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Structure and Macromolecular Composition of the Jelly Coats of the Urodele Ambystoma mexicanum
Author(s) -
Carroll Edward J.,
Palmer Richard,
Ruibal Rodolfo
Publication year - 1992
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1992.00501.x
Subject(s) - staining , amino acid , chemistry , mole , phosphotungstic acid , chromatography , reagent , glycoprotein , biochemistry , molecular mass , microbiology and biotechnology , biology , enzyme , genetics , catalysis
Cleavage‐stage embryos of the neotenic urodele Ambystoma mexicanum are surrounded by a fertilization envelope and four macroscopic jelly coats termed J 1 (innermost) through J 4 (outermost). In sections prepared for light microscopy, each of the jelly layers stained with protein stains and the periodic acid‐Schiff's reagent, but only J 1 stained with alcian blue at pH 2.5. These results suggest that each layer consists of proteins and glycoproteins and that J 1 uniquely contains some sulfate esters. Only J 4 was solubilized with alkaline mercaptan treatment in situ , however, the isolated inner jelly complex (J 1 , J 2 and J 3 ) was easily dissolved in this reagent suggesting that solvent access is impaired in situ . A single alcian blue‐staining component plus one protein‐staining component were detected on reducing polyacrylamide gel electrophoresis of outer jelly (J 4 ). In the inner jelly complex (J 1 , J 2 , J 3 ), two protein‐staining components were detected and no alcian blue‐staining components were observed. A predominant polypeptide of 110,000 molecular weight was detected and purified to homogeneity on reducing and denaturing gels of the inner jelly complex. Amino acid analysis of the polypeptide demonstrated a slightly higher fraction of acidic over basic amino acids (Glx+Asx=18.1 mole% vs . Arg + Lys = 11.7 mole%). The N‐terminal amino acid was Glu and the sequence of the first eleven amino acids was determined.