miR-200家族在西农萨能奶山羊乳腺组织中的表达分析

Expression Profiles of miR-200 Family in Mammary Gland of Xinong Saanen Dairy Goat

笔者拟获得山羊miR-200家族乳腺组织表达谱,研究miR-200家族成员之间表达相关性及miR-200家族成员与山羊乳成分的相关性。通过定量PCR,检测miR-200家族在西农萨能奶山羊泌乳中期和干奶期乳腺组织中的表达量;利用Pearson相关系数分析miR-200家族不同成员表达量之间的相关性,同时分析miR-200家族成员与山羊乳成分之间的相关关系;利用miRanda和TargetScan 6.2软件分析、RNAhybrid和PITA软件预测miR-200家族的靶基因。结果表明,miR-200家族在奶山羊泌乳中期的乳腺组织中的表达量极显著高于干奶期(P<0.01);miR-200a与miR-141之间的表达量显著相关(P<0.05),miR-200b与miR-200c之间的表达量极显著相关(P<0.01);泌乳中期奶山羊乳腺组织中miR-200c的表达量与乳蛋白、非脂固形物(SNF)、冰点(FPD)的含量显著相关(P<0.05);经软件分析及预测发现,miR-200a/miR-141靶向作用于在乳脂合成中起关键作用的基因STAT4。miR-200家族可能对山羊乳蛋白及乳脂合成具有一定的调控作用。

The aim of the study was to establish the expression profiles of miR-200 family in mam- mary gland tissues of Xinong Saanen dairy goats, and to analyze the correlation between miR-200 family and milk composition. Real-Time qPCR was used for detecting the expression of miR-200 family in mammary gland during mid-lactation and dry period. Pearson＇s correlation coefficient analysis was used to determine the correlations of different miR-200 family members and goat milk composition. MiRanda, TargetScan 6. 2, RNAhybrid, and PITA software were used {or predicting the target genes of miR-200 family. Results showed that the expression levels of all miR-200 family members during mid-lactation were significantly higher than that during dry peri- od （P 〈 0.01）. Correlation analysis showed the significant correlations between miR-200a and miR-141 （P〈0.05）, and miR-200b and miR-200c （P^0.01）. Furthermore, the expression lev- els of miR-200c significantly correlated with the contents of goat milk protein, solids-not-fat （SNF）, and Freezing point depression （FPD） （P〈0.05）. We also found STAT4, a key regula- tor for milk fat synthesis, was a predicted target genes of miR-200a and miR-141. We concluded that miR-200 family might regulate milk protein and fatty acid synthesis in lactating goats.