Investigating structural impact of a valine to isoleucine substitution on anti-Müllerian hormone in silico and genetic association of the variant and AMH expression with egg production in chickens

Anti-Müllerian hormone(AMH) acts in maintaining orderly cyclic recruitment of early follicles, suggesting that it is a promising candidate for influencing animal reproductive efficiency. This study aimed to elucidate the effect of a missense mutation of Val~(566) Ile on the structure of AMH protein and the genetic association of Val~(566) Ile and AMH expression with egg production in chickens. Structural perturbations of Val~(566) Ile were predicted by homology modeling. The association of the variant with the number of eggs was tested using a quantitative trait transmission disequilibrium test model. AMH expression in granulosa cells in Lueyang black-boned chickens was compared with that in Nick chickens. The Val~(566) of AMH is a nonconservative amino acid among mammals and birds, but its hydrophobicity is completely conservative. The substitution of Val~(566) for Ile~(566) potentially disrupted hydrogen bonds and solvent accessibility of 22 residues and created a short α-helix in the C terminus of AMH. Despite having striking structure-disrupting potential, the variant was not statistically associated with the number of eggs(P0.05) in the Lueyang black-boned chickens. We did not detect differential expression of AMH between Lueyang black-boned chickens and Nick chickens(P0.05). These results confirmed the structural impact of Val~(566) Ile, but suggested that Val~(566) Ile and AMH expression might not be the major genetic determinants for egg production in Lueyang black-boned chickens.