水産養殖研究開発ジャーナル

概要

Presence of Neurosteroids and Expression of Neuropeptides in the Brain of Indian Salmon, Eleutheronema tetradactylum

Moses R*, Malini H, Kalarani A, Vinodha V

The Indian Salmon (Eleutheronema tetradactylum) is one of the most commercially significant species with high nutritional value. This species of fish was abundantly available in India during the early 1950s but it has been fast declining in the Indian coast in the recent years due to over exploitation and overfishing. Besides, there is very limited genomic information available on this species. The present study encompasses brain steroid profile using HPLC (high-performance liquid chromatography) and gene expression analysis of peptides such as leptin receptor and insulin receptor-a in the brain of the fish using RT-PCR (Real Time-Polymerase Chain Reaction). The presence of different concentrations of steroids such as progesterone and pregnenolone were recorded in the whole brain of immature and vitellogenic female samples. On the other hand, these hormones as well as 17α-pregnenolone were detected in various regions of brain. Expression of insulin receptor-a was noticed in the female brain and not in the male brain at the immature reproductive stage. Leptin receptor was found to be expressed both in the female and male brain samples. Although the different levels of steroids and the expression of peptide receptors were found in the brain of Indian Salmon, the interrelation between the steroids and peptides were not elucidated from this study. Subsequent studies using Next Generation Sequencing (NGS) will provide a better understanding of this fish. Further, this can aid in promoting culture practices and induced breeding techniques of E. tetradactylum. In the long run, this can assist in bringing back the population of this fish in Indian waters and strengthen its importance as a fishery resource.