title: Association of single nucleotide polymorphisms in the  bovine leptin and leptin receptor genes with growth and ultrasound carcass  traits in Nellore cattle.
abstract: Given the important role of leptin in metabolism, we  looked for a possible association of leptin and leptin receptor polymorphisms  with carcass and growth traits in Nellore cattle. We examined associations of  leptin and leptin receptor SNPs with ultrasound carcass (longissimus dorsi  muscle area (ribeye area), backfat thickness and rump fat thickness and growth  traits (weaning weight adjusted to 210 days of age, yearling weight adjusted to  550 days of age, weight gain of weaning to yearling and scrotal circumference  adjusted to 550 days of age) of 2162 Bos primigenius indicus (Nellore)  animals. Allele and genotypic frequencies were calculated for each marker.  Allele substitution, additive and dominance effects of the polymorphisms were  also evaluated. Some alleles of the molecular markers had low frequencies,  lower than 1%, in the sample analyzed, although the same polymorphisms described  for B. p. taurus cattle were found. Due to very low allelic frequencies,  the E2JW, A59V and UASMS2 markers were not included in the analysis, because  they were almost fixed. E2FB was found to be significantly associated with  weight gain, ribeye area and backfat thickness. The promoter region markers,  C963T and UASMS1, were also found to be significantly associated with ribeye  area. T945M was significantly associated with weight gain. We conclude that the  leptin and receptor gene markers would be useful for marker-assisted selection.
authors.affiliation: Merial Saúde Animal Ltda., Campinas, SP, Brasil.
authors.forename: R C G
authors.initials: RC
authors.lastname: da Silva
authors.forename: J B S
authors.initials: JB
authors.lastname: Ferraz
authors.forename: F V
authors.initials: FV
authors.lastname: Meirelles
authors.forename: J P
authors.initials: JP
authors.lastname: Eler
authors.forename: J C C
authors.initials: JC
authors.lastname: Balieiro
authors.forename: D C
authors.initials: DC
authors.lastname: Cucco
authors.forename: E C
authors.initials: EC
authors.lastname: Mattos
authors.forename: F M
authors.initials: FM
authors.lastname: Rezende
authors.forename: S L
authors.initials: SL
authors.lastname: Silva
mesh_terms: D000483:Alleles; D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000254:growth & development*; D005787:Gene Frequency / Q000235:genetics; D056726:Genetic Association Studies; D005819:Genetic Markers; D005838:Genotype; D020738:Leptin / Q000235:genetics*; D008460:Meat; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D054411:Receptors, Leptin / Q000235:genetics*; D014465:Ultrasonics
chemical_list: D005819:Genetic Markers; D020738:Leptin; D054411:Receptors, Leptin