Identification of oxidative stress responsive microRNA (miRNA) in economically important fishes of Bangladesh

Abstract

Distinct stress conditions, such as oxidative stress can alter microRNAs (miRNAs) expression that is known to regulate cellular processes. MicroRNAs (miRNAs) are a family of single-stranded RNA molecules about 22 nucleotides in length, which can regulate protein-coding gene expression in various organisms by post-transcriptional repression of mRNA. As there is no miRNAs study in fish species, this study was performed to identify the specific stress-responsive miRNAs in economically important fish of Bangladesh. Firstly, nucleotide databases such as ESTs (Expressed Sequence Tags) and GSSs (Genome Survey Sequences) of Rohu (Labeo rohita), Catla (Catla catla), Silver carp (Hypophthalmichthys molitrix), Climbing perch (Anabas testudineus), Hilsa (Tenualosa ilisha), and Gangetic mystus(Mystus cavasius) were mined against known fish miRNAs database to identify evolutionarily conserved miRNAs in these fish species. Secondly, a database on stress responsive miRNA in fish was built and then the study confirmed the presence of miR-21 (oxidative stress responsive miRNA) in these fish including Zebrafish (Danio rerio).The target genes of all studied miRNAs were further predicted using in silico approach and the possible regulating mechanisms of miRNA were discussed. This study deemed to employ experimental and computational methodsfor the first time to identify miRNAs in fish of Bangladesh. Future perspectives of this study are to focus on function, stress dose-responses and temporal expression of the identified miRNAs and to facilitate their use as initial markers for stress responses.