Lampert K P, Schartl M
Department of Physiological Chemistry I, Biocenter, University of Wuerzburg, Am Hubland, 97074 Würzburg, Germany.
Philos Trans R Soc Lond B Biol Sci. 2008 Sep 12;363(1505):2901-9. doi: 10.1098/rstb.2008.0040.
Clonal reproduction in vertebrates can always be traced back to hybridization events as all known unisexual vertebrates are hybrids between recognized species or genetically defined races. Interestingly, clonal vertebrates often also rely on interspecific matings for their reproduction because gynogenesis (sperm-dependent parthenogenesis) and hybridogenesis are common modes of propagation. While in most cases these hybridization events leave no hereditary traces in the offspring, occasionally the genome exclusion mechanism fails and either small parts of male genetic material remain inside the oocyte in the form of microchromosomes, or fusion of the sperm nucleus with the oocyte nucleus leads to polyploid individuals. In this review, we highlight the important role of hybridization for the origin and evolution of a unisexual hybrid: the Amazon molly, Poecilia formosa.
脊椎动物的克隆繁殖总是可以追溯到杂交事件,因为所有已知的单性脊椎动物都是公认物种或基因定义的种族之间的杂交后代。有趣的是,克隆脊椎动物在繁殖时通常也依赖种间交配,因为雌核发育(依赖精子的孤雌生殖)和杂种生殖是常见的繁殖方式。虽然在大多数情况下,这些杂交事件不会在后代中留下遗传痕迹,但偶尔基因组排除机制会失效,要么雄性遗传物质的小部分以微染色体的形式留在卵母细胞内,要么精核与卵母细胞核融合导致多倍体个体。在这篇综述中,我们强调了杂交对于一种单性杂种——亚马孙帆鳉(Poecilia formosa)的起源和进化的重要作用。