University of Cambridge, Department of Genetics, Downing Street, Cambridge CB2 3EH, UK.
University of Cambridge, Department of Genetics, Downing Street, Cambridge CB2 3EH, UK.
Curr Biol. 2023 Sep 11;33(17):3545-3560.e13. doi: 10.1016/j.cub.2023.07.006. Epub 2023 Jul 28.
Facultative parthenogenesis enables sexually reproducing organisms to switch between sexual and asexual parthenogenetic reproduction. To gain insights into this phenomenon, we sequenced the genomes of sexually reproducing and parthenogenetic strains of Drosophila mercatorum and identified differences in the gene expression in their eggs. We then tested whether manipulating the expression of candidate gene homologs identified in Drosophila mercatorum could lead to facultative parthenogenesis in the non-parthenogenetic species Drosophila melanogaster. This identified a polygenic system whereby increased expression of the mitotic protein kinase polo and decreased expression of a desaturase, Desat2, caused facultative parthenogenesis in the non-parthenogenetic species that was enhanced by increased expression of Myc. The genetically induced parthenogenetic Drosophila melanogaster eggs exhibit de novo centrosome formation, fusion of the meiotic products, and the onset of development to generate predominantly triploid offspring. Thus, we demonstrate a genetic basis for sporadic facultative parthenogenesis in an animal.
兼性孤雌生殖使有性生殖生物能够在有性和孤雌生殖之间切换。为了深入了解这一现象，我们对有性生殖和孤雌生殖的果蝇 mercatorum 品系进行了基因组测序，并鉴定了它们卵子中基因表达的差异。然后，我们测试了操纵在果蝇 mercatorum 中鉴定出的候选基因同源物的表达是否可以导致非孤雌生殖的果蝇 melanogaster 物种的兼性孤雌生殖。这确定了一个多基因系统，其中有丝分裂蛋白激酶 polo 的表达增加和去饱和酶 Desat2 的表达减少导致非孤雌生殖的果蝇 melanogaster 物种的兼性孤雌生殖，而 Myc 的表达增加则增强了这种生殖方式。遗传诱导的果蝇 melanogaster 孤雌生殖卵表现出从头形成中心体、减数分裂产物的融合以及开始发育以产生主要为三倍体后代。因此，我们证明了动物中偶发性兼性孤雌生殖的遗传基础。
