/290, designed to detect the polymerase gene of SaV and norovirus. Thirty four (30.1%) samples were positive for SaV and five amplicons were sequenced. Phylogenetic analyses placed BRA29-MS/04 and BRA52-PR/05 sequences into the GIII of SaV genus. BRA04-SC/04, BRA21-RS/04, and BRA37-MG/05 demonstrated low identity with the Cowden strain but were closely related (up to 86.3%) to the Japanese and Dutch SaV strains, grouping together in a new cluster (GVIII?) in the phylogenetic tree. SaV infection was detected more frequently (p=0.0001) in animals between 22 and 28 days of age, in equal frequencies in piglets with and without diarrhea (p=0.59), and in the five Brazilian States. In this study, such as other unclassified worldwide SaVs, the Brazilian strains showed high genetic variability. Furthermore, the distribution and frequency of SaV infection provides evidence that the virus is circulating in Brazilian pig herds.

  7. Sex differences in clinical and genetic determinants of levodopa peak-dose dyskinesias in Parkinson disease: an exploratory study.

    Science.gov (United States)

    Zappia, Mario; Annesi, Grazia; Nicoletti, Giuseppe; Arabia, Gennarina; Annesi, Ferdinanda; Messina, Demetrio; Pugliese, Pierfrancesco; Spadafora, Patrizia; Tarantino, Patrizia; Carrideo, Sara; Civitelli, Donatella; De Marco, Elvira V; Cirò-Candiano, Innocenza C; Gambardella, Antonio; Quattrone, Aldo

    2005-04-01

    Several factors, both clinical and genetic, may account for the risk of developing levodopa-induced peak-dose dyskinesias (PDD) in patients with Parkinson disease, but it is unclear how these factors interact for modulating the individual susceptibility for PDD. To examine clinical and genetic risk factors for determining individual susceptibility of PDD in patients with Parkinson disease. Cohort study. Referral center for Parkinson disease in Calabria, southern Italy. Patients Two hundred fifty patients with Parkinson disease were screened for the presence or absence of PDD following a short-term levodopa administration, and 215 subjects were available for further evaluations, including genotypic analysis of the CA dinucleotide short tandem repeat (CAn-STR) polymorphism located in the dopamine receptor D2 gene (DRD2). One hundred five patients (48.8%) exhibited PDD following short-term levodopa administration, and 110 patients (51.2%) did not. Multivariate logistic regression analysis showed that independent predictors for the occurrence of PDD were female sex, earlier age at onset of Parkinson disease, longer duration of treatment, and higher dose of levodopa. Genetic factors related to the DRD2 CAn-STR polymorphism were not independent predictors for PDD in the total population, but they had a strong protective effect on the appearance of PDD when the multivariate analysis was performed in men (odds ratio, 0.34 [95% confidence interval, 0.14-0.84]). In women, a genetic protective effect on PDD was not evident. Risk factors for PDD, both clinical and genetic, act in different ways for men and women. Genetic factors related to the DRD2 polymorphic status have a protective effect on PDD development in men but not in women. A female sex-related effect for the risk of PDD may be so strong that it overcomes any protective effect due to genetic factors.

  8. Effect of host Bactrocera dorsalis sex on yield and quality of the Parasitoid Fopius arisanus

    Science.gov (United States)

    This study examines the effect of host Bactrocera dorsalis sex on performance of the parasitoid Fopius arisanus to enable use of a genetic sexing strain (GSS) to transfer this parasitoid to regions where B.dorsalis is not established. Experiments on the sex ratio and yield of F. arisanus did not ind...

  9. Estimation of genetic parameters for growth, carcass and overfeeding traits in a white geese strain

    Directory of Open Access Journals (Sweden)

    Guy Gérard

    2000-07-01

    Full Text Available Abstract In an experimental strain of white plumage geese created in 1989, two experiments were carried out from 1993 to 1995 in order to estimate genetic parameters for growth, and carcass composition traits in non-overfed animals, and genetic parameters for growth and fatty liver formation in overfed animals. Four hundred and thirty-one non-overfed animals were bred and slaughtered at 11 weeks of age; they were measured for forearm length, keel bone length, chest circumference and breast depth before and after slaughtering. The carcasses were partly dissected in order weigh breast, breast muscle and skin + fat, and abdominal fat. Four hundred and seventy-seven overfed animals were slaughtered at 20 weeks of age; they were measured for "paletot" (breast meat, bone and meat from wings, bone and meat from thigh and legs weight and liver weight. In these two experiments, the weights had moderate to high heritability values. Breast depth measured on live animals showed a low heritability value. In overfed animals, liver weight showed a high heritability value. Liver weight could be increased by selection without a great effect on "paletot" weight. Thus, obtaining a white plumage geese strain for fatty liver production by selection would be difficult because only 20% of overfed animals had fatty liver. The results did not allow to conclude on the influence of selection on liver weight on carcass traits such as muscle or fatty tissue weight.

  10. Estimation of genetic parameters for growth, carcass and overfeeding traits in a white geese strain

    Science.gov (United States)

    Larzul, Catherine; Rouvier, Roger; Rousselot-Pailley, Daniel; Guy, Gérard

    2000-01-01

    In an experimental strain of white plumage geese created in 1989, two experiments were carried out from 1993 to 1995 in order to estimate genetic parameters for growth, and carcass composition traits in non-overfed animals, and genetic parameters for growth and fatty liver formation in overfed animals. Four hundred and thirty-one non-overfed animals were bred and slaughtered at 11 weeks of age; they were measured for forearm length, keel bone length, chest circumference and breast depth before and after slaughtering. The carcasses were partly dissected in order weigh breast, breast muscle and skin + fat, and abdominal fat. Four hundred and seventy-seven overfed animals were slaughtered at 20 weeks of age; they were measured for "paletot" (breast meat, bone and meat from wings, bone and meat from thigh and legs) weight and liver weight. In these two experiments, the weights had moderate to high heritability values. Breast depth measured on live animals showed a low heritability value. In overfed animals, liver weight showed a high heritability value. Liver weight could be increased by selection without a great effect on "paletot" weight. Thus, obtaining a white plumage geese strain for fatty liver production by selection would be difficult because only 20% of overfed animals had fatty liver. The results did not allow to conclude on the influence of selection on liver weight on carcass traits such as muscle or fatty tissue weight. PMID:14736387

  11. Estimation of genetic parameters for growth, carcass and overfeeding traits in a white geese strain.

    Science.gov (United States)

    Larzul, C; Rouvier, R; Rousselot-Pailley, D; Guy, G

    2000-01-01

    In an experimental strain of white plumage geese created in 1989, two experiments were carried out from 1993 to 1995 in order to estimate genetic parameters for growth, and carcass composition traits in non-overfed animals, and genetic parameters for growth and fatty liver formation in overfed animals. Four hundred and thirty-one non-overfed animals were bred and slaughtered at 11 weeks of age; they were measured for forearm length, keel bone length, chest circumference and breast depth before and after slaughtering. The carcasses were partly dissected in order weigh breast, breast muscle and skin + fat, and abdominal fat. Four hundred and seventy-seven overfed animals were slaughtered at 20 weeks of age; they were measured for "paletot" (breast meat, bone and meat from wings, bone and meat from thigh and legs) weight and liver weight. In these two experiments, the weights had moderate to high heritability values. Breast depth measured on live animals showed a low heritability value. In overfed animals, liver weight showed a high heritability value. Liver weight could be increased by selection without a great effect on "paletot" weight. Thus, obtaining a white plumage geese strain for fatty liver production by selection would be difficult because only 20% of overfed animals had fatty liver. The results did not allow to conclude on the influence of selection on liver weight on carcass traits such as muscle or fatty tissue weight.

  12. Cell-Specific Cre Strains For Genetic Manipulation in Salivary Glands.

    Directory of Open Access Journals (Sweden)

    Eri O Maruyama

    Full Text Available The secretory acinar cells of the salivary gland are essential for saliva secretion, but are also the cell type preferentially lost following radiation treatment for head and neck cancer. The source of replacement acinar cells is currently a matter of debate. There is evidence for the presence of adult stem cells located within specific ductal regions of the salivary glands, but our laboratory recently demonstrated that differentiated acinar cells are maintained without significant stem cell contribution. To enable further investigation of salivary gland cell lineages and their origins, we generated three cell-specific Cre driver mouse strains. For genetic manipulation in acinar cells, an inducible Cre recombinase (Cre-ER was targeted to the prolactin-induced protein (Pip gene locus. Targeting of the Dcpp1 gene, encoding demilune cell and parotid protein, labels intercalated duct cells, a putative site of salivary gland stem cells, and serous demilune cells of the sublingual gland. Duct cell-specific Cre expression was attempted by targeting the inducible Cre to the Tcfcp2l1 gene locus. Using the R26Tomato Red reporter mouse, we demonstrate that these strains direct inducible, cell-specific expression. Genetic tracing of acinar cells using PipGCE supports the recent finding that differentiated acinar cells clonally expand. Moreover, tracing of intercalated duct cells expressing DcppGCE confirms evidence of duct cell proliferation, but further analysis is required to establish that renewal of secretory acinar cells is dependent on stem cells within these ducts.

  13. Cell-Specific Cre Strains For Genetic Manipulation in Salivary Glands.

    Science.gov (United States)

    Maruyama, Eri O; Aure, Marit H; Xie, Xiaoling; Myal, Yvonne; Gan, Lin; Ovitt, Catherine E

    2016-01-01

    The secretory acinar cells of the salivary gland are essential for saliva secretion, but are also the cell type preferentially lost following radiation treatment for head and neck cancer. The source of replacement acinar cells is currently a matter of debate. There is evidence for the presence of adult stem cells located within specific ductal regions of the salivary glands, but our laboratory recently demonstrated that differentiated acinar cells are maintained without significant stem cell contribution. To enable further investigation of salivary gland cell lineages and their origins, we generated three cell-specific Cre driver mouse strains. For genetic manipulation in acinar cells, an inducible Cre recombinase (Cre-ER) was targeted to the prolactin-induced protein (Pip) gene locus. Targeting of the Dcpp1 gene, encoding demilune cell and parotid protein, labels intercalated duct cells, a putative site of salivary gland stem cells, and serous demilune cells of the sublingual gland. Duct cell-specific Cre expression was attempted by targeting the inducible Cre to the Tcfcp2l1 gene locus. Using the R26Tomato Red reporter mouse, we demonstrate that these strains direct inducible, cell-specific expression. Genetic tracing of acinar cells using PipGCE supports the recent finding that differentiated acinar cells clonally expand. Moreover, tracing of intercalated duct cells expressing DcppGCE confirms evidence of duct cell proliferation, but further analysis is required to establish that renewal of secretory acinar cells is dependent on stem cells within these ducts.

  14. Exopolysaccharide production by a genetically engineered Enterobacter cloacae strain for microbial enhanced oil recovery.

    Science.gov (United States)

    Sun, Shanshan; Zhang, Zhongzhi; Luo, Yijing; Zhong, Weizhang; Xiao, Meng; Yi, Wenjing; Yu, Li; Fu, Pengcheng

    2011-05-01

    Microbial enhanced oil recovery (MEOR) is a petroleum biotechnology for manipulating function and/or structure of microbial environments existing in oil reservoirs for prolonged exploitation of the largest source of energy. In this study, an Enterobacter cloacae which is capable of producing water-insoluble biopolymers at 37°C and a thermophilic Geobacillus strain were used to construct an engineered strain for exopolysaccharide production at higher temperature. The resultant transformants, GW3-3.0, could produce exopolysaccharide up to 8.83 g l(-1) in molasses medium at 54°C. This elevated temperature was within the same temperature range as that for many oil reservoirs. The transformants had stable genetic phenotype which was genetically fingerprinted by RAPD analysis. Core flooding experiments were carried out to ensure effective controlled profile for the simulation of oil recovery. The results have demonstrated that this approach has a promising application potential in MEOR. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Mother-offspring distances reflect sex differences in fine-scale genetic structure of eastern grey kangaroos.

    Science.gov (United States)

    King, Wendy J; Garant, Dany; Festa-Bianchet, Marco

    2015-05-01

    Natal dispersal affects life history and population biology and causes gene flow. In mammals, dispersal is usually male-biased so that females tend to be philopatric and surrounded by matrilineal kin, which may lead to preferential associations among female kin. Here we combine genetic analyses and behavioral observations to investigate spatial genetic structure and sex-biased dispersal patterns in a high-density population of mammals showing fission-fusion group dynamics. We studied eastern grey kangaroos (Macropus giganteus) over 2 years at Wilsons Promontory National Park, Australia, and found weak fine-scale genetic structure among adult females in both years but no structure among adult males. Immature male kangaroos moved away from their mothers at 18-25 months of age, while immature females remained near their mothers until older. A higher proportion of male (34%) than female (6%) subadults and young adults were observed to disperse, although median distances of detected dispersals were similar for both sexes. Adult females had overlapping ranges that were far wider than the maximum extent of spatial genetic structure found. Female kangaroos, although weakly philopatric, mostly encounter nonrelatives in fission-fusion groups at high density, and therefore kinship is unlikely to strongly affect sociality.

  16. Mother–offspring distances reflect sex differences in fine-scale genetic structure of eastern grey kangaroos

    Science.gov (United States)

    King, Wendy J; Garant, Dany; Festa-Bianchet, Marco

    2015-01-01

    Natal dispersal affects life history and population biology and causes gene flow. In mammals, dispersal is usually male-biased so that females tend to be philopatric and surrounded by matrilineal kin, which may lead to preferential associations among female kin. Here we combine genetic analyses and behavioral observations to investigate spatial genetic structure and sex-biased dispersal patterns in a high-density population of mammals showing fission–fusion group dynamics. We studied eastern grey kangaroos (Macropus giganteus) over 2 years at Wilsons Promontory National Park, Australia, and found weak fine-scale genetic structure among adult females in both years but no structure among adult males. Immature male kangaroos moved away from their mothers at 18–25 months of age, while immature females remained near their mothers until older. A higher proportion of male (34%) than female (6%) subadults and young adults were observed to disperse, although median distances of detected dispersals were similar for both sexes. Adult females had overlapping ranges that were far wider than the maximum extent of spatial genetic structure found. Female kangaroos, although weakly philopatric, mostly encounter nonrelatives in fission–fusion groups at high density, and therefore kinship is unlikely to strongly affect sociality. PMID:26045958

  17. Genetic structure and rabies spread potential in raccoons: the role of landscape barriers and sex-biased dispersal.

    Science.gov (United States)

    Côté, Héloïse; Garant, Dany; Robert, Karine; Mainguy, Julien; Pelletier, Fanie

    2012-06-01

    Identifying natural barriers to movements of hosts associated with infectious diseases is essential for developing effective control strategies. Raccoon rabies variant (RRV) is a zoonosis of concern for humans because its main vector, the raccoon (Procyon lotor), is found near residential areas. In Québec, Canada, all cases of RRV found in raccoons since 2006 were detected on the eastern side of the Richelieu River, suggesting that this river acts as a barrier to gene flow and thus the potential for RRV to spread. The objectives of this study were to characterize the genetic structure of raccoon populations and assess the effect of the Richelieu River on the population structure in southern Québec, Canada. We also evaluated whether RRV spread potential differed between sex and at a larger spatial scale. Our analyses revealed a weak signal of genetic differentiation among individuals located on each side of the Richelieu River. At a larger spatial scale, genetic structuring was weak. Our results suggest that rivers might not always efficiently restrain raccoon movements and spread of RRV. We suggest that the difference in genetic structure found between sexes can be partly explained by male movements during the breeding season in winter, when ice bridges allow passage over most rivers in Québec.

  18. Genetic mutations of avian leukosis virus subgroup J strains extended their host range.

    Science.gov (United States)

    Shen, Yanwei; Cai, Liming; Wang, Yanming; Wei, Rongrong; He, Menglian; Wang, Shanhui; Wang, Guihua; Cheng, Ziqiang

    2014-03-01

    The genetic diversity of avian leukosis virus subgroup J (ALV-J) is determined not only by the env gene, but also by its 3' UTR and 3' LTR. They all play important roles in extending the host range and tumour development. In the present study, one ALV-J strain (ZB110604-6) from Black-Bone Silky Fowl (BSF) and three ALV-J strains (ZB110604-3/4/5) from grey partridge (GP), which bore multiple tumours and breed in one house of Farm A, were demonstrated extending their host to GP, while two other ALV-J strains (LC110515-3/4) from BSF of Farm B could not infect the embryo fibroblast of GP. The BSF is a unique species of chicken in China, while the GP is a close relative of the pheasant that previously demonstrated resistance to ALV-J. Histopathology showed that various tumours were induced by ALV-J in the two species. Phylogenetic tree analysis showed that the isolates from Farms A and B, rather than species, belong to two different clusters of ALV-J. Genetic mutations analysis revealed that the isolates obtained from Farm A showed a higher frequency of mutation in the hypervariable region 2 domain than in other variable regions of the gp85 gene. From the nucleotide alignment of the 3' UTR and 3' LTR gene, and the spectrum of tumours observed in this study, we speculate that the deletions or mutations in the redundant transmembrane region, E element and U3 (CAAT boxes, CArG box and Y box) might associate with tumour formation and development. The extension of the host range of ALV-J to the GP suggested that housing different species together provides more opportunities for ALV-J to evolve rapidly.

  19. Environmental and genetic factors affecting mutability to aminoglycoside antibiotics among Escherichia coli K12 strains

    Directory of Open Access Journals (Sweden)

    Monteiro A.C.M.

    2003-01-01

    Full Text Available Environmental and genetic factors affecting the in vitro spontaneous mutation frequencies to aminoglycoside resistance in Escherichia coli K12 were investigated. Spontaneous mutation frequencies to kanamycin resistance were at least 100 fold higher on modified Luria agar (L2 plates, when compared to results obtained in experiments carried out with Nutrient agar (NA plates. In contrast to rifampincin, the increased mutability to kanamycin resistance could not be attributed to a mutator phenotype expressed by DNA repair defective strains. Kanamycin mutant selection windows and mutant preventive concentrations on L2 plates were at least fourfold higher than on NA plates, further demonstrating the role of growth medium composition on the mutability to aminoglycosides. Mutability to kanamycin resistance was increased following addition of sorbitol, suggesting that osmolarity is involved on the spontaneous mutability of E. coli K12 strains to aminoglycosides. The spontaneous mutation rates to kanamycin resistance on both L2 and NA plates were strictly associated with the selective antibiotic concentrations. Moreover, mutants selected at different antibiotic concentrations expressed heterogeneous resistance levels to kanamycin and most of them expressing multiple resistance to all tested aminoglycoside antibiotics (gentamicin, neomycin, amykacin and tobramycin. These results will contribute to a better understanding of the complex nature of aminoglycoside resistance and the emergence of spontaneous resistant mutants among E. coli K12 strains.

  20. Evaluation of genetic and phenotypic consistency of Bacillus coagulans MTCC 5856: a commercial probiotic strain.

    Science.gov (United States)

    Majeed, Muhammed; Nagabhushanam, Kalyanam; Natarajan, Sankaran; Sivakumar, Arumugam; Eshuis-de Ruiter, Talitha; Booij-Veurink, Janine; de Vries, Ynte P; Ali, Furqan

    2016-04-01

    Commercial probiotics preparation containing Bacillus coagulans have been sold in the market for several decades. Due to its high intra-species genomic diversity, it is very likely that B. coagulans strain may alter in different ways over multiple years of production. Therefore, the present study focuses to evaluate the genetic consistency and probiotic potential of B. coagulans MTCC 5856. Phenotypic and genotypic techniques including biochemical profiling, 16S rRNA sequencing, GTG 5″, BOX PCR fingerprinting, and Multi-Locus-Sequence typing (MLST) were carried out to evaluate the identity and consistency of the B. coagulans MTCC 5856. Further, in vitro probiotic potential, safety and stability at ambient temperature conditions of B. coagulans MTCC 5856 were evaluated. All the samples were identified as B. coagulans by biochemical profiling and 16S rRNA sequencing. GTG 5″, BOX PCR fingerprints and MLST studies revealed that the same strain was present over 3 years of commercial production. B. coagulans MTCC 5856 showed resistance to gastric acid, bile salt and exhibited antimicrobial activity in in-vitro studies. Additionally, B. coagulans MTCC 5856 was found to be non-mutagenic, non-cytotoxic, negative for enterotoxin genes and stable at ambient temperature (25 ± 2 °C) for 36 months. The data of the study verified that the same strain of B. coagulans MTCC 5856 was present in commercial preparation over multiple years of production.

  1. Genetic and antigenic analysis of Chlamydia pecorum strains isolated from calves with diarrhea.

    Science.gov (United States)

    Ohtani, Akifumi; Kubo, Masahito; Shimoda, Hiroshi; Ohya, Kenji; Iribe, Tadashi; Ohishi, Daiki; Endoh, Daiji; Omatsu, Tsutomu; Mizutani, Tetsuya; Fukushi, Hideto; Maeda, Ken

    2015-07-01

    Chlamydia pecorum (designated 22-58) was isolated in 2010 in HmLu-1 cells from the jejunum of a calf which died of necrotizing enterocolitis in Yamaguchi Prefecture, Japan. Immunohistochemical staining identified C. pecorum positive reactions in the jejunal villi. C. pecorum, designated 24-100, was isolated from the feces of a calf with diarrhea in another farm in Yamaguchi Prefecture in 2012. A significant increase in neutralizing antibody titers against C. pecorum was confirmed in paired sera. Nucleotide sequence identities of omp1 genes of the 2 isolates were 100%. The isolates were genetically and antigenically more closely related to C. pecorum Bo/Yokohama strain isolated from cattle with enteritis in Japan than to the other prototype strains, Bo/Maeda isolated from cattle with pneumonia and Ov/IPA isolated from sheep with polyarthritis. These results indicate that C. pecorum strains similar to 22-58 and 24-100 might be endemic in Yamaguchi Prefecture and cause enteric disease in cattle.

  2. Genetic Vaccination against Experimental Infection with Myotropic Parasite Strains of Trypanosoma cruzi

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    Adriano Fernando Araújo

    2014-01-01

    Full Text Available In earlier studies, we reported that a heterologous prime-boost regimen using recombinant plasmid DNA followed by replication-defective adenovirus vector, both containing Trypanosoma cruzi genes encoding trans-sialidase (TS and amastigote surface protein (ASP 2, provided protective immunity against experimental infection with a reticulotropic strain of this human protozoan parasite. Herein, we tested the outcome of genetic vaccination of F1 (CB10XBALB/c mice challenged with myotropic parasite strains (Brazil and Colombian. Initially, we determined that the coadministration during priming of a DNA plasmid containing the murine IL-12 gene improved the immune response and was essential for protective immunity elicited by the heterologous prime-boost regimen in susceptible male mice against acute lethal infections with these parasites. The prophylactic or therapeutic vaccination of resistant female mice led to a drastic reduction in the number of inflammatory infiltrates in cardiac and skeletal muscles during the chronic phase of infection with either strain. Analysis of the electrocardiographic parameters showed that prophylactic vaccination reduced the frequencies of sinus arrhythmia and atrioventricular block. Our results confirmed that prophylactic vaccination using the TS and ASP-2 genes benefits the host against acute and chronic pathologies caused by T. cruzi and should be further evaluated for the development of a veterinary or human vaccine against Chagas disease.

  3. Why Don't Smart Teens Have Sex? A Behavioral Genetic Approach

    Science.gov (United States)

    Harden, Kathryn P.; Mendle, Jane

    2011-01-01

    Academic achievement and cognitive ability have been shown to predict later age at first sexual intercourse. Using a sample of 536 same-sex twin pairs who were followed longitudinally from adolescence to early adulthood, this study tested whether relations between intelligence, academic achievement, and age at first sex were due to unmeasured…

  4. Comparative genetic mapping in Fragaria virginiana reveals autosomal origin of sex chromosome

    Science.gov (United States)

    Although most flowering plants are hermaphrodite, separate sexes (dioecy) have evolved repeatedly. The evolution of sex chromosomes from autosomes can often, but not always, accompany this transition. Thus, many have argued that plant genera that contain both hermaphroditic and dioecious members pro...

  5. Disorders of Sex Development : Clinical outcomes, (epi)genetic regulation and germ cell cancer

    NARCIS (Netherlands)

    Y.G. van der Zwan (Yvonne )

    2013-01-01

    markdownabstract__Abstract__ One of the most fundamental aspects of early human development is establishment of sex, which can be defined as the biological qualities that differentiate between male and female. The process of normal sex development is strictly controlled by functionality of a number

  6. Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster

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    Robert M. Griffin

    2016-12-01

    Full Text Available Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i typically show relatively less standing genetic variation than the autosomes, (ii exhibit more variation in males compared to females because of dosage compensation, and (iii potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila melanogaster. To achieve unbiased estimates of X and autosomal additive genetic variance, we use 80 chromosome substitution lines; 40 for the X chromosome and 40 combining the two major autosomes, which we assay for sex-specific and cross-sex genetic (covariation. We find significant X and autosomal additive genetic variance for both traits in both sexes (with reservation for X-linked variation of aging in females, but no conclusive evidence for depletion of X-linked variation (measured through females. Males display more X-linked variation for lifespan than females, but it is unclear if this is due to dosage compensation since also autosomal variation is larger in males. Finally, our results suggest that the X chromosome is enriched for sex-specific genetic variation in lifespan but results were less conclusive for aging overall. Collectively, these results suggest that the X chromosome has reduced capacity to respond to sexually concordant selection on lifespan from standing genetic variation, while its ability to respond to sexually antagonistic selection may be augmented.

  7. Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster.

    Science.gov (United States)

    Griffin, Robert M; Schielzeth, Holger; Friberg, Urban

    2016-12-07

    Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i) typically show relatively less standing genetic variation than the autosomes, (ii) exhibit more variation in males compared to females because of dosage compensation, and (iii) potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila melanogaster To achieve unbiased estimates of X and autosomal additive genetic variance, we use 80 chromosome substitution lines; 40 for the X chromosome and 40 combining the two major autosomes, which we assay for sex-specific and cross-sex genetic (co)variation. We find significant X and autosomal additive genetic variance for both traits in both sexes (with reservation for X-linked variation of aging in females), but no conclusive evidence for depletion of X-linked variation (measured through females). Males display more X-linked variation for lifespan than females, but it is unclear if this is due to dosage compensation since also autosomal variation is larger in males. Finally, our results suggest that the X chromosome is enriched for sex-specific genetic variation in lifespan but results were less conclusive for aging overall. Collectively, these results suggest that the X chromosome has reduced capacity to respond to sexually concordant selection on lifespan from standing genetic variation, while its ability to respond to sexually antagonistic selection may be augmented.

  8. Plant genetics. A Y-chromosome-encoded small RNA acts as a sex determinant in persimmons.

    Science.gov (United States)

    Akagi, Takashi; Henry, Isabelle M; Tao, Ryutaro; Comai, Luca

    2014-10-31

    In plants, multiple lineages have evolved sex chromosomes independently, providing a powerful comparative framework, but few specific determinants controlling the expression of a specific sex have been identified. We investigated sex determinants in the Caucasian persimmon, Diospyros lotus, a dioecious plant with heterogametic males (XY). Male-specific short nucleotide sequences were used to define a male-determining region. A combination of transcriptomics and evolutionary approaches detected a Y-specific sex-determinant candidate, OGI, that displays male-specific conservation among Diospyros species. OGI encodes a small RNA targeting the autosomal MeGI gene, a homeodomain transcription factor regulating anther fertility in a dosage-dependent fashion. This identification of a feminizing gene suppressed by a Y-chromosome-encoded small RNA contributes to our understanding of the evolution of sex chromosome systems in higher plants. Copyright © 2014, American Association for the Advancement of Science.

