White hair development model animal, white hair development model animal establishment method, gray hair development model animal passage method, white hair development research method, white hair development control means screening method, white hair development control composition

摘要

A model animal causing the white hair development as'a non-human mammalian animal with a phenotype such that the color of the hair first growing after birth is black or almost black and the model animal then causes the spontaneous white hair development following aging, where (1) the activated RET gene is genetically inserted in a hetero form and (2) the endothelin receptor B (Ednrb) gene is deficient in a hetero form, or the Ednrb gene is deficient in the homo form or in a hetero form and the Ednrb gene is genetically inserted in the homo form or in a hetero form under the DbH promoter. In accordance with the invention, there is provided a model animal causing the white hair development, which is the most suitable for research works about the mechanism of the white hair development and research works about a pharmaceutical preparation or a treatment capable of preventing the white hair development.