Quattro J M, Avise J C, Vrijenhoek R C
Center for Theoretical and Applied Genetics, Rutgers University, New Brunswick, NJ 08903-0231, USA.
Proc Natl Acad Sci U S A. 1992 Jan 1;89(1):348-52. doi: 10.1073/pnas.89.1.348.
Genetic diversity in mtDNA was assessed within the unisexual (all female) hybridogenetic fish Poeciliopsis monacha-occidentalis and the two sexual species from which it arose. Results confirm that P. monacha was the maternal ancestor and that paternal leakage of P. occidentalis mtDNA has not occurred. Of particular interest is the high level of de novo mutational divergence within one hybridogenetic lineage that on the basis of independent zoogeographic considerations, protein electrophoretic data, and tissue grafting analysis is of monophyletic (single hybridization) origin. Using a conventional mtDNA clock calibration, we estimate that this unisexual clade might be >100,000 generations old. Contrary to conventional belief, this result shows that some unisexual vertebrate lineages can achieve a substantial evolutionary age.
对单性（全雌性）杂交起源的鱼类西方食蚊鱼（Poeciliopsis monacha-occidentalis）及其两个有性生殖的亲本物种的线粒体DNA（mtDNA）遗传多样性进行了评估。结果证实，西方食蚊鱼的母本祖先是蒙氏食蚊鱼（P. monacha），且西方食蚊鱼的线粒体DNA不存在父系渗漏现象。特别值得关注的是，在一个基于独立的动物地理学考量、蛋白质电泳数据以及组织移植分析判定为单系起源（单次杂交）的杂交起源谱系中，存在高水平的新生突变分歧。使用传统的线粒体DNA分子钟校准方法，我们估计这个单性谱系可能已经存在超过100,000代。与传统观念相反，这一结果表明一些单性脊椎动物谱系可以达到相当长的进化年龄。