  9. Avoidance Expression in Rats as a Function of Signal-Shock Interval: Strain and Sex Differences

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    Richard J Servatius

    2015-07-01

    Full Text Available Inbred Wistar Kyoto (WKY rats express inhibited temperament, increased sensitivity to stress, and exaggerated expressions of avoidance. A long-standing observation for lever press escape/avoidance learning in rats is the duration of the warning signal (WS determines whether avoidance is expressed over escape. Outbred female Sprague-Dawley (SD rats trained with a 10-s WS efficiently escaped, but failed to exhibit avoidance; avoidance was exhibited to a high degree with WSs longer than 20-s. We examined this longstanding WS duration function and extended it to male SD and male and female WKY rats. A cross-over design with two WS durations (10 s or 60 s was employed. Rats were trained (20 trials/session in four phases: acquisition (10 sessions, extinction (10 sessions, re-acquisition (8 sessions and re-extinction (8 sessions. Consistent with the literature, female and male SD rats failed to express avoidance to an appreciable degree with a 10-s WS. When these rats were switched to a 60-s WS, performance levels in the initial session of training resembled the peak performance of rats trained with a 60-s WS. Therefore, the avoidance relationship was acquired, but not expressed at 10-s WS. Further, poor avoidance at 10-s does not adversely affect expression at 60-s. Failure to express avoidance with a 10-s WS likely reflects contrasting reinforcement value of avoidance, not a reduction in the amount of time available to respond or competing responses. In contrast, WKY rats exhibited robust avoidance with a 10-s WS, which was most apparent in female WKY rats. Exaggerated expression of avoidances by WKY rats, especially female rats, further confirms this inbred strain as a model of anxiety vulnerability.

  10. Trichloroethylene-induced formic aciduria: effect of dose, sex and strain of rat.

    Science.gov (United States)

    Yaqoob, Noreen; Evans, Andrew R; Lock, Edward A

    2013-02-08

    The industrial solvent trichloroethylene (TCE) has been reported to increase the excretion of formic acid in the urine of male Fischer 344 (F-344) rats following large oral doses. We have examined the dose-response relationship for formic aciduria in male and female Fischer 344 rats, the effect of some known metabolites of TCE and examined the response in male Wistar rats to help understand its relevance to renal toxicity. We report that doses of TCE as low as 8 mg/kg for 3 days to both male and female F344 rats produced formic aciduria. The formic aciduria was time-dependent being more marked after 3 doses compared to one dose in male F344 rats and to a lesser extent in female F344 rats. TCE administration to male Wistar rats produced less formic aciduria than in male F344 rats, indicating a strain difference in response. As TCE is primarily metabolised by cytochrome P450 2E1, Wistar rats were administered inducers of cytochrome P450 2E1 followed by TCE, this increased formic acid excretion to a concentration similar to that observed in male F344 rats, indicating a role for P450. Administration of the major metabolites of TCE, trichloroethanol and trichloroacetic acid to male F344 rats also produced a marked and sustained formic aciduria, while the metabolite of TCE formed via glutathione conjugation had no effect on formic acid excretion. The mechanism whereby this response occurs is currently not understood, but the formic acid excreted is not a metabolite of TCE, but appears to be due to interference with the metabolic utilisation of formate by a down stream metabolite of TCE. Over the three days of the studies no histopathological evidence of kidney toxicity was observed in F344 rats given TCE, indicating that the perturbation of formate metabolism does not lead to acute renal injury.

  11. Genetic and physical maps around the sex-determining M-locus of the dioecious plant asparagus.

    Science.gov (United States)

    Telgmann-Rauber, Alexa; Jamsari, Ari; Kinney, Michael S; Pires, J Chris; Jung, Christian

    2007-09-01

    Asparagus officinalis L. is a dioecious plant. A region called the M-locus located on a pair of homomorphic sex chromosomes controls the sexual dimorphism in asparagus. The aim of this work was to clone the region determining sex in asparagus from its position in the genome. The structure of the region encompassing M should be investigated and compared to the sex-determining regions in other dioecious model species. To establish an improved basis for physical mapping, a high-resolution genetic map was enriched with AFLP markers closely linked to the target locus by carrying out a bulked segregant analysis. By screening a BAC library with AFLP- and STS-markers followed by chromosome walking, a physical map with eight contigs could be established. However, the gaps between the contigs could not be closed due to a plethora of repetitive elements. Surprisingly, two of the contigs on one side of the M-locus did not overlap although they have been established with two markers, which mapped in a distance as low as 0.25 cM flanking the sex locus. Thus, the clustering of the markers indicates a reduced recombination frequency within the M-region. On the opposite side of the M-locus, a contig was mapped in a distance of 0.38 cM. Four closely linked BAC clones were partially sequenced and 64 putative ORFs were identified. Interestingly, only 25% of the ORFs showed sequence similarity to known proteins and ESTs. In addition, an accumulation of repetitive sequences and a low gene density was revealed in the sex-determining region of asparagus. Molecular cytogenetic and sequence analysis of BACs flanking the M-locus indicate that the BACs contain highly repetitive sequences that localize to centromeric and pericentromeric locations on all asparagus chromosomes, which hindered the localization of the M-locus to the single pair of sex chromosomes. We speculate that dioecious Silene, papaya and Asparagus species may represent three stages in the evolution of XX, XY sex

  12. Longitudinal decline of leukocyte telomere length in old age and the association with sex and genetic risk.

    Science.gov (United States)

    Berglund, Kari; Reynolds, Chandra A; Ploner, Alexander; Gerritsen, Lotte; Hovatta, Iiris; Pedersen, Nancy L; Hägg, Sara

    2016-07-01

    Telomeres are DNA-protein structures at the ends of chromosomes. Leukocyte telomere length (LTL) shortening has been associated with advanced age. However, most studies use cross-sectional data, hence, the aim of our study was to model longitudinal trajectories of LTL attrition across 20 years at old age. Assessments of LTL were done by qPCR in SATSA (Swedish Adoption/Twin Study of Aging; N=636 individuals). Cross-sectional and longitudinal associations with age were estimated, the latter using latent growth curve analysis. A genetic risk score (GRS) for LTL was further assessed and included in the models. We confirmed an inverse cross-sectional association of LTL with age (B=-0.0022 T/S-ratio; 95% CI: -0.0035, -0.0009, p-value=0.0008). Longitudinal LTL analyses adjusted for sex (1598 samples; ≤5 measurements) suggested modest average decline until 69 years of age but accelerating decline after 69 years, with significant inter-individual variation. Women had on average ~6% T/S-ratio units longer LTL at baseline, and inclusion of the GRS improved the model where four risk alleles was equivalent to the effect size difference between the sexes. In this cohort of old individuals, baseline LTL varied with age, sex and genetic background. The rate of change of LTL accelerated with age and varied considerably between individuals.

  13. The Genetically Remote Pathogenic Strain NVH391-98 of the Bacillus cereus Group Represents the Cluster of Thermophilic Strains

    Energy Technology Data Exchange (ETDEWEB)

    Auger, Sandrine; Galleron, Nathalie; Bidnenko, Elena; Ehrlich, S. Dusko; Lapidus, Alla; Sorokin, Alexei

    2007-10-02

    Bacteria of the Bacillus cereus group are known to cause food poisoning. A rare phylogenetically remote strain, NVH391-98, was recently characterized to encode a particularly efficient cytotoxin K presumably responsible for food poisoning. This pathogenic strain and its close relatives can be phenotypically distinguished from other strains of the B. cereus group by the inability to grow at temperatures below 17 degrees C and by the ability to grow at temperatures from 48 to 53 degrees C. A temperate phage, phBC391A2, residing in the genome of NVH391-98 allows us to distinguish the three known members of this thermophilic strain cluster.

  14. Homozygosity by descent mapping of blood pressure in the Old Order Amish: evidence for sex specific genetic architecture

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    McArdle Patrick F

    2007-10-01

    Full Text Available Abstract Background High blood pressure is a well established risk factor for morbidity and mortality acting through heart disease, stroke and cardiovascular disease. Genome wide scans have linked regions of nearly every human chromosome to blood pressure related traits. We have capitalized on beneficial qualities of the Old Order Amish of Lancaster, PA, a closed founder population with a relatively small number of founders, to perform a genome wide homozygosity by descent mapping scan. Each individual in the study has a non zero probability of consanguinity. Systolic and diastolic blood pressures are shown to have appreciable dominance variance components. Results Areas of two chromosomes were identified as suggestive of linkage to SBP and 5 areas to DBP in either the overall or sex specific analyses. The strongest evidence for linkage in the overall sample was to Chromosome 18q12 (LOD = 2.6 DBP. Sex specific analyses identified a linkage on Chromosome 4p12-14 (LOD in men only = 3.4 SBP. At Chromosome 2q32-33, an area where we previously reported significant evidence for linkage to DBP using a conventional identity by descent approach, the LOD was 1.4; however an appreciable sex effect was observed with men accounting for most of the linkage (LOD in men only = 2.6. Conclusion These results add evidence to a sex specific genetic architecture to blood pressure related traits, particularly in regions of linkage on chromosome 2, 4 and 18.

  15. Genetic diversity of b-glucuronidase activity among 14 strains of the dominant human gut anaerobe Ruminococcus gnavus

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    Diane Beaud

    2006-01-01

    Full Text Available Bacterial beta-glucuronidase activity in the gut increases the enterohepatic circulation of toxic compounds and plays a major role in the etiology of colon cancer. Previously, we had found that the gus gene, which codes for beta-glucuronidase in a dominant anaerobic species of the gut microbiota, Ruminococcus gnavus strain E1, is transcribed as part of an operon that includes three ORFs that code for beta-glucoside permeases of the phosphotransferase systems. This genetic organization had never been described. We have now compared beta-glucuronidase activity and the genetic environment of the gus gene in 14 strains of Ruminococcus gnavus.We found that five out of the seven glucuronidase-positive R. gnavus strains possessed another glucuronidase gene different from the gusA operon of R. gnavus E1. This dominant commensal intestinal species appears to have a high degree of genetic diversity in the genes that control beta-glucuronidase activity.

  16. Genetic diversity of Mycobacterium avium subspecies paratuberculosis and the influence of strain type on infection and pathogenesis: a review.

    Science.gov (United States)

    Stevenson, Karen

    2015-06-19

    Mycobacterium avium subspecies paratuberculosis (Map) is an important pathogen that causes a chronic, progressive granulomatous enteritis known as Johne's disease or paratuberculosis. The disease is endemic in many parts of the world and responsible for considerable losses to the livestock and associated industries. Diagnosis and control are problematic, due mostly to the long incubation period of the disease when infected animals show no clinical signs and are difficult to detect, and the ability of the organism to survive and persist in the environment. The existence of phenotypically distinct strains of Map has been known since the 1930s but the genetic differentiation of Map strain types has been challenging and only recent technologies have proven sufficiently discriminative for strain comparisons, tracing the sources of infection and epidemiological studies. It is important to understand the differences that exist between Map strains and how they influence both development and transmission of disease. This information is required to develop improved diagnostics and effective vaccines for controlling Johne's disease. Here I review the current classification of Map strain types, the sources of the genetic variability within strains, growth characteristics and epidemiological traits associated with strain type and the influence of strain type on infection and pathogenicity.

  17. A novel multiplex PCR discriminates Bacillus anthracis and its genetically related strains from other Bacillus cereus group species.

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    Hirohito Ogawa

    Full Text Available Anthrax is an important zoonotic disease worldwide that is caused by Bacillus anthracis, a spore-forming pathogenic bacterium. A rapid and sensitive method to detect B. anthracis is important for anthrax risk management and control in animal cases to address public health issues. However, it has recently become difficult to identify B. anthracis by using previously reported molecular-based methods because of the emergence of B. cereus, which causes severe extra-intestinal infection, as well as the human pathogenic B. thuringiensis, both of which are genetically related to B. anthracis. The close genetic relation of chromosomal backgrounds has led to complexity of molecular-based diagnosis. In this study, we established a B. anthracis multiplex PCR that can screen for the presence of B. anthracis virulent plasmids and differentiate B. anthracis and its genetically related strains from other B. cereus group species. Six sets of primers targeting a chromosome of B. anthracis and B. anthracis-like strains, two virulent plasmids, pXO1 and pXO2, a bacterial gene, 16S rRNA gene, and a mammalian gene, actin-beta gene, were designed. The multiplex PCR detected approximately 3.0 CFU of B. anthracis DNA per PCR reaction and was sensitive to B. anthracis. The internal control primers also detected all bacterial and mammalian DNAs examined, indicating the practical applicability of this assay as it enables monitoring of appropriate amplification. The assay was also applied for detection of clinical strains genetically related to B. anthracis, which were B. cereus strains isolated from outbreaks of hospital infections in Japan, and field strains isolated in Zambia, and the assay differentiated B. anthracis and its genetically related strains from other B. cereus group strains. Taken together, the results indicate that the newly developed multiplex PCR is a sensitive and practical method for detecting B. anthracis.

  18. A novel multiplex PCR discriminates Bacillus anthracis and its genetically related strains from other Bacillus cereus group species.

    Science.gov (United States)

    Ogawa, Hirohito; Fujikura, Daisuke; Ohnuma, Miyuki; Ohnishi, Naomi; Hang'ombe, Bernard M; Mimuro, Hitomi; Ezaki, Takayuki; Mweene, Aaron S; Higashi, Hideaki

    2015-01-01

    Anthrax is an important zoonotic disease worldwide that is caused by Bacillus anthracis, a spore-forming pathogenic bacterium. A rapid and sensitive method to detect B. anthracis is important for anthrax risk management and control in animal cases to address public health issues. However, it has recently become difficult to identify B. anthracis by using previously reported molecular-based methods because of the emergence of B. cereus, which causes severe extra-intestinal infection, as well as the human pathogenic B. thuringiensis, both of which are genetically related to B. anthracis. The close genetic relation of chromosomal backgrounds has led to complexity of molecular-based diagnosis. In this study, we established a B. anthracis multiplex PCR that can screen for the presence of B. anthracis virulent plasmids and differentiate B. anthracis and its genetically related strains from other B. cereus group species. Six sets of primers targeting a chromosome of B. anthracis and B. anthracis-like strains, two virulent plasmids, pXO1 and pXO2, a bacterial gene, 16S rRNA gene, and a mammalian gene, actin-beta gene, were designed. The multiplex PCR detected approximately 3.0 CFU of B. anthracis DNA per PCR reaction and was sensitive to B. anthracis. The internal control primers also detected all bacterial and mammalian DNAs examined, indicating the practical applicability of this assay as it enables monitoring of appropriate amplification. The assay was also applied for detection of clinical strains genetically related to B. anthracis, which were B. cereus strains isolated from outbreaks of hospital infections in Japan, and field strains isolated in Zambia, and the assay differentiated B. anthracis and its genetically related strains from other B. cereus group strains. Taken together, the results indicate that the newly developed multiplex PCR is a sensitive and practical method for detecting B. anthracis.

  19. Differences in sexual size dimorphism among farmed tilapia species and strains undergoing genetic improvement for body weight

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    C.E. Lind

    2015-05-01

    Full Text Available Many tilapia (Oreochromis spp. farmers produce all-male populations because of the superior growth rate of males compared to females. To investigate differences in body weight at harvest of males and females among different tilapia strains, we analyzed data from 62,787 individuals collected from pedigreed breeding programs of O. niloticus (GIFT from Malaysia, the Abbassa line from Egypt, and the Akosombo line from Ghana, O. shiranus (the Bunda College-Domasi selection line, O. aureus (a selection line under development in Abbassa, Egypt, and a selection line from Israel and a synthetic selection line of Red tilapia under development in Jitra, Malaysia, derived from stock from Malaysia, Taiwan and Thailand (O. sp.. Mixed models were separately fitted to the data from each selection line. There was a significant sex effect in all strains (P < 0.001. A significant (P < 0.001 sex by generation interaction was observed in all strains (scale effect, not reversal of rankings, except Red tilapia and O. shiranus. Least squares means showed a large range in the magnitude of body weight differences between sexes across the seven strains. The largest percentage difference between females and males was in O. aureus from Egypt (female body weight was 52.2% that of males at harvest, whereas the smallest difference was observed in the GIFT strain of O. niloticus (female body weight 84.7% that of males. Female to male body weight percentages for Red tilapia, O. shiranus, Egypt O. niloticus, Israeli O. aureus and Ghana O. niloticus were 81.3, 81.0, 69.1, 61.7 and 61.0, respectively. We discuss the results in relation to the potential productivity improvements due to superior growth rates of all-male culture compared to mixed-sex culture in tilapia populations differing in the female to male body weight ratio.

  20. Venezuelan equine encephalitis in Panama: fatal endemic disease and genetic diversity of etiologic viral strains.

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    Evelia Quiroz

    2009-06-01

    Full Text Available Venezuelan equine encephalitis (VEE is a reemerging, mosquito-borne viral disease of the neotropics that is severely debilitating and sometimes fatal to humans. Periodic epidemics mediated by equine amplification have been recognized since the 1920s, but interepidemic disease is rarely recognized. We report here clinical findings and genetic characterization of 42 cases of endemic VEE detected in Panama from 1961-2004. Recent clusters of cases occurred in Darien (eastern Panama and Panama provinces (central Panama near rainforest and swamp habitats. Patients ranged from 10 months to 48 years of age, and the more severe cases with neurological complications, including one fatal infection, were observed in children. The VEE virus strains isolated from these cases all belonged to an enzootic, subtype ID lineage known to circulate among sylvatic vectors and rodent reservoir hosts in Panama and Peru. These findings underscore endemic VEE as an important but usually neglected arboviral disease of Latin America.

  1. Venezuelan equine encephalitis in Panama: fatal endemic disease and genetic diversity of etiologic viral strains.

    Science.gov (United States)

    Quiroz, Evelia; Aguilar, Patricia V; Cisneros, Julio; Tesh, Robert B; Weaver, Scott C

    2009-06-30

    Venezuelan equine encephalitis (VEE) is a reemerging, mosquito-borne viral disease of the neotropics that is severely debilitating and sometimes fatal to humans. Periodic epidemics mediated by equine amplification have been recognized since the 1920s, but interepidemic disease is rarely recognized. We report here clinical findings and genetic characterization of 42 cases of endemic VEE detected in Panama from 1961-2004. Recent clusters of cases occurred in Darien (eastern Panama) and Panama provinces (central Panama) near rainforest and swamp habitats. Patients ranged from 10 months to 48 years of age, and the more severe cases with neurological complications, including one fatal infection, were observed in children. The VEE virus strains isolated from these cases all belonged to an enzootic, subtype ID lineage known to circulate among sylvatic vectors and rodent reservoir hosts in Panama and Peru. These findings underscore endemic VEE as an important but usually neglected arboviral disease of Latin America.

  2. MECHANISMS OF RESISTANCE TO CIPROFLOXACIN AND GENETIC DIVERSITY OF ESCHERICHIA COLI STRAINS ORIGINATING FROM URINE CULTURES PERFORMED FOR ROMANIAN ADULTS.

    Science.gov (United States)

    Cristea, Violeta Corina; Oprea, Mihaela; Neacşu, Gabriela; Gîlcă, Ramona; Popa, Mircea Ioan; Usein, Codruţa-Romaniţa

    2015-01-01

    Urinary tract infections (UTI) with Escherichia coli are among the most common infections presenting in general practice. Fluoroquinolones (FQs) are relied on for their empirical therapy but recent reports indicate a concerning increase in the percentage of FQ-resistant E. coli isolates in many countries, including Romania. Sixty E. coli strains with ciprofloxacin resistance and cephalosporin susceptibility isolated from urine specimens of non-hospitalized patients during a five-month period (October 2014 - February 2015) were further analyzed to determine the molecular basis of FQ resistance (i.e. mutations in chromosomal gyrA, gyrB, parC genes and presence of plasmid-borne qnrA, qnrB, qnrS, and aac(6'-Ib-cr genes), the phylogenetic background (i.e. phylogenetic groups A, B1, B2, C, D, E, F or clade I), O25b/ST131 status, and genetic relatedness inferred from the XbaI pulsed-field gel electrophoresis (PFGE) profiles as a measure of isolate-specific genetic composition. The PCR-based phylotyping showed that most strains were assigned to non-B2 phylogenetic groups (i.e. group A/21 strains, group B1/14 strains, group B2/10 strains, group C/8 strains, group D/3 strains, group F/4 strains). Already described chromosomal mutations associated to FQ resistance were found, the strains being double gyrA mutants (i.e. Ser83Leu, Asp87Asn) with one or two parC mutations (e.g. Ala56Thr, Ser80Ile, Glu84Gly). Seven percent of the strains harboured plasmid-borne genes qnrS1 (2 strains) and aac(6'-Ib-cr (2 strains). Based on the PCR results, 15% of the strains were members of the O25b/ST131 clone and possessed the gyrA/parC allele combination which is considered as hallmark of H30 subclone. PFGE genotyping revealed a genetically diverse population of FQ-resistant E. coli. ST131 strains displayed more homogeneous PFGE profiles than non-ST131. The ST131 cluster extended to 77.74% similarity versus 60% overall. These findings underscore the need for ongoing surveillance to capture the

  3. Sex-linked dominant

    Science.gov (United States)

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  4. Multilocus Microsatellite Typing reveals intra-focal genetic diversity among strains of Leishmania tropica in Chichaoua Province, Morocco.

    Science.gov (United States)

    Krayter, Lena; Alam, Mohammad Zahangir; Rhajaoui, Mohamed; Schnur, Lionel F; Schönian, Gabriele

    2014-12-01

    In Morocco, cutaneous leishmaniasis (CL) caused by Leishmania (L.) tropica is a major public health threat. Strains of this species have been shown to display considerable serological, biochemical, molecular biological and genetic heterogeneity; and Multilocus Enzyme Electrophoresis (MLEE), has shown that in many countries including Morocco heterogenic variants of L. tropica can co-exist in single geographical foci. Here, the microsatellite profiles discerned by MLMT of nine Moroccan strains of L. tropica isolated in 2000 from human cases of CL from Chichaoua Province were compared to those of nine Moroccan strains of L. tropica isolated between 1988 and 1990 from human cases of CL from Marrakech Province, and also to those of 147 strains of L. tropica isolated at different times from different worldwide geographical locations within the range of distribution of the species. Several programs, each employing a different algorithm, were used for population genetic analysis. The strains from each of the two Moroccan foci separated into two phylogenetic clusters independent of their geographical origin. Genetic diversity and heterogeneity existed in both foci, which are geographically close to each other. This intra-focal distribution of genetic variants of L. tropica is not considered owing to in situ mutation. Rather, it is proposed to be explained by the importation of pre-existing variants of L. tropica into Morocco.

  5. Influence of heat stress, sex and genetic groups on reference genes stability in muscle tissue of chicken.

    Science.gov (United States)

    Cedraz de Oliveira, Haniel; Pinto Garcia, Antonio Amandio; Gonzaga Gromboni, Juliana Gracielle; Vasconcelos Farias Filho, Ronaldo; Souza do Nascimento, Carlos; Arias Wenceslau, Amauri

    2017-01-01

    Quantitative RT-PCR is an important technique for assessing gene expression. However, a proper normalization of reference genes prior to expression analyses of target genes is necessary. The best normalizer is that gene which remains stable in all samples from different treatments. The aim of this study was to identify stable reference genes for normalization of target genes in muscle tissue from three genetically divergent chickens groups (Peloco, Cobb 500® and Caneluda) under environmental (heat stress and comfort) and sex influence. Expressions of ten reference genes were tested for stability in breast muscular tissue (Pectoralis major muscle). Samples were obtained from 36 males and females of two backyard breeds (Caneluda and Peloco) and one commercial line (Cobb 500®) under two environments. The heat stress and comfort temperature were 39 and 23°C, respectively. Animals were housed in the Animal Science Department at Universidade Estadual do Sudoeste da Bahia. We analyzed the expression data by four statistical tools (SLqPCR, NormFinder, Bestkeeper and Comparative CT). According to these tools, genes stability varied according to sex, genetic group and environment, however, some genes remained stable in all analyzes. There was no difference between the most stable genes for sex effect, being MRPS27 more stable for both males and females. In general, MRPS27 was the most stable gene. Within the three genetic groups, the most stable genes were RPL5, HMBS and EEF1 to Cobb 500®, Peloco and Caneluda, respectively. Within the environment, the most stable gene under comfort and heat stress conditions was HMBS and MRPS27, respectively. BestKeeper and Comparative Ct were less correlated (28%) and SLqPCR and NormFinder were the most correlated (98%). MRPS27, RPL5 and MRPS30 genes were considered stable according the overall ranking and can be used as normalizer of relative expression of target genes in muscle tissue of chickens under heat stress.

  6. A genetic polymorphism in the sex-linked ATP5A1 gene is associated with individual fitness in Ovenbirds (Seiurus aurocapilla)

    Science.gov (United States)

    Judith D. Toms; Lori S. Eggert; Wayne J. Arendt; John. Faaborg

    2012-01-01

    While testing genetic sexing techniques in Ovenbirds (Seiurus aurocapilla),we found a genetic polymorphism in the ATP5A1 gene in 38% of individuals. The Z ' allele included changes in both intronic and exonic portions of the sequenced region, but there was no evidence that this changed the resulting ATP synthase product. Males that had one or more copies of...

  7. Enhanced ethanol fermentation of brewery wastewater using the genetically modified strain E. coli KO11.

    Science.gov (United States)

    Rao, Kripa; Chaudhari, Vaibhav; Varanasi, Sasidhar; Kim, Dong-Shik

    2007-02-01

    We have used liquid waste obtained from a beer brewery process to produce ethanol. To increase the productivity, genetically modified organism, Escherichia coli KO11, was used for ethanol fermentation. Yeast was also used to produce ethanol from the same feed stock, and the ethanol production rates and resulting concentrations of sugars and ethanol were compared with those of KO11. In the experiments, first the raw wastewater was directly fermented using two strains with no saccharification enzymes added. Then, commercial enzymes, alpha-amylase, pectinase, or a combination of both, were used for simultaneous saccharification and fermentation, and the results were compared with those of the no-enzyme experiments for KO11 and yeast. Under the given conditions with or without the enzymes, yeast produced ethanol more rapidly than E. coli KO11, but the final ethanol concentrations were almost the same. For both yeast and KO11, the enzymes were observed to enhance the ethanol yields by 61-84% as compared to the fermentation without enzymes. The combination of the two enzymes increased ethanol production the most for the both strains. The advantages of using KO11 were not demonstrated clearly as compared to the yeast fermentation results.

