Department of Animal Sciences, University of Illinois, 1207 W. Gregory Dr., Urbana, IL 61801, USA.
Funct Integr Genomics. 2011 Mar;11(1):151-6. doi: 10.1007/s10142-010-0186-z. Epub 2010 Aug 31.
Cows experiencing severe postpartal negative energy balance (NEB) are at greater risk of developing mastitis than cows in positive energy balance (PEB). Our objectives were to compare mammary tissue gene expression profiles between lactating cows (n = 5/treatment) subjected to feed restriction to induce NEB and cows fed ad libitum to maintain PEB in order to identify genes involved in immune response and cellular metabolism that may predispose cows to an intramammary infection in non-infected mammary gland. The NEB cows were feed-restricted to 60% of calculated net energy for lactation requirements, and cows fed PEB cows were fed the same diet ad libitum. At 5 days after feed restriction, one rear mammary gland from all cows was biopsied for RNA extraction and transcript profiling using microarray and quantitative PCR. Energy balance (NEB vs. PEB) resulted in 278 differentially expressed genes (DEG). Among up-regulated DEG (n = 180), Ingenuity Pathway Analysis® identified lipid metabolism (8) and molecular transport (14) as some of the most enriched molecular functions. Genes down-regulated by NEB (98) were associated with cell growth and proliferation (21) and cell death (18). Results indicate that DEG due to NEB in mid-lactation were associated with numerous biological functions but we did not identify genes that could, a priori, be associated with risk of intramammary infection in non-infected mammary glands. Further studies with early postpartal cows are required.
处于严重产后负能平衡（NEB）的奶牛比处于正能平衡（PEB）的奶牛更容易发生乳腺炎。我们的目的是比较泌乳奶牛（每组 5 头）的乳腺组织基因表达谱，这些奶牛因限制饲料而诱导 NEB，而奶牛则自由采食以维持 PEB，以确定参与免疫反应和细胞代谢的基因，这些基因可能使奶牛易患非感染乳腺的乳腺炎。NEB 奶牛的饲料限制在计算出的泌乳净能需求的 60%，而 PEB 奶牛则自由采食相同的饲料。在限制饲料后 5 天，所有奶牛的一个后乳腺进行活检，用于 RNA 提取和微阵列及定量 PCR 转录谱分析。能量平衡（NEB 与 PEB）导致 278 个差异表达基因（DEG）。在上调的 DEG 中（n = 180），IPA®分析确定脂质代谢（8）和分子转运（14）是最丰富的分子功能之一。NEB 下调的基因（n = 98）与细胞生长和增殖（21）和细胞死亡（18）有关。结果表明，泌乳中期由于 NEB 而产生的 DEG 与许多生物学功能有关，但我们没有发现可以预先确定与非感染乳腺乳腺炎风险相关的基因。需要对早期产后奶牛进行进一步研究。
