TRANSCRIPTOME ANALYSIS OF SHEEP EMBRYOS IN VIVO BASED ON SINGLE CELL RNA-SEQ

Objective: The purpose of the present study was to explore the transcriptome differences of sheep embryos. Embryos were at different developmental stages in order to assess the differences of the function, classification and metabolic pathway of differentially expressed genes and to provide a theoretical basis for revealing the regulatory mechanism of sheep early embryo development. Materials and methods: 8-cell, 16-cell, morula and blastocysts were collected and the sequencing library was constructed by the Smart-Seq2 amplification technology. The transcriber was sequenced by Illumina HiSeqXten high-throughput sequencing technology and the effective sequences were analyzed by functional annotation and related bioinformatic analysis. Results: The results indicated that the Clean reads of 8-cell, 16-cell, morula and early blastocysts embryos were 44169859048957974, of which 93.71-95.29% reads were compared with the reference genome sequence of sheep; We used FDR 0.05 and Fold Change 2 as the criteria to screen for differential genes by comparing pairwise differences at four stage during embryo development. A total of 8281 differentially expressed mRNAs were identified, including 840 in E16vsE8, 6631 in E32vsE16, 810 in BlavsE32. Using the GO enrichment analysis, we explored the function of the DEGs.No significant difference was found at E16 vs E8.At E32 vs E16,Cellular components contained 127 significance terms (P < 0.05), 92 terms were significant enriched in molecular function, And biological processes involved 338 significance terms; At Bla vs E32,Cellular components contained 7 significance terms (P <0.05). A total of 40 significance KEGG pathway terms were enriched in E32 vs E16. Conclusions: In this study, individual embryonic transcriptome sequencing of sheep was established for high-throughput sequencing and analysis of the transcriptomes of sheep 8-cell, 16-cell, morula, and early blastocysts. The number of differentially expressed genes was identified at different stages of sheep embryo development and the function, classification and metabolic pathway of differentially expressed genes were obtained. The current study offers substantial information on the identification of the sheep embryo transcriptome, revealing the molecular regulatory mechanism of sheep embryo development. and selects 30 key genes, and its function needs further exploration and research.