MOE Key Laboratory of Biosystems Homeostasis and Protection, State Conservation Center for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Science, Shantou University, Shantou 515063, China.
Int J Mol Sci. 2022 Oct 12;23(20):12140. doi: 10.3390/ijms232012140.
The gut microbiota forms a complex microecosystem in vertebrates and is affected by various factors. As a key intrinsic factor, sex has a persistent impact on the formation and development of gut microbiota. Few studies have analyzed sexual dimorphism of gut microbiota, particularly in wild animals. We used 16S rRNA gene sequencing to analyze the gut microbiota of juvenile and adult Chinese alligators, and untargeted metabolomics to study serum metabolomes of adult alligators. We observed significant sexual differences in the community diversity in juvenile, but not adult, alligators. In terms of taxonomic composition, the phylum Fusobacteriota and genus were highly abundant in adult alligators, similar to those present in carnivorous fishes, whereas the gut microbiota composition in juvenile alligators resembled that in terrestrial reptiles, indicating that adults are affected by their wild aquatic environment and lack sex dimorphism in gut microbiota. The correlation analysis revealed that the gut microbiota of adults was also affected by cyanobacteria in the external environment, and this effect was sex-biased and mediated by sex hormones. Overall, this study reveals sexual differences in the gut microbiota of crocodilians and their convergence in the external environment, while also providing insights into host-microbiota interactions in wildlife.
肠道微生物群在脊椎动物中形成一个复杂的微生态系统，受多种因素影响。作为一个关键的内在因素，性别对肠道微生物群的形成和发育有持久的影响。很少有研究分析肠道微生物群的性别二态性，特别是在野生动物中。我们使用 16S rRNA 基因测序来分析幼年和成年扬子鳄的肠道微生物群，并进行非靶向代谢组学研究来分析成年扬子鳄的血清代谢组。我们观察到在幼年扬子鳄中，肠道微生物群落的多样性存在显著的性别差异，但在成年扬子鳄中则没有。在分类组成方面，厚壁菌门和属在成年扬子鳄中高度丰富，类似于肉食性鱼类中的情况，而幼年扬子鳄的肠道微生物群组成则类似于陆地爬行动物，表明成年扬子鳄受到其野生水生环境的影响，并且其肠道微生物群没有性别二态性。相关性分析表明，成年扬子鳄的肠道微生物群也受到外部环境中蓝藻的影响，这种影响存在性别偏向，并且受到性激素的介导。总的来说，这项研究揭示了鳄鱼肠道微生物群的性别差异及其在外部环境中的趋同，同时也为野生动物中的宿主-微生物相互作用提供了新的见解。
