Data from: Tropical Drosophila pandora carry Wolbachia infections causing cytoplasmic incompatibility or male killing

Wolbachia infections have been described in several Drosophila species, but relatively few have been assessed for phenotypic effects. Cytoplasmic incompatibility (CI) is the most common phenotypic effect that has been detected, while some infections cause male killing or feminization, and many Wolbachia infections have few host effects. Here, we describe two new infections in a recently described species, Drosophila pandora, one of which causes near-complete CI and near-perfect maternal transmission (the “CI” strain). The other infection is a male killer (the “MK” strain), which we confirm by observing reinitiation of male production following tetracycline treatment. No incompatibility was detected in crosses between CI strain males and MK strain females, and rare MK males do not cause CI. Molecular analyses indicate that the CI and MK infections are distantly related and the CI infection is closely related to the wRi infection of Drosophila simulans. Two population surveys indicate that all individuals are infected with Wolbachia, but the MK infection is uncommon. Given patterns of incompatibility among the strains, the infection dynamics is expected to be governed by the relative fitness of the females, suggesting that the CI infection should have a higher fitness. This was evidenced by changes in infection frequencies and sex ratios in population cages initiated at different starting frequencies of the infections.沃尔巴克氏体（Wolbachia）感染已在多种果蝇属（Drosophila）物种中被报道，但针对其表型效应的评估研究相对较少。细胞质不相容（Cytoplasmic incompatibility，CI）是目前已检测到的最常见表型效应；部分沃尔巴克氏体感染会引发雄性致死或雌性化现象，而多数感染对宿主几乎无显著影响。本研究针对新定名的果蝇物种果蝇潘多拉（Drosophila pandora），报道了两株全新的沃尔巴克氏体感染：其中一株可引发近乎完全的细胞质不相容，且几乎能通过母系完美传递，命名为'CI株'；另一株为雄性致死株（MK株），我们通过四环素（tetracycline）处理后观察到雄性繁殖能力恢复的现象，证实了其雄性致死特性。CI株雄虫与MK株雌虫的杂交实验中未检测到细胞质不相容现象，且罕见的MK雄虫不会引发CI效应。分子分析结果显示，CI株与MK株的亲缘关系较远，而CI株与拟果蝇（Drosophila simulans）的wRi株系亲缘关系密切。两项种群调查结果表明，该物种所有个体均感染沃尔巴克氏体，但MK株的感染率较低。结合各菌株间的不相容模式，感染动态预计由雌虫的相对适合度决定，这提示CI株的适合度更高。这一结论可通过以不同初始感染频率建立的种群笼中，感染频率与性比的变化得到验证。