Comparison of white and black axolotl chromatophores in vitro

Abstract

Inst i t nt ion of Tifslkington. Cold Spring Harbor, AT. Y . TEN FIGURES INTRODUCTIOSTissue cultures of prospective pigment cells from white and black strains of the Mexican axolotl, Siredon weximzzim, have been studied for the purpose of determining \diether there is any demonstrable basis within the cliromatopliores theniselves for the phenotypic differences in pigmentation between the two strains. Haecker ('07) showed that the white coiiditioii is the result of a Mendelian recessive gene, to which he gave the symbol cl. The present investigation deals with the question, does the gene d act directly 011 tlie chroniatophores? The method of culturing neural, crest in vitro was applied to the study of gene-determined pigment patterns by Tmitty and Bodenstein ( '39), ~v h o demonstrated that factors responsible for the contrasting patterns of Tr.ltzrrzis toroszis and 2'. rivzilaris were intrinsic to the propigrnent cells of these species.The importance in the asolotl of pattern-determining factors extrinsic to the chrornatophores is indicated by the fact that reciprocal transplantations of neui-a1 crest between ernhryos of the white and black strains (DuSliane, '35, '39) do not produce areas of donor-type patterns in the host animals. DuShane has suggested from the evidence of tliese transplantation experiments that in tlie axolotl the propigment cells do not possess all the requisites for self-cliffereiitiatiori, but depend on their tissue environment for some suhstaiice . 4SOI.OT18 CHBOMATOPHORES IN T'ITRO

Neural crest and the origin of species‐specific pattern

“…Their reliance on intrinsic differences in the number, distribution, and color of intracellular pigment granules as a means to keep track of donor versus host tissues was actually a proxy for a neural crest‐derived lineage (i.e., melanocytes), something which was suggested by Harrison () and others but which remained debatable at the time (Dorris, ; DuShane, ; Harrison, ; Holtfreter, ; Raven, ). Soon thereafter, numerous efforts were underway to determine the extent to which neural crest cells establish inter‐ and intra‐specific pigment patterns and to sort out the effects and/or role of interactions with epidermis (Clark Dalton, ; Harrison, ; Hörstadius, ; Macmillan, ). For example, neural crest transplants among the tiger salamander, spotted salamander, or white and black strains of the Mexican salamander revealed that the “characteristic adult spots of the graft are in most cases distinctly different from those of the host, and are similar to those of donor adults” (DuShane, , p. 25).…”