EVOLUTIONARY AND CELLH BIOLOGICAL STUDIES ON Wolbachia, ENDOCELLULAR SYMBIOTIC MICROORGANISMS

沃尔巴克氏体是一组遗传性立克次体样细菌，存在于许多节肢动物中，已知会导致宿主的各种生殖改变，包括雌性化、孤雌生殖和细胞质不相容。对印度粉蛾、扁桃蛾和地中海粉蛾进行了沃尔巴克氏体感染检测。我们检测到cautella和两株kuehniella感染，一株来自土浦市，另一株来自横滨市。间点疟原虫未检出沃尔巴克氏体。根据编码沃尔巴克氏体细胞表面蛋白的wsp基因序列，估计了cautella和kuehniella携带沃尔巴克氏体的系统发育位置。我们还进行了杂交实验来检验细胞质不相容性。结果表明，沃尔巴克氏体在cautella中引起完全的细胞质不相容：在感染的雄性和未感染的雌性杂交中未观察到卵孵化。土村株和横滨株均表现出部分细胞质不亲和性，但两株细胞质不亲和性水平差异显著。土仓株系和横滨株系不亲和性杂交的卵孵化率分别为60.8%和16.9%。

Wolbachia are a group of inherited Rickettia-like bacteria found in a number of arthropods and known to cause various reproductive alterations of their hosts, including feminization, parthenogenesis and cytoplasmic incompatibility. We examined Wolbachia infection in three species of moths belonging to the sub-family Phycitinae, the Indian meal moth Plodia interpunctella, the almond moth Ephestia cautella and the Mediterranean flour moth Ephestia kuehniella. We detected infections in E. cautella and two strains of E. kuehniella, one from Tsuchiura city and the other from Yokohama city. Wolbachia was not detected in P. interpunctella. The phylogenetic positions of Wolbachia harbored by E. cautella and E. kuehniella were estimated based on the sequences of the wsp gene that encodes a Wolbachia cell surface protein. We also performed crossing experiments to examine cytoplasmic incompatibility. It was shown that Wolbachia in E. cautella caused complete cytoplasmic incompatibility : no egg-hatch was observed in the cross between infected males and uninfected females. Both Tsuchiura and Yokohama strains of E. kuehniella showed partial cytoplasmic incompatibility, but the levels were significantly different between the two strains. The rates of egg hatch in the incompatible crosses within Tsuchiura and Yokohama strains were 60.8% and 16.9%, respectively.