Adult mosquitoes inherit a bacterial community from larvae via transstadial transmission, an understudied process that may influence host-microbe interactions. Microbes contribute to important host life history traits, and analyzing transmitted microbial communities, the interrelationship between larval and adult-associated microbiota, and factors influencing host-microbe relationships provides targets for research. During its larval stage, the yellow fever mosquito (Aedes aegypti) hosts the trichomycete gut fungus Zancudomyces culisetae, and fungal colonization coincides with environmental perturbations in the digestive tract microecosystem. Natural populations are differentially exposed to fungi, thereby potentially harboring distinct microbiota and experiencing disparate host-microbe interactions. This study’s objectives were to characterize larval and initial adult microbiomes, investigate variation in diversity and distribution of microbial communities across individuals, and assess whether larval fungal colonization impacted microbiomes at these developmental stages. Laboratory-based fungal infestation assays, sequencing of 16S rRNA gene amplicons, and bacterial load quantification protocols revealed that initial adult microbiomes varied in diversity and distribution. Larval fungal colonization had downstream effects on initial adult microbiomes, significantly reducing microbial community variation, shifting relative abundances of certain bacterial families, and influencing transstadial transmission outcomes of particular genera. Further, abundances of several families consistently decreased in adults relative to levels in larvae, possibly reflecting impacts of host development on specific bacterial taxa. These findings demonstrated that a prolific gut fungus impacted mosquito-associated microbiota at two developmental stages in an insect connected with global human health.

IMPORTANCE Mosquitoes are widespread vectors of numerous human pathogens and harbor microbiota known to affect host phenotypic traits. However, little research has directly investigated how bacterial communities associated with larvae and adults are connected. We characterized whole-body bacterial communities in mosquito larvae preceding pupation and in newly emerged adults, and investigated whether a significant biotic factor, fungal colonization of the larval hindgut, impacted these microbiomes. Results showed that fungal colonization reduced microbial community variation across individuals and differentially impacted the outcomes of transstadial transmission for certain bacterial genera, revealing downstream effects of the fungus on initial adult microbiomes. The importance of our research is in providing a thorough comparative analysis of whole-body microbiota harbored in larvae and adults of the yellow fever mosquito (Aedes aegypti) and in demonstrating the important role a widespread gut fungus played in a host-associated microbiome.

成年蚊子通过跨虫传播从幼虫那里继承了细菌群落，这是一个未被充分研究的过程，可能会影响宿主与微生物的相互作用。微生物是重要的宿主生活史特征，分析传播的微生物群落，幼虫与成虫相关的微生物群之间的相互关系以及影响宿主与微生物关系的因素为研究提供了目标。在其幼虫期，黄热蚊（Aedes aegypti）寄养了毛癣菌肠真菌Zancudomyces culisetae，并且真菌定植与消化道微生态系统中的环境扰动相吻合。自然种群有区别地暴露于真菌，从而潜在地藏有独特的微生物群并经历不同的宿主-微生物相互作用。这项研究的目的是表征幼虫和最初的成人微生物群，调查个体中微生物群落多样性和分布的变化，并评估在这些发育阶段，幼虫真菌定殖是否影响了微生物群。基于实验室的真菌侵染试验，16S rRNA基因扩增子测序以及细菌载量定量方案表明，最初的成年微生物群在多样性和分布方面均存在差异。幼虫真菌定殖对最初的成人微生物群有下游影响，大大减少了微生物群落的变化，改变了某些细菌家族的相对丰度，并影响了特定属的跨地传播结果。此外，相对于幼虫的水平，成年后几个家庭的丰度持续下降，这可能反映了宿主发育对特定细菌类群的影响。这些发现表明，在与全球人类健康有关的昆虫的两个发育阶段中，大量的肠道真菌影响了与蚊子相关的微生物群。可能反映了宿主发育对特定细菌类群的影响。这些发现表明，在与全球人类健康有关的昆虫的两个发育阶段中，大量的肠道真菌影响了与蚊子相关的微生物群。可能反映了宿主发育对特定细菌类群的影响。这些发现表明，在与全球人类健康有关的昆虫的两个发育阶段中，大量的肠道真菌影响了与蚊子相关的微生物群。

重要性蚊子是多种人类病原体的广泛传播媒介，并具有已知会影响宿主表型性状的微生物群。但是，很少有研究直接调查与幼虫和成虫相关的细菌群落是如何连接的。我们对化p之前的蚊子幼虫和新生的成虫的全身细菌群落进行了特征分析，并调查了重要的生物因子（幼虫后肠的真菌定植）是否影响了这些微生物群落。结果表明，真菌定殖减少了个体之间的微生物群落变异，并差异性地影响了某些细菌属的跨界传播结果，揭示了真菌对最初的成年微生物群的下游影响。埃及伊蚊（Aedes aegypti），并在证明重要的作用中，广泛的肠道真菌在宿主相关的微生物组中发挥了作用。