Distribution of keratan sulphate and chondroitin sulphate in wild type and white mutant axolotl embryos during neural crest cell migration.
In embryos of the white mutant axolotl, prospective pigment cells are unable to migrate from the neural crest (NC) due to a deficiency in the subepidermal extracellular matrix (ECM). This raises the question of the molecular nature of this functional defect. Some PGs can inhibit cell migration on ECM molecules in vitro, and an excess of this class of molecules in the migratory pathways of neural crest cells might cause the restricted migration of prospective pigment cells seen in the white mutant embryo. In the present study, we use several monoclonal antibodies against epitopes on keratan sulphate (KS) and chondroitin sulphate (CS) and LM immunofluorescence to examine the distribution of these glycosaminoglycans at initial (stage 30) and advanced (stage 35) stages of neural crest cell migration. Most KS epitopes are more widely distributed in the white mutant than in the wild type embryo, whereas CS epitopes show very similar distributions in mutant and wild type embryos. This is confirmed quantitatively by immunoblotting: certain KS epitopes are more abundant in the white mutant. TEM immunogold staining reveals that KS as well as CS are present both in the basal lamina and in the interstitial ECM in both types of embryos. It remains to be investigated whether the abundance of certain KS epitopes in the white mutant embryo might contribute to the deficiency in supporting pigment cell migration shown by its ECM.
Olsson
L
L
Department of Environmental and Developmental Biology, Uppsala University, Sweden.
Stigson
M
M
Perris
R
R
Sorrell
J M
JM
Löfberg
J
J
D000557:Ambystoma / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement; D002642:Chick Embryo; D002809:Chondroitin Sulfates / Q000378:metabolism*; D002850:Chromatography, Gel; D005109:Extracellular Matrix / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D015151:Immunoblotting; D007632:Keratan Sulfate / Q000378:metabolism*; D016253:Microscopy, Immunoelectron; D009154:Mutation; D009432:Neural Crest / Q000196:embryology / Q000378:metabolism*; D010860:Pigments, Biological / Q000378:metabolism
D010860:Pigments, Biological; D002809:Chondroitin Sulfates; D007632:Keratan Sulfate