Assessment of positional candidate genes myf5 and igf1 for growth on bovine chromosome 5 in commercial lines of Bos taurus1

Abstract

Quantitative trait loci for growth traits in beef cattle have been previously reported and fine-mapped in three chromosomal regions of 0 to 30 cM, 55 to 70 cM, and 70 to 80 cM of bovine chromosome 5. In this study, we further examined the association between gene-specific single nucleotide polymorphisms (SNP) of two positional candidate genes, bovine myogenic factor 5 (myf5) and insulin-like growth factor-1 (igf1), in the QTL regions and the birth weight (BWT), preweaning average daily gain (PWADG), and average daily gain on feed (ADGF) in commercial lines of Bos taurus. The QTL regions for the growth traits identified using a haplotype association analysis, which included the gene-specific SNP markers for both genes in this study, were in agreement with previous studies. The gene-specific SNP marker association analysis indicated that the SNP in myf5 had a significant additive effect on PWADG in the M1 line of Beefbooster Inc. (P < 0.10), and a significant additive effect (P < 0.05) and a significant dominance effect (P < 0.10) on ADGF in the M3 line of Beefbooster Inc. When the data from the two commercial lines were pooled, the SNP in myf5 showed a significant association with PWADG (P < 0.10) and with ADGF (P < 0.05). The association between the SNP and BWT, however, did not reach a significance level in the M1 line, the M3 line, or across the lines. For igf1, no significant association between the SNP and the growth traits was detected in either the M1 line or the M3 line, whereas there was only a significant dominance effect (P < 0.10) on BWT detected for the SNP in igfl when the data from the two commercial lines were pooled. These results suggest that myf5 is a strong candidate gene that influences PWADG and ADGF in beef cattle. The SNP of igf1 may not be a causative or close to the causative mutation that affects the three growth traits in the populations of beef cattle examined in this study. Other SNP of igf1 and myf5 or other genes in their respective chromosomal regions, however, should also be studied.

Association of GH and IGF-1 polymorphisms with growth traits in a synthetic beef cattle breed

“…Investigating growth and beef carcass fatness traits in an Angus x Brahman crossbreed, Kim et al (2003) found a QTL in chromosome 5 for BW (48 cM) and YW (50cM). However, the results from SNP analysis of the IGF-1 gene in Beefbooster lines M1 and M3 did not confirm IGF-1 as the locus controlling these growth traits (Li et al, 2004).…”

Candidate SNPs for carcass and meat traits in Nelore animals and in their crosses with Bos taurus

“…The intron location indicates the possibility of direct and indirect effects of the SNP on phenotypes. This SNP of MYF5 was associated with average daily gain, and pre-and postweaning in B. taurus (Li et al, 2004b). In another study, the SNP was associated to live weight at 24 months of age, in Hanwoo cattle (B. taurus) (Bhuiyan et al, 2009).…”

“…Other polymorphisms of MYF5 were associated with growth traits in Canadian commercial beef cattle (Li et al, 2004b), in Korean Hanwoo cattle (Chung & Kim 2005;Bhuiyan et al, 2009) and in the Chinese cattle breed Qinchuan (Zhang et al, 2007), which are all B. taurus. The specific MYF5 SNP observed in the present study was initially described by Drogemuller & Kempers (2000) and is located in the intron 2.…”

“…Ge et al (1997) identified a single-nucleotide polymorphism (SNP) in the regulatory region of IGF1, located 512 pb upstream of its first codon (AF_017143.1:g.198C>T). This SNP was later associated to growth and carcass composition in Bos taurus and in B. taurus x B. indicus crosses (Ge et al, 2001;Li et al, 2004b;Curi et al, 2005;Islam et al, 2009).…”

Quantitative trait locus affecting birth weight on bovine chromosome 5 in a F2 Gyr x Holstein population

“…Li et al (2002), using chromosome 5 haplotypes for association studies with growth traits in commercial populations of Bos taurus identified three chromosomic regions (0 to 30 cM, 55 to 70 cM, and 70 to 80 cM) that showed significant association with birth 674 QTL for birth weight in bovine chromosome 5 weight. However, the association of the igf-1 gene with birth weight was refuted by Machado et al (2003b) and by Li et al (2004), the latter authors having performed candidate gene analysis between the single nucleotide polymorphisms (SNPs) of chromosome 5 and growth and carcass traits. According to Li et al (2004) SNPs detected in the igf-1 gene should not be responsible, nor even be tightly linked to, the mutation that affects growth and carcass traits in that beef cattle population.…”