Collaborative Research: mtDNA and the Evolution of Fishes

Vrijenhoek和Avise将调查单性斜纹夜蛾及其两性后代的线粒体DNA(MtDNA)变异和系统发育，以利用这些非典型遗传系统提供的独特优势来解决两个对进化生物学具有广泛意义的问题：(1)mtDNA的遗传是严格母性的吗？以及(2)通过无性或半有性方式繁殖的脊椎动物的进化寿命和系统发育关系是什么？将对杂交菌株进行研究，以寻找来自父系的mtDNA证据，表明mtDNA偶尔会在父系中低水平地泄漏到受精卵中。雌核发育和杂交发育都将从线粒体DNA系统发育的角度进行研究。通过比较单性品系和它们的有性繁殖后代内部和之间的mtDNA变异性，研究人员将估计这个复合体中鱼类的年龄、克隆多样性和系统发育起源。这些结果应该有助于解决长期以来对单性分类群进化寿命的担忧，从而解决无性繁殖的进化后果。

Vrijenhoek and Avise will survey mitochondrial DNA (mtDNA) variation and phylogeny in unisexual Poeciliopsis fishes and their bisexual progenitors in order to capitalize upon the unique advantages afforded by these atypical genetic systems for addressing two questions of broad significance to evolutionary biology: (1) is the inheritance of mtDNA strictly maternal? and (2) what are the evolutionary longevities and phylogenetic relationships of vertebrates that reproduce by asexual or semi- sexual means? The hybridogenetic strains will be studied for evidence of paternally-derived mtDNA indicative of occasional, low-level "paternal leakage" of mtDNA into zygotes. Both gynogenetic and hybridogenetic Poeciliopsis will be studied in terms of mtDNA phylogeny. By comparing mtDNA variability within and among the unisexual strains and their sexually-reproducing progenitors, the investigators will estimate the ages, clonal diversities, and phylogenetic origins of fish in this complex. Results should help in addressing long-standing concerns about the evolutionary longevities of unisexual taxa, and hence about the evolutionary consequences of asexual reproduction.