The small RNA-Seq of ovary in Penaeus monodon. Penaeus monodon

Plenty of evidence shows that microRNAs (miRNAs) post-transcriptionally regulate gene expression and are involved in a wide range of biological and metabolic processes, such as regulation of individual development, abiotic stress response, and innate immune response. However, the roles of miRNAs involved in ovarian development remains largely unknown in crustaceans, especially in shrimps. In the present study, the high-throughput sequencing of small RNAs was carried out for exploring the specific miRNAs that involved in ovarian development in the black tiger shrimp (Penaeus monodon). Two small RNA libraries were primarily constructed from undevelopment (UNDEV group) and development (DEV group) ovarian tissues in P. monodon, respectively. In total, 43 miRNAs that significant differentially expressed were identified between the two groups (P-value ≤ 0.05, |log2 ratio| ≥ 1), and then the expression profiles were validated by qRT-PCR. In order to further clarify the role of the differentially expressed miRNAs functioned during the process of ovarian development, the target gene prediction was performed. In total, 4,102 target genes of 43 miRNAs were predicted, then clustered by the KEGG database, only four specific pathways related to ovarian development were obtained (P-value < 0.05). Besides, the dual-luciferase reporter assays and integrated expression analysis were also conducted for further clarifying the interaction between the miRNAs and their target mRNAs. Our present study provided some information about function of miRNAs involved in ovarian development stages of the P. monodon, which could be useful for a better understanding of the regulatory mechanism of the shrimp ovarian development and reproduction.