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Mosaic Expression of the Reeler and Normal Phenotypes in the Cerebral Cortex in Reeler ‐Normal Chimeras at a Late Embryonic Stage
Author(s) -
MIKOSHIBA KATSUHIKO,
YOKOYAMA MINESUKE,
NISHIMURA YOZO,
KATSUKI MOTOYA,
NOMURA TATSUJI,
TSUKADA YASUZO
Publication year - 1985
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.1985.00737.x
Subject(s) - reeler , phenotype , mosaic , biology , embryonic stem cell , cortex (anatomy) , neuroscience , stage (stratigraphy) , cerebral cortex , embryo , anatomy , microbiology and biotechnology , chimera (genetics) , genetics , reelin , gene , extracellular matrix , history , paleontology , archaeology
The cerebral cortex of reeler ‐normal chimera embryos was studied by hematoxylin‐eosin staining and fractographic scanning electron microscopy in comparison with the cortices of normal and reeler mutant mice. The cerebral cortex of normal mice had a plexiform layer, which was composed of a fine meshwork of matrix cell processes. Spindle shaped neuroblasts formed a radial lining columnar structure, which was formed by attachment of migrating neuroblasts to the radial bundles. The cerebral cortex of reeler mutants did not show a plexiform layer and the cells were round with no radially columnar structures, and no radial bundles. In reeler ‐normal chimera embryos, the thickness of the plexiform layer varied in different parts of the cerebral cortex. In parts where the plexiform layer was present, neuroblasts were spindle‐shaped and had a radially oriented columnar structure (normal type). But where the plexiform layer was absent, the neuroblasts were round with a radial architecture ( reeler type). Intermediates between the reeler and control types were also observed. Since mosaic expression of the two phenotypes, was observed in chimeras, the reeler abnormality is apparently not caused by humoral factors. The possible mechanism of cell migration is discussed.