Investigations into the GDF8 g+6723G-A polymorphism in New Zealand Texel sheep1

Abstract

This work investigated effects of carrying 0, 1, or 2 copies of the A allele resulting from the g+6723G-A transition in growth differentiation factor gene (GDF8) in New Zealand Texel-cross sheep at different lamb ages and carcass weights. Two Texel-cross sires carrying 1 copy of the A allele were mated to approximately 200 ewes carrying 0, 1, or 2 copies of the A allele. A total of 187 progeny were generated and genotyped to determine whether they were carrying 0, 1, or 2 copies of the A allele. The progeny were assigned to 1 of 4 slaughter groups balanced for the 3 genotypes, sex, and sire. The 4 groups were slaughtered commercially when their average BW (across all progeny in the slaughter group) reached 33, 40, 43, and 48 kg, respectively. Measurements of BW, and carcass dimensions and yield were made on all animals using Viascan (a commercial 2-dimensional imaging system that estimates lean content of the carcass as a percentage of total carcass weight). Additional measurements were made on the fourth slaughter group, which was computed tomography scanned at each slaughter time point to obtain 4 serial measures of lean and fat as estimated from the computed tomography images. The A allele did not have an effect on any BW traits. The A allele was associated with increased muscle and decreased fat across the variety of measures of muscling and fat, explaining between 0.2 and 1.1 of a residual SD unit. Estimates for an additive effect were significant and were positive for muscle and negative for fat traits. No dominance effect estimates (positive or negative) were significant. There was no significant interaction between A allele number and carcass weight or slaughter group for any trait. This is the first systematic study of the effect of the A allele copy number over a range of carcass weights (13 to 20 kg) and ages and results suggest the size of the effect across these endpoints is proportionately the same. Testing for the A allele therefore offers breeders the potential to improve rates of genetic gain for lean-meat yield across most production systems.

Polymorphisms in the ovine myostatin gene are associated with birth weight but not with weight gain in Iranian Makoei sheep

“…Quantitative trait locus studies in sheep have shown that the myostatin gene has a major effect on muscular development in Belgian Texel (Marcq et al, 2002) and muscling depth in New Zealand Romney (Hickford et al, 2009), Norwegian White (Boman et al, 2009), Cha-rollais (Hadjipavlou et al, 2009), and New Zealand Texel sheep (Johnson et al, 2009). The objective of present study was to characterize potential variations in the ovine myostatin gene and their association with birth weight and weight gain in Iranian Makoei sheep.…”

Correlation Analysis Between Myostatin Gene Polymorphisms and Carcass Traits in New Zealand Romney Sheep

“…For example a single nucleotide polymorphism (SNP; g.6223G˃A) has been detected in the 3'-UTR of myostatin gene in Belgian Texel sheep (Clop et al, 2006). The same SNP was also detected in other breeds including Australian Texel sheep (Kijas et al, 2007), Charollais sheep (Hadjipavlou et al, 2008), New Zealand Texel sheep (Johnson et al, 2009) and White Suffolk, Poll Dorest and Lincoln sheep in Australia (Kijas et al, 2007). This SNP has been found to affect muscle hypertrophy in Belgian Texel sheep (Clop et al, 2006), muscle depth in Charollais sheep (Hadjipavlou et al, 2008) and birth weight, mean lean yield and total muscle yield in New Zealand Romney sheep (Han et al, 2010).…”

“…Hickford et al (2009) proved that, the presence of allele A was associated with the decreased leg and total yield, whereas the presence of allele B was associated with increased loin yield and loin yield%. Testing the presence/absence of A allele in NZ Texel sheep proved that the presence of A allele was associated with higher slaughter weight, shoulder yield%, loin yield%, leg yield% and total yield (Johnson et al, 2009).…”

Genetic markers in sheep meat breeding

“…Кроме того, плацента является эндокринным органом, который синтезирует широкий спектр стероидных и пептидных Clop et al, 2006;Johnson et al, 2009;Boman et al, 2010;Masri et al, 2011a, b Callipyge phenotype (CLPG) Increases the size of the caudal muscle and leanness and improves stiffness Byrne et al, 2010;Caiment et al, 2010;Everts et al, 2010;Warner et al, 2010;Bi, Kuang, 2012;Sun et al, 2012;Tellam et al, 2012 Carwell, LoinMax Thickens muscles without affecting the deposition of fat, possible changes in the shape of muscles, a shift toward the predominance of muscle IIb and IIx fibers Greenwood et al, 2006;Nicol et al, 2009;Masri et al, 2010 Texel Calpain (CAPN1) Muscle growth and meat with a delicate texture after slaughter Sazili et al, 2004 Calpastatin (CAST) Performance marker for weight gain and meat quality Whipple et al, 1990;Shackelford et al, 1991a, b;Koohmaraie, 1992;Palmer et al, 1999 Plant гормонов, регулирующих развитие фетоплацентарной единицы и изменяющих материнскую физиологию для поддержания беременности (Gootwine, Rozov, 2006;Murphy et al, 2006). Плацента многих видов животных, включая человека, приматов, грызунов и жвачных животных, выделяет гор-моны, структурно связанные с гипофизом: гормон роста (GH) и пролактин (Anthony et al, 1995;Lacroix et al, 1996;Soares, 2004).…”