Assessment of DGAT1 and LEP gene polymorphisms in three Nelore (Bus indicus) lines selected for growth and their relationship with growth and carcass traits.

The aim of. this study was to analyze LEP and DGAT1 gene polymorphisms in 3 Nelore lines selected for growth and to evaluate their effects on growth and carcass traits. Traits analyzed were birth, weaning, and yearling weight, rump height, LM area, backfat thickness, and rump fat thickness obtained by ultrasound. Two SNP in the LEP gene [LEP 1620(A/G) and LEP 305(T/C)] and the K232A mutation in the DCAT1 gene were analyzed. The sample consisted of 357 Nelore heifers from 2 lines selected for yearling weight and a control line, established in 1980, at the Estaçäo Experimental de Zootecnia de Sertãozinho (Sertãozinho, Brazil). Three genotypes were obtained for eachmarker. Differences in allele frequencies among the 3 lines were only observed for the DCAT1 K23M polymorphism, with the frequency of the A allele being greater in the control line than in the selected lines. The DGAT1 K23M mutation was associated only with rump height, whereas LEP 1620(A/C) was associated with weaning weight and LEP 305(T/C) with birth weight and backfat thickness. However, more studies, with larger data sets, are necessary before these makers can be used for marker-assisted-selection. [ABSTRACT FROM AUTHOR]