Laboratory of Animal Physiology, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan.
Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan.
J Anim Sci. 2018 Jun 4;96(6):2226-2237. doi: 10.1093/jas/skx016.
The length and density of rumen papillae starts to increase during weaning and growth of ruminants. This significant development increases the intraruminal surface area and the efficiency of VFA (acetate, propionate, butyrate, etc.) uptake. Thus, it is important to investigate the factors controlling the growth and development of rumen papillae during weaning. This study aimed to compare the transcriptomes of rumen papillae in suckling and weaned calves. Total RNA was extracted from the rumen papillae of 10 male Japanese Black calves (5 suckling calves, 5 wk old; 5 weaned calves, 15 wk old) and used in RNA-sequencing. Transcript abundance was estimated and differentially expressed genes were identified and these data were then used in Ingenuity Pathway Analysis (IPA) to predict the major canonical pathways and upstream regulators. Among the 871 differentially expressed genes screened by IPA, 466 genes were upregulated and 405 were downregulated in the weaned group. Canonical pathway analysis showed that "atherosclerosis" was the most significant pathway, and "tretinoin," a derivative of vitamin A, was predicted as the most active upstream regulator during weaning. Analyses also predicted IgG, lipopolysaccharides, and tumor-necrosis factor-α as regulators of the microbe-epithelium interaction that activates rumen-related immune responses. The functional category and the up-regulators found in this study provide a valuable resource for studying new candidate genes related to the proliferation and development of rumen papillae from suckling to weaning Japanese Black calves.
反刍动物在断奶和生长过程中，瘤胃乳头的长度和密度开始增加。这种显著的发展增加了瘤胃内表面面积和 VFA（乙酸、丙酸、丁酸等）吸收效率。因此，研究控制断奶期间瘤胃乳头生长和发育的因素非常重要。本研究旨在比较哺乳期和断奶期日本黑牛犊瘤胃乳头的转录组。从 10 头雄性日本黑牛犊（5 头哺乳期犊牛，5 周龄；5 头断奶犊牛，15 周龄）的瘤胃乳头中提取总 RNA，并用于 RNA-seq。估计转录丰度，鉴定差异表达基因，并使用 Ingenuity Pathway Analysis (IPA) 对这些数据进行分析，以预测主要的经典途径和上游调控因子。在 IPA 筛选的 871 个差异表达基因中，466 个基因在断奶组中上调，405 个基因下调。经典途径分析表明，“动脉粥样硬化”是最显著的途径，维生素 A 的衍生物视黄醇在断奶期间被预测为最活跃的上游调控因子。分析还预测 IgG、脂多糖和肿瘤坏死因子-α 是调节微生物-上皮相互作用的调节剂，这种相互作用激活了与瘤胃相关的免疫反应。本研究中发现的功能类别和上调调控因子为研究与哺乳期到断奶期日本黑牛犊瘤胃乳头增殖和发育相关的新候选基因提供了有价值的资源。
