CircRNA landscape of non-pregnant endometrium during the estrus cycle in dairy goats

Abstract

Endometrial development is a complicated process involving numerous regulatory factors. Circular RNAs (circRNAs) have been known as a member of the naturally occurring non-coding RNA family, and are reportedly crucial for a variety of physiological processes. This study investigated the circRNA landscape of non-pregnant endometrium of dairy goats during estrus. Non-pregnant endometrial samples of goats at estrus day 5 (Ed5) and estrus day 15 (Ed15) were used to methodically analyze the circRNA landscape using strand-specific Ribo-Zero RNA-Seq. A total of 2 331 differentially expressed (P<0.05) circRNAs (DEciRs) between Ed5 and Ed15 were discovered in the goat endometrium. It was found that Nipped-B-like (NIPBL) and calcium responsive transcription factor (CARF) may participate in the development of the endometrium by decreasing (P<0.05) the levels of their circRNA-transcript forms. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of DEciR host genes (hgDEciRs) revealed that tight junctions and GTPases may be involved in endometrial development during the estrus cycle. A total of 2 331 DEciRs were discovered in the endometrium at Ed5 and Ed15. Based on GO and KEGG enrichment analyses, it could be inferred that tight junctions and GTPases are likely to play an important role in the development of goat endometrium during the estrus cycle. This circRNA study greatly enhances our knowledge of global trends in the development of non-pregnant endometrium during the estrus cycle in goats; these results help us to better understand the molecular regulation of endometrial development in dairy goats.