基于转录组分析夏季鸡舍前后端不同温度对小型白羽肉鸡胸肌生长发育的影响

Effects of Different Temperatures at the Front and Rear Ends of the Henhouse in Summer on Growth and Development of Breast Muscle of Small White-feather Broilers Based on Gene Transcriptome

试验旨在探究夏季鸡舍前后端不同温度对小型白羽肉鸡胸肌生长发育影响的分子调控机制。试验选取初始体重相近的8只19日龄小型白羽肉鸡母鸡,随机挑选4只放于鸡舍前端(湿帘端),另外4只放置在鸡舍后端(风机端),期间对两组温度进行实时监测,在40日龄时进行屠宰测定和采集胸肌作为试验样本进行转录组测序,筛选可能影响鸡舍前后端鸡胸肌发育差异的相关差异表达基因,在GO和KEGG数据库中进行功能注释、富集分析和聚类分析,进行实时荧光定量qPCR验证。结果显示:试验期间在9∶00~18∶00时,位于鸡舍后端(风机端)的平均温度显著高于鸡舍前端(湿帘端)的平均温度(P<0.05),其他时间平均温度基本相同。40日龄屠宰时,鸡舍后端组宰前活重、屠体重、全净膛重、全净膛率、半净膛重、半净膛率、胸肌重和胸肌率均显著低于鸡舍前端组(P<0.05),但屠宰率差异不显著(P>0.05)。鸡舍前、后端小型白羽肉鸡胸肌转录组测序数据得到的73个差异表达基因中,与鸡舍前端组相比,鸡舍后端组表达量上调的有46个,表达量下调的有27个。差异表达基因LPIN1、SESN2、FOS和MICAL2与肌肉生长发育有关且在鸡舍后端组均显著下调(P<0.05)。研究表明:位于鸡舍前、后端的小型白羽肉鸡在生长过程中体重发育和肌肉发育存在较大差异,而筛选到的差异基因将为今后进一步研究影响小型白羽肉鸡肌肉生长发育的分子调控机制提供参考。

The aim of this experiment was to explore the molecular regulatory mechanism of the effects of different temperatures at the front and rear ends of the henhouse on the growth and development of breast muscle of small white feathered broilers in summer.A total of eight 19-day-age female small white-feather broilers with similar initial body weight were selected for the experiment,and 4 were randomly selected to be placed at the front end of the henhouse(wet curtain end)and the other 4 were placed at the back end of the henhouse(fan end).During the experiment,temperature of the two groups was monitored in real time,slaughtering was conducted at the age of 40 days,and the chest muscle was collected as experimental samples for transcriptome sequencing.The differentially expressed genes that might affect the development difference of breast muscle in front and back of chicken houses were screened,and functional annotation,enrichment analysis and cluster analysis were performed in GO and KEGG databases for real-time fluorescence quantitative qPCR validation.The results showed that the average temperature at the rear end of the henhouse(fan end)was significantly higher than that at the front end of the henhouse(wet curtain end)from 9∶00 to 18∶00 during the test period,and the average temperature at other times was basically the same.At 40 days of age,live weight before slaughter,carcass weight,full evisceration weight,full evisceration rate,half evisceration weight,half evisceration rate,pectoral muscle weight and breast muscle rate in the rear end group of the henhouse were significantly lower than those in the front end group of the henhouse(P<0.05),but there was no significant difference in slaughter rate(P>0.05).A total of 73 differentially expressed genes were obtained from breast muscle transcriptome sequencing data of small white-feather broilers at the front and rear end of the henhouse.Compared with the front end group of the henhouse,46 genes were up-regulated and 27 genes were down-regulated in the rear end group of the henhouse.The differentially expressed genes LPIN1,SESN2,FOS and MICAL2 were associated with muscle growth and development,and were significantly down-regulated in the rear end group of henhouse(P<0.05).The results indicated that there were significant differences in body weight development and muscle development in small whitefeather broilers located at the front and back of the chicken house,and the differential genes screened would provide reference for further research on the molecular regulatory mechanisms that affected the development of molecular marker-assisted breeding for muscle growth performance of small white-feather broilers.