Data from: Feminizing Wolbachia endosymbiont disrupts maternal sex chromosome inheritance in a butterfly species

Wolbachia is a maternally inherited ubiquitous endosymbiotic bacterium of arthropods that displays a diverse repertoire of host reproductive manipulations. For the first time, we demonstrate that Wolbachia manipulates sex chromosome inheritance in a sexually reproducing insect. Eurema mandarina butterfly females on Tanegashima Island, Japan, are infected with the wFem Wolbachia strain and produce all-female offspring, while antibiotic treatment results in male offspring. Fluorescence in situ hybridization (FISH) revealed that wFem-positive and wFem-negative females have Z0 and WZ sex chromosome sets, respectively, demonstrating the predicted absence of the W chromosome in wFem-infected lineages. Genomic quantitative polymerase chain reaction (qPCR) analysis showed that wFem-positive females lay only Z0 eggs that carry a paternal Z, whereas females from lineages that are naturally wFem-negative lay both WZ and ZZ eggs. In contrast, antibiotic treatment of adult wFem females resulted in the production of Z0 and ZZ eggs, suggesting that this Wolbachia strain can disrupt the maternal inheritance of Z chromosomes. Moreover, most male offspring produced by antibiotic-treated wFem females had a ZZ karyotype, implying reduced survival of Z0 individuals in the absence of feminizing effects of Wolbachia. Antibiotic treatment of wFem-infected larvae induced male-specific splicing of the doublesex (dsx) gene transcript, causing an intersex phenotype. Thus, the absence of the female-determining W chromosome in Z0 individuals is functionally compensated by Wolbachia-mediated conversion of sex determination. We discuss how Wolbachia may manipulate the host chromosome inheritance and that Wolbachia may have acquired this coordinated dual mode of reproductive manipulation first by the evolution of female-determining function and then cytoplasmically induced disruption of sex chromosome inheritance.沃尔巴克氏体（Wolbachia）是一类广泛分布于节肢动物体内、可通过母系遗传的内共生细菌，能够对宿主实施多样化的生殖操控策略。本研究首次证实，沃尔巴克氏体可在有性生殖昆虫中调控性染色体的遗传模式。栖息于日本种子岛的曼氏黄粉蝶（Eurema mandarina）雌性个体若感染wFem株沃尔巴克氏体，所产后代均为雌性；而经抗生素处理后，其后代则全部为雄性。荧光原位杂交（Fluorescence in situ hybridization, FISH）结果显示，感染wFem株与未感染该菌株的雌性个体分别携带Z0和WZ型性染色体组，这证实了感染wFem株的种群中确实不存在W染色体。基因组定量聚合酶链式反应（genomic quantitative polymerase chain reaction, qPCR）分析表明，感染wFem株的雌性个体仅产出携带父本Z染色体的Z0型卵；而天然未感染wFem株的种群雌性个体，则可产生WZ和ZZ两种类型的卵。与之相反，对成年感染wFem株的雌性个体施以抗生素处理后，其产出的卵包含Z0和ZZ两种类型，这提示该株沃尔巴克氏体能够干扰Z染色体的母系遗传。此外，经抗生素处理的感染wFem株的雌性个体所产生的雄性后代中，绝大多数具有ZZ核型，这意味着在缺乏沃尔巴克氏体的雌性化效应时，Z0型个体的存活率会显著降低。对感染wFem株的幼虫施以抗生素处理，可诱导双性（doublesex, dsx）基因转录本发生雄性特异性剪接，进而产生间性表型。综上，Z0型个体中负责雌性决定的W染色体缺失，可通过沃尔巴克氏体介导的性别决定转换实现功能补偿。本研究还讨论了沃尔巴克氏体可能通过何种机制调控宿主染色体遗传，并提出该菌株可能首先进化出雌性决定功能，再通过细胞质诱导的性染色体遗传干扰，获得这种协同双重生殖操控模式。