Navigation Links
The genetics of the white horse unraveled

The white horse is an icon for dignity which has had a huge impact on human culture across the world. An international team led by researchers at Uppsala University has now identified the mutation causing this spectacular trait and show that white horses carry an identical mutation that can be traced back to a common ancestor that lived thousands of years ago. The study is interesting for medical research since this mutation also enhance the risk for melanoma. The paper is published on July 20 on the website of Nature Genetics.

The great majority of white horses carry the dominant mutation Greying with age. A Grey horse is born coloured (black, brown or chestnut) but the greying process starts already during its first year and they are normally completely white by six to eight years of age but the skin remains pigmented. Thus, the process resembles greying in humans but the process is ultrafast in these horses. The research presented now demonstrates that all Grey horses carry exactly the same mutation which must have been inherited from a common ancestor that lived thousands of years ago.

- It is a fascinating thought that once upon a time a horse was born that turned grey and subsequently white and the people that observed it were so fascinated by its spectacular appearance that they used the horse for breeding so that the mutation could be transmitted from generation to generation, says Leif Andersson who led the study. Today about one horse in ten carries the mutation for Greying with age.

It is obvious that humans across the world have greatly valued these white horses as documented by the rich collection of stories and paintings featuring white horses. In the paper the white horse as an icon for dignity is illustrated by reproducing a painting from the late 17th century of the Swedish king Karl XI on his white horse Brilliant.

The Grey horse is also very interesting from a medical point of view since the mutation also predisposes for development of melanoma. About 75% of Grey horses older than 15 years of age have a benign form of melanoma that in some cases develops into a malignant melanoma. Thus, the study reported today has also given new insight in a molecular pathway that may lead to tumour development.

We propose that the Grey mutation stimulates growth of melanocytes and that this leads to a premature loss of the melanocyte stem cells needed for hair pigmentation whereas the mutation promotes an expansion of some of the melanocytes causing skin pigmentation, says Leif Andersson.

Domestic animals constitute extraordinary models for evolution of biological diversity as already recognized by Charles Darwin. The white horse is a beautiful illustration of the importance of regulatory mutations as a major underlying mechanism for phenotypic diversity within and between species. The Grey mutation does not change any protein structure but it affects the genetic regulation of two genes. The researchers found that the white horses carry an extra copy of a DNA segment located in one of these genes.

It is very likely that regulatory mutations like the one we found in these white horses constitute the dominating class of mutations explaining differences between breeds of domestic animals as well as between species like humans and chimpanzee, concludes Leif Andersson.


Contact: Leif Andersson
Uppsala University

Related biology news :

1. Genetics determine optimal drug dose of common anticoagulant
2. American College of Medical Genetics responds to new FDA labeling decision for warfarin
3. Rutgers Genetics receives $7.8 million for autism research
4. UD leads $5.3-million research project on rice epigenetics
5. UD leads $5.3-million research project on rice epigenetics
6. Wasp genetics study suggests altruism evolved from maternal behavior
7. Maynard Olson receives $500,000 Gruber Genetics Prize
8. UBC discovery unlocks tree genetics, gives new hope for pine beetle defense
9. Ecologists, material scientists pursue genetics of diatoms elegant, etched casing
10. Scientists achieve major genetics breakthrough
11. Environmental epigenetics has potential for preventing and treating disease
Post Your Comments:
(Date:11/10/2015)... 2015 About signature verification ... to identify and verify the identity of an ... the secure and accurate method of authentication and ... individual because each individual,s signature is highly unique. ... dynamic signature of an individual is compared and ...
(Date:11/2/2015)...  SRI International has been awarded a contract of ... to the National Cancer Institute (NCI) PREVENT Cancer Program ... modern testing and support facilities, and analytical instrumentation to ... studies to evaluate potential cancer prevention drugs. ... Drug Development Program is an NCI-supported pipeline to bring ...
(Date:10/29/2015)... 29, 2015  Rubicon Genomics, Inc., today announced ... of its DNA library preparation products, including the ... ThruPLEX Plasma-seq kit. ThruPLEX Plasma-seq has been optimized ... NGS libraries for liquid biopsies--the analysis of cell-free ... applications in cancer and other conditions. Eurofins Scientific ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... , November 25, 2015 Studies ... and human plaque and pave the way for more effective ... in cats     --> ... commonly diagnosed health problems in cats, yet relatively little was ... Two collaborative studies have been conducted by researchers from the ...
(Date:11/25/2015)... ... November 25, 2015 , ... ... of Black Aerospace Professionals (OPBAP) has been formalized with the signing of a ... leaders met with OPBAP leaders Capt. Karl Minter and Capt. Albert Glenn Tuesday, ...
(Date:11/24/2015)... Nov. 24, 2015  Asia-Pacific (APAC) holds the ... (CRO) market. The trend of outsourcing to low-cost ... but higher volume share for the region in ... however, margins in the CRO industry will improve. ... ( ), finds that the market ...
(Date:11/24/2015)... , Nov. 24, 2015 /CNW/ - iCo Therapeutics ... today reported financial results for the quarter ended ... expressed in Canadian dollars and presented under International ... United States ," said Andrew Rae ... advancements regarding iCo-008 are not only value enriching ...
Breaking Biology Technology: