Characterization of OAR1 and OAR18 QTL associated with muscle depth in British commercial terminal sire sheep

Matika, Oswald; Sechi, Stefania; Pong‐Wong, Ricardo; Houston, Ross D.; Clop, Alex; Woolliams, John; Bishop, Stephen

doi:10.1111/j.1365-2052.2010.02121.x

Cited by 18 publications

(27 citation statements)

References 19 publications

(59 reference statements)

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“… Walling et al (2004) reported evidence of a quantitative trait locus (QTL) segregating in the United Kingdom's Texel sheep population which significantly increased longissimus dorsi (loin) muscle depth (by 1.15–2.00 mm, as measured ultrasonically over the third lumbar vertebra). With similar results (QTL effect of +2.57 mm) observed from an analysis including existing and new Texel family data, the QTL, later termed the Texel muscling QTL (TM-QTL), was further verified by Matika et al (2006) . Located on the distal end of the ovine chromosome 18 (OAR18) ( Walling et al, 2004; Matika et al, 2006 ), the TM-QTL sits in the same region as the Callipyge ( CLPG ) and Carwell loci ( Cockett et al, 1994; Nicoll et al, 1998 ), which are also known to affect carcass muscling.…”

Section: Introductionsupporting

confidence: 59%

Effect of the Texel muscling QTL (TM-QTL) on spine characteristics in purebred Texel lambs

Donaldson

Lambe

Maltin

et al. 2014

Small Ruminant Research

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Previous work showed that the Texel muscling QTL (TM-QTL) results in pronounced hypertrophy in the loin muscle, with the largest phenotypic effects observed in lambs inheriting a single copy of the allele from the sire. As the loin runs parallel to the spinal vertebrae, and the development of muscle and bone are closely linked, the primary aim of this study was to investigate if there were any subsequent associations between TM-QTL inheritance and underlying spine characteristics (vertebrae number, VN; spine region length, SPL; average length of individual vertebrae, VL) of the thoracic, lumbar, and thoracolumbar spine regions. Spine characteristics were measured from X-ray computed tomography (CT) scans for 142 purebred Texel lambs which had been previously genotyped. Least-squares means were significantly different between genotype groups for lumbar and thoracic VN and lumbar SPL. Similarly for these traits, contrasts were shown to be significant for particular modes of gene action but overall were inconclusive. In general, the results showed little evidence that spine trait phenotypes were associated with differences in loin muscling associated with the different TM-QTL genotypes.

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Section: Introductionsupporting

confidence: 59%

Effect of the Texel muscling QTL (TM-QTL) on spine characteristics in purebred Texel lambs

Donaldson

Lambe

Maltin

et al. 2014

Small Ruminant Research

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“…Additionally, the Carwell QTL (synonymous with LM-QTL, LoinMax) (Nicoll, 2007), which also lies in the region of OAR18 and affects loin muscling to a similar degree as TM-QTL, also appears to have a non-additive mode of inheritance (Jopson et al, 2001;Nicoll, 2007). Lastly, previous work on TM-QTL by Matika et al (2011), examining maternal and paternal variance components for the TM-QTL in commercial Texel lambs, using ultrasound muscle depth as their phenotype, reported results that were also consistent with paternal polar overdominance.…”

Section: Introductionmentioning

confidence: 58%

“…TM-QTL affects loin muscling in Texel sheep. The initial study by Walling et al 2004 showed an effect of +4% to +7% on ultrasound muscle depth, and in a larger population in a follow-on study Matika et al (2011) showed an effect of +8% to +17% in 6 out of 36 Texel families. This effect was confirmed in Texel sired crossbred lambs out of Mule ewes (Macfarlane et al, 2009) and also out of Welsh Mountain ewes (Masri et al, 2011).…”

Section: Discussionmentioning

confidence: 94%

“…Based on the maternal and paternal variance components for muscle depth in their data Matika et al (2011) hypothesised that the TM-QTL is characterised by a paternal polar overdominant pattern of expression, although the structure of their study could not provide direct evidence of this form of imprinting. The present study reports, for the first time, the effect of the inheritance of TM-QTL from the dam, either alone or together with TM-QTL from the sire and provides supporting evidence for a polar overdominant pattern of expression for the TM-QTL's effect on loin muscling (ultrasound muscle depth, CT muscle depth, width, area and volume and dissected weight).…”

Section: Discussionmentioning

confidence: 97%

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Effect and mode of action of the Texel muscling QTL (TM-QTL) on carcass traits in purebred Texel lambs

