Cryptic community structure and metabolic interactions among the heritable facultative symbionts of the pea aphid
Cryptic community structure and metabolic interactions among the heritable facultative symbionts of the pea aphid
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DOI：
10.1111/jeb.14216
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发表时间：
2023-09-13
影响因子：
2.1
通讯作者：
Russell, Jacob A.
中科院分区：
文献类型：
--
作者：
Peng, Linyao;Hoban, Jessica;Russell, Jacob A.
大多数昆虫的血液中都含有有影响力的、但非必需的可遗传微生物。这些共生体群落表现出较低的多样性。但它们频繁的多物种特性引发了一些有趣的问题，比如共生体-共生体在宿主适应中的协同作用，以及共生体群落本身的稳定性。在这项研究中，我们建立在美国豌豆蚜虫Acyrthosiphon pisum种群中物种定义的共生群落结构的知识基础上。通过广泛的共生基因分型，我们发现豌豆蚜虫的微生物组可以在共生菌株水平上更精确地定义，菌株变异形成了先前报道的9种共感染趋势中的5种。现场数据提供了协同适应度效应和共生搭便车效应的混合证据，揭示了这些共同感染趋势的原因和后果。为了测试宿主内的代谢相互作用是否能预测常见与罕见的菌株定义的群落，我们利用了我们的优势，群落定义的共生菌株与12种豌豆蚜虫衍生的伽马变形菌的高相关性，并进行了基因组测序。利用代谢互补指数进行基因组推断，发现一对共生菌-共生沙雷氏菌和病毒立克次体之间具有很高的合作潜力。应用扩展网络算法，通过额外使用豌豆蚜虫和专门的布氏菌共生体基因组，沙雷氏菌和立克次体成为唯一需要双方扩展全息代谢的共生体群落。通过它们共同扩展生物素生物合成途径，这些共生体可能跨越缺失的空白，在它们营养有限、以韧皮部为食的宿主体内形成多方共生关系。最近，在沙雷氏菌和立克次体的生物素途径中，互补基因失活进一步提出了关于共生关系起源和宿主-共生体相互依赖性的问题。
Most insects harbour influential, yet non-essential heritable microbes in their hemocoel. Communities of these symbionts exhibit low diversity. But their frequent multi-species nature raises intriguing questions on roles for symbiont-symbiont synergies in host adaptation, and on the stability of the symbiont communities, themselves. In this study, we build on knowledge of species-defined symbiont community structure across US populations of the pea aphid, Acyrthosiphon pisum. Through extensive symbiont genotyping, we show that pea aphids' microbiomes can be more precisely defined at the symbiont strain level, with strain variability shaping five out of nine previously reported co-infection trends. Field data provide a mixture of evidence for synergistic fitness effects and symbiont hitchhiking, revealing causes and consequences of these co-infection trends. To test whether within-host metabolic interactions predict common versus rare strain-defined communities, we leveraged the high relatedness of our dominant, community-defined symbiont strains vs. 12 pea aphid-derived Gammaproteobacteria with sequenced genomes. Genomic inference, using metabolic complementarity indices, revealed high potential for cooperation among one pair of symbionts-Serratia symbiotica and Rickettsiella viridis. Applying the expansion network algorithm, through additional use of pea aphid and obligate Buchnera symbiont genomes, Serratia and Rickettsiella emerged as the only symbiont community requiring both parties to expand holobiont metabolism. Through their joint expansion of the biotin biosynthesis pathway, these symbionts may span missing gaps, creating a multi-party mutualism within their nutrient-limited, phloem-feeding hosts. Recent, complementary gene inactivation, within the biotin pathways of Serratia and Rickettsiella, raises further questions on the origins of mutualisms and host-symbiont interdependencies.