Abstract: [Objective] To transcriptomically identify the differentially expressed genes （DEGs） in maternal ovary with the development of fetus in sheep. [Method] F₁ hybrids of Scottish black-faced sheep and Texel sheep were used as experimental animals, and the transcriptomic analysis profiles were collected on 23^th day, 35^th day and 100^th day of gestation, respectively. A total of 18 transcriptomic data samples of sheep ovaries in the above three periods of gestation were downloaded from SRA in NCBI, a high-throughput sequencing data storing database. The transcriptomic data were standardized using Z-Score method. Comparative transcriptomic analysis was carried out between 23^th day and 35^th day of gestation as well as between 35^th day and 100^th day of gestation. The limma package of R language was used for analysis of differential gene expression to screen DEGs, and P-Value < 0.05 and |logFC| ≥ 2 were used as screening conditions for DEGs. DAVID online software was used to annotate DEGs and analyze their functional enrichment, and P-Value < 0.05 was used as a significant enrichment marker of signaling pathway. [Result]A total of 54 DEGs in sheep ovaries were screened between 23^th day and 35^th day of gestation, and a total of 68 DEGs were screened between 35^th day and 100^th day of gestation. The genes of HSP90AA1,HSP90AB1,MMP2 and HSP90B1 were observed in both groups of the DEGs. The 54 DEGs identified between 23^th day and 35^th day of gestation were found to be significantly enriched in six signaling pathways, including protein processing in endoplasmic reticulum, ribosome, estrogen, proteoglycans in cancer, dilated cardiomyopathy, and hypertrophic cardiomyopathy. The 68 DEGs identified between 35^th day and 100^th day of gestation were found to be significantly enriched in eleven signaling pathways, including cancer, focal adhesion, antigen processing and presentation, extracellular matrix （ECM）-receptor interaction, bacterial invasion of epithelial cells, protein processing in endoplasmic reticulum, ribosome, estrogen, PI3K-Akt, proteoglycans in cancer, and prostate cancer. [Conclusion] The gene expressions of HSP90AA1、HSP90AB1、MMP2 and HSP90B1 in estrogen signaling pathway during gestation have significant changes, indicating that these genes may play important roles in sheep gestation maintenance.

Key words: sheep, transcriptome, gestation, ovary