Screening Of Pork Key Function Genes And The Effect Of Selenium On The Expression Of Key Genes

This study was to explore and use of the genetic resources of the local breed Xiang pig.In the first place,Guizhou local pig(Xiang pig)and foreign pig(big white pig)with better meat quality were selected as experimental materials.Six 90-Day pigs with the same parity and similar body weight were castrated from Jiangxiang pig and purebred big white pig,slaughtered,collected the longissimus dorsi muscle,and extracted the total RNA of longissimus dorsi muscle.The gene differential expression profiles of the longissimus dorsi of Xiang pig and big white pig were obtained by bioinformatics analysis.The reliability of the sequencing data was verified by real-time fluorescence quantitative analysis.Selw and sbp1 genes were screened out.Furthermore,the effects of different concentrations of selenium(0,0.02,0.1,0.5 and2.5 ug/ml)on the proliferation and the expression of selw and sbp1 genes of skeletal muscle satellite cells were studied.The main results are as follows:(1)45568778 and 47475542 raw reads were obtained by high-throughput RNA sequencing.After data filtering,42834534 clean reads were obtained in large white pigs and 41202134 clean reads in Xiang Pigs.Compared with the number of reads at the only position in the reference gene sequence,there were 27635302 in large white pigs and 26143070 in Xiang Pigs,with a matching rate of 64.52%and 63.45%respectively.Compared to the reference genome,the read distribution areas are mainly divided into exon,intron and intergenic.In this experiment,the reads content of large white pig and Xiang pig is higher than that of exon,which is more than 80%;while the reads content of large white pig and Xiang pig is lower than that of intron and intergenic,which is less than 10%.Finally,the overall quality of RNA SEQ was evaluated,R~2 was 0.95.It shows that the original data of high quality and reliability are obtained in this experiment.We screened the difference gene between Xiang pig and big white pig by using the read which was the only position in the reference gene sequence.Through the analysis of gene expression Venn diagram,13247 genes were expressed in the longissimus dorsi of Xiang pig and big white pig,510 genes were specifically expressed in big white pig,and 992 genes were specifically expressed in Xiang pig.Differential gene cluster analysis showed that different cluster differential gene expression was formed in Xiang pig and big white pig.According to the volcanic map,318 differential genes were found in the longissimus dorsi muscle of Xiang pig and big white pig,184 genes were up-regulated and 134 genes were down regulated.Four main biochemical metabolic pathways and signal pathways were screened by enrichment analysis of differential genes go and KEGG.Adenosine monophosphate activated protein kinase signaling pathway(AMPK signaling pathway),transcription factor signaling pathway(FOXO signaling pathway),pyruvate metabolism pathway(pyruvate metabolism pathway)and fatty acid metabolism pathway(fatty acid metabolism pathway).There are 15,13,8 and 8 differentially expressed genes in total screened 44 differentially expressed genes.Fourteen differentially expressed genes were selected from Xiang pig and big white pig,and real-time fluorescence quantitative verification of sequencing data showed that the results were consistent with the sequencing data.A high expression gene selw in the longissimus dorsi muscle of large white pig and a high expression gene sbp1 in the longissimus dorsi muscle of Xiang pig were screened out.Both genes are related to selenium,so they are screened out for the next experiment.(2)The effect of selenium concentration on cell proliferation and expression of key functional genes of meat quality.As a whole,selenium is cytotoxic.The lower the concentration is,the better the cell growth will be.When the concentration is too high(2.5ug/ml),the cell will die.After adding different concentrations of selenium,the expression of selw gene increased with cell proliferation(P<0.05),and the best concentration was 0.02%.The expression of sbp1 gene was up-regulated in cell proliferation and differentiation(P<0.05),and the best concentration was 0.1%.The results of this study can provide a good basis for the follow-up study of selw and sbp1gene function.