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A Freeze‐Fracture Study of the Cortex of Xenopus laevis Eggs
Author(s) -
CHARBONNEAU MICHEL,
GREY ROBERT D.,
BASKIN RONALD J.,
THOMAS DANIEL
Publication year - 1986
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.1986.00075.x
Subject(s) - xenopus , endoplasmic reticulum , intramembranous ossification , membrane , electron microscope , granule (geology) , biophysics , anatomy , cortical neurons , ultrastructure , cortex (anatomy) , biology , chemistry , microbiology and biotechnology , neuroscience , biochemistry , physics , paleontology , gene , optics
The organization of the cortex of Xenopus laevis eggs was investigated by freeze‐fracture electron microscopy. The cortical endoplasmic reticulum (CER) formed a network surrounding and interconnecting the cortical granules. It formed junctions with the plasma membrane and was confluent with the ER in subcortical regions. Intramembranous particles (IMP 1 ) were only present in the P face of the CER, the E face being apparently devoid of pits and particles. Arrays of densely packed IMP 1 , having a mean diameter of 17 nm, were restricted to the microvillar region of the plasma membrane. The cortical granule membrane also contained IMP 1 (mean diameter, 21 nm) that were sparsely and randomly distributed. Several types of cortical granule seemed to exist based on an analysis of the distribution of the different IMP sizes.