Association of single nucleotide polymorphisms in the leptin gene with carcass and meat quality traits of beef cattle1

Abstract

Studies with different populations are required to properly characterize the robustness of associations of polymorphisms in candidate genes with economically important traits across beef cattle populations before this sort of genetic information can be used efficiently in breeding and management decisions. The objective of this study was to evaluate the association of previously reported SNP in the bovine leptin gene with carcass and meat quality traits from a large sample of crossbred beef cattle. Five SNP (UASMS1, UASMS2, UASMS3, E2JW, and E2FB) were genotyped on 1,111 crossbred bulls, heifers, and steers. The measured traits included fat, lean, and bone yield (%) by partial rib dissection, grade fat, LM area, HCW, quality grade, LM i.m. fat, and tenderness evaluation of LM and semitendinosus muscle. Only four SNP were analyzed (UASMS1, UASMS2, E2JW, and E2FB), because UASMS1 and UASMS3 were completely linked. A uni-variate mixed-inheritance animal model was used to evaluate the association of either genotypes or haplo-types with the traits. The two leptin exon 2 SNP were associated with fat and lean yield and grade fat (E2JW, P < 0.01; E2FB, P < 0.05), and they interacted in their effect on LM tenderness (P < 0.01). The leptin promoter SNP were either not associated with any of the traits (UASMS2) or with fat yield only (UASMS1). Three haplotypes (TCAC, CCAT, TTAC) were at high frequency in the population (88%) and had similar effects on all the traits. Compared with the common haplotypes, one haplotype (CCTT) showed a significantly different effect on fat and lean yield and grade fat (P < 0.01), and one haplotype (TTTT) had a different effect on LM tenderness (P < 0.03). Therefore, important associations between SNP within the leptin gene with lean yield, fatness (fat yield and subcutaneous fat), and tenderness were detected. Results confirm some of the previously reported associations, but diverge with respect to others, showing that further efforts are required to validate some prospective associations.

Preliminary identification and characterisation of leptin gene polymorphism in Indian goats

“…However, this SNP should not affect the splicing process, as potential splicing sites do not extend more than 20Á30 bases into the intron (Garrigan & Edwards 1999). Several SNPs have been previously reported in introns and exons of the leptin gene among different breeds of cattle (Schenkel et al 2005). Associations of polymorphisms in leptin with carcass and meat quality traits were also reported in Iranian sheep (Barzehkar et al 2009) and exon 3 of pigs (Amills et al 2007).…”

Recent advances in cattle functional genomics and their application to beef quality

“…Confirmations for the calpain and calpastatin genes have been reported by several authors (Page et al, 2004;Casas et al, 2006;Morris et al, 2006;Schenkel et al, 2006). For marbling several of the genes have been confirmed in some studies while in others some tests have failed to be confirmed (Thaller et al, 2003;Nkrumah et al, 2004;Barendse et al, 2005;Kononoff et al, 2005;Nkrumah et al, 2005;Pollak, 2005;Schenkel et al, 2005;Barendse et al, 2006;Rincker et al, 2006). Marbling is a more difficult trait to work with than tenderness, since it is a visual inspection of the carcass and hence is a measurement with a greater error, which means that it will require larger samples than normal to be detected.…”

Prospecting candidate SNPs for backfat in Canchim beef cattle

“…In these analyses, performed using the ASREML software (Gilmour et al, 2000) according to Schenkel et al (2005), we formed 32 contemporary groups (CG) based on the variables birth year, herd, genetic group (CA or MA), and sex. We excluded from the subsequent analysis any CGs with fewer than two individuals.…”