Novel single nucleotide polymorphisms in candidate genes for growth in tilapia ( Oreochromis niloticus )

ABSTRACT The objective of the present work was to identify and validate single nucleotide variations located in candidate genes to growth traits in tilapia (Oreochromis niloticus). Two transitions were identified in the promoter region of the growth hormone gene (GH); eight nucleotide changes were identified in introns and promoter region of the IGF-I gene; and a transition (T/C) was identified in the Myogenin gene (MyoG). The highest genotypic frequency (0.8) for GHpA1 and MyoG was found in the GG and TT homozygous individuals, while the highest frequency (0.9) for GHpB1 was observed in the CT heterozygous fish. There was no genotypic frequency in the CC homozygous tilapia for the GHpB1 and MyoG markers. Based on their allelic frequencies, validation as novel single nucleotide polymorphisms (SNP) of those variations located at O. niloticus GH and MyoG genes was possible. These new markers will allow their association with growth traits in tilapia to be exploited in order to determine their potential use as assisted-selection markers.