title: Alleles of the cholesterol 7 alpha-hydroxylase (CYP7) gene in pigs selected for high or low plasma total cholesterol.
abstract: Crossbred pigs were selected for high (HTC) or low (LTC) plasma total cholesterol (TC). Pigs from the seventh (n = 51) and eighth (n = 92) generations were used to determine restriction fragment length polymorphisms (RFLP). Using TaqI restriction enzyme digestion, the frequencies of two alleles (2.8- or 5.0-kb fragments) of the cholesterol 7 alpha-hydroxylase (CYP7) gene were determined in the two populations as a potential indicator of TC concentration at 8 weeks of age. Only the 2.8-kb fragment allele was present in the 26 HTC pigs tested in Generation 7. In the LTC pigs both the 2.8- and 5.0-kb alleles were present in 12 pigs, and only the 5.0-kb allele was present in 13 pigs. The allele frequencies of the 2.8 and 5.0 fragments, respectively, were .26 and .74 in LTC pigs and 1.00 and 0 in HTC pigs. There was an association (P < .001) between the 5.0- and 2.8-kb CYP7 alleles, respectively, and low and high TC concentrations. In Generation 8, all HTC pigs were homozygous for the 2.8-kb allele. The 5.0 kb allele was present in all LTC pigs tested and was homozygous in 57% of LTC pigs. Mean plasma TC was 105.0 mg/dl in 30 pigs homozygous for the 2.8-kb allele in Generation 8; means for LTC pigs were 53.5 and 60.4 mg/dl in 35 pigs homozygous for the 5.0-kb allele and in 27 heterozygous pigs, respectively. High TC was associated with the presence of the 2.8-kb allele, and low TC was associated with the presence of the 5.0-kb allele in both Generations 7 and 8. We conclude that TaqI RFLP analysis of the CYP7 gene is a reliable indicator for TC in these swine.
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030-2600, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Davis
authors.forename: W G
authors.initials: WG
authors.lastname: Pond
authors.forename: M
authors.initials: M
authors.lastname: Wheeler
authors.forename: K
authors.initials: K
authors.lastname: Ishimura-Oka
authors.forename: D R
authors.initials: DR
authors.lastname: Su
authors.forename: C M
authors.initials: CM
authors.lastname: Li
authors.forename: H J
authors.initials: HJ
authors.lastname: Mersmann
mesh_terms: D000483:Alleles; D000818:Animals; D002784:Cholesterol / Q000097:blood*; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics*; D003433:Crosses, Genetic; D005260:Female; D005838:Genotype; D006579:Heterozygote; D006720:Homozygote; D008297:Male; D012150:Polymorphism, Restriction Fragment Length; D013552:Swine / Q000097:blood / Q000235:genetics*
chemical_list: D002784:Cholesterol; D002790:Cholesterol 7-alpha-Hydroxylase