Evaluation of the Binding Affinity of a Gonadotropin-Releasing Hormone Analogue (GnRH-a) Buserelin through In Silico and In Vivo testing in Clarias magur

Aim: To evaluate the binding affinity and biological potency of gonadotropin releasing hormone analogue (GnRHa) Buserelin (‎C60H86N16O13) based on in silico and in vivo testing for induced breeding in Clarias magur. Background: Many attempts have been made to induce C. magur but encouraging results have not yet been achieved. Hence, it is the need of the hour to find out more potent analogues or other bio-molecules for induced breeding in C. magur to facilitate sustainable aquaculture. Objective: To determine the binding affinity of C. magur GnRH receptor through in silico and its validation for induced breeding of C. magur. Methods: Buserelin (‎C60H86N16O13) was selected as the potential GnRHa after screening several peptides for their binding energy with the C. magur GnRH receptor. The induced breeding trial was set up at ICAR-CIFE Powarkheda Centre, M.P. India, and Buserelin was administered in different doses to the brooders along with the dopamine inhibitor domperidone. The standard treatment with the commercial salmon GnRH (sGnRH) analogue Ovaprim® (Syndel, USA) was used as the control. Results: The 3-D structure of C. magur GnRH receptor was generated using MODELLER software. Molecular docking studies revealed the binding preference of the receptor as chicken (c) GnRH-II > Buserelin > sGnRH > catfish (cf) GnRH > human (m) GnRH. Though Buserelin showed better binding affinity compared to sGnRH, induced breeding experiments with magur showed similar performance of the ligands at the equivalent dose of 20 µg/kg B.W., but the spontaneous release of milt from the males was not obsereved in both the cases. Significantly better reproductive parameters were recorded with Buserelin at the dose of 30 µg/kg B.W. Conclusion: The study revealed that that the GnRHa Buserelin can be used as an effective inducing agent for breeding in C. magur.