The polymorphisms of bovine cocaine- and amphetamine-regulated transcripts and their associations with cattle (Bos taurus) growth traits.

We investigated the polymorphisms of bovine cocaine- and amphetamine-regulated transcripts (CART ). The coding and regulating regions of CART were screened in 7 cattle breeds by the single-stranded conformation polymorphism (SSCP) technique. The four loci (C1,C2, C3 and C4) studied were all polymorphic. Polymerase chain reaction (PCR) products representing different SSCP variants were sequenced and a total of 9 single-nucleotide polymorphisms (SNPs) were found. The associations between polymorphic loci and the growth traits of Nanyang cattle were analysed. The results indicated that genotype A1A1 of the C1 locus was associated with a higher body weight (P less than 0.05) than heterozygous A1B1. Genotype A2A2 of the C2 locus was associated with lower body weight and average daily weight gain (P < or = 0.001) than heterozygous A2B2. C3 and C4 loci had no significant effect on Nanyang cattle growth traits (P > 0.05).