Data from: Maternally transmitted non-bacterial male killer in Drosophila biauraria

A maternally inherited, all-female trait is widely found among arthropods, which is caused by bacterial endosymbionts such as Wolbachia, Rickettsia, Spiroplasma and Cardinium We discovered a single female of Drosophila biauraria, collected from Tomakomai, Hokkaido, Japan, that produced all-female offspring. This all-female trait was maternally inherited in the iso-female line (SP12F) by backcrossing with males of a normal line (SP11-20) with a 1:1 sex ratio derived from the same population. The all-female trait was not affected by tetracycline treatment performed for two consecutive generations. However, the microinjection of filter-sterilised homogenate of SP12F females into SP11-20 females established all-female matrilines. Our data suggest the role of transmissible agents, most likely viruses, but not bacteria or protists, as the possible cause of the all-female phenotype, which is likely to be achieved by killing of male embryos because egg hatch rates of SP12F were nearly half as those of SP11-20. This is the first report in Diptera to demonstrate a maternally inherited virus-like element as the cause of the male-killing phenotype in D. biauraria.

母系遗传的全雌表型广泛分布于节肢动物类群，此类表型通常由沃尔巴克氏体（Wolbachia）、立克次体（Rickettsia）、螺原体（Spiroplasma）以及卡多菌（Cardinium）等细菌内共生体所介导。本研究从日本北海道苫小牧市采集的双斑果蝇（Drosophila biauraria）中，发现一只仅产生雌性后代的雌性个体。通过与来自同一种群、性比为1:1的正常品系（SP11-20）的雄性个体回交，该全雌表型可在单雌系SP12F中稳定母系遗传。连续两代经四环素处理后，该全雌表型未受显著影响。但将SP12F雌性个体的过滤除菌匀浆显微注射至SP11-20雌性个体体内后，成功构建了全雌母系品系。本研究数据表明，可传播因子（极有可能为病毒，而非细菌或原生生物）是该全雌表型的潜在诱因；该表型可能通过杀伤雄性胚胎实现，因为SP12F的卵孵化率仅约为SP11-20的一半。本研究是双翅目昆虫中首次报道，由母系遗传的类病毒因子引发双斑果蝇的雄性致死表型。