基于转录组测序和血清指标测定对牛肾周脂肪的脂质代谢和内分泌功能解析

Analysis of Lipid Metabolism and Endocrine Function of Perirenal Fat in Cattle Based on Transcriptome Sequencing and Serum Index Measurements

旨在筛选西门塔尔牛与安格斯牛肾周脂肪的差异表达基因,分析2个品种牛血清指标差异,以期对肾周脂肪的脂质代谢和内分泌功能进行解析,为牛品种选育打下基础。选取相同月龄的西门塔尔牛和安格斯牛各3头,饲喂前采集空腹血液分离血清进行血清生化指标测定;屠宰后,采取相同大小的肾周脂肪,提取总RNA后进行转录组测序分析,使用DEGseq方法对各个样品的基因表达水平进行差异检测,对差异表达基因进行GO分析和KEGG分析,并使用实时荧光定量PCR验证测序结果。结果表明,安格斯牛血清中白蛋白(ALB2)、尿素氮(UREAL)和葡萄糖(GLUC3)含量显著低于西门塔尔牛(P<0.05),甘油三酯(TRIGL)含量显著高于西门塔尔牛(P<0.05)。转录组结果显示,2个品种牛肾周脂肪间的差异表达基因为1743,其中1361个基因上调表达,382个基因下调表达。差异表达基因GO功能富集结果显示,差异基因显著富集到52个生物学功能,主要与细胞过程和细胞有关;KEGG富集结果显示,差异表达基因主要在Fat digestion and absorption、cAMP、PPAR和Rap1等信号通路显著富集,最终筛选出与脂质代谢相关的基因SCD5、APOA4、PTX3、OLR1和PRKCZ。通过实时荧光定量PCR测定差异基因的相对表达量,结果显示,测序结果和实时荧光定量PCR结果一致,说明测序结果可靠,研究获得的差异基因可作为肉牛品种培育的基础资料。

This study aims to screen the differentially expressed genes in perirenal fat of Simmental cattle and Angus cattle,and analyze the differences in serum indexes between the two breeds,in order to determine the lipid metabolism and endocrine function of perirenal fat,so as to lay a foundation for cattle breed selection.Three Simmental cattle and three Angus cattle of the same age were selected,and fasting blood was collected before feeding to separate and for determination of serum biochemical indexes.After slaughter,perirenal fat of the same size was sampled,and total RNA was extracted for transcriptome sequencing analysis.The differentially expressed genes(DEGs)were identified using the DEGseq method,and GO and KEGG analysis were performed.The sequencing results were verified using Real-time fluorescence quantitative PCR.The results showed that:the serum contents of albumin(ALB2),urea nitrogen(UREAL)and glucose(GLUC3)in Angus cattle were significantly lower than that of Simmental cattle(P<0.05),and the contents of triglyceride(TRIGL)were significantly higher than that of Simmental cattle(P<0.05).Transcriptome results showed that 1743 genes were differentially expressed between the perirenal fats of two breeds.Among that,1361 and 382 genes were up regulated and down regulated,respectively.GO analysis showed that DEGs were significantly enriched to 52 biological functions,which were mainly related to cellular processes and cells.KEGG analysis showed that DEGs were significantly enriched mainly in fat digestion and absorption,cAMP,PPAR and Rap1 signaling pathways.Five genes(SCD5,APOA4,PTX3,OLR1 and PRKCZ)related to lipid metabolism were identified,and the sequencing results of these five genes were verified by Real-time fluorescence quantitative PCR,these results indicated that the sequencing results were reliable and the obtained differential genes could be used as basic data for breeding beef cattle breeds.