| Abstract: | The Mexican axolotl (Ambystoma mexicanum) provides a well-defined set of color genes which are useful for various types of analyses. These include the a (albino), m (melanoid), ax (axanthic), and d (white) genes. In addition, various combinations of these genes and a number of as yet undescribed mutants also exist. Three of these mutants (a, ax, and m) have defects associated with specific neural-crest-derived pigment cell types. The fourth mutant (d) appears to provide an unsuitable environment for the migration and maintenance of pigment cells. In one case (m), detailed information concerning the specific nature of the genetic defect is available. The goal of this article is to demonstrate ways in which the existing information on the axolotl color genes can best be utilized in terms of understanding not only the mutant phenotypes, but basic concepts in the cell and developmental biology of pigmentation as well. Thus, an attempt has been made to sort through the genetic and biochemical data relevant to these mutants in order to stimulate renewed interest in a more detailed pursuit of such studies. |
