Cellular Localization of Two Rickettsia Symbionts in the Digestive System and within the Ovaries of the Mirid Bug, Macrolophous pygmaeus
Cellular Localization of Two Rickettsia Symbionts in the Digestive System and within the Ovaries of the Mirid Bug, Macrolophous pygmaeus
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DOI：
10.3390/insects11080530
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发表时间：
2020-08-01
期刊：
影响因子：
3
通讯作者：
Zchori-Fein, Einat
中科院分区：
文献类型：
--
作者：
Dally, Maria;Lalzar, Maya;Zchori-Fein, Einat
像大多数昆虫一样，那些既以猎物为食又以植物材料为食的昆虫体内含有共生细菌。然而，细菌在这些杂食性消费者的饮食习惯中的参与还有待调查。在本研究中，我们采取了第一步，对测试的假设，即细菌共生体参与的杂食性bugMacrolophus pygmaeus的食性。我们（I）表征了M的微生物组（细菌和真菌的集合）。pygmaeus，和（II）确定的身份和位置的最占优势的细菌物种内的主机。我们发现M。pygmaeusmicrobiome以两种立克次体Rickettsiaspecies，R.贝利安河柠檬酸。这些细菌在虫子的消化系统中大量存在，每种细菌都表现出独特的分布模式，并且在大多数情况下，在肠道中不共享相同的细胞。这些结果强烈表明，宿主虫可能通过在其肠道中宿主两种占主导地位的共生细菌来获得一些营养益处。节肢动物体内的细菌共生体是常见的，其作用各不相同，对生物防治效果有显著影响。pygmaeus宿主共生的Wolbachia引起细胞质不亲和性，两种立克次体，R.贝利安河在所有测试的个体中发现的柠檬菌。为了验证两种立克次体与M.通过对这3种共生菌在该虫消化系统中的分布规律的研究，我们首次发现了这3种共生菌在该虫的微生物组中占主导地位，并描述了这2种立克次体在该虫消化系统中的分布规律。虽然两种立克次体都位于某些肠道细菌细胞中，在盲肠和马氏管的两种性别，每个物种有一个独特的细胞占有模式和特定的分布沿着消化系统隔间。偶尔，这两个物种被发现在一个细胞。在雌性中，两种立克次体都在生殖室中检测到，卵巢内的卵巢管顶端，但在卵母细胞中没有检测到。虽然这些立克次体分布模式的原因尚不清楚，但它可能与宿主在捕食猎物或植物时的营养有关。
Simple Summary Like most insects, those that feed on both prey and plant materials harbor symbiotic bacteria in their body. Yet the involvement of bacteria in the feeding habits of these omnivorous consumers has yet to be investigated. In the present study, we took the first step toward testing the hypothesis that bacterial symbionts are involved in the feeding habits of the omnivorous bugMacrolophus pygmaeus. We (I) characterized the microbiome (the assembly of bacteria and fungi) ofM. pygmaeus, and (II) determined the identity and location of the most dominant bacteria species within the host body. We found thatM. pygmaeusmicrobiome is dominated by twoRickettsiaspecies,R. belliandR. limoniae. These bacteria are found in high numbers in the digestive system of the bug, each exhibiting a unique distribution pattern, and for the most part, do not share the same cells in the gut. These results strongly suggest that the host bug may gain some nutritional benefits by hosting the two dominant symbiotic bacteria in its gut. Bacterial symbionts in arthropods are common, vary in their effects, and can dramatically influence the outcome of biological control efforts.Macrolophus pygmaeus(Heteroptera: Miridae), a key component of biological control programs, is mainly predaceous but may also display phytophagy.M. pygmaeushosts symbioticWolbachia, which induce cytoplasmic incompatibility, and twoRickettsiaspecies,R. belliiandR. limoniae, which are found in all individuals tested. To test possible involvement of the twoRickettsiaspecies in the feeding habits ofM. pygmaeus, we first showed that the microbiome of the insect is dominated by these three symbionts, and later described the distribution pattern of the twoRickettsiaspecies in its digestive system. Although bothRickettsiaspecies were located in certain gut bacteriocyes, in caeca and in Malpighian tubules of both sexes, each species has a unique cellular occupancy pattern and specific distribution along digestive system compartments. Infrequently, both species were found in a cell. In females, bothRickettsiaspecies were detected in the germarium, the apical end of the ovarioles within the ovaries, but not in oocytes. Although the cause for theseRickettsiadistribution patterns is yet unknown, it is likely linked to host nutrition while feeding on prey or plants.