Microbiomes of a specialist caterpillar are consistent across different habitats but also resemble the local soil microbial communities

Background: Insect-associated microorganisms can provide a wide range of benefits to their host, but insect dependency on these microbes varies greatly. The origin and functionality of insect microbiomes is not well understood. Many caterpillars can harbor symbionts in their gut that impact host metabolism, nutrient uptake and pathogen protection. Despite our lack of knowledge on the ecological factors driving microbiome assemblages of wild caterpillars, they seem to be highly variable and influenced by diet and environment. Several recent studies have shown that shoot-feeding caterpillars acquire part of their microbiome from the soil. Here, we examine microbiomes of a monophagous caterpillar (Tyria jacobaeae) collected from its natural host plant (Jacobaeae vulgaris) growing in three different environments: coastal dunes, natural inland grasslands and riverine grasslands, and compare the bacterial communities of the wild caterpillars to those of soil samples collected from underneath ...研究背景：与昆虫共生的微生物可为宿主提供广泛益处，但昆虫对这类微生物的依赖程度差异极大。目前学界对昆虫微生物组（microbiome）的起源与功能机制尚未形成充分认知。许多鳞翅目幼虫（caterpillar）的肠道内可定植共生微生物（symbionts），这些共生体能够影响宿主代谢、营养摄取与病原体防御。尽管我们对驱动野生鳞翅目幼虫微生物组群落组装的生态因子仍缺乏了解，但现有研究显示其微生物组具有高度变异性，且受取食环境与宿主饮食的共同影响。近期多项研究表明，取食嫩梢的鳞翅目幼虫可从土壤中获取部分自身微生物组。 本研究针对单食性鳞翅目幼虫（Tyria jacobaeae）开展分析，其样本采集自生长于三种不同生境的天然宿主植物Jacobaeae vulgaris：沿海沙丘、天然内陆草原与河岸草原；同时将野生幼虫的细菌群落与采集自该宿主植物下方的土壤样本进行对比……