  8. A Pseudomonas putida strain genetically engineered for 1,2,3-trichloropropane bioremediation.

    Science.gov (United States)

    Samin, Ghufrana; Pavlova, Martina; Arif, M Irfan; Postema, Christiaan P; Damborsky, Jiri; Janssen, Dick B

    2014-09-01

    1,2,3-Trichloropropane (TCP) is a toxic compound that is recalcitrant to biodegradation in the environment. Attempts to isolate TCP-degrading organisms using enrichment cultivation have failed. A potential biodegradation pathway starts with hydrolytic dehalogenation to 2,3-dichloro-1-propanol (DCP), followed by oxidative metabolism. To obtain a practically applicable TCP-degrading organism, we introduced an engineered haloalkane dehalogenase with improved TCP degradation activity into the DCP-degrading bacterium Pseudomonas putida MC4. For this purpose, the dehalogenase gene (dhaA31) was cloned behind the constitutive dhlA promoter and was introduced into the genome of strain MC4 using a transposon delivery system. The transposon-located antibiotic resistance marker was subsequently removed using a resolvase step. Growth of the resulting engineered bacterium, P. putida MC4-5222, on TCP was indeed observed, and all organic chlorine was released as chloride. A packed-bed reactor with immobilized cells of strain MC4-5222 degraded >95% of influent TCP (0.33 mM) under continuous-flow conditions, with stoichiometric release of inorganic chloride. The results demonstrate the successful use of a laboratory-evolved dehalogenase and genetic engineering to produce an effective, plasmid-free, and stable whole-cell biocatalyst for the aerobic bioremediation of a recalcitrant chlorinated hydrocarbon. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  9. A novel anesthesia regime enables neurofunctional studies and imaging genetics across mouse strains.

    Science.gov (United States)

    Petrinovic, Marija M; Hankov, Georges; Schroeter, Aileen; Bruns, Andreas; Rudin, Markus; von Kienlin, Markus; Künnecke, Basil; Mueggler, Thomas

    2016-04-15

    Functional magnetic resonance imaging (fMRI) has revolutionized neuroscience by opening a unique window that allows neurocircuitry function and pathological alterations to be probed non-invasively across brain disorders. Here we report a novel sustainable anesthesia procedure for small animal neuroimaging that overcomes shortcomings of anesthetics commonly used in rodent fMRI. The significantly improved preservation of cerebrovascular dynamics enhances sensitivity to neural activity changes for which it serves as a proxy in fMRI readouts. Excellent cross-species/strain applicability provides coherence among preclinical findings and is expected to improve translation to clinical fMRI investigations. The novel anesthesia procedure based on the GABAergic anesthetic etomidate was extensively validated in fMRI studies conducted in a range of genetically engineered rodent models of autism and strains commonly used for transgenic manipulations. Etomidate proved effective, yielded long-term stable physiology with basal cerebral blood flow of ~0.5 ml/g/min and full recovery. Cerebrovascular responsiveness of up to 180% was maintained as demonstrated with perfusion- and BOLD-based fMRI upon hypercapnic, pharmacological and sensory stimulation. Hence, etomidate lends itself as an anesthetic-of-choice for translational neuroimaging studies across rodent models of brain disorders.

  10. Genetics of Bone Mineralization and Morphology in Inbred Mice: Analysis of the HcB/Dem Recombinant Congenic Strains

    Science.gov (United States)

    2005-04-01

    data for parameters with skewed distil- 3- PONT BEND MODULUS butions. Results of this analysis are summarized in Table 2. Ir TT . We used these data to...the pathogenesis of osteoporosis. I Bone Miner Res 9:739- [be murine strength is achieved. 743. 1002 YERSHOV ET AL. 16. Demant P, Hart AA 1986...Recombinant congenic strains--a 37. Linder E, Schork N 1994 Genetic dissection of complex traits. new tool for analyzing genetic traits determined by more than

  11. Genetic diversity and symbiotic compatibility among rhizobial strains and Desmodium incanum and Lotus spp. plants.

    Science.gov (United States)

    Granada, Camille E; Strochein, Marcos; Vargas, Luciano K; Bruxel, Manuela; de Sá, Enilson Luiz Saccol; Passaglia, Luciane M P

    2014-06-01

    This work aimed to evaluate the symbiotic compatibility and nodulation efficiency of rhizobia isolated from Desmodium incanum, Lotus corniculatus, L. subbiflorus, L. uliginosus and L. glaber plants by cross-inoculation. Twelve reference strains and 21 native isolates of rhizobia were genetically analyzed by the BOX-PCR technique, which showed a high genetic diversity among the rhizobia studied. The isolates were also characterized based on their production of indolic compounds and siderophores, as well as on their tolerance to salinity. Fifteen of the 33 rhizobia analyzed were able to produce indolic compounds, whereas 13 produced siderophores. All the tested rhizobia were sensitive to high salinity, although some were able to grow in solutions of up to 2% NaCl. Most of the native rhizobia isolated from L. uliginosus were able to induce nodulation in all plant species studied. In a greenhouse experiment using both D. incanum and L. corniculatus plants, the rhizobia isolate UFRGS Lu2 promoted the greatest plant growth. The results demonstrate that there are native rhizobia in the soils of southern Brazil that have low host specificity and are able to induce nodulation and form active nodules in several plant species.

  12. Genetic diversity and symbiotic compatibility among rhizobial strains and Desmodium incanum and Lotus spp. plants

    Directory of Open Access Journals (Sweden)

    Camille E Granada

    2014-06-01

    Full Text Available This work aimed to evaluate the symbiotic compatibility and nodulation efficiency of rhizobia isolated from Desmodium incanum, Lotus corniculatus, L. subbiflorus, L. uliginosus and L. glaber plants by cross-inoculation. Twelve reference strains and 21 native isolates of rhizobia were genetically analyzed by the BOX-PCR technique, which showed a high genetic diversity among the rhizobia studied. The isolates were also characterized based on their production of indolic compounds and siderophores, as well as on their tolerance to salinity. Fifteen of the 33 rhizobia analyzed were able to produce indolic compounds, whereas 13 produced siderophores. All the tested rhizobia were sensitive to high salinity, although some were able to grow in solutions of up to 2% NaCl. Most of the native rhizobia isolated from L. uliginosus were able to induce nodulation in all plant species studied. In a greenhouse experiment using both D. incanum and L. corniculatus plants, the rhizobia isolate UFRGS Lu2 promoted the greatest plant growth. The results demonstrate that there are native rhizobia in the soils of southern Brazil that have low host specificity and are able to induce nodulation and form active nodules in several plant species.

  13. Staphylococcus aureus infective endocarditis versus bacteremia strains: Subtle genetic differences at stake.

    Science.gov (United States)

    Bouchiat, Coralie; Moreau, Karen; Devillard, Sébastien; Rasigade, Jean-Philippe; Mosnier, Amandine; Geissmann, Tom; Bes, Michèle; Tristan, Anne; Lina, Gérard; Laurent, Frédéric; Piroth, Lionel; Aissa, Nejla; Duval, Xavier; Le Moing, Vincent; Vandenesch, François

    2015-12-01

    Infective endocarditis (IE)((1)) is a severe condition complicating 10-25% of Staphylococcus aureus bacteremia. Although host-related IE risk factors have been identified, the involvement of bacterial features in IE complication is still unclear. We characterized strictly defined IE and bacteremia isolates and searched for discriminant features. S. aureus isolates causing community-acquired, definite native-valve IE (n=72) and bacteremia (n=54) were collected prospectively as part of a French multicenter cohort. Phenotypic traits previously reported or hypothesized to be involved in staphylococcal IE pathogenesis were tested. In parallel, the genotypic profiles of all isolates, obtained by microarray, were analyzed by discriminant analysis of principal components (DAPC)((2)). No significant difference was observed between IE and bacteremia strains, regarding either phenotypic or genotypic univariate analyses. However, the multivariate statistical tool DAPC, applied on microarray data, segregated IE and bacteremia isolates: IE isolates were correctly reassigned as such in 80.6% of the cases (C-statistic 0.83, P<0.001). The performance of this model was confirmed with an independent French collection IE and bacteremia isolates (78.8% reassignment, C-statistic 0.65, P<0.01). Finally, a simple linear discriminant function based on a subset of 8 genetic markers retained valuable performance both in study collection (86.1%, P<0.001) and in the independent validation collection (81.8%, P<0.01). We here show that community-acquired IE and bacteremia S. aureus isolates are genetically distinct based on subtle combinations of genetic markers. This finding provides the proof of concept that bacterial characteristics may contribute to the occurrence of IE in patients with S. aureus bacteremia.

  14. Genetic Analysis of the VP1 Region of Human Enterovirus 71 Strains Isolated in Fuyang, China, During 2008

    Institute of Scientific and Technical Information of China (English)

    Shao-hui MA; Jian-sheng LIU; Jing-jing WANG; Hai-jing SHI; Hui-juan YANG; Jun-ying CHEN; Long-ding LIU; Qi-han LI

    2009-01-01

    Enterovirus 71 (EV71) is a common cause of Hand, foot, and mouth disease (HFMD) and may also cause severe neurological diseases, such as encephalitis and poliomyelitis-like paralysis. To examine the genetic diversity of EV71, we determined and analyzed the complete VP1 sequences (891 nucleotides) from nine EV71 strains isolated in Fuyang, China. We found that nine EV71 strains isolated were over 98% homologous at the nucleotide level and 93%-100% homologous to members of the C4 subgenogroup. At the amino acid level, these Fuyang strains were 99% -100% homologous to one another, 97%-100% homologous to members of the C4 subgenogroup, and the histidine(H) at amino acid position 22 was conserved among the Fuyang strains. The results indicate that Fuyang isolates belong to genotype C4, and an H at position 22 appears to be a marker for the Fuyang strains.

  15. Genetic labelling and application of the isoproturon-mineralizing Sphingomonas sp. strain SRS2 in soil and rhizosphere

    DEFF Research Database (Denmark)

    Kristensen, K.E.; Jacobsen, C.S.; Hansen, L.H.

    2006-01-01

    AIMS: To construct a luxAB-labelled Sphingomonas sp. strain SRS2 maintaining the ability to mineralize the herbicide isoproturon and usable for monitoring the survival and distribution of strain SRS2 on plant roots in laboratory systems. METHODS AND RESULTS: We inserted the mini-Tn5-luxAB marker...... into strain SRS2 using conjugational mating. In the transconjugant mutants luciferase was produced in varying levels. The mutants showed significant differences in their ability to degrade isoproturon. One luxAB-labelled mutant maintained the ability to mineralize isoproturon and was therefore selected...... for monitoring colonization of barley roots. CONCLUSIONS: We successfully constructed a genetically labelled isoproturon-mineralizing-strain SRS2 and demonstrated its ability to survive in soil and its colonization of rhizosphere. SIGNIFICANCE AND IMPACT OF THE STUDY: The construction of a luxAB-labelled strain...

  16. Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster

    OpenAIRE

    Robert M. Griffin; Holger Schielzeth; Urban Friberg

    2016-01-01

    Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i) typically show relatively less standing genetic variation than the autosomes, (ii) exhibit more variation in males compared to females because of dosage compensation, and (iii) potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila me...

  17. The value of genetic information for diabetes risk prediction - differences according to sex, age, family history and obesity.

    Directory of Open Access Journals (Sweden)

    Kristin Mühlenbruch

    Full Text Available BACKGROUND: Genome-wide association studies have identified numerous single nucleotide polymorphisms associated with type 2 diabetes through the past years. In previous studies, the usefulness of these genetic markers for prediction of diabetes was found to be limited. However, differences may exist between substrata of the population according to the presence of major diabetes risk factors. This study aimed to investigate the added predictive value of genetic information (42 single nucleotide polymorphisms in subgroups of sex, age, family history of diabetes, and obesity. METHODS: A case-cohort study (random subcohort N = 1,968; incident cases: N = 578 within the European Prospective Investigation into Cancer and Nutrition Potsdam study was used. Prediction models without and with genetic information were evaluated in terms of the area under the receiver operating characteristic curve and the integrated discrimination improvement. Stratified analyses included subgroups of sex, age (<50 or ≥50 years, family history (positive if either father or mother or a sibling has/had diabetes, and obesity (BMI< or ≥30 kg/m(2. RESULTS: A genetic risk score did not improve prediction above classic and metabolic markers, but - compared to a non-invasive prediction model - genetic information slightly improved the area under the receiver operating characteristic curve (difference [95%-CI]: 0.007 [0.002-0.011]. Stratified analyses showed stronger improvement in the older age group (0.010 [0.002-0.018], the group with a positive family history (0.012 [0.000-0.023] and among obese participants (0.015 [-0.005-0.034] compared to the younger participants (0.005 [-0.004-0.014], participants with a negative family history (0.003 [-0.001-0.008] and non-obese (0.007 [0.000-0.014], respectively. No difference was found between men and women. CONCLUSION: There was no incremental value of genetic information compared to standard non-invasive and metabolic

  18. Comparative Genomics Revealed Genetic Diversity and Species/Strain-Level Differences in Carbohydrate Metabolism of Three Probiotic Bifidobacterial Species

    Directory of Open Access Journals (Sweden)

    Toshitaka Odamaki

    2015-01-01

    Full Text Available Strains of Bifidobacterium longum, Bifidobacterium breve, and Bifidobacterium animalis are widely used as probiotics in the food industry. Although numerous studies have revealed the properties and functionality of these strains, it is uncertain whether these characteristics are species common or strain specific. To address this issue, we performed a comparative genomic analysis of 49 strains belonging to these three bifidobacterial species to describe their genetic diversity and to evaluate species-level differences. There were 166 common clusters between strains of B. breve and B. longum, whereas there were nine common clusters between strains of B. animalis and B. longum and four common clusters between strains of B. animalis and B. breve. Further analysis focused on carbohydrate metabolism revealed the existence of certain strain-dependent genes, such as those encoding enzymes for host glycan utilisation or certain membrane transporters, and many genes commonly distributed at the species level, as was previously reported in studies with limited strains. As B. longum and B. breve are human-residential bifidobacteria (HRB, whereas B. animalis is a non-HRB species, several of the differences in these species’ gene distributions might be the result of their adaptations to the nutrient environment. This information may aid both in selecting probiotic candidates and in understanding their potential function as probiotics.

  19. Sex determination

    OpenAIRE

    McCullagh, W. McK. H.

    2013-01-01

    How the sex of offspring is determined has puzzled philosophers and scientists for millennia. Modern science has identified both genetic and environmental factors, but the question is still not yet fully answered.

  20. Sex and the single squirrel: a genetic view of forest management in the Pacific Northwest.

    Science.gov (United States)

    Sally. Duncan

    2003-01-01

    Forest management throughout the world is producing simplified forests. There is growing concern that these forests maintain neither complete vertebrate communities nor conditions favorable to maintenance of genetic diversity of those vertebrate populations that do find habitat in simply structured stands. Genetics is increasingly being used as a basis for management...

  1. Age of dam and sex of calf adjustments and genetic parameters for gestation length in Charolais cattle.

    Science.gov (United States)

    Crews, D H

    2006-01-01

    To estimate adjustment factors and genetic parameters for gestation length (GES), AI and calving date records (n = 40,356) were extracted from the Canadian Charolais Association field database. The average time from AI to calving date was 285.2 d (SD = 4.49 d) and ranged from 274 to 296 d. Fixed effects were sex of calf, age of dam (2, 3, 4, 5 to 10, > or = 11 yr), and gestation contemporary group (year of birth x herd of origin). Variance components were estimated using REML and 4 animal models (n = 84,332) containing from 0 to 3 random maternal effects. Model 1 (M1) contained only direct genetic effects. Model 2 (M2) was G1 plus maternal genetic effects with the direct x maternal genetic covariance constrained to zero, and model 3 (M3) was G2 without the covariance constraint. Model 4 (M4) extended G3 to include a random maternal permanent environmental effect. Direct heritability estimates were high and similar among all models (0.61 to 0.64), and maternal heritability estimates were low, ranging from 0.01 (M2) to 0.09 (M3). Likelihood ratio tests and parameter estimates suggested that M4 was the most appropriate (P or = 11-yr-old cows, respectively. Bivariate animal models were used to estimate genetic parameters for GES with birth and adjusted 205-d weaning weights, and postweaning gain. Direct GES was positively correlated with direct birth weight (BWT; 0.34 +/- 0.04) but negatively correlated with maternal BWT (-0.20 +/- 0.07). Maternal GES had a low, negative genetic correlation with direct BWT (-0.15 +/- 0.05) but a high and positive genetic correlation with maternal BWT (0.62 +/- 0.07). Generally, GES had near-zero genetic correlations with direct and maternal weaning weights. Results suggest that important genetic associations exist for GES with BWT, but genetic correlations with weaning weight and postweaning gain were less important.

  2. Multilocus analysis reveals large genetic diversity in Kluyveromyces marxianus strains isolated from Parmigiano Reggiano and Pecorino di Farindola cheeses.

    Science.gov (United States)

    Fasoli, Giuseppe; Barrio, Eladio; Tofalo, Rosanna; Suzzi, Giovanna; Belloch, Carmela

    2016-09-16

    In the present study, we have analysed the genetic diversity in Kluyveromyces marxianus isolated from Parmigiano Reggiano and Pecorino di Farindola cheesemaking environment. Molecular typing methods inter-RTL fingerprint and mtDNA RFLPs, as well as, sequence diversity and heterozygosity in the intergenic region between KmSSB1 and KmRIO2 genes and analysis of the mating locus were applied to 54 K. marxianus strains. Inter-RTL fingerprint revealed a large degree of genetic heterogeneity and clustering allowed differentiation of K. marxianus strains from different geographical origins. In general, inter-LTR profiles were more discriminating than RFLPs of mtDNA; however our results also indicate that both techniques could be complementary unveiling different degrees of genetic diversity. Sequence analysis of the intergenic region between KmSSB1 and KmRIO2 genes revealed 26 variable positions in which a double peak could be observed in the sequence chromatogram. Further analysis revealed the presence of heterozygous strains in the K. marxianus population isolated from Parmigiano Reggiano. On the other hand, all strains isolated from Pecorino di Farindola were homozygous. Two very different groups of haplotypes could be observed as well as mixtures between them. Phylogenetic reconstruction divided K. marxianus dairy strains into two separate populations. A few heterozygous strains in an intermediate position between them could also be observed. Mating type locus analysis revealed a large population of diploid strains containing both MATa and MATα alleles and few haploid strains, most of them presenting the MATα allele. Different scenarios explaining the presence and maintaining of homozygous and heterozygous diploids as well as hybrids between them in the Parmigiano Reggiano K. marxianus population are proposed. A principal component analysis supported the large differences between K. marxianus isolated from Parmigiano Reggiano and Pecorino di Farindola.

  3. Why Sex?

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2006-01-01

    It is assumed that most organisms have sex because the resulting genetic recombination allows Darwinian selection to work better. It is now shown that in water fleas, recombination does lead to fewer deleterious mutations.......It is assumed that most organisms have sex because the resulting genetic recombination allows Darwinian selection to work better. It is now shown that in water fleas, recombination does lead to fewer deleterious mutations....

  4. Suitability of PER.C6 cells to generate epidemic and pandemic influenza vaccine strains by reverse genetics

    NARCIS (Netherlands)

    Koudstaal, W.; Hartgroves, L.; Havenga, M.; Legastelois, I.; Ophorst, C.; Siewerts, M.; Zuijdgeest, D.; Vogels, R.; Custers, J.; Boer-Luijtze, E. de; Leeuw, O. de; Cornelissen, L.; Goudsmit, J.; Barclay, W.

    2009-01-01

    Reverse genetics, the generation of influenza viruses from cDNA, presents a rapid method for creating vaccine strains. The technique necessitates the use of cultured cells. Due to technical and regulatory requirements, the choice of cell lines for production of human influenza vaccines is limited. P

  5. Suitability of PER.C6 cells to generate epidemic and pandemic influenza vaccine strains by reverse genetics

    NARCIS (Netherlands)

    Koudstaal, W.; Hartgroves, L.; Havenga, M.; Legastelois, I.; Ophorst, C.; Siewerts, M.; Zuijdgeest, D.; Vogels, R.; Custers, J.; Boer-Luijtze, E. de; Leeuw, O. de; Cornelissen, L.; Goudsmit, J.; Barclay, W.

    2009-01-01

    Reverse genetics, the generation of influenza viruses from cDNA, presents a rapid method for creating vaccine strains. The technique necessitates the use of cultured cells. Due to technical and regulatory requirements, the choice of cell lines for production of human influenza vaccines is limited. P

  6. In vitro biofilm formation of commensal and pathogenic Escherichia coli strains: impact of environmental and genetic factors

    DEFF Research Database (Denmark)

    Reisner, A.; Krogfelt, Karen; Klein, B.M.

    2006-01-01

    Our understanding of Escherichia coli biofilm formation in vitro is based on studies of laboratory K-12 strains grown in standard media. However, pathogenic E. coli isolates differ substantially in their genetic repertoire from E. coli K-12 and are subject to heterogeneous environmental condition...

  7. Conflict and cooperation over sex: the consequences of social and genetic polyandry for reproductive success in dunnocks.

    Science.gov (United States)

    Santos, Eduardo S A; Santos, Luana L S; Lagisz, Malgorzata; Nakagawa, Shinichi

    2015-11-01

    Conflict and cooperation within and between the sexes are among the driving forces that lead to the evolution of mating systems. Among mating strategies, female genetic polyandry and male reproductive cooperation pose challenging evolutionary questions regarding the maintenance of systems where one sex suffers from reduced fitness. Here, we investigate the consequences of social and genetic polyandry for reproductive success of females and males in a population of the dunnock, Prunella modularis. We show that female multiple mating ameliorates the negative effects of inbreeding. We, however, found little evidence that females engage in extra-group (pair) mating with less related or more heterozygous males. Breeding in socially polyandrous groups reduced the amount of paternity lost to extra-group males, such that, on average, cobreeding and monogamous males fledged a similar number of young. Importantly, c. 30% of cobreeding male dyads were related, suggesting they could gain indirect fitness benefits. Taken together, cobreeding males achieve equivalent reproductive success to monogamous counterparts under most circumstances. Our study has revealed unexpected complexities in the variable mating system of dunnocks in New Zealand. Our results differ from the well-known Cambridge dunnock study and can help our understanding of the evolution and maintenance of various breeding systems in the animal kingdom.

  8. Genetic diversity of Venezuelan alphaviruses and circulation of a Venezuelan equine encephalitis virus subtype IAB strain during an interepizootic period.

    Science.gov (United States)

    Medina, Gladys; Garzaro, Domingo J; Barrios, Miguel; Auguste, Albert J; Weaver, Scott C; Pujol, Flor H

    2015-07-01

    Several species of alphaviruses have been previously described in the Americas, some of which are associated with encephalitis and others are associated with arthralgia. Venezuelan equine encephalitis virus (VEEV) and eastern equine encephalitis virus (EEEV) are endemic to Venezuela, with the former being responsible for major outbreaks of severe and often fatal disease in animals and humans. The aim of this study was to analyze the genetic diversity of Venezuelan alphaviruses isolated during two decades (1973-1999) of surveillance in northern Venezuela. Phylogenetic analysis indicated the circulation of a VEEV subtype IAB strain 8 years after the last reported outbreak. Thirteen strains within two subclades of South American lineage III of EEEV were also found in Venezuela. Considerable genetic variability was observed among Venezuelan Una virus strains, which were widely distributed among the clades. The first Venezuelan Mayaro sequence was also characterized.

  9. Genetic Diversity of Venezuelan Alphaviruses and Circulation of a Venezuelan Equine Encephalitis Virus Subtype IAB Strain During an Interepizootic Period

    Science.gov (United States)

    Medina, Gladys; Garzaro, Domingo J.; Barrios, Miguel; Auguste, Albert J.; Weaver, Scott C.; Pujol, Flor H.

    2015-01-01

    Several species of alphaviruses have been previously described in the Americas, some of which are associated with encephalitis and others are associated with arthralgia. Venezuelan equine encephalitis virus (VEEV) and eastern equine encephalitis virus (EEEV) are endemic to Venezuela, with the former being responsible for major outbreaks of severe and often fatal disease in animals and humans. The aim of this study was to analyze the genetic diversity of Venezuelan alphaviruses isolated during two decades (1973–1999) of surveillance in northern Venezuela. Phylogenetic analysis indicated the circulation of a VEEV subtype IAB strain 8 years after the last reported outbreak. Thirteen strains within two subclades of South American lineage III of EEEV were also found in Venezuela. Considerable genetic variability was observed among Venezuelan Una virus strains, which were widely distributed among the clades. The first Venezuelan Mayaro sequence was also characterized. PMID:25940191

  10. Transition from Environmental to Partial Genetic Sex Determination in Daphnia through the Evolution of a Female-Determining Incipient W Chromosome.

    Science.gov (United States)

    Reisser, Céline M O; Fasel, Dominique; Hürlimann, Evelin; Dukič, Marinela; Haag-Liautard, Cathy; Thuillier, Virginie; Galimov, Yan; Haag, Christoph R

    2016-12-21

    Sex chromosomes can evolve during the evolution of genetic sex determination (GSD) from environmental sex determination (ESD). Despite theoretical attention, early mechanisms involved in the transition from ESD to GSD have yet to be studied in nature. No mixed ESD-GSD animal species have been reported, except for some species of Daphnia, small freshwater crustaceans in which sex is usually determined solely by the environment, but in which a dominant female sex-determining locus is present in some populations. This locus follows Mendelian single-locus inheritance, but has otherwise not been characterized genetically. We now show that the sex-determining genomic region maps to the same low-recombining peri-centromeric region of linkage group 3 (LG3) in three highly divergent populations of D. magna, and spans 3.6 Mb. Despite low levels of recombination, the associated region contains signs of historical recombination, suggesting a role for selection acting on several genes thereby maintaining linkage disequilibrium among the 36 associated SNPs. The region carries numerous genes involved in sex differentiation in other taxa, including transformer2 and sox9 Taken together, the region determining the genetic females shows characteristics of a sex-related supergene, suggesting that LG3 is potentially an incipient W chromosome despite the lack of significant additional restriction of recombination between Z and W. The occurrence of the female-determining locus in a pre-existing low recombining region illustrates one possible form of recombination suppression in sex chromosomes. D. magna is a promising model for studying the evolutionary transitions from ESD to GSD and early sex chromosome evolution.

  11. Genetic traits of Vibrio cholerae O1 Haitian isolates that are absent in contemporary strains from Kolkata, India.

    Science.gov (United States)

    Ghosh, Priyanka; Naha, Arindam; Pazhani, G P; Ramamurthy, T; Mukhopadhyay, Asish K

    2014-01-01

    The world's worst cholera epidemic in Haiti (2010) coerced to trace the origin and dissemination of the causative agent Vibrio cholerae O1 for proper management of cholera. Sequence analysis of the Haitian strain showed several variations in the genes encoding cholera toxin B subunit (ctxB); toxin-co-regulated pilus (tcpA), repeat in toxins (rtxA), quinolone resistance-determining region (QRDR) of gyrase A (gyrA), rstB of RS element along with the change in the number of repeat sequences at the promoter region of ctxAB. Our earlier studies showed that variant tcpA (tcpA CIRS) and ctxB (ctxB7) first appeared in Kolkata during 2003 and 2006, respectively. The present study revealed that a variant rtxA was first isolated in Kolkata during 2004 and probably formed the genetic background for the emergence of the ctxB7 allele as we were unable to detect a single strain with the combination of El Tor rtxA and ctxB7. The variant gyrA was first time detected in Kolkata during 1994. The Kolkata strains contained four heptad repeats (TTTTGAT) in their CT promoter regions whereas Haitian strains carried 5 heptad repeats. Haitian strains had 3 nucleotide deletions at the rstB gene, which is a unique feature of the classical biotype strains. But the Kolkata strains did not have such deletion mutations in the rstB. Our study demonstrated the existence of some Haitian genetic traits in Kolkata isolates along with the dissimilarities in genomic content with respect to rstB and ctxAB promoter region. Finally, we conclude that Haitian variant strain may be evolved due to sequential event in the Indian subcontinent strain with some cryptic modification in the genome.

