Reductive genome evolution, host-symbiont co-speciation and uterine transmission of endosymbiotic bacteria in bat flies
Reductive genome evolution, host-symbiont co-speciation and uterine transmission of endosymbiotic bacteria in bat flies
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DOI：
10.1038/ismej.2011.125
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发表时间：
2012-03-01
期刊：
影响因子：
11
通讯作者：
Fukatsu, Takema
中科院分区：
文献类型：
--
作者：
Hosokawa, Takahiro;Nikoh, Naruo;Fukatsu, Takema
蝙蝠科蝙蝠以其极端的形态和生理特征而闻名，特别适合蝙蝠的体外寄生吸血生活方式，包括没有翅膀，头部和眼睛缩小，子宫和乳腺高度发达的腺养胎盘，以及与内共生细菌有关的特征。调查了日本夜蛾科蝙蝠4属8种27个种群的细菌内共生菌。在所有被检测的夜蛾种类中，一致地检测到一种独特的伽马蛋白细菌，它与其他昆虫的内共生体如里氏杆菌属(Riesia spp.)灵长类的虱子和亚瑟王的种类。形形色色的昆虫。在成虫中，内共生菌定位于腹部特定的细菌细胞中，表明宿主与共生体之间存在密切的联系。在成年雌性幼虫的乳腺管腔中也发现了内共生菌，这表明子宫内共生菌通过乳腺液垂直传播给幼虫。在金氏青霉的成年雌性体内，我们发现了一种以前未知的夜蛾科共生器官：位于第五腹板肿胀内的一对大型细菌体。内共生体基因始终表现出腺嘌呤/胸腺嘧啶偏向的核苷酸组成和加速的分子进化速度。据估计，内共生菌基因组高度缩减，大小类似于0.76Mb。内共生菌的系统发育较好地反映了寄主昆虫的系统发育，表明夜蛾科在进化过程中存在严格的垂直传播和寄主-共生共生现象。建议将内共生枝命名为‘Candidatus Aschnera chinzeii’。《ISME期刊》(2012年)6577-587；doi：10.1038/ismej.2011.125；2011年9月22日在线发布
Bat flies of the family Nycteribiidae are known for their extreme morphological and physiological traits specialized for ectoparasitic blood-feeding lifestyle on bats, including lack of wings, reduced head and eyes, adenotrophic viviparity with a highly developed uterus and milk glands, as well as association with endosymbiotic bacteria. We investigated Japanese nycteribiid bat flies representing 4 genera, 8 species and 27 populations for their bacterial endosymbionts. From all the nycteribiid species examined, a distinct clade of gammaproteobacteria was consistently detected, which was allied to endosymbionts of other insects such as Riesia spp. of primate lice and Arsenophonus spp. of diverse insects. In adult insects, the endosymbiont was localized in specific bacteriocytes in the abdomen, suggesting an intimate host-symbiont association. In adult females, the endosymbiont was also found in the cavity of milk gland tubules, which suggests uterine vertical transmission of the endosymbiont to larvae through milk gland secretion. In adult females of Penicillidia jenynsii, we discovered a previously unknown type of symbiotic organ in the Nycteribiidae: a pair of large bacteriomes located inside the swellings on the fifth abdominal ventral plate. The endosymbiont genes consistently exhibited adenine/thymine biased nucleotide compositions and accelerated rates of molecular evolution. The endosymbiont genome was estimated to be highly reduced, similar to 0.76Mb in size. The endosymbiont phylogeny perfectly mirrored the host insect phylogeny, indicating strict vertical transmission and host-symbiont co-speciation in the evolutionary course of the Nycteribiidae. The designation 'Candidatus Aschnera chinzeii' is proposed for the endosymbiont clade. The ISME Journal (2012) 6, 577-587; doi: 10.1038/ismej.2011.125; published online 22 September 2011