Abstract

The Pit-1 gene was studied as a candidate for genetic markers of growth traits in Chinese cattle in this study. The single-strand conformation polymorphism method was used to identify polymorphism in the Pit-1 intron 5. One single nucleotide polymorphism, Pit1I5, was found in intron 5. The frequencies of allele A of Nanyang cattle (NY), Qinchuan cattle (QC), Jiaxianhong cattle (JX), Luxi cattle (LX) and Holstein cow (H) populations were 0.444, 0.477, 0.538, 0.523 and 0.475, respectively. Associations of the polymorphisms with growth traits in Nanyang cattle were analyzed using a general linear model procedure. The following parameters were greater in individuals with AA genotype than with AB genotype: body weight, average day gain, body height, chest girth at six, 12, 18 and 24 months (P<0.01), respectively. Body weight and body size also showed a trend of allele A > allele B in other age groups. Therefore, genotype AA maybe a dominant genotype and allele A may be a dominant allele. These results imply that allele A of Pit-1 gene may likely affect growth traits positively.

Key words: Beef cattle, growth traits, Pit-1 intron 5, polymorphism.

Abbreviation

NY, Nanyang cattle; QC, Qinchuan cattle; JX, Jiaxianhong cattle; LX, Luxi cattle; H, Holstein cow.