An international team led by researchers at Uppsala University (Uppsala University) has identified a special type of genetic mutation in the white horses, which can be traced back to their common ancestor who lived thousands of years ago. The study also interesting from a medical point of view, since this mutation also increases the risk of melanoma.
The vast majority of white horses is a dominant mutation that causes them to turn gray as they mature. The white horse is born colored (black, brown or chestnut) but the graying process starts already during the first year of life, and hair turns white horses usually completely at the age of six or seven years, but the skin remains pigmented.
Thus, the process resembles graying in humans, but the white horses this process is extremely fast. Results of the study indicate that all the white horses carry exactly the same mutation which must have been inherited from a common ancestor that lived thousands of years ago.
According to the theory once upon a time a horse was born, which has quickly become dull and, in the end, all white. A stunning color white horse people are so fascinated that they decided to breed them specifically, transferring, so the mutation from generation to generation. Today about one horse in ten carries the mutation that leads to an age-bloom.
Obviously, people around the world praised the white horses. There are numerous stories and paintings depicting the white horses. White horse as a symbol of dignity, there is, for example, in the picture of the XVII century, depicting the Swedish King Karl XI on his white horse with diamonds.
In addition, the white horse is very interesting from a medical point of view, since the mutation also predisposes to the development of melanoma. Approximately 75% of white horses older than 15 years have a benign form of melanoma that in some cases develops into a malignant tumor. Thus, this study also provides a new perspective on the molecular mechanism of tumor development.
Scientists theorize that mutation stimulates melanocytes (cells that produce melanin under ultraviolet light), and that this leads to premature loss melanotsitovyh stem cells needed for hair pigmentation.
Pets are a wonderful model of the evolution of biological diversity. White Horse - a great example of the importance of regulatory mutations as the main mechanisms of phenotypic diversity in the population. Learned mutation does not alter the structure of the protein, but it affects the genetic regulation of two genes. Researchers have found that white horses has an additional copy of a DNA segment located in one of these genes.
It is very likely that regulatory mutations like the one that scientists have found the white horses constitute the dominating class of mutations explaining the differences between breeds (such as pets) and between species (eg, humans and chimpanzees). Want to be the first to know about the most important - free news ticker, be the first.