Gene expression in bovine rumen epithelium during weaning identifies molecular regulators of rumen development and growth
Gene expression in bovine rumen epithelium during weaning identifies molecular regulators of rumen development and growth
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DOI：
10.1007/s10142-012-0308-x
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发表时间：
2013-03-01
影响因子：
2.9
通讯作者：
Chung, Hoyoung
中科院分区：
文献类型：
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作者：
Connor, Erin E.;Baldwin, Ransom L.;Chung, Hoyoung
在断奶期间，瘤胃中的上皮细胞功能响应于从前反刍动物环境到真正反刍动物环境的转换而转变，以确保有效的营养吸收和代谢。为了确定受断奶影响的基因网络在牛瘤胃中，荷斯坦公牛犊饲喂商业牛奶添加剂（MRO），直到42日龄，然后提供牛奶+果园草干草（MH）或牛奶+谷物为基础的犊牛料（MG）的饮食。从在四个时间点处死的小牛中提取瘤胃上皮RNA：饲喂MRO饮食时的14日龄（n = 3）和42日龄（n = 3）以及饲喂MH和MG饮食时的56日龄（n = 3/饮食）和70日龄（n = 3/饮食），通过微阵列杂交进行转录谱分析。使用差异表达的排列分析A（R）进行了五个两组比较，以鉴定在MRO饮食中第14天和第42天之间、MRO饮食第42天和MG或MH饮食第56天之间以及MG和MH饮食第56天和第70天之间随时间和发育阶段的差异表达基因。对断奶期间差异表达基因的免疫途径分析（IPA）表明，前5个基因网络涉及参与脂质代谢、细胞形态和死亡、细胞生长和增殖、分子运输和细胞周期的分子。鉴定了在断奶期间瘤胃微生物群的建立和相关的瘤胃上皮炎症中起作用的推定基因。转录因子PPAR-alpha的激活被IPA软件鉴定为瘤胃上皮分子变化的重要调节因子，其在从反刍前到反刍的过渡期间在乳头状突起发育和脂肪酸氧化中起作用。因此，瘤胃发育的分子标记物和调控瘤胃上皮分化和生长的基因网络被鉴定用于选择用于改善和评估瘤胃发育和功能的靶标和方法，特别是在生长中的小牛中。
During weaning, epithelial cell function in the rumen transitions in response to conversion from a pre-ruminant to a true ruminant environment to ensure efficient nutrient absorption and metabolism. To identify gene networks affected by weaning in bovine rumen, Holstein bull calves were fed commercial milk replacer only (MRO) until 42 days of age, then were provided diets of either milk + orchardgrass hay (MH) or milk + grain-based calf starter (MG). Rumen epithelial RNA was extracted from calves sacrificed at four time points: day 14 (n = 3) and day 42 (n = 3) of age while fed the MRO diet and day 56 (n = 3/diet) and day 70 (n = 3/diet) while fed the MH and MG diets for transcript profiling by microarray hybridization. Five two-group comparisons were made using Permutation Analysis of Differential ExpressionA (R) to identify differentially expressed genes over time and developmental stage between days 14 and 42 within the MRO diet, between day 42 on the MRO diet and day 56 on the MG or MH diets, and between the MG and MH diets at days 56 and 70. Ingenuity Pathway Analysis (IPA) of differentially expressed genes during weaning indicated the top 5 gene networks involving molecules participating in lipid metabolism, cell morphology and death, cellular growth and proliferation, molecular transport, and the cell cycle. Putative genes functioning in the establishment of the rumen microbial population and associated rumen epithelial inflammation during weaning were identified. Activation of transcription factor PPAR-alpha was identified by IPA software as an important regulator of molecular changes in rumen epithelium that function in papillary development and fatty acid oxidation during the transition from pre-rumination to rumination. Thus, molecular markers of rumen development and gene networks regulating differentiation and growth of rumen epithelium were identified for selecting targets and methods for improving and assessing rumen development and function, particularly in the growing calf.