WHITE HAIR DEVELOPMENT MODEL ANIMAL, METHOD FOR ESTABLISHING WHITE HAIR DEVELOPMENT MODEL ANIMAL, METHOD FOR PASSAGE OF WHITE HAIR DEVELOPMENT MODEL ANIMAL, METHOD FOR STUDY ON WHITE HAIR DEVELOPMENT, SCREENING METHOD FOR WHITE HAIR DEVELOPMENT-CONTR

摘要

A model animal for the development of white hairs, which has such a phenotype that black or almost black hairs are grown after birth and white hairs are spontaneously developed with aging. This model animal is a non-human mammal, more preferably a rodential animal, particularly preferably a mouse or rat which has a genotype where an activated RET gene is transformed heterozygously and where an endothelin receptor B (Ednrb) gene is heterozygously deficient or alternatively an Ednrb gene is homozygously or heterozygously deficient and the Ednrb gene is homozygously or heterozygously introduced under the control of a DbH promoter. Thus, a white hair development model animal can be provided which is most suitable for the study on the mechanism of white hair development in human or the research on pharmaceutical preparations or treatments for preventing the development of white hairs.