Signorovitch Ana, Hur Jae, Gladyshev Eugene, Meselson Matthew
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138 Department of Biology, Harvey Mudd College, Claremont, California 91711.
Genetics. 2015 Jun;200(2):581-90. doi: 10.1534/genetics.115.176719. Epub 2015 May 14.
Rotifers of Class Bdelloidea are common freshwater invertebrates of ancient origin whose apparent asexuality has posed a challenge to the view that sexual reproduction is essential for long-term evolutionary success in eukaryotes and to hypotheses for the advantage of sex. The possibility nevertheless exists that bdelloids reproduce sexually under unknown or inadequately investigated conditions. Although certain methods of population genetics offer definitive means for detecting infrequent or atypical sex, they have not previously been applied to bdelloid rotifers. We conducted such a test with bdelloids belonging to a mitochondrial clade of Macrotrachela quadricornifera. This revealed a striking pattern of allele sharing consistent with sexual reproduction and with meiosis of an atypical sort, in which segregation occurs without requiring homologous chromosome pairs.
蛭形轮虫纲的轮虫是起源古老的常见淡水无脊椎动物，其明显的无性生殖对有性生殖是真核生物长期进化成功所必需的这一观点以及关于性别的优势假说构成了挑战。然而，蛭形轮虫仍有可能在未知或研究不足的条件下进行有性生殖。尽管群体遗传学的某些方法为检测罕见或非典型的有性生殖提供了决定性手段，但此前尚未应用于蛭形轮虫。我们对属于四棘巨管轮虫线粒体分支的蛭形轮虫进行了这样的测试。这揭示了一种与有性生殖和非典型减数分裂一致的显著等位基因共享模式，在这种模式中，分离发生时不需要同源染色体对。
