Bioinformatics Analysis of the Melanocortin 1 Receptor Gene (MC1R) in the Southern Platyfish Xiphophorus maculatus (Günther, 1866)

Abstract

The Southern platyfish Xiphophorus maculatus is one of the most popular ornamental fish used widely as a premier model system in understanding the genetic basis of color pattern polymorphism. Coloration in X. maculatus is found to be linked with melanin synthesis. Melanocortin genes are involved in the synthesis of melanin pigments. Bioinformatic analysis of the MC1R gene of X. maculatus revealed a 966 bp open reading frame encoding 322 amino acids. The deduced MC1R protein sequence was predicted to possess 7transmembrane G-protein-coupled receptor (7TM GPCR) domain from amino acids 59 to 299 (241 amino acids). The predicted three dimensional structure of the MC1R protein contains seven helices (α1 to α7) from amino acid residues 48-67, 80-102,122-144, 165-187, 197-219, 240-262 and 277-299 respectively within the transmembrane region. In the extracellular region, the presence of amino acid residues from N-terminal position 6-Serine, 8-Leucine, 17-Proline, 20-Glutamic acid, 25-Asparagine and 26-Glutamic acid were predicted to be the binding sites of the receptor. The intracellular region comprising of amino acids residues from 68-79, 145-164, 220-239 and 300-322 interacts with the G protein. The predicted model of the MC1R protein of X. maculatus provides a detailed view of the structure and shows tremendous scope in the field of aquaculture as a target protein/model especially in enhancing fish body coloration.

Keywords

• xiphophorus maculatus
• mc1r
• gpcr
• southern platyfish