Open AccessRADIATION DEPIGMENTATION OF MOUSE HAIR: A STUDY OF FOLLICULAR MELANOCYTE POPULATIONS
Author(s) -
Potten Christopher S.
Publication year - 1968
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.1968.tb00321.x
Subject(s) - melanocyte , hair follicle , depigmentation , melanin , follicle , biology , dermal papillae , follicular phase , microbiology and biotechnology , endocrinology , genetics , melanoma
The radiation depigmentation of mouse hair has been studied by a technique enabling melanocyte per follicle counts to be made. Distributions for normal skin show a large peak corresponding to the zigzag hair type. Changes in the frequency distributions of melanocytes per follicle after irradiation are presented for Strong F and DBA‐1 mice irradiated in anagen or telogen stages of hair growth. These distributions clearly suggest the existence of some precursor cells, and the dose‐response curves obtained by defining radiation survivors as follicles containing more than ten melanocytes gives the sensitivity of these cells to inactivation. D 0 values are 180–220 rads. A melanocyte‐melanoblast model is proposed for the follicular melanocyte cycle which can be outlined as follows: The telogen follicle contains a small number of amelanotic melanocytes that survived through catagen. These cells possess the ability to repopulate the follicle with melanocytes. In catagen functional and/or amelanotic melanocytes are lost at random. Genes for dilution (possibly only when modified by other coat colour genes) and radiation both increase the chance of melanocyte loss at catagen by altering the melanocyte‐dermal papilla relationship. One way in which this is affected is by a shortening of the dendrites. A feedback may operate in the follicle so that the full complement of melanocytes is achieved whatever number of melanocytes persists in telogen.