A Characterization and Comparative Analysis of Ovary Transcriptome in Locally Adopted Xiangxi and Angus Cattle

The regulatory mechanisms controlling the ovary development in the Xiangxi cattle are still largely unknown, yet the growth and development of ovary is a complex process that plays a crucial role in reproduction. In this study, we performed a transcriptome analysis based on the RNA sequencing (RNA-Seq) of Xiangxi cattle and Angus cattle tissue obtained from 8 months of age to identify which genes are differentially expressed and to investigate their temporal expression profiles. The results showed that a total of 165 differential genes were annotated, of which 58 were annotated in the GO database and 73 were annotated in the KEGG database. A total of 12 comparatively concentrated signal pathways were obtained. Among them, the osteoclast differentiation signaling pathway (ko04380) was the most involved in differentially expressed genes. The other signaling pathways were amphetamine addiction, herpes simplex infection, caffeine metabolism, cocaine addiction, pertussis, ECM-receptor interaction, toll-like receptor signaling pathway, and glycosphingolipid biosynthesis - ganglio series. Functional analysis also showed that the differentially expressed genes were involved in various Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. GO annotations indicated that the genes related to biological processes, and molecular events were significantly active. KEGG pathway analysis showed that the osteoclast differentiation signaling pathway in Xiangxi ovary transcriptome data, at the end ECM–receptor interaction pathways. Moreover, several novel pathways, were significantly enriched despite having no evident associations with the reproductive function. Our findings provide a molecular resource for further investigation of the general molecular mechanism of Xiangxi cattle ovary and offer new insights to understand comprehensively the specificity of local cattle breeds reproduction.