Lattorff H M G, Moritz R F A, Fuchs S
Institut für Zoologie, Molekulare Okologie, Martin-Luther-Universität Halle-Wittenberg, Hoher Weg 4, D-06099 Halle (Saale), Germany.
Heredity (Edinb). 2005 May;94(5):533-7. doi: 10.1038/sj.hdy.6800654.
The evolution and maintenance of parthenogenetic species are a puzzling issue in evolutionary biology. Although the genetic mechanisms that act to restore diploidy are well studied, the underlying genes that cause the switch from sexual reproduction to parthenogenesis have not been analysed. There are several species that are polymorphic for sexual and parthenogenetic reproduction, which may have a genetic basis. We use the South African honeybee subspecies Apis mellifera capensis to analyse the genetic control of thelytoky (asexual production of female workers). Due to the caste system of honeybees, it is possible to establish classical backcrosses using sexually reproducing queens and drones of both arrhenotokous and thelytokous subspecies, and to score the frequency of parthenogenesis in the resulting workers. We found Mendelian segregation for thelytoky of egg-laying workers, which appears to be controlled by a single major gene (th). The segregation pattern indicates a recessive allele causing thelytoky. We found no evidence for maternal transmission of bacterial endosymbionts controlling parthenogenesis. Thelytokous parthenogenesis of honeybee workers appears to be a classical qualitative trait, because we did not observe mixed parthenogenesis (amphitoky), which might be expected in the case of multi-locus inheritance.
孤雌生殖物种的进化与维持是进化生物学中一个令人困惑的问题。尽管恢复二倍体的遗传机制已得到充分研究，但导致从有性生殖转变为孤雌生殖的潜在基因尚未得到分析。有几个物种在有性生殖和孤雌生殖方面具有多态性，这可能有遗传基础。我们利用南非蜜蜂亚种海角蜜蜂（Apis mellifera capensis）来分析产雌孤雌生殖（雌性工蜂的无性繁殖）的遗传控制。由于蜜蜂的等级制度，可以利用产雄孤雌生殖和产雌孤雌生殖亚种的有性生殖蜂王和雄蜂建立经典回交，并统计后代工蜂中孤雌生殖的频率。我们发现产卵工蜂的产雌孤雌生殖符合孟德尔分离规律，这似乎由一个主要基因（th）控制。分离模式表明一个隐性等位基因导致产雌孤雌生殖。我们没有发现控制孤雌生殖的细菌内共生体母系传播的证据。蜜蜂工蜂的产雌孤雌生殖似乎是一个典型的质量性状，因为我们没有观察到混合孤雌生殖（兼性孤雌生殖），而在多基因座遗传的情况下可能会出现这种情况。
