Emerging Role of Small Non-coding (MicroRNAs) During Regulation of Endocrine Function in Fishes

The genome complexity and its duplication is a serious concern in fishes while understanding the fish physiology and other biological activity, etc. However, non-coding RNAs such as microRNAs are playing a vital role in regulating genes at a post-transcriptional level associated with developmental biology, metabolism, physiology, and reproduction, etc. Earlier studies depicted that microRNAs are highly conserved and regulates multiple genes by inducing mRNA degradation or translational repression via targeting at complementary sites of mRNA. Advancement in the next-generation sequencing technology and bioinformatics field have been helpful in identifying or solve biological questions in fishes using genome and/or transcriptome sequencing. In this paper, we have deliberated the role of microRNAs in fish nutritional physiology and reproduction. We have given a detailed account of advances in the investigation of miRNAs and their crucial role in the metabolic activity as well as gonadal development in fish species. The identified miRNAs can be utilized as biomarkers for elucidating the complex network of metabolism and reproductive physiology in fishes. This can be a further important source of miRNAs database for the development of antagomir (miRNA inhibitors) for functional level studies during nutritional programming or modulating the reproductive biology of fishes.