Correlation analysis of growth hormone gene and growth traits and in silico protein investigation in European sea bass (Dicentrarchus labrax).

Genetic variations within a partial region of the growth hormone (GH) gene and their associations with growth traits were investigated in European sea bass (Dicentrarchus labrax) using DNA sequencing. Five haplotypes and ten novel single nucleotide polymorphisms were identified in the GH gene of European sea bass. In silico analysis revealed two amino acid substitutions between the reference and our partial protein sequence, specifically serine to leucine and serine to threonine. Both variations were located within the α1 helix, which also contains H34, a zinc-binding residue. The genotypes at the g.1611T>C locus of the GH gene were found to be significantly associated with total weight, fillet weight and head length. Additionally, the association between GH g.1557A>T genotypes and both preanal and abdominal lengths was statistically significant. Similarly, the genotypes of g. 1857 C>T loci having the synonymous mutation in phenylalanine amino acid were significantly associated with standard length. The haplotype 4 reported the highest weight and length traits than the other haplotypes. It was concluded that haplotype 4 could be used as a potential genetic marker for selective breeding programs of European sea bass under Mediterranean conditions.