Antlers are hallmark organ of deer, exhibiting a relatively high growth rate among mammals, and requiring large amounts of nutrients to meet its development. The rumen microbiota plays key roles in nutrient metabolism. However, changes in the microbiota and metabolome in the rumen during antler growth are largely unknown. We investigated rumen microbiota (liquid, solid, ventral epithelium, and dorsal epithelium) and metabolic profiles of sika deer at the early (EG), metaphase (MG) and fast growth (FG) stages. Our data showed greater concentrations of acetate and propionate in the rumens of sika deer from the MG and FG groups than in those of the EG group. However, microbial diversity decreased during antler growth, and was negatively correlated with short-chain fatty acid (SCFA) levels. , , and were the dominant bacteria in the liquid, solid, ventral epithelium, and dorsal epithelium fractions. The proportions of , , and increased significantly in the liquid or dorsal epithelium fractions. Untargeted metabolomics analysis revealed that the metabolites also changed significantly, revealing 237 significantly different metabolites, among which the concentrations of γ-aminobutyrate and creatine increased during antler growth. Arginine and proline metabolism and alanine, aspartate and glutamate metabolism were enhanced. The co-occurrence network results showed that the associations between the rumen microbiota and metabolites different among the three groups. Our results revealed that the different rumen ecological niches were characterized by distinct microbiota compositions, and the production of SCFAs and the metabolism of specific amino acids were significantly changed during antler growth.

中文翻译：

---

鹿角生长过程中瘤胃生态位微生物群落和代谢组的变化

鹿角是鹿的标志性器官，在哺乳动物中表现出相对较高的生长速度，并且需要大量的营养来满足其发育。瘤胃微生物群在营养代谢中发挥着关键作用。然而，鹿角生长过程中瘤胃微生物群和代谢组的变化在很大程度上是未知的。我们研究了梅花鹿早期 (EG)、中期 (MG) 和快速生长 (FG) 阶段的瘤胃微生物群（液体、固体、腹侧上皮和背侧上皮）和代谢特征。我们的数据显示，MG 和 FG 组梅花鹿瘤胃中乙酸和丙酸的浓度高于 EG 组。然而，微生物多样性在鹿角生长过程中下降，并且与短链脂肪酸（SCFA）水平呈负相关。 、 、 和 是液体、固体、腹侧上皮和背侧上皮部分中的优势细菌。 、 、 和 的比例在液体或背侧上皮部分中显着增加。非靶向代谢组学分析显示，代谢物也发生了显着变化，揭示了237种显着不同的代谢物，其中γ-氨基丁酸和肌酸的浓度在鹿茸生长过程中增加。精氨酸和脯氨酸代谢以及丙氨酸、天冬氨酸和谷氨酸代谢增强。共现网络结果表明，三组瘤胃微生物群和代谢物之间的关联不同。我们的结果表明，不同的瘤胃生态位具有不同的微生物群组成，并且在鹿角生长过程中短链脂肪酸的产生和特定氨基酸的代谢发生显着变化。