Penaeus monodon Transcriptome or Gene expression. Penaeus monodon

There is plenty of evidence showing that microRNAs (miRNAs) post-transcriptionally regulate gene expression and are involved in a wide range of biological and metabolic processes, including regulation of development, abiotic stress response, and innate immune responses. However, the roles of miRNAs in ovarian development remain largely unknown in crustaceans, especially in shrimp. In the present study, high-throughput sequencing of small RNAs was performed to find specific miRNAs that are involved in ovarian development in the black tiger shrimp (Penaeus monodon). Two small RNA libraries were constructed from undeveloped (UNDEV group) and developed (DEV group) ovarian tissues in P. monodon. In total, 43 differentially expressed miRNAs were identified between the two groups (P ≤ 0.05, |log2 ratio| ≥ 1), and their expression profiles were validated by RT-qPCR. In order to further clarify the functional roles of these differentially expressed miRNAs during ovarian development, target gene prediction was performed. In total, 4,102 target genes of 43 miRNAs were predicted, and then clustered by the Kyoto Encyclopedia of Genes and Genomes (KEGG) database; only four specific pathways related to ovarian development were obtained (P < 0.05). Dual-luciferase reporter assays and integrated expression analysis were also conducted to further clarify the interaction between the miRNAs and their target mRNAs. This study provides important information about the function of miRNAs involved in ovarian developmental stages in P. monodon, which could be useful to better understand the regulatory mechanisms of shrimp ovarian development and reproduction.