Obligate Gut Symbiotic Association with Caballeronia in the Mulberry Seed Bug Paradieuches dissimilis (Lygaeoidea: Rhyparochromidae)
Obligate Gut Symbiotic Association with Caballeronia in the Mulberry Seed Bug Paradieuches dissimilis (Lygaeoidea: Rhyparochromidae)
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DOI：
10.1007/s00248-022-02117-2
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发表时间：
2022-09-30
影响因子：
3.6
通讯作者：
Kikuchi, Yoshitomo
中科院分区：
文献类型：
--
作者：
Ishigami, Kota;Jang, Seonghan;Kikuchi, Yoshitomo
许多昆虫体内都有共生细菌，共生微生物对宿主的代谢起着至关重要的作用。异翅目超科Coreoidea和Lygaeoidea臭虫的成员在它们的肠道中有Caballeronia属的共生体。与coreo总科昆虫的共生关系相比，lygaeo总科昆虫的共生关系尚不清楚。本研究通过组织学观察、共生菌培养、16S rRNA基因扩增子测序和共生菌感染检测等方法，研究了桑树种子虫Paradieuches dissimilis （Lygaeoidea: Rhyparochromidae）的共生关系。组织学观察和培养结果表明，P. dissimilis在其后中肠隐窝中含有Caballeronia共生体。野外采集的异种假单胞菌16S rRNA基因扩增子测序结果证实，Caballeronia属在异种假单胞菌自然居群中肠居优势地位。此外，PCR检测结果表明，虫卵不含共生菌，幼虫水平获取环境土壤中的共生菌。感染和饲养实验表明，无共生的非共生个体体色异常，体型小，存活率低，没有个体成虫，表明桑籽虫与Caballeronia共生体之间存在专一性的合作共生关系。
Many insects possess symbiotic bacteria in their bodies, and microbial symbionts play pivotal metabolic roles for their hosts. Members of the heteropteran superfamilies Coreoidea and Lygaeoidea stinkbugs harbor symbionts of the genus Caballeronia in their intestinal tracts. Compared with symbiotic associations in Coreoidea, those in Lygaeoidea insects are still less understood. Here, we investigated a symbiotic relationship involving the mulberry seed bug Paradieuches dissimilis (Lygaeoidea: Rhyparochromidae) using histological observations, cultivation of the symbiont, 16S rRNA gene amplicon sequencing, and infection testing of cultured symbionts. Histological observations and cultivation revealed that P. dissimilis harbors Caballeronia symbionts in the crypts of its posterior midgut. 16S rRNA gene amplicon sequencing of field-collected P. dissimilis confirmed that the genus Caballeronia is dominant in the midgut of natural populations of P. dissimilis. In addition, PCR diagnostics showed that the eggs were free of symbiotic bacteria, and hatchlings horizontally acquired the symbionts from ambient soil. Infection and rearing experiments revealed that symbiont-free aposymbiotic individuals had abnormal body color, small body size, and, strikingly, a low survival rate, wherein no individuals reached adulthood, indicating an obligate cooperative mutualism between the mulberry seed bug and Caballeronia symbionts.