The Experts below are selected from a list of 17592 Experts worldwide ranked by ideXlab platform

Ze Zhang - One of the best experts on this subject based on the ideXlab platform.

  • nucleotide diversity and selection signature in the domesticated silkworm bombyx mori and wild silkworm bombyx mandarina
    Journal of Insect Science, 2011
    Co-Authors: Yihong Shen, Hirohisa Kishino, Ze Zhang
    Abstract:

    To investigate the patterns of nucleotide diversity in domesticated silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) and its wild relative, Chinese wild silkworm, Bombyx mandarina Moore, we sequenced nine nuclear genes. Neutrality test and coalescent simulation for these genes were performed to look at Bottleneck intensity and selection signature; linkage disequilibrium (LD) within and between loci was employed to investigate allele association. As a result, B. mori lost 33–49% of nucleotide diversity relative to wild silkworm, which is similar to the loss levels found in major cultivated crops. Diversity of B. mori is significantly lower than that of B. mandarina measured as πtotal (0.01166 vs. 0.1741) or θW(0.01124 vs. 0.02206). Bottleneck intensity of domesticated silkworm is 1.5 (in terms of k = Nb/d, Nb-Bottleneck Population size; d-Bottleneck duration) with different durations. Gene DefA showed signature of artificial selection by all analysis methods and might experience strong artificial selection in B. mori during domestication. For nine loci, both curves of LD decay rapidly within 200 bp and drop slowly when distance is > 200 bp, although that of B. mori decays slower than B. mandarina at loci investigated. However, LD could not be estimated at DefA in B. mori and at ER in both silkworms. Elevated LD observed in B. mori may be indicator of selection and demographic events.

W. C. Jordan - One of the best experts on this subject based on the ideXlab platform.

  • Genetic diversity and Population structure in the endangered giant otter, Pteronura brasiliensis
    Conservation Genetics, 2011
    Co-Authors: R. S. A. Pickles, J. J. Groombridge, V. D. Zambrana Rojas, D. Gottelli, C. V. Ariani, P. Van Damme, W. C. Jordan
    Abstract:

    We assessed levels of genetic diversity and investigated patterns of Population structure in three remnant Populations of the endangered giant otter, Pteronura brasiliensis, using microsatellite loci. All Populations displayed moderate to low levels of heterozygosity and allelic richness (HO 0.56–0.57, AR 4.00–5.15) and effective Population sizes were low (NE 10.8–54) although only the Itenez Population exhibited the signature of a genetic Bottleneck. Population structure analyses revealed a pattern in which the Populations of the Upper Amazon, Orinoco and Essequibo drainages comprised partially differentiated segments of a northern South American metaPopulation, whereas the Population of the Itenez appeared isolated. The observed patterns are congruent with previous mitochondrial DNA analysis which suggested the Itenez and northern South American groups constitute two evolutionary significant units. The results presented here should be considered in planning future policies aiming to manage the recovery of the giant otter across its range.

Yihong Shen - One of the best experts on this subject based on the ideXlab platform.

  • nucleotide diversity and selection signature in the domesticated silkworm bombyx mori and wild silkworm bombyx mandarina
    Journal of Insect Science, 2011
    Co-Authors: Yihong Shen, Hirohisa Kishino, Ze Zhang
    Abstract:

    To investigate the patterns of nucleotide diversity in domesticated silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) and its wild relative, Chinese wild silkworm, Bombyx mandarina Moore, we sequenced nine nuclear genes. Neutrality test and coalescent simulation for these genes were performed to look at Bottleneck intensity and selection signature; linkage disequilibrium (LD) within and between loci was employed to investigate allele association. As a result, B. mori lost 33–49% of nucleotide diversity relative to wild silkworm, which is similar to the loss levels found in major cultivated crops. Diversity of B. mori is significantly lower than that of B. mandarina measured as πtotal (0.01166 vs. 0.1741) or θW(0.01124 vs. 0.02206). Bottleneck intensity of domesticated silkworm is 1.5 (in terms of k = Nb/d, Nb-Bottleneck Population size; d-Bottleneck duration) with different durations. Gene DefA showed signature of artificial selection by all analysis methods and might experience strong artificial selection in B. mori during domestication. For nine loci, both curves of LD decay rapidly within 200 bp and drop slowly when distance is > 200 bp, although that of B. mori decays slower than B. mandarina at loci investigated. However, LD could not be estimated at DefA in B. mori and at ER in both silkworms. Elevated LD observed in B. mori may be indicator of selection and demographic events.

R. S. A. Pickles - One of the best experts on this subject based on the ideXlab platform.

  • Genetic diversity and Population structure in the endangered giant otter, Pteronura brasiliensis
    Conservation Genetics, 2011
    Co-Authors: R. S. A. Pickles, J. J. Groombridge, V. D. Zambrana Rojas, D. Gottelli, C. V. Ariani, P. Van Damme, W. C. Jordan
    Abstract:

    We assessed levels of genetic diversity and investigated patterns of Population structure in three remnant Populations of the endangered giant otter, Pteronura brasiliensis, using microsatellite loci. All Populations displayed moderate to low levels of heterozygosity and allelic richness (HO 0.56–0.57, AR 4.00–5.15) and effective Population sizes were low (NE 10.8–54) although only the Itenez Population exhibited the signature of a genetic Bottleneck. Population structure analyses revealed a pattern in which the Populations of the Upper Amazon, Orinoco and Essequibo drainages comprised partially differentiated segments of a northern South American metaPopulation, whereas the Population of the Itenez appeared isolated. The observed patterns are congruent with previous mitochondrial DNA analysis which suggested the Itenez and northern South American groups constitute two evolutionary significant units. The results presented here should be considered in planning future policies aiming to manage the recovery of the giant otter across its range.

Guoling Chen - One of the best experts on this subject based on the ideXlab platform.

  • novel microsatellite markers reveal low genetic diversity and evidence of heterospecific introgression in the critically endangered chinese crested tern thalasseus bernsteini
    Global Ecology and Conservation, 2021
    Co-Authors: Guoling Chen, Jia Yang, Chenqing Zheng, Xiaohui Gao, Leyang Yuan, Siyu Wang, Zhongyong Fan, Gang Song, Shuihua Chen
    Abstract:

    Abstract The Chinese Crested Tern, Thalasseus bernsteini, is one of the most endangered seabird species in the world, with only small breeding Populations of around 100 individuals. To profile the genetic properties of this Population, we screened 200 short tandem repeat sequences from a de novo assembled genome of the Great Crested Tern, T. bergii, which is the sister species of T. bernsteini. We designed a panel of 12 novel microsatellites, and genotyped nine and 23 individuals of T. bernsteini and T. bergii, respectively. The results showed that T. bernsteini genetic diversity was lower than that of T. bergii, and no inbreeding was detected. There was no sign of recent Bottleneck events in the two species, but T. bernsteini showed signals of a post-Bottleneck Population expansion. Gene flow analysis indicated introgression between the two species, but the magnitude from T. bernsteini to T. bergii was higher than the opposite. This could be explained by Hubb’s principle, which states that there is a propensity of rarer species to reproduce with abundant congeners. Overall, our efforts provide useful genetic tools for conservation genetic studies of T. bernsteini and potentially other crested terns which face several natural and anthropogenic threats. The findings of this study further highlight that introgression may be a neglected factor in species conservation that needs to be seriously considered for conservation management. Availability of data and materials The dataset of all microsatellite are available from the corresponding author upon request.