Analysis on lncRNA and mRNA expression profiles of IGF3-induced ovarian maturation in spotted scat (Scatophagus argus)

Abstract

Insulin-like growth factor 3 (IGF3) has been found to induce ovarian maturation in teleost, but its molecular regulatory mechanism remains unknown. Long non-coding RNAs (lncRNAs) have been reported to be involved in multiple biological processes, including reproduction. In this study, lncRNAs and mRNAs involved in IGF3-induced ovarian maturation were evaluated in spotted scat (Scatophagus argus). With IGF3 treatment, we identified 153 differentially expressed (DE) mRNAs and 55 DE lncRNAs in ovarian tissues. Gene Ontology (GO) enrichment analysis showed that target genes of DE lncRNAs and DE mRNAs were enriched with a high degree of overlap, including reproduction, metabolic process, reproductive process, growth, cell, membrane, cell junction, nucleic acid binding transcription factor activity, catalytic activity, signal transducer activity, and so on. Then Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis included ErbB signaling pathway, homologous recombination, Hedgehog signaling pathway, Wnt signaling pathway, mismatch repair, oocyte meiosis, cell cycle, gap junction, FoxO signaling pathway, glycolysis/gluconeogenesis, mismatch repair, and Insulin signaling pathway. We identified DEGs: ccnd2, rpa1, h4k20, dnm2, ska2, ctsl, kcnma1, sparc, cdh13, fkbp, and leprot, that are involved in the courses of oocyte maturation, such as oocyte meiosis, oocyte hydration, extracellular matrix (ECM) remodel, and reproductive endocrine functions. A lncRNA-mRNA network was constructed, and we found that two lncRNAs, MSTRG.30211.1 and MSTRG.3260.6, were related to most of the DEGs which are involved in oocyte maturation. RT-qPCR analysis showed that these two lncRNAs were mainly expressed in the ovary. The results demonstrated that lncRNAs might be involved in the reproductive processes in S. argus. Taken together, this study provides the first lncRNA profile in the ovary of S. argus and further insight into lncRNA-mRNA regulation mechanisms of IGF3-induced ovarian maturation.