关键词: 贺兰山, 岩羊, 肠道菌群, 组成结构, 性别

Abstract: The gut microbiota play an important role in regulating the physiological health of wild animals, and their composition can be influenced by a range of factors. In recent years, there has been a growing interest in the field of gender differences in animal gut microbiota, yet relevant studies on blue sheep remain scarce. In this study, fresh feces were collected from blue sheep (Pseudois nayaur) in the Helan Mountains using the line transect method during the summer and winter of 2017 in the Helan Mountain National Nature Reserve, Ningxia. The fecal samples from 81 non-repetitive individuals underwent 16S rRNA sequencing and were grouped according to season and gender. The objective was to investigate the differences in gut microbiota diversity and composition between the sexes of blue sheep inhabiting the eastern slopes of the Helan Mountains. Additionally, the study aimed to explore potential mechanisms through which gender influences gut microbiota. The results showed that Firmicutes and Bacteroidetes were the predominant phyla within the gut microbiota of blue sheep in the Helan Mountains. The alpha diversity analysis demonstrated that the Shannon index of the gut microbiota of female blue sheep was significantly higher than that of males during the summer (P < 0. 01), but there was no significant difference in the Chao1 and Shannon indices between male and female blue sheep during the winter (P > 0. 05). The PCoA and Anosim analyses revealed highly significant differences in the gut microbiota structure of male and female blue sheep, both in summer and winter (P < 0. 01). The results of the T-tests and LEfSe analyses revealed that the relative abundance of Firmicutes, Melainabacteria, Ruminococcaceae, Clostridia, and Clostridiales in females was significantly higher than that in males during the summer period, while the relative abundance of Bacteroidetes , Bacteroidia, Bacteroidales, Mailhella, Bacteroides, and Tyzzerella was significantly lower in females than in males (P < 0. 05). In winter, the abundance of Euryarchaeota, Proteobacteria, Methanocor pusculum, and Mailhella was found to be significantly higher in females than in males (P < 0. 05). Conversely, the abundance of Lachnospiraceae, Odoribacter, and unidentified_Christensenellaceae in males was significantly higher than that in females (P < 0. 05). This study indicated that there were highly significant differences in the composition structure of the gut microbiota between male and female blue sheep in the Helan Mountains during both summer and winter, but the gut microbiota differed was highly significant different only in summer. The observed phenomenon may be attributed to differences in the level of sex hormones, dietary habits, and physiological differences. This study aimed to explore the characteristics of gender differences in gut microbiota of blue sheep in the Helan Mountains across different seasons. The findings enrich the basic biological data of wild blue sheep, provide a theoretical basis for the in-depth study of the gut microbiota of blue sheep, and support the scientific protection of blue sheep within the nature reserve.

Key words: Helan Mountain, Blue sheep, Gut microbiota, Composition structure, Gender