RNA-Seq Transcriptome Analysis to Unravel the Gene Expression Profile of Ovarian Development in Xiangxi Cattle

The molecular mechanisms which regulate the developmental processes of ovary and result in increased reproductive efficiency of beef cattle need further investigations for optimum beef production. The study was designed to screen the signaling pathways and to investigate the genes related to development of ovarian tissues of Xiangxi cattle at different age (6, 18 and 30 months) by transcriptome sequencing and bioinformatics analysis. Illumina II high-throughput sequencing technology was used to seq transcriptomes of nine Xiangxi cattles ovarian tissues at different ages. The total number of ovarian genes assembled were compared with reference genome sequences, differentially expressed gene analysis, KEGG and GO enrichment analysis and finally the candidate genes screening were performed. The results showed that about 68.51 Gb clean data was obtained and clean data of each sample reached to the 6.10 Gb. A total of 26243 expressed genes were screened, of which 4866 genes were new and have not been annotated in any database. A total of 594 differentially expressed genes were annotated between 6 and 30-months groups. Similarly, a total of 141 differentially expressed genes were annotated between 18and 30-mths groups. Among these, the members of G-protein coupled receptors family like follicle-stimulating hormone receptor (FSHR) and Insulin-like 3 peptides (INSL3) participate in signaling pathways. These results suggest that FSHR and INSL3 may be related to the reproductive development and reproductive performance of ovarian tissues in Xiangxi cattle and play an important role.