Comprehensive analysis of miRNA-mRNA/lncRNA during gonadal development of triploid female rainbow trout (Oncorhynchus mykiss)

Background: Chromosomal ploidy manipulation is one of the means to create excellent germplasm. Triploid fish could provide an ideal sterile model for the mechanism research of abnormality in meiosis. The complete understanding of the coding and noncoding RNAs regulating sterility caused by meiosis abnormality is still not well understood. Results: : By high-throughput sequencing, we compared the expression profiles of gonadal mRNA, long non-coding RNA (lncRNA), and microRNA (miRNA) at different developmental stages [65 days post fertilisation (dpf), 180 dpf, and 600 dpf] between the diploid (XX) and triploid (XXX) female rainbow trout. A majority of differentially expressed (DE) RNAs were identified, and 22 DE mRNAs related to oocyte meiosis and homologous recombination were characterized. The predicted miRNA-mRNA/lncRNA networks of 3 developmental stages were constructed based on the target pairs of DE lncRNA-miRNA and DE mRNA-miRNA. According to the networks, meiosis-related gene of ccne1 was targeted by dre-miR-15a-5p_R+1, and 6 targeted DE lncRNAs were identified. Also, RT-qPCR was performed to validate the credibility of the network. Conclusions: : This study explored the potential interplay between coding and noncoding RNAs during the gonadal development of polyploid fish. It provides full insights into polyploidy-associated effects on fertility of fish. These differentially expressed coding and noncoding RNAs provide a novel resource for studying genome diversity of polyploid induction.