Deciphering Oxidative Stress Responsive Microrna (Mirna) in Hilsa (Tenualosa ilisha) and Rohu (Labeo rohita)

microRNAs (miRNAs) and their target gene expression under oxidative stress play a crucial role in cellular antioxidant regulation. Information on oxidative stress responsive miRNA and their target genes of the fishes of Bangladesh is not reported yet. This study was performed to profile oxidative stress-responsive miRNAs by computational and experimental methods in economically important fish of Bangladesh. Using in silico approach, we could not trace any miRNA of fish of Bangladesh as none has been reported yet in existing databases. We, therefore enlist here the miRNAs that are expressed under different stress conditions in fish applying an extensive literature review. From the list, we selected 10 potential oxidative stressresponsive miRNAs followed by predicting their target genes using miRNA target prediction software (TargetScan Fish). This study decoded the mature sequences of oxidative stress-responsive miRNA (miR-21) in Hilsa (Tenualosa ilisha) and Rohu (Labeo rohita) through specific miRNA primer-based cDNA fragment sequencing. Next, we identified an oxidative stress responsive gene, programmed cell death 4b (pdcd4b) in hilsa genome and showed that the hilsa miR-21 binds within coding sequence region of the predicted hilsa pdcd4b. This study is pioneer in decoding oxidative stress responsive miRNA in fish of Bangladesh using an experimental and bioinformatics approach.