Mutation found that causes White Spotting Pattern in White Parks and White Galloway Cattle
White Parks and Galloway are ancient breeds of cattle found primarily in Great Britain. Within these breeds there are four different white spotting phenotypes. These phenotypes are solid, well-marked, strongly marked, and mismarked (white or almost white). The well-marked and strongly marked patterns are the most desirable and result in color being left on the ears, nose, and legs as well as some small colored spots being present on the body. More of these small colored blotches will be present in well marked vs strongly marked individuals but all of the colored spots will be located horizontally along the torso. Although the well-marked and strongly marked patterns are the most desirable, a high percentage of calves from parents with the desired patterns are born either solid or mismarked. In order to better understand the genetics behind this white spotting pattern researchers analyzed four genes that are known to cause coat color variations in cattle. These genes are MC1R, TYR, KITLG, and KIT.
When no unknown color altering mutations were found in these genes, researchers searched for a recently discovered mutation that has been designated Cs29. This mutation is a very interesting mutation. It is the result of part of one chromosome being transferred to another chromosome. In this case the the KIT gene is involved. The KIT gene which is normally found in cattle on chromosome 6 is responsible for numerous white spotting patterns across many species. KIT gene mutations have been found to cause white spotting patterns in Humans, Horses, Cattle, Mice, Rats, Dogs, Cats, Swine...well you get the picture, the list is extensive. The interesting thing about this mutation however, is that a copy of the KIT gene isn't where it is supposed to be. The duplicate copy of the KIT gene has moved from cattle chromosome 6 to cattle chromosome 29 and muscled its way aboard. The result however, is somewhat more predictable, another white spotting pattern.
The Cs29 mutation was first found in Belgian Blue cattle where the mutation results in a phenotype that is termed “color sided”. It is inherited in a semi-dominant manner which means that cattle with two copies of the mutation have more white than animals with only one copy. In the case of White Parks and White Galloway this results in an almost white individual that is termed “mismarked”. However, breeding two individuals that lack the preferred phenotype (in this case a solid animal and a mismarked animal) will result in 100% of offspring being born with the desired well-marked and strongly marked patterns.
Researchers hope that research into translocation mutations such as Cs29 may result in breakthroughs in diseases such as cancer. It is theorized that translocation mutations may be one cause of cancerous cells in humans
1. Brenig, B. et al. Molecular genetics of coat colour variations in White Galloway and White Park cattle. Animal genetics 44, 450–3 (2013).