A variation of simple repeat sequence in the promoter region of the bovinegrowth hormone (bGH) gene in beef cattle is similar to water buffalo

A simple repeat sequence variation (AAG repeat) was detested in the promote r region of the bovine growth hormone (bGH) gene upstream the TATA box. The G(1) allele with only one AAG repeat and the G(2) allele with two AAG repe ats were observed in the beef breeds Nelore, Guzerat and Chianina. In the d airy breeds Gyr, Holstein and Brown Swiss only the G(2) allele was present. Gene frequency for the G(2) allele was 0.144 in Nelore, 0.10 in Guzerat an d 0.091 in Chianina. Heterozygous individuals can be identified by the pres ence of heteroduplex bands on polyacrylamide gels. Sequence analysis furthe r revealed that the G(1) allele is identical to the water buffalo GH gene p romoter region. It has not yet been established whether variants in the pro moter region have any effect on the level of transcription of the bGH gene.