Okinawa Institute of Science & Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan.
Faculty of Tropical AgriSciences, Czech University of Life Sciences, Prague, Czech Republic.
Commun Biol. 2024 Nov 6;7(1):1449. doi: 10.1038/s42003-024-07146-w.
Termites digest wood using Carbohydrate-Active Enzymes (CAZymes) produced by gut bacteria with whom they have cospeciated at geological timescales. Whether CAZymes were encoded in the genomes of their ancestor's gut bacteria and transmitted to modern termites or acquired more recently from bacteria not associated with termites is unclear. We used gut metagenomes from 195 termites and one Cryptocercus, the sister group of termites, to investigate the evolution of termite gut bacterial CAZymes. We found 420 termite-specific clusters in 81 bacterial CAZyme gene trees, including 404 clusters showing strong cophylogenetic patterns with termites. Of the 420 clusters, 131 included at least one bacterial CAZyme sequence associated with Cryptocercus or Mastotermes, the sister group of all other termites. Our results suggest many bacterial CAZymes have been encoded in the genomes of termite gut bacteria since termite origin, indicating termites rely upon many bacterial CAZymes endemic to their guts to digest wood.
白蚁利用肠道细菌产生的碳水化合物活性酶（CAZymes）来消化木材，这些肠道细菌与白蚁在地质时间尺度上共同进化。CAZymes 是由其祖先肠道细菌编码并传递给现代白蚁的，还是最近从与白蚁无关的细菌中获得的，目前尚不清楚。我们使用了来自 195 种白蚁和一种 Cryptocercus（白蚁的姐妹群）的肠道宏基因组来研究白蚁肠道细菌 CAZymes 的进化。我们在 81 个细菌 CAZyme 基因树中发现了 420 个白蚁特异性聚类，其中 404 个聚类与白蚁表现出强烈的共进化模式。在这 420 个聚类中，有 131 个聚类至少包含一个与 Cryptocercus 或 Mastotermes（所有其他白蚁的姐妹群）相关的细菌 CAZyme 序列。我们的研究结果表明，许多细菌 CAZymes 自白蚁起源以来就已被编码在白蚁肠道细菌的基因组中，这表明白蚁依赖于其肠道中特有的许多细菌 CAZymes 来消化木材。