  12. SKHIN/Sprd, a new genetically defined inbred hairless mouse strain for UV-induced skin carcinogenesis studies.

    Science.gov (United States)

    Perez, Carlos; Parker-Thornburg, Jan; Mikulec, Carol; Kusewitt, Donna F; Fischer, Susan M; Digiovanni, John; Conti, Claudio J; Benavides, Fernando

    2012-03-01

    Strains of mice vary in their susceptibility to ultra-violet (UV) radiation-induced skin tumors. Some strains of hairless mice (homozygous for the spontaneous Hr(hr) mutation) are particularly susceptible to these tumors. The skin tumors that develop in hairless mice resemble, both at the morphologic and molecular levels, UV-induced squamous cell carcinomas (SCC) and their precursors in human. The most commonly employed hairless mice belong to the SKH1 stock. However, these mice are outbred and their genetic background is not characterized, which makes them a poor model for genetic studies. We have developed a new inbred strain from outbred SKH1 mice that we named SKHIN/Sprd (now at generation F31). In order to characterize the genetic background of this new strain, we genotyped a cohort of mice at F30 with 92 microsatellites and 140 single nucleotide polymorphisms (SNP) evenly distributed throughout the mouse genome. We also exposed SKHIN/Sprd mice to chronic UV irradiation and showed that they are as susceptible to UV-induced skin carcinogenesis as outbred SKH1 mice. In addition, we proved that, albeit with low efficiency, inbred SKHIN/Sprd mice are suitable for transgenic production by classical pronuclear microinjection. This new inbred strain will be useful for the development of transgenic and congenic strains on a hairless inbred background as well as the establishment of syngeneic tumor cell lines. These new tools can potentially help elucidate a number of features of the cutaneous response to UV irradiation in humans, including the effect of genetic background and modifier genes.

  13. Genetic and ecophysiological traits of Synechococcus strains isolated from coastal and open ocean waters of the Arabian Sea.

    Science.gov (United States)

    Bemal, Suchandan; Anil, Arga Chandrashekar

    2016-11-01

    The picocyanobacterium Synechococcus is a prominent primary producer in the marine environment. The marine Synechococcus strains are clustered into different clades representing ecologically distinct genotypes. In this study, we compared phylogeny, photophysiology and cell cycles of four novel phycoerythrin-containing Synechococcus strains (clade II of subcluster 5.1) isolated from different depths of the water column (surface and subsurface waters) in coastal and offshore regions of the eastern Arabian Sea. The surface water strains possessed a lesser number of thylakoid layers and had a higher zeaxanthin to chlorophyll a ratio than subsurface strains indicating possible influence of light intensity available at their niche. The DNA distribution pattern of the four strains was bimodal in optimal cellular physiology conditions with cell division restricted to the light period and synchronized with the light-dark cycle. The presence of phycourobilin or phycoerythrobilin and the ratio between these two chromophores in all four strains varied according to available spectral wavelength in situ This study indicates that the timing of cell division is conserved within these genotypically identical Synechococcus strains, despite their having different chromophore ratios. We conclude that the timing of cell division of the Synechococcus strains has a genetic basis rather than being determined by phenotypic characters, such as chromophore content and ratio.

  14. Contrasting effects of chloride on growth, reproduction, and toxicant sensitivity in two genetically distinct strains of Hyalella azteca.

    Science.gov (United States)

    Soucek, David J; Mount, David R; Dickinson, Amy; Hockett, J Russell; McEwen, Abigail R

    2015-10-01

    The strain of Hyalella azteca (Saussure: Amphipoda) commonly used for aquatic toxicity testing in the United States has been shown to perform poorly in some standardized reconstituted waters frequently used for other test species. In 10-d and 42-d experiments, the growth and reproduction of the US laboratory strain of H. azteca was shown to vary strongly with chloride concentration in the test water, with declining performance observed below 15 mg/L to 20 mg/L. In contrast to the chloride-dependent performance of the US laboratory strain of H. azteca, growth of a genetically distinct strain of H. azteca obtained from an Environment Canada laboratory in Burlington, Ontario, Canada, was not influenced by chloride concentration. In acute toxicity tests with the US laboratory strain of H. azteca, the acute toxicity of sodium nitrate increased with decreasing chloride in a pattern similar not only to that observed for control growth, but also to previous acute toxicity testing with sodium sulfate. Subsequent testing with the Burlington strain showed no significant relationship between chloride concentration and the acute toxicity of sodium nitrate or sodium sulfate. These findings suggest that the chloride-dependent toxicity shown for the US laboratory strain may be an unusual feature of that strain and perhaps not broadly representative of aquatic organisms as a whole.

  15. Changes in extracellular levels of amygdala amino acids in genetically fast and slow kindling rat strains.

    Science.gov (United States)

    Shin, Rick S; Anisman, Hymie; Merali, Zul; McIntyre, Dan C

    2002-08-01

    A neurochemical basis for many of the epilepsies has long been suspected to result from an imbalance between excitatory and inhibitory neurotransmitter mechanisms. Data supporting changes in extrasynaptic amino acid levels during epileptogenesis, however, remain controversial. In the present study, we used in vivo microdialysis to measure the levels of extracellular GABA (gamma-aminobutyric acid) and glutamate during seizure development in rats with a genetic predisposition for (Fast), or against (Slow), amygdala kindling. Dialysates were collected from both amygdalae before, during, and up to 12 min after a threshold-triggered amygdala afterdischarge (AD). One hour later, samples were again collected from both amygdalae in response to a hippocampal threshold AD. Daily amygdala kindling commenced the next day but without dialysis. After the rats were fully kindled, the same protocol was again employed. Amino acid levels were not consistently increased above baseline with triggered seizures in either strain. Instead, before kindling, a focal seizure in the Slow rats was associated with a large decrease in GABA in the non-stimulated amygdala, while amino acid levels in the Fast rats remained near baseline in both amygdalae. Similar results were seen after kindling. By contrast, before and after kindling, hippocampal stimulation caused large decreases in all amino acid levels in both amygdalae in both strains. These data suggest that, in response to direct stimulation, extracellular amino acid concentrations remain stable in tissues associated with either greater natural (Fast) or induced (kindled Fast/Slow) excitability, but are lowered with indirect stimulation (hippocampus) and/or low excitability.

  16. Serotype and genetic diversity of human rhinovirus strains that circulated in Kenya in 2008.

    Science.gov (United States)

    Milanoi, Sylvia; Ongus, Juliette R; Gachara, George; Coldren, Rodney; Bulimo, Wallace

    2016-05-01

    Human rhinoviruses (HRVs) are a well-established cause of the common cold and recent studies indicated that they may be associated with severe acute respiratory illnesses (SARIs) like pneumonia, asthma, and bronchiolitis. Despite global studies on the genetic diversity of the virus, the serotype diversity of these viruses across diverse geographic regions in Kenya has not been characterized. This study sought to characterize the serotype diversity of HRV strains that circulated in Kenya in 2008. A total of 517 archived nasopharyngeal samples collected in a previous respiratory virus surveillance program across Kenya in 2008 were selected. Participants enrolled were outpatients who presented with influenza-like (ILI) symptoms. Real-time RT-PCR was employed for preliminary HRV detection. HRV-positive samples were amplified using RT-PCR and thereafter the nucleotide sequences of the amplicons were determined followed by phylogenetic analysis. Twenty-five percent of the samples tested positive for HRV. Phylogenetic analysis revealed that the Kenyan HRVs clustered into three main species comprising HRV-A (54%), HRV-B (12%), and HRV-C (35%). Overall, 20 different serotypes were identified. Intrastrain sequence homology among the Kenyan strains ranged from 58% to 100% at the nucleotide level and 55% to 100% at the amino acid level. These results show that a wide range of HRV serotypes with different levels of nucleotide variation were present in Kenya. Furthermore, our data show that HRVs contributed substantially to influenza-like illness in Kenya in 2008. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  17. Genetic susceptibility of the arterial wall is an important determinant of atherosclerosis in C57BL/6 and FVB/N mouse strains

    DEFF Research Database (Denmark)

    Shim, Jeong; Handberg, Aase; Östergren, Eva-Britt Caroline

    2011-01-01

    How genetic variations among inbred mouse strains translate into differences in atherosclerosis susceptibility is of significant interest for the development of new therapeutic strategies. The objective of the present study was to examine whether genetically controlled arterial wall properties in...... influence atherosclerosis susceptibility in FVB/N (FVB) and C57BL/6 (B6) apolipoprotein E knockout (apoE(-/-)) mouse strains....

  18. Genetic Differences between Two Strains of Xylella fastidiosa Revealed by Suppression Subtractive Hybridization†

    OpenAIRE

    Harakava,Ricardo; Gabriel, Dean W.

    2003-01-01

    Suppression subtractive hybridization was used to rapidly identify 18 gene differences between a citrus variegated chlorosis (CVC) strain and a Pierce's disease of grape (PD) strain of Xylella fastidiosa. The results were validated as being highly representative of actual differences by comparison of the completely sequenced genome of a CVC strain with that of a PD strain.

  19. Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing

    DEFF Research Database (Denmark)

    Immonen, Elina; Collet, Marie; Goenaga, Julieta

    2016-01-01

    Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex...... to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity...... beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due...

  20. Genetic diversity among Bacillus anthracis, Bacillus cereus and Bacillus thuringiensis strains using repetitive element polymorphism-PCR.

    Science.gov (United States)

    Brumlik, Michael J; Bielawska-Drózd, Agata; Zakowska, Dorota; Liang, Xudong; Spalletta, Ronald A; Patra, Guy; Delvecchio, Vito G

    2004-01-01

    Repetitive element polymorphism-PCR (REP-PCR) is one of the tools that has been used to elucidate genetic diversity of related microorganisms. Using the MB1 primer, REP-PCR fingerprints from 110 Bacillus strains within the "B. cereus group" have identified eighteen distinct categories, while other more distantly related bacterial species fell within six additional categories. All Bacillus anthracis strains tested were found to be monomorphic by fluorophore-enhanced REP-PCR (FERP) fingerprinting using the MB1 primer. In contrast, other non- B. anthracis isolates displayed a high degree of polymorphism. Dendrogramic analysis revealed that the non- B. anthracis strains possessing the Ba813 chromosomal marker were divided into two clusters. One of the clusters shared identity with the B. cereus strains examined.

  1. Sex-stratified Genome-wide Association Studies Including 270,000 Individuals Show Sexual Dimorphism in Genetic Loci for Anthropometric Traits

    OpenAIRE

    Randall, J. C.; Winkler, T.W.; Kutalik, Z.; Berndt, S.I.; Jackson, A.U.; Monda, K.L.; Kilpelainen, T.O.; Esko, T; Magi, R.; Li, S.; Workalemahu, T; Feitosa,M. F.; Croteau-Chonka, D.C.; Day, F. R.; Fall, T.

    2013-01-01

    Given the anthropometric differences between men and women and previous evidence of sex-difference in genetic effects, we conducted a genome-wide search for sexually dimorphic associations with height, weight, body mass index, waist circumference, hip circumference, and waist-to-hip-ratio (133,723 individuals) and took forward 348 SNPs into follow-up (additional 137,052 individuals) in a total of 94 studies. Seven loci displayed significant sex-difference (FDR<5%), including four previousl...

  2. Purification, biochemical characterization, and genetic cloning of the phytase produced by Burkholderia sp. strain a13.

    Science.gov (United States)

    Graminho, Eduardo Rezende; Takaya, Naoki; Nakamura, Akira; Hoshino, Takayuki

    2015-01-01

    A phytase-producing bacterium, Burkholderia sp. a13 (JCM 30421), was isolated from Lake Kasumigaura by enrichment cultivation using minimum medium containing phytic acid as the sole phosphorus source. The phytase production by strain a13 was induced by the presence of phytic acid and repressed by the addition of glucose. The purified enzyme had a molecular weight of 44 kDa and a phytase activity of 174 μmol min(-1) mg(-1). The enzyme showed broad substrate specificity, but the highest activity was observed with phytic acid. The enzyme activity was strongly inhibited by Cu(2+), Zn(2+), Hg(2+), and iodoacetic acid, indicating the requirement of a thiol group for the activity. Genetic cloning reveals that the mature portion of this enzyme consists of 428 amino acids with a calculated molecular weight of 46 kDa. The amino acid sequence showed the highest similarity to the phytase produced by Hafnia alvei with 48% identity; it also contained histidine acid phosphatase (HAP) motifs (RHGXRXP and HD), indicating the classification of this enzyme in the HAP phytase family. We have successfully expressed the cloned gene in Escherichia coli from its putative initiation codon, showing that the gene actually encodes the phytase.

  3. Genetics of hybrid male sterility among strains and species in the Drosophila pseudoobscura species group.

    Science.gov (United States)

    McDermott, Shannon R; Noor, Mohamed A F

    2011-07-01

    Taxa in the early stages of speciation may bear intraspecific allelic variation at loci conferring barrier traits in hybrids such as hybrid sterility. Additionally, hybridization may spread alleles that confer barrier traits to other taxa. Historically, few studies examine within- and between-species variation at loci conferring reproductive isolation. Here, we test for allelic variation within Drosophila persimilis and within the Bogota subspecies of D. pseudoobscura at regions previously shown to contribute to hybrid male sterility. We also test whether D. persimilis and the USA subspecies of D. pseudoobscura share an allele conferring hybrid sterility in a D. pseudoobscura bogotana genetic background. All loci conferred similar hybrid sterility effects across all strains studied, although we detected some statistically significant quantitative effect variation among D. persimilis alleles of some hybrid incompatibility QTLs. We also detected allelism between D. persimilis and D. pseudoobscura USA at a second chromosome hybrid sterility QTL. We hypothesize that either the QTL is ancestral in D. persimilis and D. pseudoobscura USA and lost in D. pseudoobscura bogotana, or gene flow transferred the QTL from D. persimilis to D. pseudoobscura USA. We discuss our findings in the context of population features that may contribute to variation in hybrid incompatibilities.

  4. A Retrospective Study on Genetic Heterogeneity within Treponema Strains: Subpopulations Are Genetically Distinct in a Limited Number of Positions.

    Directory of Open Access Journals (Sweden)

    Darina Čejková

    Full Text Available Pathogenic uncultivable treponemes comprise human and animal pathogens including agents of syphilis, yaws, bejel, pinta, and venereal spirochetosis in rabbits and hares. A set of 10 treponemal genome sequences including those of 4 Treponema pallidum ssp. pallidum (TPA strains (Nichols, DAL-1, Mexico A, SS14, 4 T. p. ssp. pertenue (TPE strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc, 1 T. p. ssp. endemicum (TEN strain (Bosnia A and one strain (Cuniculi A of Treponema paraluisleporidarum ecovar Cuniculus (TPLC were examined with respect to the presence of nucleotide intrastrain heterogeneous sites.The number of identified intrastrain heterogeneous sites in individual genomes ranged between 0 and 7. Altogether, 23 intrastrain heterogeneous sites (in 17 genes were found in 5 out of 10 investigated treponemal genomes including TPA strains Nichols (n = 5, DAL-1 (n = 4, and SS14 (n = 7, TPE strain Samoa D (n = 1, and TEN strain Bosnia A (n = 5. Although only one heterogeneous site was identified among 4 tested TPE strains, 16 such sites were identified among 4 TPA strains. Heterogeneous sites were mostly strain-specific and were identified in four tpr genes (tprC, GI, I, K, in genes involved in bacterial motility and chemotaxis (fliI, cheC-fliY, in genes involved in cell structure (murC, translation (prfA, general and DNA metabolism (putative SAM dependent methyltransferase, topA, and in seven hypothetical genes.Heterogeneous sites likely represent both the selection of adaptive changes during infection of the host as well as an ongoing diversifying evolutionary process.

  5. Genetic characterization of Shiga toxin-producing Escherichia coil O26 : H11 strains isolated from animal, food, and clinical samples

    NARCIS (Netherlands)

    Krueger, Alejandra; Lucchesi, Paula M. A.; Mariel Sanso, A.; Etcheverria, Analia I.; Bustamante, Ana V.; Burgan, Julia; Fernandez, Luciana; Fernandez, Daniel; Leotta, Gerardo; Friedrich, Alexander W.; Padola, Nora L.; Rossen, John W. A.

    2015-01-01

    The Shiga-toxin producing Escherichia coli (STEC) may cause serious illness in human. Here we analyze O26:H11 strains known to be among the most reported STEC strains causing human infections. Genetic characterization of strains isolated from animal, food, and clinical specimens in Argentina showed

  6. Genetic variations in FSH action affect sex hormone levels and breast tissue size in infant girls

    DEFF Research Database (Denmark)

    Henriksen, Louise Scheutz; Hagen, Casper P; Assens, Maria

    2016-01-01

    , especially FSHR -29G>A and FSHR 2039A>G, affect female hormone profile and glandular breast tissue development already during minipuberty. Thus, genetic variations of FSH signaling appear to determine the individual set point of the hypothalamic-pituitary-gonadal axis already early in life.......Context: Single nucleotide polymorphisms altering FSH action (FSHB -211G>T, FSHR -29G>A, and FSHR 2039A>G) are associated with peripubertal and adult levels of reproductive hormones and age at pubertal onset in girls. Objective: To investigate whether genetic polymorphisms altering FSH action...... present in homozygotes. FSHB -211T carriers had smaller breast tissue size than girls who without a minor allele; GT+TT 10.5 (confidence interval 9.4 -11.5) mm vs GG 12.1 (confidence interval 11.4-12.8) mm, P = .014. Conclusions: Our study indicates that 3 genetic polymorphisms altering FSH action...

  7. Correlations between the ages of Alnus host species and the genetic diversity of associated endosymbiotic Frankia strains from nodules

    Institute of Scientific and Technical Information of China (English)

    DAI Yumei; ZHANG Chenggang; XIONG Zhi; ZHANG Zhongze

    2005-01-01

    Nodule samples were collected from four alder species: Alnus nepalensis, A. sibirica, A. tinctoria and A. mandshurica growing in different environments on Gaoligong Mountains,Yunnan Province of Southwest China and on Changbai Mountains, Jilin Province of Northeast China. PCR-RFLP analysis of the IGS between nifD and nifK genes was directly applied to uncultured Frankia strains in the nodules. A total of 21 restriction patterns were obtained. The Frankia population in the nodules of A. nepalensis had the highest genetic diversity among all four Frankia populations; by contrast, the population in the nodules of A. mandshurica had the lowest degree of divergence; the ones in the nodules of A. sibirica and A. tinctoria were intermediate. A dendrogram, which was constructed based on the genetic distance between the restriction patterns, indicated that Frankia strains from A. sibirica and A. tinctoria had a close genetic relationship. Frankia strains from A. nepalensis might be the ancestor of Frankia strains infecting other Alnus species. From these results and the inference of the ages of Alnus host species, it is deduced that there was a co-evolution between Alnus and its microsymbiont Frankia in China.

  8. Lack of sex-biased dispersal promotes fine-scale genetic structure in alpine ungulates

    Science.gov (United States)

    Roffler, Gretchen H.; Talbot, Sandra L.; Luikart, Gordon; Sage, George K.; Pilgrim, Kristy L.; Adams, Layne G.; Schwartz, Michael K.

    2014-01-01

    Identifying patterns of fine-scale genetic structure in natural populations can advance understanding of critical ecological processes such as dispersal and gene flow across heterogeneous landscapes. Alpine ungulates generally exhibit high levels of genetic structure due to female philopatry and patchy configuration of mountain habitats. We assessed the spatial scale of genetic structure and the amount of gene flow in 301 Dall’s sheep (Ovis dalli dalli) at the landscape level using 15 nuclear microsatellites and 473 base pairs of the mitochondrial (mtDNA) control region. Dall’s sheep exhibited significant genetic structure within contiguous mountain ranges, but mtDNA structure occurred at a broader geographic scale than nuclear DNA within the study area, and mtDNA structure for other North American mountain sheep populations. No evidence of male-mediated gene flow or greater philopatry of females was observed; there was little difference between markers with different modes of inheritance (pairwise nuclear DNA F ST = 0.004–0.325; mtDNA F ST = 0.009–0.544), and males were no more likely than females to be recent immigrants. Historical patterns based on mtDNA indicate separate northern and southern lineages and a pattern of expansion following regional glacial retreat. Boundaries of genetic clusters aligned geographically with prominent mountain ranges, icefields, and major river valleys based on Bayesian and hierarchical modeling of microsatellite and mtDNA data. Our results suggest that fine-scale genetic structure in Dall’s sheep is influenced by limited dispersal, and structure may be weaker in populations occurring near ancestral levels of density and distribution in continuous habitats compared to other alpine ungulates that have experienced declines and marked habitat fragmentation.

  9. Virulence and pathogenesis of the MSW and MSD strains of Californian myxoma virus in European rabbits with genetic resistance to myxomatosis compared to rabbits with no genetic resistance.

    Science.gov (United States)

    Silvers, L; Inglis, B; Labudovic, A; Janssens, P A; van Leeuwen, B H; Kerr, P J

    2006-04-25

    The pathogenesis of two Californian strains of myxoma virus (MSW and MSD) was examined in European rabbits (Oryctolagus cuniculus) that were either susceptible to myxomatosis (laboratory rabbits) or had undergone natural selection for genetic resistance to myxomatosis (Australian wild rabbits). MSW was highly lethal for both types of rabbits with average survival times of 7.3 and 9.4 days, respectively, and 100% mortality. Classical clinical signs of myxomatosis were not present except in one rabbit that survived for 13 days following infection. Previously described clinical signs of trembling and shaking were observed in laboratory but not wild rabbits. Despite the high resistance of wild rabbits to myxomatosis caused by South American strains of myxoma virus, the MSW strain was of such high virulence that it was able to overcome resistance. The acute nature of the infection, relatively low viral titers in the tissues and destruction of lymphoid tissues, suggested that death was probably due to an acute and overwhelming immunopathological response to the virus. No virus was found in the brain. The MSD strain was attenuated compared to previously published descriptions and therefore was only characterized in laboratory rabbits. It is concluded that Californian MSW strain of myxoma virus is at the extreme end of a continuum of myxoma virus virulence but that the basic pathophysiology of the disease induced is not broadly different to other strains of myxoma virus.

  10. Hypercholesterolemia with consumption of PFOA-laced Western diets is dependent on strain and sex of mice.

    Science.gov (United States)

    Rebholz, Sandra L; Jones, Thomas; Herrick, Robert L; Xie, Changchun; Calafat, Antonia M; Pinney, Susan M; Woollett, Laura A

    Perfluorooctanoic acid (PFOA) is a man-made surfactant with a number of industrial applications. It has a long half-life environmentally and biologically. Past studies suggest a direct relationship between plasma cholesterol and PFOA serum concentrations in humans and an inverse one in rodents fed standard rodent chow, making it difficult to examine mechanisms responsible for the potential PFOA-induced hypercholesterolemia and altered sterol metabolism. To examine dietary modification of PFOA-induced effects, C57BL/6 and BALB/c mice were fed PFOA in a fat- and cholesterol-containing diet. When fed these high fat diets, PFOA ingestion resulted in marked hypercholesterolemia in male and female C57BL/6 mice and less robust hypercholesterolemia in male BALB/c mice. The PFOA-induced hypercholesterolemia appeared to be the result of increased liver masses and altered expression of genes associated with hepatic sterol output, specifically bile acid production. mRNA levels of genes associated with sterol input were reduced only in C57BL/6 females, the mice with the greatest increase in plasma cholesterol levels. Strain-specific PFOA-induced changes in cholesterol concentrations in mammary tissues and ovaries paralleled changes in plasma cholesterol levels. mRNA levels of sterol-related genes were reduced in ovaries of C57BL/6 but not in BALB/c mice and not in mammary tissues. Our data suggest that PFOA ingestion leads to hypercholesterolemia in mice fed fat and cholesterol and effects are dependent upon the genetic background and gender of the mice with C57BL/6 female mice being most responsive to PFOA.

  11. Hypercholesterolemia with consumption of PFOA-laced Western diets is dependent on strain and sex of mice

    Directory of Open Access Journals (Sweden)

    Sandra L. Rebholz

    2016-01-01

    Full Text Available Perfluorooctanoic acid (PFOA is a man-made surfactant with a number of industrial applications. It has a long half-life environmentally and biologically. Past studies suggest a direct relationship between plasma cholesterol and PFOA serum concentrations in humans and an inverse one in rodents fed standard rodent chow, making it difficult to examine mechanisms responsible for the potential PFOA-induced hypercholesterolemia and altered sterol metabolism. To examine dietary modification of PFOA-induced effects, C57BL/6 and BALB/c mice were fed PFOA in a fat- and cholesterol-containing diet. When fed these high fat diets, PFOA ingestion resulted in marked hypercholesterolemia in male and female C57BL/6 mice and less robust hypercholesterolemia in male BALB/c mice. The PFOA-induced hypercholesterolemia appeared to be the result of increased liver masses and altered expression of genes associated with hepatic sterol output, specifically bile acid production. mRNA levels of genes associated with sterol input were reduced only in C57BL/6 females, the mice with the greatest increase in plasma cholesterol levels. Strain-specific PFOA-induced changes in cholesterol concentrations in mammary tissues and ovaries paralleled changes in plasma cholesterol levels. mRNA levels of sterol-related genes were reduced in ovaries of C57BL/6 but not in BALB/c mice and not in mammary tissues. Our data suggest that PFOA ingestion leads to hypercholesterolemia in mice fed fat and cholesterol and effects are dependent upon the genetic background and gender of the mice with C57BL/6 female mice being most responsive to PFOA.

  12. Strain Dependent Genetic Networks for Antibiotic-Sensitivity in a Bacterial Pathogen with a Large Pan-Genome.

    Directory of Open Access Journals (Sweden)

    Tim van Opijnen

    2016-09-01

    Full Text Available The interaction between an antibiotic and bacterium is not merely restricted to the drug and its direct target, rather antibiotic induced stress seems to resonate through the bacterium, creating selective pressures that drive the emergence of adaptive mutations not only in the direct target, but in genes involved in many different fundamental processes as well. Surprisingly, it has been shown that adaptive mutations do not necessarily have the same effect in all species, indicating that the genetic background influences how phenotypes are manifested. However, to what extent the genetic background affects the manner in which a bacterium experiences antibiotic stress, and how this stress is processed is unclear. Here we employ the genome-wide tool Tn-Seq to construct daptomycin-sensitivity profiles for two strains of the bacterial pathogen Streptococcus pneumoniae. Remarkably, over half of the genes that are important for dealing with antibiotic-induced stress in one strain are dispensable in another. By confirming over 100 genotype-phenotype relationships, probing potassium-loss, employing genetic interaction mapping as well as temporal gene-expression experiments we reveal genome-wide conditionally important/essential genes, we discover roles for genes with unknown function, and uncover parts of the antibiotic's mode-of-action. Moreover, by mapping the underlying genomic network for two query genes we encounter little conservation in network connectivity between strains as well as profound differences in regulatory relationships. Our approach uniquely enables genome-wide fitness comparisons across strains, facilitating the discovery that antibiotic responses are complex events that can vary widely between strains, which suggests that in some cases the emergence of resistance could be strain specific and at least for species with a large pan-genome less predictable.