Macfarlane

Lambe

Matika

et al. 2014

animal

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TM-QTL is a quantitative trait locus (QTL) on ovine chromosome 18 (OAR18) known to affect loin muscling in Texel sheep. Previous work suggested that its mode of inheritance is consistent with paternal polar overdominance, but this has yet to be formally demonstrated. This study used purebred Texel sheep segregating for TM-QTL to confirm its presence in the chromosomal region in which it was first reported and to determine its pattern of inheritance. To do so, this study used the first available data from a Texel flock, which included homozygote TM-QTL carriers (TM/TM; n = 34) in addition to homozygote non-carriers (+ / + ; n = 40 and, heterozygote TM-QTL-carriers inheriting TM-QTL from their sire (TM/ + ; n = 53) or their dam (+ /TM; n = 17). Phenotypes included a wide range of loin muscling, carcass composition and tissue distribution traits. The presence of a QTL affecting ultrasound muscle depth on OAR18 was confirmed with a paternal QTL effect ranging from + 0.54 to + 2.82 mm UMD (s.e. 0.37 to 0.57 mm) across the sires segregating for TM-QTL. Loin muscle width, depth and area, loin muscle volume and dissected M. longissimus lumborum weight were significantly greater for TM/ + than + / + lambs (+2.9% to + 7.9%; P < 0.05). There was significant evidence that the effect of TM-QTL on the various loin muscling traits measured was paternally polar overdominant ( P < 0.05). In contrast, there was an additive effect of TM-QTL on both live weight at 20 weeks and carcass weight; TM/TM animals were significantly ( P < 0.05) heavier than + / + (+11.1% and + 7.3%, respectively) and + /TM animals (+11.9% and + 11.7%, respectively), with TM/ + intermediate. Weights of the leg, saddle and shoulder region (corrected for carcass weight) were similar in the genotypic groups. There was a tendency for lambs inheriting TM-QTL from their sire to be less fat with slightly more muscle than non-carriers. For example, carcass muscle weight measured by live animal CT-scanning was 2.8% higher in TM/ TM than + / + lambs ( P < 0.05), carcass muscle weight measured by carcass CT-scanning was 1.36% higher in TM/ + than + / + lambs ( P < 0.05), and weight of fat trimmed from the carcass cuts was significantly lower for TM/ + than + / + lambs (−11.2%; P < 0.05). No negative effects of TM-QTL on carcass traits were found. Optimal commercial use of TM-QTL within the sheep industry would require some consideration, due to the apparently different mode of action of the two main effects of TM-QTL (on growth and muscling).

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“…Animals targeted for FEC sampling were part of a larger study exploring the use of markers in commercial sheep flocks (Matika et al, 2010). Initially, 335 Suffolk records in 13 half-sib families and 927 Texel in 26 half-sib families were available after correcting for Mendelian genotyping errors (Table 1).…”

Section: Animals Sampledmentioning

confidence: 99%

Confirmation of two quantitative trait loci regions for nematode resistance in commercial British terminal sire breeds

Matika

Pong‐Wong

Woolliams

et al. 2011

Animal

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Sheep internal parasites (nematodes) remain a major health challenge and are costly for pasture-based production systems. Most current breeding programmes for nematode resistance are based on indicator traits such as faecal egg counts (FEC), which are costly and laborious to collect. Hence, genetic markers for resistance would be advantageous. However, although some quantitative trait loci (QTL) have been identified, these QTL are often not consistent across breeds and few breeding strategies for nematode resistance in sheep are currently using molecular information. In this study, QTL for nematode resistance on ovine chromosomes (OAR) 3 and 14, previously identified in the Blackface breed, were explored using commercial Suffolk (n 5 336) and Texel lambs (n 5 879) sampled from terminal sire breeder flocks in the United Kingdom. FEC were used as the indicator trait for nematode resistance, and these were counted separately for Nematodirus and Strongyles genera. Microsatellite markers were used to map the QTL and the data were analysed using interval mapping regression techniques and variance component analysis. QTL for Nematodirus and Strongyles FEC were found to be segregating on OAR3 at 5% chromosome region-wide significance threshold in both Suffolk and Texel sheep, and Nematodirus FEC QTL were segregating on OAR14 in both breeds. In addition, QTL for growth traits were also found to be segregating at 5% chromosome region-wide on OAR3 and OAR14. The confirmation that FEC QTL segregate in the same position in three widely used breeds widens their potential applicability to purebred Blackface, Suffolk and Texel sheep, with benefits likely to be observed in their commercial crossbred progeny.

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Characterization of OAR1 and OAR18 QTL associated with muscle depth in British commercial terminal sire sheep

Cited by 18 publications

References 19 publications

Effect of the Texel muscling QTL (TM-QTL) on spine characteristics in purebred Texel lambs

Effect of the Texel muscling QTL (TM-QTL) on spine characteristics in purebred Texel lambs

Effect and mode of action of the Texel muscling QTL (TM-QTL) on carcass traits in purebred Texel lambs

Confirmation of two quantitative trait loci regions for nematode resistance in commercial British terminal sire breeds

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