Journal of Heredity Advance Access published online on October 14, 2008
Journal of Heredity, doi:10.1093/jhered/esn085
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Brief Communications |
Ancestral T-Box Mutation Is Present in Many, but Not All, Short-Tailed Dog Breeds
From the Medical Biochemistry and Developmental Biology, Institute of Biomedicine, University of Helsinki, PO Box 63, 00014 Helsinki, Finland (Hytönen and Sainio); the Institut de Génétique et Développement, UMR 6061 CNRS/Université de Rennes1, Faculté de Médecine, 35043 Rennes Cedex, France (Grall, Hédan, Dréano, Seguin, Galibert, and André); the Antagene, Research and analysis laboratory in animal genomics, 2 allée des séquoias, 69760 Limonest, France (Delattre and Thomas); the DNA Sequencing Laboratory, Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland (Paulin); and the Department of Medical Genetics and Department of Basic Veterinary Sciences, University of Helsinki and the Folkhälsan Institute of Genetics, Department of Molecular Genetics, PO Box 63, 00014 Helsinki, Finland (Hytönen and Lohi)
Address correspondence to Marjo K. Hytönen at the address above, or e-mail: marjo.hytonen{at}helsinki.fi.
Dogs differ greatly in their morphological characteristics including various tail phenotypes. Congenitally short-tailed dogs are present in many breeds; however, the causative mutation located in the T-box transcription factor T gene (C189G) had only been described in the bobtailed Pembroke Welsh Corgis. We investigated here the presence of the T gene mutation in 23 other breeds (360 dogs, including 156 natural short tailed) in which natural bobtailed dogs exist. 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. No dogs were found to be homozygous for the C189G mutation, suggesting that the homozygous condition is lethal. In order to study the effect of the T gene mutation on litter size, we compared the number of puppies born from short-tailed parents to that born from long-tailed parents. In the Swedish Vallhund breed, we observed a 29% decrease in the litter size when both parents were short tailed. 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.
Key Words: dog • mutation • short-tail phenotype • T-box transcription factor T
* These authors equally contributed to the work
These laboratories equally contributed to the work
Corresponding Editor: Elaine Ostrander
Received April 17, 2008
Revised September 10, 2008
Accepted September 15, 2008