  13. Strain Dependent Genetic Networks for Antibiotic-Sensitivity in a Bacterial Pathogen with a Large Pan-Genome.

    Science.gov (United States)

    van Opijnen, Tim; Dedrick, Sandra; Bento, José

    2016-09-01

    The interaction between an antibiotic and bacterium is not merely restricted to the drug and its direct target, rather antibiotic induced stress seems to resonate through the bacterium, creating selective pressures that drive the emergence of adaptive mutations not only in the direct target, but in genes involved in many different fundamental processes as well. Surprisingly, it has been shown that adaptive mutations do not necessarily have the same effect in all species, indicating that the genetic background influences how phenotypes are manifested. However, to what extent the genetic background affects the manner in which a bacterium experiences antibiotic stress, and how this stress is processed is unclear. Here we employ the genome-wide tool Tn-Seq to construct daptomycin-sensitivity profiles for two strains of the bacterial pathogen Streptococcus pneumoniae. Remarkably, over half of the genes that are important for dealing with antibiotic-induced stress in one strain are dispensable in another. By confirming over 100 genotype-phenotype relationships, probing potassium-loss, employing genetic interaction mapping as well as temporal gene-expression experiments we reveal genome-wide conditionally important/essential genes, we discover roles for genes with unknown function, and uncover parts of the antibiotic's mode-of-action. Moreover, by mapping the underlying genomic network for two query genes we encounter little conservation in network connectivity between strains as well as profound differences in regulatory relationships. Our approach uniquely enables genome-wide fitness comparisons across strains, facilitating the discovery that antibiotic responses are complex events that can vary widely between strains, which suggests that in some cases the emergence of resistance could be strain specific and at least for species with a large pan-genome less predictable.

  14. Genetic variations of live attenuated plague vaccine strains (Yersinia pestis EV76 lineage) during laboratory passages in different countries.

    Science.gov (United States)

    Cui, Yujun; Yang, Xianwei; Xiao, Xiao; Anisimov, Andrey P; Li, Dongfang; Yan, Yanfeng; Zhou, Dongsheng; Rajerison, Minoarisoa; Carniel, Elisabeth; Achtman, Mark; Yang, Ruifu; Song, Yajun

    2014-08-01

    Plague, one of the most devastating infectious diseases in human history, is caused by the bacterial species Yersinia pestis. A live attenuated Y. pestis strain (EV76) has been widely used as a plague vaccine in various countries around the world. Here we compared the whole genome sequence of an EV76 strain used in China (EV76-CN) with the genomes of Y. pestis wild isolates to identify genetic variations specific to the EV76 lineage. We identified 6 SNPs and 6 Indels (insertions and deletions) differentiating EV76-CN from its counterparts. Then, we screened these polymorphic sites in 28 other strains of EV76 lineage that were stored in different countries. Based on the profiles of SNPs and Indels, we reconstructed the parsimonious dissemination history of EV76 lineage. This analysis revealed that there have been at least three independent imports of EV76 strains into China. Additionally, we observed that the pyrE gene is a mutation hotspot in EV76 lineages. The fine comparison results based on whole genome sequence in this study provide better understanding of the effects of laboratory passages on the accumulation of genetic polymorphisms in plague vaccine strains. These variations identified here will also be helpful in discriminating different EV76 derivatives. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Genetic and non-genetic indirect effects for harvest weight in the GIFT strain of Nile tilapia (Oreochromis niloticus)

    NARCIS (Netherlands)

    Khaw, H.L.; Ponzoni, R.W.; Yee, H.Y.; Aziz, M.A.; Bijma, P.

    2016-01-01

    Trait values of individuals are affected not only by their genetic makeup, but also by environmental factors and interactions with other individuals. The heritable effect of an individual on the trait values of other individuals it interacts with is known as an indirect genetic effect (IGE). Such IG

  16. The capability of tyramine production and correlation between phenotypic and genetic characteristics of Enterococcus faecium and Enterococcus faecalis strains

    Directory of Open Access Journals (Sweden)

    Eleonora eBargossi

    2015-12-01

    Full Text Available The aim of this study was to investigate the diversity of tyramine production capability of four Enterococcus strains in buffered systems in relation to their genetic characteristics and environmental conditions. Cells of the strains Enterococcus faecalis EF37 and ATCC 29212, and Enterococcus faecium FC12 and FC643 were re-suspended in phosphate/citrate buffers with different pH, NaCl concentration and incubation temperature. At intervals, cell viability and tyramine production were assessed by plate counting and HPLC analysis, respectively. The activity of a purified tyrosine decarboxylase (TDC was determined under the same conditions, as a reference. Reduced loss in cell viability was observed in all the tested conditions, except for pH 4 after 24 h. The TDC activity was greatly heterogeneous within the enterococci: EF37 and FC12 produced the higher tyramine concentrations, ATCC 29212 showed a reduced decarboxylase activity, while EF643 did not accumulate detectable amounts of tyramine in all the conditions assayed. Among the considerate variables, temperature was the most influencing factor on tyramine accumulation for enterococcal cells.To further correlate the phenotypic and genetic characteristics of the enterococci, the TDC operon region carrying the genes tyrosine decarboxylase (tyrDC, tyrosine/tyramine permease (tyrP, and Na+/H+ antiporter (nhaC-2 was amplified and sequenced. The genetic organization and nucleotide sequence of this operon region were highly conserved in the enterococcal strains of the same species. The heterogeneity in tyramine production found between the two E. faecalis strains could be ascribed to different regulation mechanisms not yet elucidated. On the contrary, a codon stop was identified in the translated tyrDC sequence of E. faecium FC643, supporting its inability to accumulate tyramine in the tested conditions. In addition, the presence of an additional putative tyrosine decarboxylase with different substrate

  17. Disorders of Sex Development and Germ Cell Cancer: genetics and microenvironment

    NARCIS (Netherlands)

    R. Hersmus (Remko)

    2012-01-01

    textabstractThe ultimate purpose of sexual reproduction, which depends on specialized male and female anatomy and physiology, is to enable continuation of a species and introduction of genetic diversity. In mammals the developmental path towards a male or a female is in principle determined at the

  18. Differences in genetic and environmental variation in adult BMI by sex, age, time period, and region

    DEFF Research Database (Denmark)

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo

    2017-01-01

    Background: Genes and the environment contribute to variation in adult body mass index [BMI (in kg/m2)], but factors modifying these variance components are poorly understood. Objective: We analyzed genetic and environmental variation in BMI between men and women from young adulthood to old age f...

  19. Differences in genetic and environmental variation in adult BMI by sex, age, time period, and region

    DEFF Research Database (Denmark)

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo

    2017-01-01

    Background: Genes and the environment contribute to variation in adult body mass index [BMI (in kg/m(2))], but factors modifying these variance components are poorly understood.Objective: We analyzed genetic and environmental variation in BMI between men and women from young adulthood to old age ...

  20. DNA repair enables sex identification in genetic material from human teeth

    NARCIS (Netherlands)

    Kovatsi, L.; Nikou, D.; Triantaphyllou, S.; Njau, S. N.; Voutsaki, S.; Kouidou, S.

    2009-01-01

    Background: The purpose of this study was to test the effectiveness of a DNA repair protocol in improving genetic testing in compromised samples, frequently encountered in Forensic Medicine. Methods: In order to stretch the experiment conditions to the limits, as far as quality of samples and DNA is

  1. The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape

    DEFF Research Database (Denmark)

    Winkler, Thomas W; Justice, Anne E; Graff, Mariaelisa

    2015-01-01

    Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially b...

  2. Cattle sex-specific recombination and genetic control from a very large pedigree

    Science.gov (United States)

    Meiotic recombination is an essential biological process that generates novel genetic variants and ensures proper segregation of chromosomes during meiosis. From a large USDA dairy cattle pedigree with over half million genotyped animals, we extracted 186,927 three-generation families, identified ov...

  3. Exploiting the genetic diversity of Beauveria bassiana for improving the biological control of the coffee berry borer through the use of strain mixtures.

    Science.gov (United States)

    Cruz, Lina P; Gaitan, Alvaro L; Gongora, Carmenza E

    2006-08-01

    Beauveria bassiana is an entomopathogen widely used to control the coffee berry borer in Colombia, as part of an Integrated Pest Management strategy. Traditionally, the development of fungal insect pathogens as biocontrol agents in crop pests has been oriented towards the selection and formulation of elite clonal strains. Instead, we explored the potential application of genetic diversity in B. bassiana by determining the effect of strain mixtures on coffee berry borer mortality compared to clonal isolates. Genomic DNA from 11 strains was characterized using internal transcribed spacers and beta-tubulin sequences as well as amplified fragment length polymorphism markers. Cluster analysis produced three genetic groups and confirmed the low but significant intraspecific genetic diversity present among the strains. Single strain virulence towards the coffee berry borer under laboratory conditions, using 1x10(6) conidia ml(-1), ranged between 89.9 and 57.5%. All the inoculations with mixtures resulted in coinfection events. Combinations of genetically similar strains showed no significant differences when their virulences were compared. However, mixtures of genetically different strains led to both antagonism and synergism. The lowest virulence percentage (57%) was obtained by putting together the most virulent strain of each group, contrary to the highest virulence percentage (93%) that resulted from mixing the three least virulent strains. The results indicate the promising potential of designing strain mixtures as an alternative for the biocontrol of Hypothenemus hampei and other pests and provide tools for the understanding of the ecological dynamics of entomopathogen populations under natural conditions.

  4. Sheltering behavior and locomotor activity in 11 genetically diverse common inbred mouse strains using home-cage monitoring.

    Directory of Open Access Journals (Sweden)

    Maarten Loos

    Full Text Available Functional genetic analyses in mice rely on efficient and in-depth characterization of the behavioral spectrum. Automated home-cage observation can provide a systematic and efficient screening method to detect unexplored, novel behavioral phenotypes. Here, we analyzed high-throughput automated home-cage data using existing and novel concepts, to detect a plethora of genetic differences in spontaneous behavior in a panel of commonly used inbred strains (129S1/SvImJ, A/J, C3H/HeJ, C57BL/6J, BALB/cJ, DBA/2J, NOD/LtJ, FVB/NJ, WSB/EiJ, PWK/PhJ and CAST/EiJ. Continuous video-tracking observations of sheltering behavior and locomotor activity were segmented into distinguishable behavioral elements, and studied at different time scales, yielding a set of 115 behavioral parameters of which 105 showed highly significant strain differences. This set of 115 parameters was highly dimensional; principal component analysis identified 26 orthogonal components with eigenvalues above one. Especially novel parameters of sheltering behavior and parameters describing aspects of motion of the mouse in the home-cage showed high genetic effect sizes. Multi-day habituation curves and patterns of behavior surrounding dark/light phase transitions showed striking strain differences, albeit with lower genetic effect sizes. This spontaneous home-cage behavior study demonstrates high dimensionality, with a strong genetic contribution to specific sets of behavioral measures. Importantly, spontaneous home-cage behavior analysis detects genetic effects that cannot be studied in conventional behavioral tests, showing that the inclusion of a few days of undisturbed, labor extensive home-cage assessment may greatly aid gene function analyses and drug target discovery.

  5. Comparison of histological, genetic, metabolomics, and lipid-based methods for sex determination in marine mussels.

    Science.gov (United States)

    Hines, Adam; Yeung, Wai Ho; Craft, John; Brown, Margaret; Kennedy, Jill; Bignell, John; Stentiford, Grant D; Viant, Mark R

    2007-10-15

    Omics technologies are increasingly being used to monitor organismal responses to environmental stressors. Previous studies have shown that species identification, an appreciation of life history traits, and organism phenotype (e.g., gender) are essential for the accurate interpretation of omics data from field samples. As marine mussels are increasingly being used in ecotoxicogenomics and monitoring, a technique to determine mussel gender throughout their annual reproductive cycle is urgently needed. This study examines four methods for sex determination in the two mussel species found in the United Kingdom, Mytilus edulis and Mytilus galloprovincialis, and their hybrid. Each of these methods-histology, a lipid-based assay, a new reverse transcriptase polymerase chain reaction (RT-PCR) assay, and nuclear magnetic resonance (NMR)-based metabolomics-initially was evaluated using sexually mature ("ripe") mussels whose gender was clearly distinguishable using histology. The methods subsequently were tested on spawned ("spent") mussels. For ripe animals, all techniques yielded high classification accuracies: histology, 100%; RT-PCR, 94.6%; lipid analysis, 90.6%; and metabolomics, 89.5%. The gender of spent animals, however, could not be determined by histology (0%) or lipid analysis (55.6%), but RT-PCR (100%) and metabolomics (88.9%) both proved to be successful. In addition, the RT-PCR, metabolomics, and lipid-based methods identified animals of mixed sex. Our findings highlight the application of a novel RT-PCR method as a robust technique for gender determination of ripe and spent mussels.

  6. Analysis of genetic relationship in mutant silkworm strains of Bombyx mori using inter simple sequence repeat (ISSR) markers

    Institute of Scientific and Technical Information of China (English)

    Dhanikachalam Velu; Kangayam M. Ponnuvel; Murugiah Muthulakshmi; Randhir K. Sinha; Syed M.H. Qadri

    2008-01-01

    Amplified inter simple sequence repeats (ISSR) markers were used to determine genetic relationships among mutant silkworm strains of Bombyx mori. Fifteen ISSR primers containing simple sequence repeat (SSR) motifs were used in this study. A total of 113 markers were produced among 20 mutant swains, of which 73.45% were found to be polymorphic. In selected mutant genetic stocks, the average number of observed allele was (1.7080±0.4567), effective alleles (1.5194±0.3950) and genetic diversity (Ht) (0.2901±0.0415). The dendrogram produced using the unweighted pair group method with arithmetic means (UPGMA) and cluster analysis made using Nei's genetic distance resulted in the formation of one major group containing 6 groups separated 20 mutant silkworm strains. Therefore, ISSR amplification is a valuable method for determining the genetic variability among mutant silkworm swains. This efficient molecular marker would be useful for characterizing a considerable number of silkworm swains maintained at the germplasm center.

  7. Estimation of indirect genetic effects in group-housed mink (Neovison vison) should account for systematic interactions either due to kin or sex

    DEFF Research Database (Denmark)

    Alemu, Setegn Worku; Berg, Peer; Janss, Luc

    2016-01-01

    Social interactions among individuals are abundant, both in wild and in domestic populations. With social interactions, the genes of an individual may affect the trait values of other individuals, a phenomenon known as indirect genetic effects (IGEs). IGEs can be estimated using linear mixed models....... Most IGE models assume that individuals interact equally to all group mates irrespective of relatedness. Kin selection theory, however, predicts that an individual will interact differently with family members versus non-family members. Here, we investigate kin- and sex-specific non-genetic social...... interactions in group-housed mink. Furthermore, we investigated whether systematic non-genetic interactions between kin or individuals of the same sex influence the estimates of genetic parameters. As a second objective, we clarify the relationship between estimates of the traditional IGE model and a family...

  8. Genetic Diversity and Virulence Potential of Shiga Toxin-Producing Escherichia coli O113:H21 Strains Isolated from Clinical, Environmental, and Food Sources

    Science.gov (United States)

    Delannoy, Sabine; Lacher, David W.; dos Santos, Luis Fernando; Beutin, Lothar; Fach, Patrick; Rivas, Marta; Hartland, Elizabeth L.; Paton, Adrienne W.; Guth, Beatriz E. C.

    2014-01-01

    Shiga toxin-producing Escherichia coli strains of serotype O113:H21 have caused severe human diseases, but they are unusual in that they do not produce adherence factors coded by the locus of enterocyte effacement. Here, a PCR microarray was used to characterize 65 O113:H21 strains isolated from the environment, food, and clinical infections from various countries. In comparison to the pathogenic strains that were implicated in hemolytic-uremic syndrome in Australia, there were no clear differences between the pathogens and the environmental strains with respect to the 41 genetic markers tested. Furthermore, all of the strains carried only Shiga toxin subtypes associated with human infections, suggesting that the environmental strains have the potential to cause disease. Most of the O113:H21 strains were closely related and belonged in the same clonal group (ST-223), but CRISPR analysis showed a great degree of genetic diversity among the O113:H21 strains. PMID:24858089

  9. Genetic relatedness of commensal Escherichia coli from nursery pigs in intensive pig production in Denmark and molecular characterization of genetically different strains

    DEFF Research Database (Denmark)

    Herrero Fresno, Ana; Larsen, Inge; Olsen, John Elmerdahl

    2015-01-01

    AIMS: To determine the genetic relatedness and the presence of virulence and antibiotic resistance genes in commensal Escherichia coli from nursery pigs in Danish intensive production. METHODS AND RESULTS: The genetic diversity of 1000 E. coli strains randomly picked (N = 50 isolates) from cultured...... faecal samples (N = 4 pigs) from five intensive Danish pigs farms was analysed by repetitive extragenic palindromic-PCR (REP-PCR) and 42 unique REP-profiles were detected (similarity commensal E. coli......-producing genes were observed in 20 isolates. CONCLUSIONS: A low genetic diversity was found in commensal gut E. coli from nursery pigs in Denmark. No correlation was observed between REP-profiles, ST-types and resistance/virulence patterns. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study analysing...

  10. Determinants of human adipose tissue gene expression: impact of diet, sex, metabolic status, and cis genetic regulation.

    Directory of Open Access Journals (Sweden)

    Nathalie Viguerie

    2012-09-01

    Full Text Available Weight control diets favorably affect parameters of the metabolic syndrome and delay the onset of diabetic complications. The adaptations occurring in adipose tissue (AT are likely to have a profound impact on the whole body response as AT is a key target of dietary intervention. Identification of environmental and individual factors controlling AT adaptation is therefore essential. Here, expression of 271 transcripts, selected for regulation according to obesity and weight changes, was determined in 515 individuals before, after 8-week low-calorie diet-induced weight loss, and after 26-week ad libitum weight maintenance diets. For 175 genes, opposite regulation was observed during calorie restriction and weight maintenance phases, independently of variations in body weight. Metabolism and immunity genes showed inverse profiles. During the dietary intervention, network-based analyses revealed strong interconnection between expression of genes involved in de novo lipogenesis and components of the metabolic syndrome. Sex had a marked influence on AT expression of 88 transcripts, which persisted during the entire dietary intervention and after control for fat mass. In women, the influence of body mass index on expression of a subset of genes persisted during the dietary intervention. Twenty-two genes revealed a metabolic syndrome signature common to men and women. Genetic control of AT gene expression by cis signals was observed for 46 genes. Dietary intervention, sex, and cis genetic variants independently controlled AT gene expression. These analyses help understanding the relative importance of environmental and individual factors that control the expression of human AT genes and therefore may foster strategies aimed at improving AT function in metabolic diseases.

  11. Carcass and meat quality traits of Iberian pig as affected by sex and crossbreeding with different Duroc genetic lines

    Directory of Open Access Journals (Sweden)

    A. Robina

    2013-11-01

    Full Text Available A total of 144 pigs were used to study the effects of sex (barrows or gilts and terminal sire line (Iberian or three genetic lines of Duroc: Duroc 1, Duroc 2 and Duroc 3 on performance and carcass and meat quality traits. Gilts showed slightly lower average daily gain, shoulder weight and trimming losses, but slightly better primal cuts yields and higher loin weight, while there was no significant effect of sex on meat quality traits or on the fatty acid composition of lard and muscle. There were important differences in performance and in carcass and primal cuts quality traits between pure Iberian pigs and all Iberian × Duroc crossbreeds evaluated, partly due to the lower slaughter weights reached by the formers. The different sire lines showed differences in several traits; Duroc 1 group showed lower backfat thickness and ham and shoulder trimming losses, and higher primal cut yields than Duroc 2 and Duroc 3 groups. Intramuscular fat (IMF content remained unaffected by crossbreeding, but meat color resulted more intense and redder in crosses from the Duroc 1 sire line. The accumulation of fatty acids in lard was not affected by Duroc sire line, while animals of the group Duroc 2 showed higher levels of monounsaturated fatty acid and lower of polyunsaturated ones in IMF. These results highlight the importance of considering not only performance, but also carcass and meat quality traits when deciding the Duroc sire line for crossbreeding in Iberian pig production.

  12. Genetic relationships between clinical and non-clinical strains of Yersinia enterocolitica biovar 1A as revealed by multilocus enzyme electrophoresis and multilocus restriction typing

    Directory of Open Access Journals (Sweden)

    Virdi Jugsharan S

    2010-05-01

    Full Text Available Abstract Background Genetic relationships among 81 strains of Y. enterocolitica biovar 1A isolated from clinical and non-clinical sources were discerned by multilocus enzyme electrophoresis (MLEE and multilocus restriction typing (MLRT using six loci each. Such studies may reveal associations between the genotypes of the strains and their sources of isolation. Results All loci were polymorphic and generated 62 electrophoretic types (ETs and 12 restriction types (RTs. The mean genetic diversity (H of the strains by MLEE and MLRT was 0.566 and 0.441 respectively. MLEE (DI = 0.98 was more discriminatory and clustered Y. enterocolitica biovar 1A strains into four groups, while MLRT (DI = 0.77 identified two distinct groups. BURST (Based Upon Related Sequence Types analysis of the MLRT data suggested aquatic serotype O:6,30-6,31 isolates to be the ancestral strains from which, clinical O:6,30-6,31 strains might have originated by host adaptation and genetic change. Conclusion MLEE revealed greater genetic diversity among strains of Y. enterocolitica biovar 1A and clustered strains in four groups, while MLRT grouped the strains into two groups. BURST analysis of MLRT data nevertheless provided newer insights into the probable evolution of clinical strains from aquatic strains.

  13. Genetic diversity among Frankia strains nodulating members of the family Casuarinaceae in Australia revealed by PCR and restriction fragment length polymorphism analysis with crushed root nodules.

    Science.gov (United States)

    Rouvier, C; Prin, Y; Reddell, P; Normand, P; Simonet, P

    1996-03-01

    DNA extracted directly from nodules was used to assess the genetic diversity of Frankia strains symbiotically associated with two species of the genus Casuarina and two of the genus Allocasuarina naturally occurring in northeastern Australia. DNA from field-collected nodules or extracted from reference cultures of Casuarina-infective Frankia strains was used as the template in PCRs with primers targeting two DNA regions, one in the ribosomal operon and the other in the nif operon. PCR products were then analyzed by using a set of restriction endonucleases. Five distinct genetic groups were recognized on the basis of these restriction patterns. These groups were consistently associated with the host species from which the nodules originated. All isolated reference strains had similar patterns and were assigned to group 1 along with six of the eight unisolated Frankia strains from Casuarina equisetifolia in Australia. Group 2 consisted of two unisolated Frankia strains from C. equisetifolia, whereas groups 3 to 5 comprised all unisolated strains from Casuarina cunninghamiana, Allocasuarina torulosa, and Allocasuarina littoralis, respectively. These results demonstrate that, contrary to the results of previous molecular studies of isolated strains, there is genetic diversity among Frankia strains that infect members of the family Casuarinacaeae. The apparent high homogeneity of Frankia strains in these previous studies probably relates to the single host species from which the strains were obtained and the origin of these strains from areas outside the natural geographic range of members of the family Casuarinaceae, where genetic diversity could be lower than in Australia.

  14. Biochemical, genetic, and epidemiologic characterization of Haemophilus influenzae biogroup aegyptius (Haemophilus aegyptius) strains associated with Brazilian purpuric fever.

    Science.gov (United States)

    Brenner, D J; Mayer, L W; Carlone, G M; Harrison, L H; Bibb, W F; Brandileone, M C; Sottnek, F O; Irino, K; Reeves, M W; Swenson, J M

    1988-08-01

    Brazilian purpuric fever (BPF) is a recently recognized fulminant pediatric disease characterized by fever, with rapid progression to purpura, hypotensive shock, and death. BPF is usually preceded by purulent conjunctivitis that has resolved before the onset of fever. Both the conjunctivitis and BPF are caused by Haemophilus influenzae biogroup aegyptius (formerly called H. aegyptius). Isolates from 15 BPF cases, mainly from blood or hemorrhagic cerebrospinal fluid, case-associated isolates from 42 persons in towns where BPF cases occurred, and control strains from 32 persons in towns without BPF cases were characterized biochemically, genetically, and epidemiologically. Results indicated that a single clone was responsible for all BPF cases identified in six Brazilian towns from 1984 through 1986. All of 15 (100%) case strains were the same clone as was 1 of 32 (3%) control strains (P = less than 10(-8). Isolates of the clone were preferentially intrarelated by DNA hybridization (99% relatedness, hydroxyapatite method at 60 and 75 degrees C) and were separable from other H. influenzae biogroup aegyptius strains (approximately 90% relatedness at 60 degrees C and 82% relatedness at 75 degrees C). All isolates of the BPF clone and no other strains contained a 24-megadalton plasmid of restriction endonuclease type 3031, were of a single multilocus enzyme mobility type, were of a single sodium dodecyl sulfate-polyacrylamide gel electrophoresis type, and were in one of two ribosomal DNA restriction patterns. All BPF clone isolates reacted with monoclonal antibodies produced from a case strain; only 3 of 62 (5%) other strains reacted with this monoclonal antibody. Ninety percent of BPF clone strains and 27% of other strains were relatively resistant to sulfamethoxazole-trimethoprim.

  15. Multilocus Sequence Typing Reveals Relevant Genetic Variation and Different Evolutionary Dynamics among Strains of Xanthomonas arboricola pv. juglandis

    Directory of Open Access Journals (Sweden)

    Marco Scortichini

    2010-11-01

    Full Text Available Forty-five Xanthomonas arboricola pv. juglandis (Xaj strains originating from Juglans regia cultivation in different countries were molecularly typed by means of MultiLocus Sequence Typing (MLST, using acnB, gapA, gyrB and rpoD gene fragments. A total of 2.5 kilobases was used to infer the phylogenetic relationship among the strains and possible recombination events. Haplotype diversity, linkage disequilibrium analysis, selection tests, gene flow estimates and codon adaptation index were also assessed. The dendrograms built by maximum likelihood with concatenated nucleotide and amino acid sequences revealed two major and two minor phylotypes. The same haplotype was found in strains originating from different continents, and different haplotypes were found in strains isolated in the same year from the same location. A recombination breakpoint was detected within the rpoD gene fragment. At the pathovar level, the Xaj populations studied here are clonal and under neutral selection. However, four Xaj strains isolated from walnut fruits with apical necrosis are under diversifying selection, suggesting a possible new adaptation. Gene flow estimates do not support the hypothesis of geographic isolation of the strains, even though the genetic diversity between the strains increases as the geographic distance between them increases. A triplet deletion, causing the absence of valine, was found in the rpoD fragment of all 45 Xaj strains when compared with X. axonopodis pv. citri strain 306. The codon adaptation index was high in all four genes studied, indicating a relevant metabolic activity.

  16. "Indoor" method of composting and genetic breeding of the strains to improve yield and quality of the almond mushroom Agaricus subrufescens

    OpenAIRE

    Zied, Diego C.; Pardo-Gimenez, A.; Savoie, Jean-Michel; Pardo-Gonzalez, J.E.; Callac, Philippe

    2011-01-01

    The aim of the present work was to evaluate the potential efficiency of an indoor composting method and the genetic breeding of strains on the agronomic performance (yield, number and weight of basidiocarps, precociousness and earliness) and quality of A. subrufescens mushrooms. The experiment followed a factorial combination (3 composts types * 4 strains) with five replicates per treatment. One strain was a hybrid between French and Brazilian isolates. Strains and composts affected a...

  17. Dioecy in Amborella trichopoda: evidence for genetically based sex determination and its consequences for inferences of the breeding system in early angiosperms.

    Science.gov (United States)

    Anger, Nicolas; Fogliani, Bruno; Scutt, Charles P; Gâteblé, Gildas

    2017-03-01

    This work aimed to gain insight into the breeding system at the base of living angiosperms through both character state reconstructions and the study of sex ratios and phenotypes in the likely sister to all other living angiosperms, Amborella trichopoda . Sex phenotypes were mapped onto a phylogeny of basally diverging angiosperms using maximum parsimony. In parallel, sex ratios and phenotypes were studied over two consecutive flowering seasons in an ex situ population of A. trichopoda , while the sex ratio of an in situ population was also assessed. Parsimony analyses failed to resolve the breeding system present at the base of living angiosperms, but indicated the importance of A. trichopoda for the future elucidation of this question. The ex situ A. trichopoda population studied showed a primary sex ratio close to 1:1, though sex ratio bias was found in the in situ population studied. Instances of sexual instability were quantified in both populations. Sex ratio data support the presence of genetic sex determination in A. trichopoda , whose further elucidation may guide inferences on the breeding system at the base of living angiosperms. Sexual instability in A. trichopoda suggests the operation of epigenetic mechanisms, and the evolution of dioecy via a gynodioecious intermediate.

  18. Polymorphism, genetic exchange and intragenic recombination of the aureolysin gene among Staphylococcus aureus strains

    Directory of Open Access Journals (Sweden)

    Kowal Julia

    2008-07-01

    Full Text Available Abstract Background Staphylococcus aureus expresses several proteases, which are thought to contribute to the virulence of this bacterium. Here we focus on aureolysin, the major thermolysin-like metalloprotease. Despite the importance of aureolysin in the physiology and pathogenesis of S. aureus, relatively little information was so far available concerning the aur gene diversity and mobility within and between the major subdivisions of the S. aureus population. Therefore, an epidemiologically and genetically diverse collection of S. aureus strains was used to determine the range of aureolysin (aur gene polymorphism. Results Sequence analyses support the conclusion that the aur gene occurs in two distinct types of related sequences. The aur gene was much more polymorphic but, at the same time, showed higher purifying selection than genes utilized for multilocus sequence typing (MLST. Gene trees constructed from aur and concatenated MLST genes revealed several putative assortative recombination events (i.e. entire aur gene exchanges between divergent lineages of S. aureus. Evidence for intragenic recombination events (i.e. exchanges of internal aur segments across aur genes was also found. The biochemical properties and substrate specificity of the two types of aureolysin purified to homogeneity were studied, revealing minor differences in their affinity to low molecular weight synthetic substrates. Conclusion Although numerous nucleotide differences were identified between the aur alleles studied, our findings showed that a strong purifying selection is acting on the aur gene. Moreover, our study distinguishes between homologous exchanges of the entire aur gene (assortative recombination between divergent S. aureus lineages and recombination events within aur genes.

  19. Genetic diversity and antimicrobial resistance  in Streptococcus agalactiae strains recovered from female carriers in the Bucharest area

    Directory of Open Access Journals (Sweden)

    Codru?a-Romani?a Usein

    2014-04-01

    Full Text Available For the first time, we used multilocus sequence typing (MLST to understand how Romanian group B streptococcus (GBS strains fit into the global GBS population structure. Colonising isolates recovered from adult human females were tested for antibiotic resistance, were molecularly serotyped based on the capsular polysaccharide synthesis (cps gene cluster and further characterised using a set of molecular markers (surface protein genes, pilus-encoded islands and mobile genetic elements inserted in the scpB-lmb intergenic region. Pulsed-field gel electrophoresis was used to complement the MLST clonal distribution pattern of selected strains. Among the 55 strains assigned to six cps types (Ia, Ib, II-V, 18 sequence types (STs were identified by MLST. Five STs represented new entries to the MLST database. The prevalent STs were ST-1, ST-17, ST-19 and ST-28. Twenty molecular marker profiles were identified. The most common profiles (rib+GBSi1+PI-1, rib+GBSi1+PI-1, PI-2b and alp2/3+PI-1, PI-2a were associated with the cps III/ST-17 and cps V/ST-1 strains. A cluster of fluoroquinolone-resistant strains was detected among the cps V/ST-19 members; these strains shared alp1 and IS1548 and carried PI-1, PI-2a or both. Our results support the usefulness of implementing an integrated genotyping system at the reference laboratory level to obtain the reliable data required to make comparisons between countries.

  20. Genetic and Phenotypic Characterization of a Salmonella enterica serovar Enteritidis Emerging Strain with Superior Intra-macrophage Replication Phenotype

    Science.gov (United States)

    Shomer, Inna; Avisar, Alon; Desai, Prerak; Azriel, Shalhevet; Smollan, Gill; Belausov, Natasha; Keller, Nathan; Glikman, Daniel; Maor, Yasmin; Peretz, Avi; McClelland, Michael; Rahav, Galia; Gal-Mor, Ohad

    2016-01-01

    Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the ubiquitous Salmonella serovars worldwide and a major cause of food-born outbreaks, which are often associated with poultry and poultry derivatives. Here we report a nation-wide S. Enteritidis clonal outbreak that occurred in Israel during the last third of 2015. Pulsed field gel electrophoresis and whole genome sequencing identified genetically related strains that were circulating in Israel as early as 2008. Global comparison linked this outbreak strain to several clinical and marine environmental isolates that were previously isolated in California and Canada, indicating that similar strains are prevalent outside of Israel. Phenotypic comparison between the 2015 outbreak strain and other clinical and reference S. Enteritidis strains showed only limited intra-serovar phenotypic variation in growth in rich medium, invasion into Caco-2 cells, uptake by J774.1A macrophages, and host cell cytotoxicity. In contrast, significant phenotypic variation was shown among different S. Enteritidis isolates when biofilm-formation, motility, invasion into HeLa cells and uptake by THP-1 human macrophages were studied. Interestingly, the 2015 outbreak clone was found to possess superior intra-macrophage replication ability within both murine and human macrophages in comparison to the other S. Enteritidis strains studied. This phenotype is likely to play a role in the virulence and host-pathogen interactions of this emerging clone. PMID:27695450

  1. Evolution-based strategy to generate non-genetically modified organisms Saccharomyces cerevisiae strains impaired in sulfate assimilation pathway.

    Science.gov (United States)

    De Vero, L; Solieri, L; Giudici, P

    2011-11-01

    An evolution-based strategy was designed to screen novel yeast strains impaired in sulfate assimilation. Specifically, molybdate and chromate resistance was used as selectable phenotype to select sulfate permease-deficient variants that unable to produce sulfites and hydrogen sulfide (H(2) S). Four Saccharomyces cerevisiae parent strains were induced to sporulate. After tetrad digestion, spore suspensions were observed under the microscope to monitor the conjugation of gametes. Then, the cell suspension was inoculated in tubes containing YPD medium supplemented with ammonium molybdate or potassium chromate. Forty-four resistant strains were obtained and then tested in microvinifications. Three strains with a low sulfite production (SO2 sulfites were selected. Our strategy enabled the selection of improved yeasts with desired oenological characteristics. Particularly, resistance to toxic analogues of sulfate allowed us to detect strains that unable to assimilate sulfates. This strategy that combines the sexual recombination of spores and application of a specific selective pressure provides a rapid screening method to generate genetic variants and select improved wine yeast strains with an impaired metabolism regarding the production of sulfites and H2S. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  2. Genetic characterization of feline calicivirus strains associated with varying disease manifestations during an outbreak season in Missouri (1995-1996).

    Science.gov (United States)

    Prikhodko, Victor G; Sandoval-Jaime, Carlos; Abente, Eugenio J; Bok, Karin; Parra, Gabriel I; Rogozin, Igor B; Ostlund, Eileen N; Green, Kim Y; Sosnovtsev, Stanislav V

    2014-02-01

    Feline calicivirus (FCV) is a common cause of mild to severe upper respiratory tract disease (URTD) in cats. FCV strain 21223 was isolated from a kitten with severe pneumonia in a disease outbreak with unusually high mortality (35 %) that occurred in a Missouri feline colony in 1995-1996. Phylogenetic analysis of the genome sequence of strain 21223 indicated the emergence of a new FCV strain. Analysis of the full-length genome sequence of a closely related (99.5 % nucleotide identity) strain, 3786, obtained from an asymptomatic animal in the same colony four months later, showed the presence of seven amino acid substitutions, with six of them located in the VP1 capsid sequence encoded by ORF2. Comparative analysis of the E-region sequences (426-521 aa ORF2) presumably involved in virus-host cell receptor interactions did not identify amino acid substitutions unique to the virulent strain. We determined the complete genome sequences of four virus isolates that were collected in regional catteries in the months following the outbreak that were associated with different manifestations of the disease (URTD, chronic stomatitis, and gingivitis). We show that genetically distinct FCV strains were cocirculating in the area, and no apparent correlation could be made between overall sequence and observed disease.

  3. IFNGR2 genetic polymorphism associated with sex-specific paranoid schizophrenia risk.

    Science.gov (United States)

    Jemli, Achraf; Inoubli, Oumaima; Trifa, Fatma; Mechri, Anouar; Zaafrane, Ferid; Gaha, Lotfi; Jrad, Besma Bel Hadj

    2017-01-01

    Considering current scientific evidence about the significant role of chronic low grade inflammation in the physiopathology of schizophrenia, it has been hypothesized that changes in pro-inflammatory cytokines such as interferon gamma may have a significant role in the predisposition to schizophrenia. This study focuses on identifying whether the functional polymorphism of interferon gamma receptor 2 (IFNGR2) is a risk factor for the development of schizophrenia. This study was conducted by the RFLP-PCR on a Tunisian population composed of 225 patients with different sub-types of schizophrenia and 166 controls. The IFNGR2 (Q64R) polymorphism analysis showed higher frequencies of minor homozygous genotype (RR) and allele (R) in all patients compared to controls (21.8% vs 10.2%; p = .006, OR = 2.54) and (44% vs 34.9%; p = .01; OR = 1.46), respectively. This correlation was confirmed only for males. This study also noted a significant increase of the mutated homozygous (RR) genotype and (R) allele frequencies of IFNGR2 in paranoid schizophrenics compared to controls (31.4% vs 10.2%; p = .001; OR = 3.34 and 47.2% vs 34.9%; p = .009; OR = 1.66, respectively). This increase remains significant after using binary logistic regression to eliminate confounding factors such as age and sex. Additionally, carriers of RR genotype have significant lower scores on the Scale of Assessment of Positive (SAPS) and negative (SANS) symptoms comparatively to the carrier of the QQ + QR genotypes, suggesting that the R recessive allele carriers could have milder symptoms. The IFNGR2Q64R polymorphism is correlated with male sex and paranoid schizophrenia. It is suggested that a chronic neuroinflammation may predispose to the paranoid schizophrenia development in men.

  4. Influence of nociception and stress-induced antinociception on genetic variation in isoflurane anesthetic potency among mouse strains.

    Science.gov (United States)

    Mogil, Jeffrey S; Smith, Shad B; O'Reilly, Meghan K; Plourde, Gilles

    2005-10-01

    Genetic background influences anesthetic potency to suppress motor response to noxious stimulation (minimum alveolar concentration [MAC]) as well as nociceptive sensitivity in unmedicated animals. However, the influence on MAC of baseline sensitivity to the noxious stimuli used to assess MAC has virtually never been studied. The authors assessed room air nociceptive sensitivity and isoflurane MAC in multiple mouse strains. Isoflurane requirement for loss of righting response (MACLORR) was also measured. One outbred and 10 inbred mouse strains were tested for latency to respond (in room air) to a tail clip (either 500 g or 2,000 g). Naive mice of the same 11 strains were tested for isoflurane MAC and MACLORR. To assess the role of opioid-mediated stress-induced antinociception, mice were also tested for nociceptive sensitivity after injection of naloxone (10 mg/kg) or saline. Robust strain differences were observed for all measures. The authors found that tail-clip latency (using a 500-g or 2,000-g clip, respectively) correlated significantly with MAC (r = -0.76 and -0.58, respectively) but not MACLORR (r = -0.10 and -0.26). Naloxone produced strain-dependent reductions in open air tail-clip latencies, and these reductions were also strongly correlated with MAC (r = -0.67 and -0.71). The authors suggest that genetic variability in isoflurane MAC (but not MACLORR) may reflect genetic variability in the underlying sensitivity to the noxious stimulus being used to measure MAC. This variable sensitivity to nociception in the awake state is at least partially mediated by endogenous antinociceptive mechanisms activated by the tail-clip stimulus itself.

  5. Comparison of Enterococcus faecium and Enterococcus faecalis Strains isolated from water and clinical samples: antimicrobial susceptibility and genetic relationships.

    Directory of Open Access Journals (Sweden)

    Gonzalo Castillo-Rojas

    Full Text Available Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation, respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE. E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species.

  6. Comparison of Enterococcus faecium and Enterococcus faecalis Strains isolated from water and clinical samples: antimicrobial susceptibility and genetic relationships.

    Science.gov (United States)

    Castillo-Rojas, Gonzalo; Mazari-Hiríart, Marisa; Ponce de León, Sergio; Amieva-Fernández, Rosa I; Agis-Juárez, Raúl A; Huebner, Johannes; López-Vidal, Yolanda

    2013-01-01

    Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area) and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation), respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE). E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species.

  7. Correlation among genetic, Euclidean, temporal, and herd ownership distances of porcine reproductive and respiratory syndrome virus strains in Quebec, Canada

    Directory of Open Access Journals (Sweden)

    Lambert Marie-Ève

    2012-06-01

    Full Text Available Abstract Background Porcine reproductive and respiratory syndrome (PRRS is a viral disease that has a major economic impact for the swine industry. Its control is mostly directed towards preventing its spread which requires a better understanding of the mechanisms of transmission of the virus between herds. The objectives of this study were to describe the genetic diversity and to assess the correlation among genetic, Euclidean and temporal distances and ownership to better understand pathways of transmission. Results A cross-sectional study was conducted on sites located in a high density area of swine production in Quebec. Geographical coordinates (longitude/latitude, date of submission and ownership were obtained for each site. ORF5 sequencing was attempted on PRRSV positive sites. Proportion of pairwise combinations of strains having ≥98% genetic homology were analysed according to Euclidean distances and ownership. Correlations between genetic, Euclidean and temporal distances and ownership were assessed using Mantel tests on continuous and binary matrices. Sensitivity of the correlations between genetic and Euclidean as well as temporal distances was evaluated for different Euclidean and temporal distance thresholds. An ORF5 sequence was identified for 132 of the 176 (75% PRRSV positive sites; 122 were wild-type strains. The mean (min-max genetic, Euclidean and temporal pairwise distances were 11.6% (0–18.7, 15.0 km (0.04-45.7 and 218 days (0–852, respectively. Significant positive correlations were observed between genetic and ownership, genetic and Euclidean and between genetic and temporal binary distances. The relationship between genetic and ownership suggests either common sources of animals or semen, employees, technical services or vehicles, whereas that between genetic and Euclidean binary distances is compatible with area spread of the virus. The latter correlation was observed only up to 5 km. Conclusions This study

  8. Common genetic variation near MC4R has a sex-specific impact on human brain structure and eating behavior.

    Directory of Open Access Journals (Sweden)

    Annette Horstmann

    Full Text Available Obesity is associated with genetic and environmental factors but the underlying mechanisms remain poorly understood. Recent genome-wide association studies (GWAS identified obesity- and type 2 diabetes-associated genetic variants located within or near genes that modulate brain activity and development. Among the top hits is rs17782313 near MC4R, encoding for the melanocortin-4-receptor, which is expressed in brain regions that regulate eating. Here, we hypothesized rs17782313-associated changes in human brain regions that regulate eating behavior. Therefore, we examined effects of common variants at rs17782313 near MC4R on brain structure and eating behavior. Only in female homozygous carriers of the risk allele we found significant increases of gray matter volume (GMV in the right amygdala, a region known to influence eating behavior, and the right hippocampus, a structure crucial for memory formation and learning. Further, we found bilateral increases in medial orbitofrontal cortex, a multimodal brain structure encoding the subjective value of reinforcers, and bilateral prefrontal cortex, a higher order regulation area. There was no association between rs17782313 and brain structure in men. Moreover, among female subjects only, we observed a significant increase of 'disinhibition', and, more specifically, on 'emotional eating' scores of the Three Factor Eating Questionnaire in carriers of the variant rs17782313's risk allele. These findings suggest that rs17782313's effect on eating behavior is mediated by central mechanisms and that these effects are sex-specific.

  9. Genetic and antigenic analysis of H5N1 viruses for selection of HA-donor virus for vaccine strains.

    Science.gov (United States)

    Bhatia, S; Kunal, A; Khandia, R; Siddiqui, A; Pateriya, A K; Sood, R

    2013-12-01

    Genetic and antigenic analysis of H5N1 viruses, isolated in India during a period from year 2006 to 2010, was carried out for selection of the potential H5-HA (haemagglutinin) gene donor virus for developing a reverse genetics based DIVA marker H5 vaccine for poultry in India. Out of the 47 H5N1 viruses (clade 2.2), 14 representative viruses were selected on the basis of amino acid sequence analysis of HA1 gene for further antigenic characterization. Using antigenic cartography, an antigenic map was constructed based on the data of cross-HI (haemagglutinin inhibition) titration of 14 sera versus 14 viruses to visualize the relatedness among the antigens and antigenic coverage of the sera. Sera against five H5N1 viruses (A/crow/Assam/142119/2008, A/chicken/West Bengal/100879/2008, A/chicken/West Bengal/155505/2009, A/chicken/West Bengal/80995/2008 and A/chicken/West Bengal/81760/2008) exhibited maximum (100 %) antigenic coverage, hence, were selected as the potential HA donor viruses. However, the virus strain A/chicken/West Bengal/80995/2008 matched completely with the consensus amino acid sequence of the 47 viruses, therefore, was considered the best HA donor candidate out of the five showing 100 % antigenic coverage. The present study demonstrates a stepwise methodology for logical selection of vaccine strain or HA gene donor strain for developing H5 vaccines using genetic and antigenic data.

  10. Detection of novel strains genetically related to Anaplasma platys in Tunisian one-humped camels (Camelus dromedarius).

    Science.gov (United States)

    Belkahia, Hanène; Ben Said, Mourad; Sayahi, Lotfi; Alberti, Alberto; Messadi, Lilia

    2015-10-29

    Little information is currently available regarding the presence of Anaplasma species in North African dromedaries. To fill this gap in knowledge, the prevalence, risk factors, and genetic diversity of Anaplasma species were investigated in Tunisian dromedary camels. A total of 226 camels from three different bioclimatic areas were sampled and tested for the presence of Anaplasma species by quantitative polymerase chain reaction (qPCR) and nested polymerase chain reaction (nPCR) assays. Detected Anaplasma strains were characterized by 16S rRNA sequence analysis. Overall infection rate of Anaplasma spp. was 17.7%, and was significantly higher in females. Notably, A. marginale, A. centrale, A. bovis, and A. phagocytophilum were not detected. Animals were severely infested by three tick species belonging to the genus Hyalomma (H. dromedarii, H. impeltatum, and H. excavatum). Alignment, similarity comparison, and phylogenetic analysis of the 16S rRNA sequence variants obtained in this study suggest that Tunisian dromedaries are infected by more than one novel Anaplasma strain genetically related to A. platys. This study reports the presence of novel Anaplasma sp. strains genetically related to A. platys in dromedaries from various bioclimatic areas of Tunisia. Findings raise new concerns about the specificity of the direct and indirect diagnostic tests routinely used to detect different Anaplasma species in ruminants and provide useful molecular information to elucidate the evolutionary history of bacterial species related to A. platys.

  11. Genetic Manipulation of Prochlorococcus Strain MIT9313: Green Fluorescent Protein Expression from an RSF1010 Plasmid and Tn5 Transposition▿

    Science.gov (United States)

    Tolonen, Andrew C.; Liszt, Gregory B.; Hess, Wolfgang R.

    2006-01-01

    Prochlorococcus is the smallest oxygenic phototroph yet described. It numerically dominates the phytoplankton community in the mid-latitude oceanic gyres, where it has an important role in the global carbon cycle. The complete genomes of several Prochlorococcus strains have been sequenced, revealing that nearly half of the genes in each genome are of unknown function. Genetic methods, such as reporter gene assays and tagged mutagenesis, are critical to unveiling the functions of these genes. Here, we describe conditions for the transfer of plasmid DNA into Prochlorococcus strain MIT9313 by interspecific conjugation with Escherichia coli. Following conjugation, E. coli bacteria were removed from the Prochlorococcus cultures by infection with E. coli phage T7. We applied these methods to show that an RSF1010-derived plasmid will replicate in Prochlorococcus strain MIT9313. When this plasmid was modified to contain green fluorescent protein, we detected its expression in Prochlorococcus by Western blotting and cellular fluorescence. Further, we applied these conjugation methods to show that a mini-Tn5 transposon will transpose in vivo in Prochlorococcus. These genetic advances provide a basis for future genetic studies with Prochlorococcus, a microbe of ecological importance in the world's oceans. PMID:17041154

  12. Genetic manipulation of Prochlorococcus strain MIT9313: green fluorescent protein expression from an RSF1010 plasmid and Tn5 transposition.

    Science.gov (United States)

    Tolonen, Andrew C; Liszt, Gregory B; Hess, Wolfgang R

    2006-12-01

    Prochlorococcus is the smallest oxygenic phototroph yet described. It numerically dominates the phytoplankton community in the mid-latitude oceanic gyres, where it has an important role in the global carbon cycle. The complete genomes of several Prochlorococcus strains have been sequenced, revealing that nearly half of the genes in each genome are of unknown function. Genetic methods, such as reporter gene assays and tagged mutagenesis, are critical to unveiling the functions of these genes. Here, we describe conditions for the transfer of plasmid DNA into Prochlorococcus strain MIT9313 by interspecific conjugation with Escherichia coli. Following conjugation, E. coli bacteria were removed from the Prochlorococcus cultures by infection with E. coli phage T7. We applied these methods to show that an RSF1010-derived plasmid will replicate in Prochlorococcus strain MIT9313. When this plasmid was modified to contain green fluorescent protein, we detected its expression in Prochlorococcus by Western blotting and cellular fluorescence. Further, we applied these conjugation methods to show that a mini-Tn5 transposon will transpose in vivo in Prochlorococcus. These genetic advances provide a basis for future genetic studies with Prochlorococcus, a microbe of ecological importance in the world's oceans.

  13. Genetic characterization of measles virus strains isolated during an epidemic cluster in Puglia, Italy 2006–2007

    Directory of Open Access Journals (Sweden)

    Martinelli Domenico

    2007-09-01

    Full Text Available Abstract The genetic characterization of wild-type measles strains isolated during an epidemic cluster of measles occurred in Puglia (South Italy, between November 2006 and January 2007, was performed. Measles virus (MV detection was carried out by a nested RT-PCR on 8 of 18 total cases. The viruses were analyzed using the standard genotyping protocols. The N gene sequences of the strains from outbreak were identical to each other, and sequence analysis revealed that the viruses belonged to genotype B3, subgroup B3.1, never identified before in Italy. An importation of measles B3.1 strains from Africa was hypothesized. Molecular surveillance will help to monitor the progress in measles elimination.

  14. Experimental envenoming of mice with venom from the scorpion Centruroides limpidus limpidus: differences in mortality and symptoms with and without antibody therapy relating to differences in age, sex and strain of mouse.

    Science.gov (United States)

    Padilla, Alejandro; Govezensky, Tzipe; Possani, Lourival D; Larralde, Carlos

    2003-06-01

    C57Bl/6J and BALB/cAnN inbred strains of mice differed significantly in mortality and symptoms when intoxicated subcutaneously with one LD(50) of venom from Centruroides limpidus limpidus. Higher mortality was observed in C57Bl/6J than in BALB/cAnN. Also, C57Bl/6J mice more quickly developed muscular and respiratory collapse whilst BALB/cAnN mice were hyperactive before dying. Also, the symptoms in the survivors lasted for 24 h in C57Bl/6J and for 2 h in BALB/cAnN. The age and sex of mice were also related to mortality: younger mice were more resistant than older mice and females were more susceptible than males, especially in the younger groups. Antivenom (horse F(ab')(2)) administration 5-10 min after envenoming of mice with one LD(50) rescued 60% of BALB/cAnN and 52% of C57Bl/6J mice, respectively. Results indicate that genetic background, gender and age differences are of consequence in the pathogenesis of C. limpidus scorpion envenomation in mice, and that timely treatment with active antivenom F(ab')(2) saves a significant fraction of intoxicated mice without statistically significant distinction of strains.

  15. Taxonomic analysis of cryptococcus species complex strain S8012 revealed Cryptococcus gattii with high heterogeneity on the genetics

    Institute of Scientific and Technical Information of China (English)

    CHEN Min; LIAO Wan-qing; WU Shao-xi; YAO Zhi-rong; PAN Wei-hua; LIAO Yong

    2011-01-01

    Background Initially, Cryptococcus (C.) neoformans was previously divided into two varieties comprising C. neoformans var. neoformans and C. neoformans var. gattii. Currently, taxonomic studies defined C. neoformans as C. species complex, which contains C. neoformans var. neoformans (serotype D), the hybrid isolates (serotype AD), C. neoformans var. grubii (serotype A) and C. gattii (serotypes B and C). However, Liao and his team once isolated a unique C. gattii isolate, namely strain S8012 with unique phenotype from cerebrospinal fluid (CSF) of a 43-year-old male patient in the Shanghai Changzheng Hospital and described as C. neoformans var. shanghaiensis in 1980s. The aim of this study was to explore the genetic background and polymorphism of Chinese clinical C. gattii isolates.Methods S8012 was analyzed as representative strain using the M13-polymerase chain reaction (PCR) fingerprinting pattern and multilocus sequence analysis including internal transcribed spacers of rDNA (ITS region), the intergenic spacer 1 regions (IGS1), RPB1, RPB2, CNLAC1, and TEF1 genes.Results The PCR fingerprinting pattern results showed strain S8012 belonged to molecular types VGI, and phylogenetic analysis suggested strain S8012 was grouped into the cluster of C. gattii environmental isolates originated from Eucalyptus camaldulensis trees in Australia.Conclusion C. gattii isolates from Chinese patients expresses high polymorphism on the phenotype, and molecular type VQI isolates from China have a close genetic relationship with the C. gattii isolates from Australia.

  16. Sex-stratified Genome-wide Association Studies Including 270,000 Individuals Show Sexual Dimorphism in Genetic Loci for Anthropometric Traits

    DEFF Research Database (Denmark)

    Randall, Joshua C; Winkler, Thomas W; Kutalik, Zoltán

    2013-01-01

    Given the anthropometric differences between men and women and previous evidence of sex-difference in genetic effects, we conducted a genome-wide search for sexually dimorphic associations with height, weight, body mass index, waist circumference, hip circumference, and waist-to-hip-ratio (133,72...

  17. A Method for the Determination of Genetic Sex in the Fathead Minnow, Pimephales promelas, to Support Testing of Endocrine-active Chemicals

    Science.gov (United States)

    Fathead minnows are used as a model fish species for the characterization of the endocrine-disrupting potential of environmental contaminants. This research describes the development of a PCR method that can determine the genetic sex in this species. This method, when incorpora...

  18. A sex-averaged genetic linkage map in coastal Douglas-fir (Pseudotsuga menziesii [Mirb] Franco var menziesii) based on RFLP and RAPD markers

    Science.gov (United States)

    K.D. Jermstad; D.L. Bassoni; N.C. Wheeler; D.B. Neale

    1998-01-01

    We have constructed a sex-averaged genetic linkage map in coastal Douglas-fir ( Pseudotsuga menziesii [Mirb.] Franco var menziesii) using a three-generation outcrossed pedigree and molecular markers. Our research objectives are to learn about genome organization and to identify markers associated with adaptive traits. The map...

  19. Sex-stratified genome-wide association studies including 270,000 individuals show sexual dimorphism in genetic loci for anthropometric traits

    NARCIS (Netherlands)

    Randall, Joshua C; Winkler, Thomas W; Kutalik, Zoltán; Berndt, Sonja I; Jackson, Anne U; Monda, Keri L; Kilpeläinen, Tuomas O; Esko, Tõnu; Mägi, Reedik; Li, Shengxu; Workalemahu, Tsegaselassie; Feitosa, Mary F; Croteau-Chonka, Damien C; Day, Felix R; Fall, Tove; Ferreira, Teresa; Gustafsson, Stefan; Locke, Adam E; Mathieson, Iain; Scherag, Andre; Vedantam, Sailaja; Wood, Andrew R; Liang, Liming; Steinthorsdottir, Valgerdur; Thorleifsson, Gudmar; Dermitzakis, Emmanouil T; Dimas, Antigone S; Karpe, Fredrik; Min, Josine L; Nicholson, George; Clegg, Deborah J; Person, Thomas; Krohn, Jon P; Bauer, Sabrina; Buechler, Christa; Eisinger, Kristina; Bonnefond, Amélie; Froguel, Philippe; Hottenga, Jouke-Jan; Prokopenko, Inga; Waite, Lindsay L; Harris, Tamara B; Smith, Albert Vernon; Shuldiner, Alan R; McArdle, Wendy L; Caulfield, Mark J; Munroe, Patricia B; Grönberg, Henrik; Chen, Yii-Der Ida; Li, Guo; Beckmann, Jacques S; Johnson, Toby; Thorsteinsdottir, Unnur; Teder-Laving, Maris; Khaw, Kay-Tee; Wareham, Nicholas J; Zhao, Jing Hua; Amin, Najaf; Oostra, Ben A; Kraja, Aldi T; Province, Michael A; Cupples, L Adrienne; Heard-Costa, Nancy L; Kaprio, Jaakko; Ripatti, Samuli; Surakka, Ida; Collins, Francis S; Saramies, Jouko; Tuomilehto, Jaakko; Jula, Antti; Salomaa, Veikko; Erdmann, Jeanette; Hengstenberg, Christian; Loley, Christina; Schunkert, Heribert; Lamina, Claudia; Wichmann, H Erich; Albrecht, Eva; Gieger, Christian; Hicks, Andrew A; Johansson, Asa; Pramstaller, Peter P; Kathiresan, Sekar; Speliotes, Elizabeth K; Penninx, Brenda; Hartikainen, Anna-Liisa; Jarvelin, Marjo-Riitta; Gyllensten, Ulf; Boomsma, Dorret I; Campbell, Harry; Wilson, James F; Chanock, Stephen J; Farrall, Martin; Goel, Anuj; Medina-Gomez, Carolina; Rivadeneira, Fernando; Estrada, Karol; Uitterlinden, André G; Hofman, Albert; Zillikens, M Carola; den Heijer, Martin; Kiemeney, Lambertus A; Maschio, Andrea; Hall, Per; Tyrer, Jonathan; Teumer, Alexander; Völzke, Henry; Kovacs, Peter; Tönjes, Anke; Mangino, Massimo; Spector, Tim D; Hayward, Caroline; Rudan, Igor; Hall, Alistair S; Samani, Nilesh J; Attwood, Antony Paul; Sambrook, Jennifer G; Hung, Joseph; Palmer, Lyle J; Lokki, Marja-Liisa; Sinisalo, Juha; Boucher, Gabrielle; Huikuri, Heikki; Lorentzon, Mattias; Ohlsson, Claes; Eklund, Niina; Eriksson, Johan G; Barlassina, Cristina; Rivolta, Carlo; Nolte, Ilja M; Snieder, Harold; Van der Klauw, Melanie M; Van Vliet-Ostaptchouk, Jana V; Gejman, Pablo V; Shi, Jianxin; Jacobs, Kevin B; Wang, Zhaoming; Bakker, Stephan J L; Mateo Leach, Irene; Navis, Gerjan; van der Harst, Pim; Martin, Nicholas G; Medland, Sarah E; Montgomery, Grant W; Yang, Jian; Chasman, Daniel I; Ridker, Paul M; Rose, Lynda M; Lehtimäki, Terho; Raitakari, Olli; Absher, Devin; Iribarren, Carlos; Basart, Hanneke; Hovingh, Kees G; Hyppönen, Elina; Power, Chris; Anderson, Denise; Beilby, John P; Hui, Jennie; Jolley, Jennifer; Sager, Hendrik; Bornstein, Stefan R; Schwarz, Peter E H; Kristiansson, Kati; Perola, Markus; Lindström, Jaana; Swift, Amy J; Uusitupa, Matti; Atalay, Mustafa; Lakka, Timo A; Rauramaa, Rainer; Bolton, Jennifer L; Fowkes, Gerry; Fraser, Ross M; Price, Jackie F; Fischer, Krista; Krjutå Kov, Kaarel; Metspalu, Andres; Mihailov, Evelin; Langenberg, Claudia; Luan, Jian'an; Ong, Ken K; Chines, Peter S; Keinanen-Kiukaanniemi, Sirkka M; Saaristo, Timo E; Edkins, Sarah; Franks, Paul W; Hallmans, Göran; Shungin, Dmitry; Morris, Andrew David; Palmer, Colin N A; Erbel, Raimund; Moebus, Susanne; Nöthen, Markus M; Pechlivanis, Sonali; Hveem, Kristian; Narisu, Narisu; Hamsten, Anders; Humphries, Steve E; Strawbridge, Rona J; Tremoli, Elena; Grallert, Harald; Thorand, Barbara; Illig, Thomas; Koenig, Wolfgang; Müller-Nurasyid, Martina; Peters, Annette; Boehm, Bernhard O; Kleber, Marcus E; März, Winfried; Winkelmann, Bernhard R; Kuusisto, Johanna; Laakso, Markku; Arveiler, Dominique; Cesana, Giancarlo; Kuulasmaa, Kari; Virtamo, Jarmo; Yarnell, John W G; Kuh, Diana; Wong, Andrew; Lind, Lars; de Faire, Ulf; Gigante, Bruna; Magnusson, Patrik K E; Pedersen, Nancy L; Dedoussis, George; Dimitriou, Maria; Kolovou, Genovefa; Kanoni, Stavroula; Stirrups, Kathleen; Bonnycastle, Lori L; Njølstad, Inger; Wilsgaard, Tom; Ganna, Andrea; Rehnberg, Emil; Hingorani, Aroon; Kivimaki, Mika; Kumari, Meena; Assimes, Themistocles L; Barroso, Inês; Boehnke, Michael; Borecki, Ingrid B; Deloukas, Panos; Fox, Caroline S; Frayling, Timothy; Groop, Leif C; Haritunians, Talin; Hunter, David; Ingelsson, Erik; Kaplan, Robert; Mohlke, Karen L; O'Connell, Jeffrey R; Schlessinger, David; Strachan, David P; Stefansson, Kari; van Duijn, Cornelia M; Abecasis, Gonçalo R; McCarthy, Mark I; Hirschhorn, Joel N; Qi, Lu; Loos, Ruth J F; Lindgren, Cecilia M; North, Kari E; Heid, Iris M

    2013-01-01

    Given the anthropometric differences between men and women and previous evidence of sex-difference in genetic effects, we conducted a genome-wide search for sexually dimorphic associations with height, weight, body mass index, waist circumference, hip circumference, and waist-to-hip-ratio (133,723 i

  20. Sex-stratified genome-wide association studies including 270,000 individuals show sexual dimorphism in genetic loci for anthropometric traits.

    Directory of Open Access Journals (Sweden)

    Joshua C Randall

    2013-06-01

    Full Text Available Given the anthropometric differences between men and women and previous evidence of sex-difference in genetic effects, we conducted a genome-wide search for sexually dimorphic associations with height, weight, body mass index, waist circumference, hip circumference, and waist-to-hip-ratio (133,723 individuals and took forward 348 SNPs into follow-up (additional 137,052 individuals in a total of 94 studies. Seven loci displayed significant sex-difference (FDR<5%, including four previously established (near GRB14/COBLL1, LYPLAL1/SLC30A10, VEGFA, ADAMTS9 and three novel anthropometric trait loci (near MAP3K1, HSD17B4, PPARG, all of which were genome-wide significant in women (P<5×10(-8, but not in men. Sex-differences were apparent only for waist phenotypes, not for height, weight, BMI, or hip circumference. Moreover, we found no evidence for genetic effects with opposite directions in men versus women. The PPARG locus is of specific interest due to its role in diabetes genetics and therapy. Our results demonstrate the value of sex-specific GWAS to unravel the sexually dimorphic genetic underpinning of complex traits.

  1. Sex-stratified genome-wide association studies including 270,000 individuals show sexual dimorphism in genetic loci for anthropometric traits

    NARCIS (Netherlands)

    Randall, Joshua C; Winkler, Thomas W; Kutalik, Zoltán; Berndt, Sonja I; Jackson, Anne U; Monda, Keri L; Kilpeläinen, Tuomas O; Esko, Tõnu; Mägi, Reedik; Li, Shengxu; Workalemahu, Tsegaselassie; Feitosa, Mary F; Croteau-Chonka, Damien C; Day, Felix R; Fall, Tove; Ferreira, Teresa; Gustafsson, Stefan; Locke, Adam E; Mathieson, Iain; Scherag, Andre; Vedantam, Sailaja; Wood, Andrew R; Liang, Liming; Steinthorsdottir, Valgerdur; Thorleifsson, Gudmar; Dermitzakis, Emmanouil T; Dimas, Antigone S; Karpe, Fredrik; Min, Josine L; Nicholson, George; Clegg, Deborah J; Person, Thomas; Krohn, Jon P; Bauer, Sabrina; Buechler, Christa; Eisinger, Kristina; Bonnefond, Amélie; Froguel, Philippe; Hottenga, Jouke-Jan; Prokopenko, Inga; Waite, Lindsay L; Harris, Tamara B; Smith, Albert Vernon; Shuldiner, Alan R; McArdle, Wendy L; Caulfield, Mark J; Munroe, Patricia B; Grönberg, Henrik; Chen, Yii-Der Ida; Li, Guo; Beckmann, Jacques S; Johnson, Toby; Thorsteinsdottir, Unnur; Teder-Laving, Maris; Khaw, Kay-Tee; Wareham, Nicholas J; Zhao, Jing Hua; Amin, Najaf; Oostra, Ben A; Kraja, Aldi T; Province, Michael A; Cupples, L Adrienne; Heard-Costa, Nancy L; Kaprio, Jaakko; Ripatti, Samuli; Surakka, Ida; Collins, Francis S; Saramies, Jouko; Tuomilehto, Jaakko; Jula, Antti; Salomaa, Veikko; Erdmann, Jeanette; Hengstenberg, Christian; Loley, Christina; Schunkert, Heribert; Lamina, Claudia; Wichmann, H Erich; Albrecht, Eva; Gieger, Christian; Hicks, Andrew A; Johansson, Asa; Pramstaller, Peter P; Kathiresan, Sekar; Speliotes, Elizabeth K; Penninx, Brenda; Hartikainen, Anna-Liisa; Jarvelin, Marjo-Riitta; Gyllensten, Ulf; Boomsma, Dorret I; Campbell, Harry; Wilson, James F; Chanock, Stephen J; Farrall, Martin; Goel, Anuj; Medina-Gomez, Carolina; Rivadeneira, Fernando; Estrada, Karol; Uitterlinden, André G; Hofman, Albert; Zillikens, M Carola; den Heijer, Martin; Kiemeney, Lambertus A; Maschio, Andrea; Hall, Per; Tyrer, Jonathan; Teumer, Alexander; Völzke, Henry; Kovacs, Peter; Tönjes, Anke; Mangino, Massimo; Spector, Tim D; Hayward, Caroline; Rudan, Igor; Hall, Alistair S; Samani, Nilesh J; Attwood, Antony Paul; Sambrook, Jennifer G; Hung, Joseph; Palmer, Lyle J; Lokki, Marja-Liisa; Sinisalo, Juha; Boucher, Gabrielle; Huikuri, Heikki; Lorentzon, Mattias; Ohlsson, Claes; Eklund, Niina; Eriksson, Johan G; Barlassina, Cristina; Rivolta, Carlo; Nolte, Ilja M; Snieder, Harold; Van der Klauw, Melanie M; Van Vliet-Ostaptchouk, Jana V; Gejman, Pablo V; Shi, Jianxin; Jacobs, Kevin B; Wang, Zhaoming; Bakker, Stephan J L; Mateo Leach, Irene; Navis, Gerjan; van der Harst, Pim; Martin, Nicholas G; Medland, Sarah E; Montgomery, Grant W; Yang, Jian; Chasman, Daniel I; Ridker, Paul M; Rose, Lynda M; Lehtimäki, Terho; Raitakari, Olli; Absher, Devin; Iribarren, Carlos; Basart, Hanneke; Hovingh, Kees G; Hyppönen, Elina; Power, Chris; Anderson, Denise; Beilby, John P; Hui, Jennie; Jolley, Jennifer; Sager, Hendrik; Bornstein, Stefan R; Schwarz, Peter E H; Kristiansson, Kati; Perola, Markus; Lindström, Jaana; Swift, Amy J; Uusitupa, Matti; Atalay, Mustafa; Lakka, Timo A; Rauramaa, Rainer; Bolton, Jennifer L; Fowkes, Gerry; Fraser, Ross M; Price, Jackie F; Fischer, Krista; Krjutå Kov, Kaarel; Metspalu, Andres; Mihailov, Evelin; Langenberg, Claudia; Luan, Jian'an; Ong, Ken K; Chines, Peter S; Keinanen-Kiukaanniemi, Sirkka M; Saaristo, Timo E; Edkins, Sarah; Franks, Paul W; Hallmans, Göran; Shungin, Dmitry; Morris, Andrew David; Palmer, Colin N A; Erbel, Raimund; Moebus, Susanne; Nöthen, Markus M; Pechlivanis, Sonali; Hveem, Kristian; Narisu, Narisu; Hamsten, Anders; Humphries, Steve E; Strawbridge, Rona J; Tremoli, Elena; Grallert, Harald; Thorand, Barbara; Illig, Thomas; Koenig, Wolfgang; Müller-Nurasyid, Martina; Peters, Annette; Boehm, Bernhard O; Kleber, Marcus E; März, Winfried; Winkelmann, Bernhard R; Kuusisto, Johanna; Laakso, Markku; Arveiler, Dominique; Cesana, Giancarlo; Kuulasmaa, Kari; Virtamo, Jarmo; Yarnell, John W G; Kuh, Diana; Wong, Andrew; Lind, Lars; de Faire, Ulf; Gigante, Bruna; Magnusson, Patrik K E; Pedersen, Nancy L; Dedoussis, George; Dimitriou, Maria; Kolovou, Genovefa; Kanoni, Stavroula; Stirrups, Kathleen; Bonnycastle, Lori L; Njølstad, Inger; Wilsgaard, Tom; Ganna, Andrea; Rehnberg, Emil; Hingorani, Aroon; Kivimaki, Mika; Kumari, Meena; Assimes, Themistocles L; Barroso, Inês; Boehnke, Michael; Borecki, Ingrid B; Deloukas, Panos; Fox, Caroline S; Frayling, Timothy; Groop, Leif C; Haritunians, Talin; Hunter, David; Ingelsson, Erik; Kaplan, Robert; Mohlke, Karen L; O'Connell, Jeffrey R; Schlessinger, David; Strachan, David P; Stefansson, Kari; van Duijn, Cornelia M; Abecasis, Gonçalo R; McCarthy, Mark I; Hirschhorn, Joel N; Qi, Lu; Loos, Ruth J F; Lindgren, Cecilia M; North, Kari E; Heid, Iris M

    Given the anthropometric differences between men and women and previous evidence of sex-difference in genetic effects, we conducted a genome-wide search for sexually dimorphic associations with height, weight, body mass index, waist circumference, hip circumference, and waist-to-hip-ratio (133,723

  2. Identification of Brucella melitensis Rev.1 vaccine-strain genetic markers: Towards understanding the molecular mechanism behind virulence attenuation.

    Science.gov (United States)

    Issa, Mohammad Nouh; Ashhab, Yaqoub

    2016-09-22

    Brucella melitensis Rev.1 is an avirulent strain that is widely used as a live vaccine to control brucellosis in small ruminants. Although an assembled draft version of Rev.1 genome has been available since 2009, this genome has not been investigated to characterize this important vaccine. In the present work, we used the draft genome of Rev.1 to perform a thorough genomic comparison and sequence analysis to identify and characterize the panel of its unique genetic markers. The draft genome of Rev.1 was compared with genome sequences of 36 different Brucella melitensis strains from the Brucella project of the Broad Institute of MIT and Harvard. The comparative analyses revealed 32 genetic alterations (30 SNPs, 1 single-bp insertion and 1 single-bp deletion) that are exclusively present in the Rev.1 genome. In silico analyses showed that 9 out of the 17 non-synonymous mutations are deleterious. Three ABC transporters are among the disrupted genes that can be linked to virulence attenuation. Out of the 32 mutations, 11 Rev.1 specific markers were selected to test their potential to discriminate Rev.1 using a bi-directional allele-specific PCR assay. Six markers were able to distinguish between Rev.1 and a set of control strains. We succeeded in identifying a panel of 32 genome-specific markers of the B. melitensis Rev.1 vaccine strain. Extensive in silico analysis showed that a considerable number of these mutations could severely affect the function of the associated genes. In addition, some of the discovered markers were able to discriminate Rev.1 strain from a group of control strains using practical PCR tests that can be applied in resource-limited settings.

  3. Genetic Diversity: Geographical Distribution and Toxin Profiles of Microcystis Strains (Cyanobacteria) in China

    Institute of Scientific and Technical Information of China (English)

    Zhong-Xing Wu; Nan-Qin Gan; Li-Rong Song

    2007-01-01

    Twenty strains of Microcystis Kütz were isolated from different freshwater bodies in China to analyze the diversity,geographical distribution and toxin profiles. Based on whole-cell polymerase chain reaction of cpcBA-IGS nucleotide sequence, the derived neighbor-joining (NJ) and maximum parsimony (MP) trees indicate that these strains of Microcystis can be divided into four clusters. The strains from south, middle and north region of China formed distinct lineages, suggesting high diversity and a geographical distribution from south to north locations. Moreover,the results being indicating high variable genotypes of the strains of the Microcystis strains from the same lake show that there is high diversity of Microcystis within a water bloom population. Comparing the results of the present study with those reported for compared with 43 strains of Microcystis from other locations, also reveals Chinese strains have high similarity with those from regions in the North Hemispherical. This suggests that the Microcystis strains in the world might have a geographical distribution. Analysis of 30 strains using the primers MCF/TER and TOX2P/TOX2M showed that there was no correlation between the gene of cpcBA-IGS and the presence of mcy. Toxic strains were founded to be predominant in different water bodies throughout China.

  4. Genetic basis of differences in myxospore count between whirling disease-resistant and -susceptible strains of rainbow trout

    Science.gov (United States)

    Fetherman, Eric R.; Winkelman, Dana L.; Schisler, George J.; Antolin, Michael F.

    2012-01-01

    We used a quantitative genetics approach and estimated broad sense heritability (h2b) of myxospore count and the number of genes involved in myxospore formation to gain a better understanding of how resistance to Myxobolus cerebralis, the parasite responsible for whirling disease, is inherited in rainbow trout Oncorhynchus mykiss. An M. cerebralis-resistant strain of rainbow trout, the German Rainbow (GR), and a wild, susceptible strain of rainbow trout, the Colorado River Rainbow (CRR), were spawned to create 3 intermediate crossed populations (an F1 cross, F2 intercross, and a B2 backcross between the F1 and the CRR). Within each strain or cross, h2b was estimated from the between-family variance of myxospore counts using full-sibling families. Estimates of h2b and average myxospore counts were lowest in the GR strain, F1 cross, and F2 intercross (h2b = 0.34, 0.42, and 0.34; myxospores fish−1 = 275, 9566, and 45780, respectively), and highest in the B2 backcross and CRR strain (h2b = 0.93 and 0.89; myxospores fish−1 = 97865 and 187595, respectively). Comparison of means and a joint-scaling test suggest that resistance alleles arising from the GR strain are dominant to susceptible alleles from the CRR strain. Resistance was retained in the intermediate crosses but decreased as filial generation number increased (F2) or backcrossing occurred (B2). The estimated number of segregating loci responsible for differences in myxospore count in the parental strains was 9 ± 5. Our results indicate that resistance to M. cerebralis is a heritable trait within these populations and would respond to either artificial selection in hatcheries or natural selection in the wild.

  5. Genetic Control of Courtship Behavior in the Housefly : Evidence for a Conserved Bifurcation of the Sex-Determining Pathway

    NARCIS (Netherlands)

    Meier, Nicole; Kaeppeli, Simone Catherine; Niessen, Monika Hediger; Billeter, Jean-Christophe; Goodwin, Stephen F.; Bopp, Daniel

    2013-01-01

    In Drosophila melanogaster, genes of the sex-determination hierarchy orchestrate the development and differentiation of sex-specific tissues, establishing sex-specific physiology and neural circuitry. One of these sex-determination genes, fruitless (fru), plays a key role in the formation of neural

  6. Differential response of rat strains to obesogenic diets underlines the importance of genetic makeup of an individual towards obesity.

    Science.gov (United States)

    Mn, Muralidhar; Smvk, Prasad; Battula, Kiran Kumar; Nv, Giridharan; Kalashikam, Rajender Rao

    2017-08-22

    Obesity, a multifactorial disorder, results from a chronic imbalance of energy intake vs. expenditure. Apart from excessive consumption of high calorie diet, genetic predisposition also seems to be equally important for the development of obesity. However, the role of genetic predisposition in the etiology of obesity has not been clearly delineated. The present study addresses this problem by selecting three rat strains (WNIN, F-344, SD) with different genetic backgrounds and exposing them to high calorie diets. Rat strains were fed HF, HS, and HFS diets and assessed for physical, metabolic, biochemical, inflammatory responses, and mRNA expression. Under these conditions: significant increase in body weight, visceral adiposity, oxidative stress and systemic pro-inflammatory status; the hallmarks of central obesity were noticed only in WNIN. Further, they developed altered glucose and lipid homeostasis by exhibiting insulin resistance, impaired glucose tolerance, dyslipidemia and fatty liver condition. The present study demonstrates that WNIN is more prone to develop obesity and associated co-morbidities under high calorie environment. It thus underlines the cumulative role of genetics (nature) and diet (nurture) towards the development of obesity, which is critical for understanding this epidemic and devising new strategies to control and manage this modern malady.

  7. Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain.

    Science.gov (United States)

    Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Abbott, James; Micklem, Chris N; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

    2016-06-14

    Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology.

  8. Inferring the geographic mode of speciation by contrasting autosomal and sex-linked genetic diversity.

    Science.gov (United States)

    Chu, Jui-Hua; Wegmann, Daniel; Yeh, Chia-Fen; Lin, Rong-Chien; Yang, Xiao-Jun; Lei, Fu-Min; Yao, Cheng-Te; Zou, Fa-Sheng; Li, Shou-Hsien

    2013-11-01

    When geographic isolation drives speciation, concurrent termination of gene flow among genomic regions will occur immediately after the formation of the barrier between diverging populations. Alternatively, if speciation is driven by ecologically divergent selection, gene flow of selectively neutral genomic regions may go on between diverging populations until the completion of reproductive isolation. It may also lead to an unsynchronized termination of gene flow between genomic regions with different roles in the speciation process. Here, we developed a novel Approximate Bayesian Computation pipeline to infer the geographic mode of speciation by testing for a lack of postdivergence gene flow and a concurrent termination of gene flow in autosomal and sex-linked markers jointly. We applied this approach to infer the geographic mode of speciation for two allopatric highland rosefinches, the vinaceous rosefinch Carpodacus vinaceus and the Taiwan rosefinch C. formosanus from DNA polymorphisms of both autosomal and Z-linked loci. Our results suggest that the two rosefinch species diverged allopatrically approximately 0.5 Ma. Our approach allowed us further to infer that female effective population sizes are about five times larger than those of males, an estimate potentially useful when comparing the intensity of sexual selection across species.

  9. Isolation and genetic characterization of an Actinobacillus pleuropneumoniae serovar K12:O3 strain.

    Science.gov (United States)

    Ito, Hiroya; Matsumoto, Atsuko

    2015-01-01

    An atypical Actinobacillus pleuropneumoniae serovar 12 strain, termed QAS106, was isolated from a clinical case of porcine pleuropneumonia in Japan. An immunodiffusion (ID) test identified the strain as serovar 12. However, the ID test also demonstrated that strain QAS106 shared antigenic determinants with both the serovar 3 and 15 reference strains. Strain QAS106 was positive in the capsular serovar 12-specific polymerase chain reaction (PCR) assay, while the PCR toxin gene profiling and omlA PCR typing assays indicated that strain QAS106 was similar to serovar 3. The nucleotide sequence of the 16S ribosomal DNA (rDNA) of strain QAS106 was identical with that of serovars 3 and 12, but it showed 99.7% identity with that of serovar 15. Nucleotide sequence analysis revealed that genes involved in biosynthesis of the capsular polysaccharide (CPS) of strain QAS106 were identical to those of serovar 12 at the amino acid level. On the other hand, strain QAS106 would express putative proteins involved in the biosynthesis of lipopolysaccharide (LPS) O-polysaccharide (O-PS), the amino acid sequences of which were identical or nearly identical to those of serovars 3 and 15. In conclusion, strain QAS106 should be recognized as K12:O3, even though typical serovar 12 strains are K12:O12. The emergence of an atypical A. pleuropneumoniae serovar 12 strain expressing a rare combination of CPS and O-PS antigens would hamper precise serodiagnosis by the use of either CPS- or LPS-based serodiagnostic methodology alone. © 2014 The Author(s).

  10. Genetic and Biochemical Characterization of Monokaryotic Progeny Strains of Button Mushroom (Agaricus bisporus).

    Science.gov (United States)

    Kwon, Hyuk Woo; Choi, Min Ah; Yun, Yeo Hong; Oh, Youn-Lee; Kong, Won-Sik; Kim, Seong Hwan

    2015-03-01

    To promote the selection of promising monokaryotic strains of button mushroom (Agaricus bisporus) during breeding, 61 progeny strains derived from basidiospores of two different lines of dikaryotic parental strains, ASI1038 and ASI1346, were analyzed by nucleotide sequencing of the intergenic spacer I (IGS I) region in their rDNA and by extracellular enzyme assays. Nineteen different sizes of IGS I, which ranged from 1,301 to 1,348 bp, were present among twenty ASI1346-derived progeny strains, while 15 different sizes of IGS I, which ranged from 700 to 1,347 bp, were present among twenty ASI1038-derived progeny strains. Phylogenetic analysis of the IGS sequences revealed that different clades were present in both the ASI10388- and ASI1346-derived progeny strains. Plating assays of seven kinds of extracellular enzymes (β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease) also revealed apparent variation in the ability to produce extracellular enzymes among the 40 tested progeny strains from both parental A. bisporus strains. Overall, this study demonstrates that characterization of IGS I regions and extracellular enzymes is useful for the assessment of the substrate-degrading ability and heterogenicity of A. bisporus monokaryotic strains.

