In other species: domestic cat , cattle , sheep

Possibly relevant human trait(s) and/or gene(s) (MIM number): 601397

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal Dominant

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2001

Cross-species summary: Also called brachyury

Species-specific name: bob-tail, bob tail

Species-specific description: Short tails (also known as bob-tails) occur as single-locus traits in a number of dog breeds.

Inheritance: autosomal dominant; early embryonic lethal when homozygous

Mapping: Jones et al. (2008) conducted an across-breed GWAS on 2,801 dogs from 147 breeds, each genotyped for 674 equally spaced SNPs, plus an additional 862 SNPs located in regions of interest. The results highlighted a region on CFA15.

Molecular basis: Noting that null mutations in the T gene (a member of the T-box family of transcription factors) in the mouse result in a phenotype very similar to that of bob-tail in dogs, Haworth et al. (2001) investigated the canine homologue of the mouse T gene as a candidate gene for bob-tails in Pembroke Welsh Corgis. Their hunch was correct: the bob-tail phenotype in this breed is due to a missense mutation (C295G; Ile63Met).

Hytönen et al. (2009) conducted a survey of this mutation (now called C189G) in 360 dogs (including 156 with short tails) from 23 other breeds. They reported that "In the 17 breeds in which the C189G mutation was observed, there was a perfect correlation between this mutation and the short-tail phenotype. However, 6 breeds did not carry the known substitution or any other mutations in the T gene coding regions. . . . Given that the T gene mutation is not present in all breeds of short-tailed dog, there must be yet other genetic factors affecting tail phenotypes to be discovered."

Breed: Corgi.

Associated gene: