Integrated analysis of differentially expressed microRNAs and mRNAs to screen miRNAs and genes related to reproduction in Macrobrachium nipponense

Female Macrobrachium nipponense has the characteristic of short sexual maturity during the breeding season, which can increase breeding risk and lead to prevalent female individual miniaturization. In this study, we characterized micro (mi)RNA-seq data of the eyestalk (E) and cerebral ganglia (B) of female M. nipponense during breeding and non-breeding seasons. A total of 393 and 189 differentially expressed miRNAs (DE miRNAs) were identified in BSE vs. NBSE and BSB vs. NBSB, respectively. The most abundant up- and down-regulated DE miRNAs were miR-124, miR-14, and miR-7. Enrichment analysis showed that DE miRNA target genes were mainly involved in 'metabolic process' and 'binding', and were associated with 'neurohormonal regulation' and 'photoreceptor activity' signaling pathways. Integrated analysis of miRNA-mRNA expression showed that the most abundant DE miRNAs were miR-14 and miR-278 in BSE vs. NBSE and BSB vs. NBSB, respectively. Four pairs of DE miRNAs and their corresponding target annotated genes were selected from the DE miRNA-mRNA interaction network (bmo-miR-316-5p/opsin protein, ame-miR-125/skeletal muscle actin 8, dmo-miR-278/sugar transporter, and tca-miR-3885-5p/5-HT1 receptor). Gene expression analysis of these four pairs in different ovary development stages showed their potential regulatory roles in ovary maturation.