Identification of unique transcriptomic signatures through integrated multispecies comparative analysis and WGCNA in bovine oocyte development

Background: Cattle (Bos taurus) are a major large livestock, however, compared with other species, the transcriptional specificity of bovine oocyte development has not been emphasised.

Results: To reveal the unique transcriptional signatures of bovine oocyte development, we used integrated multispecies comparative analysis and weighted gene co-expression network analysis (WGCNA) to perform bioinformatic analysis of the germinal follicle (GV) and second meiosis (MII) gene expression profile from cattle, sheep, pigs and mice. We found that the expression levels of most genes were down-regulated from GV to MII in all species. Next, the multispecies comparative analysis showed more genes involved in the regulation of cAMP signalling during bovine oocyte development. Moreover, the green module identified by WGCNA was closely related to bovine oocyte development. Finally, integrated multispecies comparative analysis and WGCNA picked up 61 bovine-specific signature genes that participate in metabolic regulation and steroid hormone biosynthesis.

Conclusion: In a short, this study provides new insights into the regulation of cattle oocyte development from a cross-species comparison.