Sustaining beneficial gut symbioses presents a major challenge for animals, including holometabolous insects. Social insects may meet such challenges through partner fidelity, aided by behavioral symbiont transfer and transgenerational inheritance through colony founders. We address such potential through colony-wide explorations across 13 eusocial, holometabolous insect species in the ant genus Cephalotes. Through amplicon sequencing, we show that previously characterized worker microbiomes are conserved in soldier castes, that adult microbiomes exhibit trends of phylosymbiosis, and that Cephalotes cospeciate with their most abundant adult-enriched symbiont. We find, also, that winged queens harbor worker-like microbiomes prior to colony founding, suggesting vertical inheritance as a means of partner fidelity. Whereas some adult-abundant symbionts colonize larvae, larval gut microbiomes are uniquely characterized by environmental bacteria from the Enterobacteriales, Lactobacillales, and Actinobacteria. Distributions across Cephalotes larvae suggest more than 40 million years of conserved environmental filtering and, thus, a second sustaining mechanism behind an ancient, developmentally partitioned symbiosis.

中文翻译：

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合作伙伴保真度和环境过滤使特定阶段的海龟蚂蚁肠道共生保持超过 4000 万年

维持有益的肠道共生对动物（包括全变态昆虫）提出了重大挑战。社会性昆虫可以通过伴侣忠诚度来应对这些挑战，借助行为共生转移和通过殖民地创始人的跨代遗传。我们通过对头足纲蚂蚁属的 13 种真​​社会性、全变态昆虫物种进行群体范围的探索来解决这种潜力。通过扩增子测序，我们表明先前表征的工人微生物组在士兵种姓中是保守的，成年微生物组表现出系统共生的趋势，而Cephalotes与他们最丰富的富含成人的共生体共生。我们还发现，有翅膀的蜂后在蜂群建立之前就拥有类似工蜂的微生物群落，这表明垂直遗传是伴侣忠诚的一种方式。尽管一些成年丰富的共生体寄生在幼虫身上，但幼虫肠道微生物组的独特特征在于来自肠杆菌、乳杆菌和放线菌的环境细菌。Cephalotes幼虫的分布表明超过 4000 万年的保守环境过滤，因此，这是一种古老的、发育分区的共生背后的第二种维持机制。