miR-17-5p in bovine oviductal fluid affects embryo development

• Published in: Molecular and cellular endocrinology Vol. 551; p. 111651
• Main Authors: Aoki, Sogo, Inoue, Yuki, Shinozawa, Akihisa, Tanaka, Keisuke, Shirasuna, Koumei, Iwata, Hisataka
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.07.2022
• Subjects: blastocyst; Bovine; cattle; culture media; Embryo development; embryogenesis; endocrinology; epithelium; Gene expression; gene expression regulation; menstrual cycle; microRNA; miRNA; Oviductal fluid; sequence analysis; miRNA; Oviductal fluid; Bovine; Gene expression; Embryo development
• ISSN: 0303-7207; 1872-8057; 1872-8057
• DOI: 10.1016/j.mce.2022.111651

This study identified microRNAs (miRNAs) in bovine oviductal fluids (OFs) and examined the effect of miR-17-5p in OFs on embryonic development to the blastocyst stage. Small RNA-seq of extracellular vesicles of OFs revealed 242 miRNAs. Additionally, analyzing expressions of randomly selected OF-miRNAs with RT-qPCR in the culture medium of oviductal epithelial cells indicated that the abundance of miRNAs in OFs increased during the luteal phase. miR-17-5p mimic-treated eight-cell-stage zona pellucida-free embryos showed improved embryonic development to the blastocyst stage. The effect of the miR-17-5p mimic was confirmed using a dual-luciferase assay and immunostaining. In addition, RNA-seq of the miR-17-5p mimic- or control-treated embryos revealed differentially expressed genes (DEGs), suggesting possible pathways that overlapped with the in silico-predicted pathways for miR-17-5p targeting genes. Furthermore, ingenuity pathway analysis of DEG predicted miR-17 to be a significant upstream regulator. Our results suggest that miR-17-5p in OFs regulates embryonic development in bovines. •miR-17-5p presents in OFs of ovulated oviduct at high frequency.•OECs secrete miRNA including miR-17-5p into the culture medium.•RNA-Seq followed by IPA supports the effect of miR-17-5p transfection.•miR-17-5p improves embryonic development to the blastocyst stage.