アザミウマ種における動的な微生物叢進化の特性評価

The insect microbiome profoundly influences host physiology and ecology, yet its composition and evolutionary dynamics in thrips remain poorly understood. Here, we present a systematic characterization of thrips-associated microbiomes through integrated metagenomic and culture-based approaches. Our analysis reveals that thrips microbiomes are dominated by both intracellular symbionts (e.g., Wolbachia and Spiroplasma) and extracellular taxa (e.g., Serratia, Pantoea, and Acinetobacter), with species-specific compositions exhibiting frequent gains and losses of bacterial lineages. We demonstrate that thrips microbiomes exhibit low interspecific microbial sharing, forming host-specific bacterial communities with minimal overlap between species. To address methodological challenges in microbiome research, we developed a dual-sequencing framework combining short-read sequencing (for comprehensive taxonomic detection) and long-read sequencing (for genomic verification), enabling the reconstruction of high-quality metagenome-assembled genomes that validated short-read findings. Furthermore, we isolated and sequenced the complete genomes of two dominant extracellular symbionts-Pantoea dispersa and Serratia marcescens-and performed pan-genome analyses. These revealed small core gene sets and expansive accessory genomes, including host-specific functional genes (e.g., hydrolases and neurotoxic N-acetyltransferases) likely involved in host adaptation. Our study provides a foundational genomic resource and a robust analytical pipeline for dissecting thrips microbiome evolution, with implications for understanding insect-microbe interactions and symbiont-mediated adaptations.