This also happens to certain sheep. They spontaneously develop an additional pair of horns. Why? What causes it No, at least for now it is not demonic possession. The answer lies in science. And in a study of the genome of more than 2,000 goats and sheep. The mystery of the goats with four horns is finally beginning to be clarified.
They are known as a polyketone. Evidence for the existence of these animals goes back several centuries. For example, the handover of a four-horned goat from the village of Bulle in Switzerland. It was registered in 1786. The destination was Queen Marie Antoinette’s estate at Versailles. However, the genetic causes of this morphological abnormality were heretofore unknown.
The study was carried out by the French National Institute for Agricultural Research. It was published in Molecular Biology and Evolution and it reveals something interesting. All poly-coated individuals carry a mutation that affects the same gene called HOXD1. This is a homeotic gene. What does it mean? This is involved in organizing the body plan during the development of the embryos. The mutation seen in sheep and goats is different. In both cases, however, this leads to a decrease in the amount of HOXD1 protein produced by the gene of the same name.
Gene and horns
The researchers were able to determine the function of the HOXD1 gene. It is intended to delimit the region where the horns can grow on either side of the animal’s head. When a genetic mutation occurs, the surface expands. And this leads to the division of the horn buds during embryonic development. As a result, the excess horns grow.
This is a new and unexpected function for a homeotic gene. It is a function that probably evolved specifically with the appearance of the Bovidae. It explains the secret of the four-horned goats and makes it possible to determine the exact area in which these characteristic organs arise, as well as their number. So if you see them … don’t call an exorcist.