  11. Genetic divergence of Toxoplasma gondii strains associated with ocular toxoplasmosis, Brazil

    National Research Council Canada - National Science Library

    Khan, Asis; Jordan, Catherine; Muccioli, Cristina; Vallochi, Adriana L; Rizzo, Luiz V; Belfort, Jr, Rubens; Vitor, Ricardo W A; Silveira, Claudio; Sibley, L David

    2006-01-01

    .... To identify the genotypes of parasite strains associated with ocular disease, we compared 25 clinical and animal isolates of Toxoplasma gondii from Brazil to previously characterized clonal lineages...

  12. Comparative genotyping of Clostridium thermocellum strains isolated from biogas plants: genetic markers and characterization of cellulolytic potential.

    Science.gov (United States)

    Koeck, Daniela E; Zverlov, Vladimir V; Liebl, Wolfgang; Schwarz, Wolfgang H

    2014-07-01

    Clostridium thermocellum is among the most prevalent of known anaerobic cellulolytic bacteria. In this study, genetic and phenotypic variations among C. thermocellum strains isolated from different biogas plants were determined and different genotyping methods were evaluated on these isolates. At least two C. thermocellum strains were isolated independently from each of nine different biogas plants via enrichment on cellulose. Various DNA-based genotyping methods such as ribotyping, RAPD (Random Amplified Polymorphic DNA) and VNTR (Variable Number of Tandem Repeats) were applied to these isolates. One novel approach - the amplification of unknown target sequences between copies of a previously discovered Random Inserted Mobile Element (RIME) - was also tested. The genotyping method with the highest discriminatory power was found to be the amplification of the sequences between the insertion elements, where isolates from each biogas plant yielded a different band pattern. Cellulolytic potentials, optimal growth conditions and substrate spectra of all isolates were characterized to help identify phenotypic variations. Irrespective of the genotyping method used, the isolates from each individual biogas plant always exhibited identical patterns. This is suggestive of a single C. thermocellum strain exhibiting dominance in each biogas plant. The genotypic groups reflect the results of the physiological characterization of the isolates like substrate diversity and cellulase activity. Conversely, strains isolated across a range of biogas plants differed in their genotyping results and physiological properties. Both strains isolated from one biogas plant had the best specific cellulose-degrading properties and might therefore achieve superior substrate utilization yields in biogas fermenters.

  13. Phenotype and genetics of progressive sensorineural hearing loss (Snhl1 in the LXS set of recombinant inbred strains of mice.

    Directory of Open Access Journals (Sweden)

    Konrad Noben-Trauth

    Full Text Available Progressive sensorineural hearing loss is the most common form of acquired hearing impairment in the human population. It is also highly prevalent in inbred strains of mice, providing an experimental avenue to systematically map genetic risk factors and to dissect the molecular pathways that orchestrate hearing in peripheral sensory hair cells. Therefore, we ascertained hearing function in the inbred long sleep (ILS and inbred short sleep (ISS strains. Using auditory-evoked brain stem response (ABR and distortion product otoacoustic emission (DPOAE measurements, we found that ISS mice developed a high-frequency hearing loss at twelve weeks of age that progressed to lower frequencies by 26 weeks of age in the presence of normal endocochlear potentials and unremarkable inner ear histology. ILS mice exhibited milder hearing loss, showing elevated thresholds and reduced DPOAEs at the higher frequencies by 26 weeks of age. To map the genetic variants that underlie this hearing loss we computed ABR thresholds of 63 recombinant inbred stains derived from the ISS and ILS founder strains. A single locus was linked to markers associated with ISS alleles on chromosome 10 with a highly significant logarithm of odds (LOD score of 15.8. The 2-LOD confidence interval spans approximately 4 Megabases located at position 54-60 Mb. This locus, termed sensorineural hearing loss 1 (Snhl1, accounts for approximately 82% of the phenotypic variation. In summary, this study identifies a novel hearing loss locus on chromosome 10 and attests to the prevalence and genetic heterogeneity of progressive hearing loss in common mouse strains.

  14. Energy, ageing, fidelity and sex: oocyte mitochondrial DNA as a protected genetic template.

    Science.gov (United States)

    de Paula, Wilson B M; Lucas, Cathy H; Agip, Ahmed-Noor A; Vizcay-Barrena, Gema; Allen, John F

    2013-07-19

    Oxidative phosphorylation couples ATP synthesis to respiratory electron transport. In eukaryotes, this coupling occurs in mitochondria, which carry DNA. Respiratory electron transport in the presence of molecular oxygen generates free radicals, reactive oxygen species (ROS), which are mutagenic. In animals, mutational damage to mitochondrial DNA therefore accumulates within the lifespan of the individual. Fertilization generally requires motility of one gamete, and motility requires ATP. It has been proposed that oxidative phosphorylation is nevertheless absent in the special case of quiescent, template mitochondria, that these remain sequestered in oocytes and female germ lines and that oocyte mitochondrial DNA is thus protected from damage, but evidence to support that view has hitherto been lacking. Here we show that female gametes of Aurelia aurita, the common jellyfish, do not transcribe mitochondrial DNA, lack electron transport, and produce no free radicals. In contrast, male gametes actively transcribe mitochondrial genes for respiratory chain components and produce ROS. Electron microscopy shows that this functional division of labour between sperm and egg is accompanied by contrasting mitochondrial morphology. We suggest that mitochondrial anisogamy underlies division of any animal species into two sexes with complementary roles in sexual reproduction. We predict that quiescent oocyte mitochondria contain DNA as an unexpressed template that avoids mutational accumulation by being transmitted through the female germ line. The active descendants of oocyte mitochondria perform oxidative phosphorylation in somatic cells and in male gametes of each new generation, and the mutations that they accumulated are not inherited. We propose that the avoidance of ROS-dependent mutation is the evolutionary pressure underlying maternal mitochondrial inheritance and the developmental origin of the female germ line.

  15. The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study

    Science.gov (United States)

    Feitosa, Mary F.; Chu, Su; Czajkowski, Jacek; Esko, Tõnu; Fall, Tove; Kilpeläinen, Tuomas O.; Lu, Yingchang; Mägi, Reedik; Mihailov, Evelin; Pers, Tune H.; Rüeger, Sina; Teumer, Alexander; Ehret, Georg B.; Ferreira, Teresa; Heard-Costa, Nancy L.; Karjalainen, Juha; Lagou, Vasiliki; Mahajan, Anubha; Neinast, Michael D.; Prokopenko, Inga; Simino, Jeannette; Teslovich, Tanya M.; Jansen, Rick; Westra, Harm-Jan; White, Charles C.; Absher, Devin; Ahluwalia, Tarunveer S.; Ahmad, Shafqat; Albrecht, Eva; Alves, Alexessander Couto; Bragg-Gresham, Jennifer L.; de Craen, Anton J. M.; Bis, Joshua C.; Bonnefond, Amélie; Boucher, Gabrielle; Cadby, Gemma; Cheng, Yu-Ching; Chiang, Charleston W. K.; Delgado, Graciela; Demirkan, Ayse; Dueker, Nicole; Eklund, Niina; Eiriksdottir, Gudny; Eriksson, Joel; Feenstra, Bjarke; Fischer, Krista; Frau, Francesca; Galesloot, Tessel E.; Geller, Frank; Goel, Anuj; Gorski, Mathias; Grammer, Tanja B.; Gustafsson, Stefan; Haitjema, Saskia; Hottenga, Jouke-Jan; Huffman, Jennifer E.; Jackson, Anne U.; Jacobs, Kevin B.; Johansson, Åsa; Kaakinen, Marika; Kleber, Marcus E.; Lahti, Jari; Leach, Irene Mateo; Lehne, Benjamin; Liu, Youfang; Lo, Ken Sin; Lorentzon, Mattias; Luan, Jian'an; Madden, Pamela A. F.; Mangino, Massimo; McKnight, Barbara; Medina-Gomez, Carolina; Monda, Keri L.; Montasser, May E.; Müller, Gabriele; Müller-Nurasyid, Martina; Nolte, Ilja M.; Panoutsopoulou, Kalliope; Pascoe, Laura; Paternoster, Lavinia; Rayner, Nigel W.; Renström, Frida; Rizzi, Federica; Rose, Lynda M.; Ryan, Kathy A.; Salo, Perttu; Sanna, Serena; Scharnagl, Hubert; Shi, Jianxin; Smith, Albert Vernon; Southam, Lorraine; Stančáková, Alena; Steinthorsdottir, Valgerdur; Strawbridge, Rona J.; Sung, Yun Ju; Tachmazidou, Ioanna; Tanaka, Toshiko; Thorleifsson, Gudmar; Trompet, Stella; Pervjakova, Natalia; Tyrer, Jonathan P.; Vandenput, Liesbeth; van der Laan, Sander W; van der Velde, Nathalie; van Setten, Jessica; van Vliet-Ostaptchouk, Jana V.; Verweij, Niek; Vlachopoulou, Efthymia; Waite, Lindsay L.; Wang, Sophie R.; Wang, Zhaoming; Wild, Sarah H.; Willenborg, Christina; Wilson, James F.; Wong, Andrew; Yang, Jian; Yengo, Loïc; Yerges-Armstrong, Laura M.; Yu, Lei; Zhang, Weihua; Zhao, Jing Hua; Andersson, Ehm A.; Bakker, Stephan J. L.; Baldassarre, Damiano; Banasik, Karina; Barcella, Matteo; Barlassina, Cristina; Bellis, Claire; Benaglio, Paola; Blangero, John; Blüher, Matthias; Bonnet, Fabrice; Bonnycastle, Lori L.; Boyd, Heather A.; Bruinenberg, Marcel; Buchman, Aron S; Campbell, Harry; Chen, Yii-Der Ida; Chines, Peter S.; Claudi-Boehm, Simone; Cole, John; Collins, Francis S.; de Geus, Eco J. C.; de Groot, Lisette C. P. G. M.; Dimitriou, Maria; Duan, Jubao; Enroth, Stefan; Eury, Elodie; Farmaki, Aliki-Eleni; Forouhi, Nita G.; Friedrich, Nele; Gejman, Pablo V.; Gigante, Bruna; Glorioso, Nicola; Go, Alan S.; Gottesman, Omri; Gräßler, Jürgen; Grallert, Harald; Grarup, Niels; Gu, Yu-Mei; Broer, Linda; Ham, Annelies C.; Hansen, Torben; Harris, Tamara B.; Hartman, Catharina A.; Hassinen, Maija; Hastie, Nicholas; Hattersley, Andrew T.; Heath, Andrew C.; Henders, Anjali K.; Hernandez, Dena; Hillege, Hans; Holmen, Oddgeir; Hovingh, Kees G; Hui, Jennie; Husemoen, Lise L.; Hutri-Kähönen, Nina; Hysi, Pirro G.; Illig, Thomas; De Jager, Philip L.; Jalilzadeh, Shapour; Jørgensen, Torben; Jukema, J. Wouter; Juonala, Markus; Kanoni, Stavroula; Karaleftheri, Maria; Khaw, Kay Tee; Kinnunen, Leena; Kittner, Steven J.; Koenig, Wolfgang; Kolcic, Ivana; Kovacs, Peter; Krarup, Nikolaj T.; Kratzer, Wolfgang; Krüger, Janine; Kuh, Diana; Kumari, Meena; Kyriakou, Theodosios; Langenberg, Claudia; Lannfelt, Lars; Lanzani, Chiara; Lotay, Vaneet; Launer, Lenore J.; Leander, Karin; Lindström, Jaana; Linneberg, Allan; Liu, Yan-Ping; Lobbens, Stéphane; Luben, Robert; Lyssenko, Valeriya; Männistö, Satu; Magnusson, Patrik K.; McArdle, Wendy L.; Menni, Cristina; Merger, Sigrun; Milani, Lili; Montgomery, Grant W.; Morris, Andrew P.; Narisu, Narisu; Nelis, Mari; Ong, Ken K.; Palotie, Aarno; Pérusse, Louis; Pichler, Irene; Pilia, Maria G.; Pouta, Anneli; Rheinberger, Myriam; Ribel-Madsen, Rasmus; Richards, Marcus; Rice, Kenneth M.; Rice, Treva K.; Rivolta, Carlo; Salomaa, Veikko; Sanders, Alan R.; Sarzynski, Mark A.; Scholtens, Salome; Scott, Robert A.; Scott, William R.; Sebert, Sylvain; Sengupta, Sebanti; Sennblad, Bengt; Seufferlein, Thomas; Silveira, Angela; Slagboom, P. Eline; Smit, Jan H.; Sparsø, Thomas H.; Stirrups, Kathleen; Stolk, Ronald P.; Stringham, Heather M.; Swertz, Morris A; Swift, Amy J.; Syvänen, Ann-Christine; Tan, Sian-Tsung; Thorand, Barbara; Tönjes, Anke; Tremblay, Angelo; Tsafantakis, Emmanouil; van der Most, Peter J.; Völker, Uwe; Vohl, Marie-Claude; Vonk, Judith M.; Waldenberger, Melanie; Walker, Ryan W.; Wennauer, Roman; Widén, Elisabeth; Willemsen, Gonneke; Wilsgaard, Tom; Wright, Alan F.; Zillikens, M. Carola; van Dijk, Suzanne C.; van Schoor, Natasja M.; Asselbergs, Folkert W.; de Bakker, Paul I. W.; Beckmann, Jacques S.; Beilby, John; Bennett, David A.; Bergman, Richard N.; Bergmann, Sven; Böger, Carsten A.; Boehm, Bernhard O.; Boerwinkle, Eric; Boomsma, Dorret I.; Bornstein, Stefan R.; Bottinger, Erwin P.; Bouchard, Claude; Chambers, John C.; Chanock, Stephen J.; Chasman, Daniel I.; Cucca, Francesco; Cusi, Daniele; Dedoussis, George; Erdmann, Jeanette; Eriksson, Johan G.; Evans, Denis A.; de Faire, Ulf; Farrall, Martin; Ferrucci, Luigi; Ford, Ian; Franke, Lude; Franks, Paul W.; Froguel, Philippe; Gansevoort, Ron T.; Gieger, Christian; Grönberg, Henrik; Gudnason, Vilmundur; Gyllensten, Ulf; Hall, Per; Hamsten, Anders; van der Harst, Pim; Hayward, Caroline; Heliövaara, Markku; Hengstenberg, Christian; Hicks, Andrew A; Hingorani, Aroon; Hofman, Albert; Hu, Frank; Huikuri, Heikki V.; Hveem, Kristian; James, Alan L.; Jordan, Joanne M.; Jula, Antti; Kähönen, Mika; Kajantie, Eero; Kathiresan, Sekar; Kiemeney, Lambertus A. L. M.; Kivimaki, Mika; Knekt, Paul B.; Koistinen, Heikki A.; Kooner, Jaspal S.; Koskinen, Seppo; Kuusisto, Johanna; Maerz, Winfried; Martin, Nicholas G; Laakso, Markku; Lakka, Timo A.; Lehtimäki, Terho; Lettre, Guillaume; Levinson, Douglas F.; Lind, Lars; Lokki, Marja-Liisa; Mäntyselkä, Pekka; Melbye, Mads; Metspalu, Andres; Mitchell, Braxton D.; Moll, Frans L.; Murray, Jeffrey C.; Musk, Arthur W.; Nieminen, Markku S.; Njølstad, Inger; Ohlsson, Claes; Oldehinkel, Albertine J.; Oostra, Ben A.; Palmer, Lyle J; Pankow, James S.; Pasterkamp, Gerard; Pedersen, Nancy L.; Pedersen, Oluf; Penninx, Brenda W.; Perola, Markus; Peters, Annette; Polašek, Ozren; Pramstaller, Peter P.; Psaty, Bruce M.; Qi, Lu; Quertermous, Thomas; Raitakari, Olli T.; Rankinen, Tuomo; Rauramaa, Rainer; Ridker, Paul M.; Rioux, John D.; Rivadeneira, Fernando; Rotter, Jerome I.; Rudan, Igor; den Ruijter, Hester M.; Saltevo, Juha; Sattar, Naveed; Schunkert, Heribert; Schwarz, Peter E. H.; Shuldiner, Alan R.; Sinisalo, Juha; Snieder, Harold; Sørensen, Thorkild I. A.; Spector, Tim D.; Staessen, Jan A.; Stefania, Bandinelli; Thorsteinsdottir, Unnur; Stumvoll, Michael; Tardif, Jean-Claude; Tremoli, Elena; Tuomilehto, Jaakko; Uitterlinden, André G.; Uusitupa, Matti; Verbeek, André L. M.; Vermeulen, Sita H.; Viikari, Jorma S.; Vitart, Veronique; Völzke, Henry; Vollenweider, Peter; Waeber, Gérard; Walker, Mark; Wallaschofski, Henri; Wareham, Nicholas J.; Watkins, Hugh; Zeggini, Eleftheria; Chakravarti, Aravinda; Clegg, Deborah J.; Cupples, L. Adrienne; Gordon-Larsen, Penny; Jaquish, Cashell E.; Rao, D. C.; Abecasis, Goncalo R.; Assimes, Themistocles L.; Barroso, Inês; Berndt, Sonja I.; Boehnke, Michael; Deloukas, Panos; Fox, Caroline S.; Groop, Leif C.; Hunter, David J.; Ingelsson, Erik; Kaplan, Robert C.; McCarthy, Mark I.; Mohlke, Karen L.; O'Connell, Jeffrey R.; Schlessinger, David; Strachan, David P.; Stefansson, Kari; van Duijn, Cornelia M.; Hirschhorn, Joel N.; Lindgren, Cecilia M.; Heid, Iris M.; North, Kari E.; Borecki, Ingrid B.; Kutalik, Zoltán; Loos, Ruth J. F.

    2015-01-01

    Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape. PMID:26426971

  16. The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study.

    Directory of Open Access Journals (Sweden)

    Thomas W Winkler

    2015-10-01

    Full Text Available Genome-wide association studies (GWAS have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI, a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE, sex-specific effects (G x SEX or age-specific effects that differed between men and women (G x AGE x SEX. For BMI, we identified 15 loci (11 previously established for main effects, four novel that showed significant (FDR<5% age-specific effects, of which 11 had larger effects in younger (<50y than in older adults (≥50y. No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.

  17. Resistance determinants and mobile genetic elements of an NDM-1-encoding Klebsiella pneumoniae strain.

    Directory of Open Access Journals (Sweden)

    Corey M Hudson

    Full Text Available Multidrug-resistant Enterobacteriaceae are emerging as a serious infectious disease challenge. These strains can accumulate many antibiotic resistance genes though horizontal transfer of genetic elements, those for β-lactamases being of particular concern. Some β-lactamases are active on a broad spectrum of β-lactams including the last-resort carbapenems. The gene for the broad-spectrum and carbapenem-active metallo-β-lactamase NDM-1 is rapidly spreading. We present the complete genome of Klebsiella pneumoniae ATCC BAA-2146, the first U.S. isolate found to encode NDM-1, and describe its repertoire of antibiotic-resistance genes and mutations, including genes for eight β-lactamases and 15 additional antibiotic-resistance enzymes. To elucidate the evolution of this rich repertoire, the mobile elements of the genome were characterized, including four plasmids with varying degrees of conservation and mosaicism and eleven chromosomal genomic islands. One island was identified by a novel phylogenomic approach, that further indicated the cps-lps polysaccharide synthesis locus, where operon translocation and fusion was noted. Unique plasmid segments and mosaic junctions were identified. Plasmid-borne blaCTX-M-15 was transposed recently to the chromosome by ISEcp1. None of the eleven full copies of IS26, the most frequent IS element in the genome, had the expected 8-bp direct repeat of the integration target sequence, suggesting that each copy underwent homologous recombination subsequent to its last transposition event. Comparative analysis likewise indicates IS26 as a frequent recombinational junction between plasmid ancestors, and also indicates a resolvase site. In one novel use of high-throughput sequencing, homologously recombinant subpopulations of the bacterial culture were detected. In a second novel use, circular transposition intermediates were detected for the novel insertion sequence ISKpn21 of the ISNCY family, suggesting that it uses

  18. Shiga toxin-producing Escherichia coli strains isolated from dairy products - Genetic diversity and virulence gene profiles.

    Science.gov (United States)

    Douëllou, T; Delannoy, S; Ganet, S; Mariani-Kurkdjian, P; Fach, P; Loukiadis, E; Montel, Mc; Thevenot-Sergentet, D

    2016-09-02

    Shiga toxin-producing Escherichia coli (STEC) are widely recognized as pathogens causing food borne disease. Here we evaluate the genetic diversity of 197 strains, mainly STEC, from serotypes O157:H7, O26:H11, O103:H2, O111:H8 and O145:28 and compared strains recovered in dairy products against strains from human, meat and environment cases. For this purpose, we characterized a set of reference-collection STEC isolates from dairy products by PFGE DNA fingerprinting and a subset of these by virulence-gene profiling. PFGE profiles of restricted STEC total DNA showed high genomic variability (0.9976 on Simpson's discriminatory index), enabling all dairy isolates to be differentiated. High-throughput real-time PCR screening of STEC virulence genes were applied on the O157:H7 and O26:H11 STEC isolates from dairy products and human cases. The virulence gene profiles of dairy and human STEC strains were similar. Nevertheless, frequency-wise, stx1 was more prevalent among dairy O26:H11 isolates than in human cases ones (87% vs. 44%) while stx2 was more prevalent among O26:H11 human isolates (23% vs. 81%). For O157:H7 isolates, stx1 (0% vs. 39%), nleF (40% vs 94%) and Z6065 (40% vs 100%) were more prevalent among human than dairy strains. Our data point to differences between human and dairy strains but these differences were not sufficient to associate PFGE and virulence gene profiles to a putative lower pathogenicity of dairy strains based on their lower incidence in disease. Further comparison of whole-genome expression and virulence gene profiles should be investigated in cheese and intestinal tract samples.

  19. Genetic diversity of Mycobacterium tuberculosis complex strains isolated from patients with pulmonary tuberculosis in Anambra State, Nigeria.

    Science.gov (United States)

    Uzoewulu, Gertrude N; Lawson, Lovett; Nnanna, Ibeh S; Rastogi, Nalin; Goyal, Madhu

    2016-03-01

    In this study, we analyzed Mycobacterium tuberculosis complex (MTC) genetic diversity in Anambra State, Nigeria based on spoligotyping followed by 5-loci exact tandem repeats (ETRs). Spoligotyping of 180 MTC strains isolated in 2009-2011 from pulmonary tuberculosis (TB) patients led to a total of 31 distinct patterns. A comparison with the SITVIT2 international database showed that all the 31 patterns could be classified as Shared-types (SITs) in this database; briefly, 26/31 SITs (n=174 isolates) matched a preexisting shared-type in the database, whereas 5/31 SITs (n=6 isolates) were newly created due to 2 or more strains belonging to an identical new pattern within this study (SIT3396) or after a match with an orphan in the database (SIT3397, SIT3398, SIT3399 and SIT3400). A total of 18/31 SITs containing 167 or 92.8% isolates were clustered within this study (2-89 isolates per cluster) while 13/31 SITs contained unique strains. Using VNTR typing, a total of 36 distinct patterns were identified; 27 patterns (n=157 isolates) matched a pattern already reported in the SITVIT2 database. Combination of both the methods generated 47 combined patterns for the 180 strains: 17 belonged to clustered isolates (n=127 isolates or 70.5%) while 30 corresponded to as many unique strains (note 23 strains could not be typed using 5-loci ETRs). No correlation was found between the spoligotyping pattern and the HIV status of the patient or drug sensitivity of the strain. This study showed that the LAM10-CAM prototype SIT61 accounted for highest number of isolates (n=89) in Anambra State, showing its relative contribution to the TB burden in the study.

  20. Use of restriction fragment length polymorphism as a genetic marker for typing Mycobacterium avium strains.

    Science.gov (United States)

    Roiz, M P; Palenque, E; Guerrero, C; Garcia, M J

    1995-05-01

    Restriction fragment length polymorphism (RFLP) was used to study 75 clinical isolates identified as Mycobacterium avium. Two repetitive insertion sequences, IS1311 and IS900, were used as DNA probes. Although less than 25% of isolates showed RFLP patterns with IS900, all strains gave banding patterns with IS1311. M. avium strains isolated from patients with AIDS exhibited marked polymorphism with both probes.

  1. Evaluation of molecular typing techniques to assign genetic diversity among Saccharomyces cerevisiae strains

    NARCIS (Netherlands)

    Baleiras Couto, M.M.; Eijsma, B.; Hofstra, H.; Huis in 't Veld, J.H.J.; Vossen, J.M.B.M. van der

    1996-01-01

    Discrimination of strains within the species Saccharomyces cerevisiae was demonstrated by the use of four different techniques to type 15 strains isolated from spoiled wine and beer. Random amplified polymorphic DNA with specific oligonucleotides and PCR fingerprinting with the microsatellite oligon

  2. Genetic complementation analysis of two independently isolated hycanthone-resistant strains of Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Livia Pica-Mattoccia

    1992-01-01

    Full Text Available The objective of this study is to determine whether various hycanthone resistant strains of schistosomes which have been independently isolated are all affected in the same gene. A strain obtained from a Brazilian patient was compared with a strain of Puerto Rican origin selected in the laboratory. If the mutation conferring resistance involved two different genes, one would expect that the progeny of a cross between the two strains would show complementation, i.e. it would be sensitive to the drug. We have performed such a cross and obtained F1 hybrid worms wich were essentially all resistant, thus suggesting that the mutation conferring resistance in the two strains involves the same gene.

  3. Experimental Population Genetics of Meiotic Drive Systems. III. Neutralization of Sex-Ratio Distortion in Drosophila through Sex-Chromosome Aneuploidy

    OpenAIRE

    Lyttle, Terrence W.

    1981-01-01

    Laboratory populations of Drosophila melanogaster were challenged by pseudo-Y drive, which mimics true Y-chromosome meiotic drive through the incorporation of Segregation Distorter (SD) in a T(Y;2) complex. This causes extreme sex-ratio distrotion and can ultimately lead to population extinction. Populations normally respond by the gradual accumulation of drive suppressors, and this reduction in strength of distortion allows the sex ratio to move closer to the optimal value of 1:1. One popula...

  4. Genetic affinities within a large global collection of pathogenic Leptospira: implications for strain identification and molecular epidemiology.

    Directory of Open Access Journals (Sweden)

    Kishore Nalam

    Full Text Available Leptospirosis is an important zoonosis with widespread human health implications. The non-availability of accurate identification methods for the individualization of different Leptospira for outbreak investigations poses bountiful problems in the disease control arena. We harnessed fluorescent amplified fragment length polymorphism analysis (FAFLP for Leptospira and investigated its utility in establishing genetic relationships among 271 isolates in the context of species level assignments of our global collection of isolates and strains obtained from a diverse array of hosts. In addition, this method was compared to an in-house multilocus sequence typing (MLST method based on polymorphisms in three housekeeping genes, the rrs locus and two envelope proteins. Phylogenetic relationships were deduced based on bifurcating Neighbor-joining trees as well as median joining network analyses integrating both the FAFLP data and MLST based haplotypes. The phylogenetic relationships were also reproduced through Bayesian analysis of the multilocus sequence polymorphisms. We found FAFLP to be an important method for outbreak investigation and for clustering of isolates based on their geographical descent rather than by genome species types. The FAFLP method was, however, not able to convey much taxonomical utility sufficient to replace the highly tedious serotyping procedures in vogue. MLST, on the other hand, was found to be highly robust and efficient in identifying ancestral relationships and segregating the outbreak associated strains or otherwise according to their genome species status and, therefo