QTL affecting body weight in a candidate region of cattle chromosome 5

Abstract

The objective of this work was to identify QTLs for liveweight in a candidate region of bovine chromosome 5. Half-sib families from two lines, one traditional and the other new, of Canchim beef cattle (5/8 Charolais + 3/8 Zebu) were genotyped for four microsatellite markers, including the microsatellite in the IGF-1 (insulin-like growth factor-1) promoter region. Significant differences in allele distribution between the two lines were found for three markers. Interval mapping analyses in this region indicated the presence of a QTL controlling birth weight (p < 0.05) and of a QTL influencing breeding value for yearling weight (p < 0.01) in the newer line of the breed. The previously identified interaction between the IGF-1 genotype and genetic group strengthens the hypothesis of a linked QTL rather than an IGF-1 effect on growth traits in the Canchim cattle.

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

“…Using the same animals as in the present study in a chromosome scan approach, Machado et al (2003) found evidence indicating the presence of a QTL controlling birth weight and another QTL influencing breeding value for yearling weight in the IGF-1 chromosome region. The most likely positions of those QTLs were at 82.8 cM and 72.9 cM, respectively.…”

Search for quantitative trait loci affecting growth and carcass traits in a cross population of beef and dairy cattle1

“…The interval flanked by markers DIK4782 and IGF-1 harbors QTL reported for carcass yield (Mizoshita et al, 2004), fat depth and retail product yield (Casas et al, 2000), dressing percentage (Stone et al, 1999;MacNeil and Grosz, 2002), and rib bone and fat (Stone et al, 1999). Quantitative trait loci for growthrelated traits have also been identified in this chromosomal region (Davis et al, 1998;Stone et al, 1999;Kim et al, 2003;Machado et al, 2003). Quantitative trait loci affecting LM area and dressing percentage (Stone et al, 1999) are also coincident with the QTL we found upstream of DIK4782 for total saleable meat proportion and rib lean proportion.…”

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

“…We found that most of the microsatellite markers in the population studied were highly polymorphic, as expected by the loci pre-selection based on the MARC database, although this was not the case for marker BM321 which presented only three alleles in our research population. Machado et al (2003b) found that in a 5/8 Charolais 3/8 Zebu crossbred population heterozygosity was between 0.468 and 0.755 (average 0.646) for the four markers used in their research. In our study heterozygosity was between 0.578 and 1.0 (average 0.865) (Table 3), this value being higher than the average heterozygosity obtained with nine microsatellites for the Gyr (0.305) and Holstein (0.339) populations by Machado et al (2003a).…”

“…Various studies have produced highly significant evidence for the presence of QTL on chromosome 5 affecting different characteristics such as ovulation rate (Kirkpatrick et al, 2000;Arias and Kirkpatrick, 2004), carcass traits (Stone et al, 1999;Casas et al, 2000;Kim et al, 2003) and birth weight Casas et al, 2002;Li et al, 2002;Machado et al, 2003b;Kim et al, 2003). The insulin-like growth factor 1 gene (igf-1) acting on growth and metabolism maps to chromosome 5.…”

“…The insulin-like growth factor 1 gene (igf-1) acting on growth and metabolism maps to chromosome 5. The QTL for growth traits can be attributed to igf-1 itself or to one or more surrounding genes such as the high growth and myf5 genes, a hypothesis reinforced by the work of Machado et al (2003b) and Kim et al (2003).…”