Repeated evolution of bacteriocytes in lygaeoid stinkbugs
Repeated evolution of bacteriocytes in lygaeoid stinkbugs
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DOI：
10.1111/1462-2920.14804
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发表时间：
2019-10-17
影响因子：
5.1
通讯作者：
Matsuura, Yu
中科院分区：
文献类型：
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作者：
Kuechler, Stefan Martin;Fukatsu, Takema;Matsuura, Yu
寄主-微生物共生往往进化出高度复杂的发育过程和定植机制，以建立稳定的联合。人们早就认识到，许多昆虫在特定的共生细胞(细菌体)或器官(细菌体)中藏匿着有益的细菌。然而，细菌在细菌细胞/细菌体形成中定植的进化起源和机制一直知之甚少。为了揭示这种进化新颖性的起源，我们研究了代表Lygaeoidae总科的五个臭虫物种的共生器官的发育，其中不同的细菌细胞/细菌体系统已经进化。我们跟踪了胚胎发育过程中共生菌在卵子中的运动，并利用整体荧光原位杂交技术确定了共生菌感染和细菌细胞形成的关键阶段。总之，观察到了三种不同的发育模式：一种是共生体从最初的共生菌团(共生球)转移到胚胎腹部的假定细菌细胞，另一种是直接结合共生球而不移位细菌细胞。在寄主分类群中，只有关系密切的物种似乎进化出了相对保守的细菌体发育类型，这表明寄主共生细胞和器官来自多个独立来源的反复进化。
Host-microbe symbioses often evolved highly complex developmental processes and colonization mechanisms for establishment of stable associations. It has long been recognized that many insects harbour beneficial bacteria inside specific symbiotic cells (bacteriocytes) or organs (bacteriomes). However, the evolutionary origin and mechanisms underlying bacterial colonization in bacteriocyte/bacteriome formation have been poorly understood. In order to uncover the origin of such evolutionary novelties, we studied the development of symbiotic organs in five stinkbug species representing the superfamily Lygaeoidea in which diverse bacteriocyte/bacteriome systems have evolved. We tracked the symbiont movement within the eggs during the embryonic development and determined crucial stages at which symbiont infection and bacteriocyte formation occur, using whole-mount fluorescence in situ hybridization. In summary, three distinct developmental patterns were observed: two different modes of symbiont transfer from initial symbiont cluster (symbiont ball) to presumptive bacteriocytes in the embryonic abdomen, and direct incorporation of the symbiont ball without translocation of bacterial cells. Across the host taxa, only closely related species seemed to have evolved relatively conserved types of bacteriome development, suggesting repeated evolution of host symbiotic cells and organs from multiple independent origins.