Integrated analysis of the expression profiles of the lncRNA-miRNA-mRNA ceRNA network in granulosa and cumulus cells from yak ovaries.

BACKGROUND

Growing oocytes acquire the ability to mature through two-way communication between gametes and surrounding somatic cumulus cells (CCs). Granulosa cells (GCs) support oocyte growth, regulate meiosis progression, and modulate global oocyte transcription activity. However, the proliferation and differentiation of the yak ovary in GCs and CCs remain unclear. To characterize the important roles of long non-coding RNA, (lncRNA), microRNA (miRNA), and messenger RNA (mRNA), whole-transcriptome analysis was performed. Real-time quantitative fluorescence PCR was performed to verify the selected RNA sequences.

RESULTS

Important gene ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways related to differentiation and oocyte development were identified for the target genes of differentially expressed lncRNAs, miRNAs, and mRNAs. In total,6223 mRNAs (2197 upregulated, 4026 downregulated), 643 lncRNAs (204 upregulated, 479 downregulated), and 559 miRNAs (311 upregulated, 248 downregulated) were significantly altered between the two groups. Target genes involved in cell adhesion, cell differentiation, regulation of developmental processes, cell proliferation, embryo development, signal transduction, apoptosis, and aromatic compound biosynthetic processes were significantly enriched. These RNAs were involved in ECM-receptor interaction, MAPK signaling, Hippo signaling, PI3K-Akt signaling, cell cycle, cell adhesion, leukocyte trans-endothelial migration, and actin cytoskeleton regulation.

CONCLUSIONS

A comprehensive analysis of the co-expression network of competing endogenous RNAs (ceRNAs) will facilitate the understanding of the process of granulosa cell proliferation and differentiation and offer a theoretical basis for the development of oocytes.