Transcriptome Analysis of Ovarian Tissues Reveals Key Genes Involved in the Prolificacy of Ussuri Raccoon Dog

Background: Ussuri raccoon dog is an important economic animal, which brings considerable economic benefits to Hebei, China. The high fertility rate of Ussuri raccoon dog is vital for its breeding industry. However, the molecular mechanism of prolificacy traits in raccoon dog remains unclear. Therefore, it is of great importance to identify the related genes and analyze the genetic mechanism of its high reproductive traits. Methods: In our study, RNA-seq was performed using ovarian tissues from six Ussuri raccoon dogs during estrus. The samples were divided into two groups based on the litter size over the last three consecutive years. We performed a standard transcriptomic analysis procedure to dig for differentially expressed genes (DEGs) and analyze gene function in detail. Result: Statistical analysis revealed a total of 612 DEGs between the low-fecundity and high-fecundity group including 277 upregulated and 335 downregulated DEGs, respectively. KEGG pathway analysis shows the DEGs enriched in several reproductive related pathways, such as the Circadian entrainment pathway. A total of 8 DEGs were identified with differential alternative splicing (DAS) events and recognized as DAS-DE genes. Among the up-regulated DAS-DE genes, ABCA6 and GPAM were found to be the most important genes regulating the prolificacy trait of Ussuri raccoon dog. The DEGs and DAS-DE genes identified in this study provide a probable genetic mechanism for improving prolificacy of Ussuri raccoon dog breeding.