Data_Sheet_2_Unique rumen micromorphology and microbiota–metabolite interactions: features and strategies for Tibetan sheep adaptation to the plateau.docx

The rumen microbiota—a symbiont to its host and consists of critical functional substances—plays a vital role in the animal body and represents a new perspective in the study of adaptive evolution in animals. This study used Slide Viewer slicing analysis system, gas chromatography, RT-qPCR and other technologies, as well as 16S and metabolomics determination methods, to measure and analyze the microstructure of rumen epithelium, rumen fermentation parameters, rumen transport genes, rumen microbiota and metabolites in Tibetan sheep and Hu sheep. The results indicate that the rumen nipple height and cuticle thickness of Tibetan sheep are significantly greater than those of Hu sheep (p < 0.01) and that the digestion and absorption of forage are greater. The levels of carbohydrate metabolism, lipid metabolism, and protein turnover were increased in Tibetan sheep, which enabled them to ferment efficiently, utilize forage, and absorb metabolic volatile fatty acids (VFAs). Tibetan sheep rumen metabolites are related to immune function and energy metabolism, which regulate rumen growth and development and gastrointestinal homeostasis. Thus, compared with Hu sheep, Tibetan sheep have more rumen papilla and cuticle corneum, and the synergistic effect of the microbiota and its metabolites is a characteristic and strategy for adapting to high-altitude environments.

瘤胃微生物组（rumen microbiota）作为宿主的共生体，含有关键功能物质，在动物机体中发挥重要作用，同时为动物适应性进化研究提供了全新视角。本研究采用Slide Viewer切片分析系统、气相色谱、实时荧光定量PCR（RT-qPCR）等技术，结合16S测序与代谢组学测定方法，对藏绵羊与湖羊的瘤胃上皮微观结构、瘤胃发酵参数、瘤胃转运基因、瘤胃微生物组及代谢物进行了检测与分析。结果显示，藏绵羊的瘤胃乳头高度与角质层厚度均显著高于湖羊（p < 0.01），牧草消化吸收效率更高。藏绵羊的碳水化合物代谢、脂质代谢及蛋白质周转水平更高，使其能够高效发酵、利用牧草并吸收代谢产生的挥发性脂肪酸（VFAs）。藏绵羊瘤胃代谢物与免疫功能及能量代谢相关，可调控瘤胃生长发育与胃肠道稳态。综上，相较于湖羊，藏绵羊拥有更发达的瘤胃乳头与角质层，微生物组与其代谢物的协同作用是其适应高海拔环境的特征与策略。