PDF(Pubmed)
Abstract：
The evolution of reproductive mode is expected to have profound impacts on the genetic composition of populations. At the same time, ecological interactions can generate close associations among species, which can in turn generate a high degree of overlap in their spatial distributions. Caenorhabditis elegans is a hermaphroditic nematode that has enabled extensive advances in developmental genetics. Caenorhabditis inopinata, the sister species of C. elegans, is a gonochoristic nematode that thrives in figs and obligately disperses on fig wasps. Here, we describe patterns of genomic diversity in C. inopinata. We performed RAD-seq on individual worms isolated from the field across three Okinawan island populations. C. inopinata is about five times more diverse than C. elegans. Additionally, C. inopinata harbors greater differences in diversity among functional genomic regions (such as between genic and intergenic sequences) than C. elegans. Conversely, C. elegans harbors greater differences in diversity between high-recombining chromosome arms and low-recombining chromosome centers than C. inopinata. FST is low among island population pairs, and clear population structure could not be easily detected among islands, suggesting frequent migration of wasps between islands. These patterns of population differentiation appear comparable with those previously reported in its fig wasp vector. These results confirm many theoretical population genetic predictions regarding the evolution of reproductive mode and suggest C. inopinata population dynamics may be driven by wasp dispersal. This work sets the stage for future evolutionary genomic studies aimed at understanding the evolution of sex as well as the evolution of ecological interactions.
摘要：
预计生殖模式的演变将对种群的遗传组成产生深远的影响。同时,生态相互作用可以在物种之间产生密切的联系，这反过来会在它们的空间分布中产生高度的重叠。秀丽隐杆线虫是一种雌雄同体的线虫，在发育遗传学方面取得了广泛的进展。棘突线虫,秀丽隐杆线虫的姐妹物种，是一种淋病线虫，在无花果中茁壮成长，并在无花果黄蜂上分散。这里,我们描述了C.inopinata的基因组多样性模式。我们对从三个冲绳岛种群中分离出的单个蠕虫进行了RAD-seq。C.inopinata的多样性是C.elegans的五倍。此外,与C.elegans相比，C.inopinata在功能基因组区域之间（例如基因序列和基因间序列之间）具有更大的多样性差异。相反，C.elegans在高重组染色体臂和低重组染色体中心之间的多样性差异比C.inopinata更大。岛屿人口对中的FST较低，岛屿之间不容易发现清晰的人口结构，表明黄蜂在岛屿之间频繁迁移。这些种群分化模式似乎与以前在其无花果黄蜂载体中报道的模式相当。这些结果证实了许多关于生殖方式进化的理论种群遗传预测，并表明木纹梭菌种群动态可能是由黄蜂扩散驱动的。这项工作为未来的进化基因组研究奠定了基础，旨在了解性别的进化以及生态相互作用的进化。
