OMIA:001355-9940 : Muscular hypertrophy (double muscling), Carwell in Ovis aries (sheep)

Categories: Muscle phene

Links to MONDO diseases: No links.

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal dominant

Considered a defect: no

Key variant known: no

Cross-species summary: Abnormal increase in muscular tissue caused entirely by enlargement of existing cells (in contrast to muscular hyperplasia, in which the abnormal increase in muscular tissue is due to the formation and growth of new, normal muscle cells)

Species-specific name: Carwell; rib-eye muscling (REM)

History: In the first stage of a Poll Dorset nucleus breeding program commenced in 1989 in Australia, progeny of sires of the Carwell stud exhibited extreme muscling (Banks, 1997). Subsequent segregation analysis implicated a single gene of large effect (Banks, unpublished). Given the similarity of phenotype to the Callipyge mutation which by then had been mapped to chromosome 18, linkage study showed that the Carwell locus also maps to chromosome 18 (Banks, unpublished). Subsequent New Zealand research (Nicoll et al., 1998) provided evidence that suggested Carwell may be allelic with Callipyge, but that the hypertrophy is restricted to the longissimus dorsi muscle, which is 8% larger. McLaren et al. (2001) identified some positional candidate genes [FN and Rob Banks; 10 Nov 2002]

Inheritance: Jopson et al. (2001) reported autosomal dominant inheritance.

Mapping: Tellam et al. (2012) reported that "The [Carwell] QTL is positioned 2–6 cM telomeric to the CSSM18 marker on OAR18 and overlaps with the site of the Callipyge mutation" (OMIA 001354-9940)

Markers: y

Genetic engineering: Unknown
Have human generated variants been created, e.g. through genetic engineering and gene editing

Clinical features: Summarising the findings of Nicoll et al. (1998) and Greenwood et al. (2006), Tellam et al. (2012) reported "The Carwell (or rib eye muscling,REM) locus identified in Australian Poll Dorset rams is associated with increased muscle depth of longissimus dorsi (also named longissimus lumborum) with no effect on fatness or liveweight. There is also a change in muscle shape and a shift from type IIa towards type IIb and IIx muscle fibers"

Breed: Poll Dorset (Sheep) (VBO_0001557).
Breeds in which the phene has been documented. For breeds in which a likely causal variant has been documented, see the variant table below

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2013). OMIA:001355-9940: Online Mendelian Inheritance in Animals (OMIA) [dataset].


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.

2012 Tellam, R.L., Cockett, N.E., Vuocolo, T., Bidwell, C.A. :
Genes contributing to genetic variation of muscling in sheep. Front Genet 3:164, 2012. Pubmed reference: 22952470. DOI: 10.3389/fgene.2012.00164.
2010 Warner, RD., Greenwood, PL., Pethick, DW., Ferguson, DM. :
Genetic and environmental effects on meat quality. Meat Sci 86:171-83, 2010. Pubmed reference: 20561754. DOI: 10.1016/j.meatsci.2010.04.042.
2007 Ron, M., Weller, J.I. :
From QTL to QTN identification in livestock--winning by points rather than knock-out: a review. Anim Genet 38:429-39, 2007. Pubmed reference: 17697134. DOI: 10.1111/j.1365-2052.2007.01640.x.
2006 Greenwood, P,L., Davis, J,J., Gaunt, G.M., Ferrier, G.R. :
Influences on the loin and cellular characteristics of the m-longissimus lumborum of Australian Poll Dorset-sired lambs. Australian Journal of Agricultural Research 57(1):1-12, 2006.
2005 Cockett, NE., Smit, MA., Bidwell, CA., Segers, K., Hadfield, TL., Snowder, GD., Georges, M., Charlier, C. :
The callipyge mutation and other genes that affect muscle hypertrophy in sheep. Genet Sel Evol 37 Suppl 1:S65-81, 2005. Pubmed reference: 15601596. DOI: 10.1051/gse:2004032.
2004 Walling, GA., Visscher, PM., Wilson, AD., McTeir, BL., Simm, G., Bishop, SC. :
Mapping of quantitative trait loci for growth and carcass traits in commercial sheep populations. J Anim Sci 82:2234-45, 2004. Pubmed reference: 15318719.
2002 Walling, G.A., Wilson, A.D., McTier, B.L., Visscher, P.M., Simm, G., Bishop, S.C. :
A candidate region approach allows efficient QTL detection in UK Suffolk and Texel populations Proceedings of the 7th World Congress on Genetics Applied to Livestock Production :paper 02.16, 2002.
2001 Jopson, N.B., Nicoll, G.B., Stevenson-Barry, J.M., Duncan, S., Greer, G.J., Bain, W.E., Gerard, E.M., Glass, B.C., Broad, T.E., McEwan, J.C. :
Mode of inheritance and effects on meat quality of the rib-eye muscling (REM) QTL in sheep Proceedings of the Association for the Advancement of Animal Breeding and Genetics 14:111-114, 2001.
McLaren, R.J., Broad, T.E., McEwan, J.C., Jopson, N.B., Robertson, T.R., Glass, B.C., Gerard, E.M., Greer, G.J., Bain, W.E., Nicoll, G.B. :
Identification of positional candidates for the Carwell locus for rib-eye muscling in sheep Plant & Animal Genome IX Conference (PAG IX) :Abstract W17-03, 2001.
1998 Nicoll, G.B., Burkin, H.R., Broad, T.E., Jopson, N.B., Greer, G.J., Bain, W.E., Wright, C.S., Dodds, K.G., Fennessy, P.F., McEwan, J.C. :
Genetic linkage of microsatellite markers to the Carwell locus for rib-eye muscling in sheep Proceedings of the 6th World Congress on Genetics Applied to Livestock Production 26:529-532, 1998.
1997 Banks, R. :
The Meat Elite project: establishment and achievements of an elite meat sheep nucleus Proceedings of the Association for the Advancement of Animal Breeding and Genetics 12:598-601, 1997.
1995 Barendse, W. :
Muscular hypertrophy gene in Poll Dorset sheep. Final Report Project M.677Meat Research Corporation, Sydney , 1995.

Edit History

  • Created by Frank Nicholas on 06 Sep 2005
  • Changed by Frank Nicholas on 18 Nov 2013