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EFFECTS OF IONOPHORE A23187 ON OOCYTES OF COMANTHUS JAPONICA (ECHINODERMATA: CRINOIDEA) *
Author(s) -
HOLLAND NICHOLAS D.
Publication year - 1980
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.1980.00203.x
Subject(s) - cortical granule , exocytosis , ionophore , granule (geology) , oocyte , extracellular , divalent , chemistry , population , biophysics , human fertilization , cytoplasm , somatosensory system , microbiology and biotechnology , membrane , anatomy , biology , embryo , biochemistry , neuroscience , paleontology , demography , organic chemistry , sociology
Micromolar amounts of divalent cation ionophore A23187 stimulate full grown (but unfertilizable) oocytes of Comanthus japonica to undergo a cortical reaction that is incomplete: first, cortical granule contents ejected at exocytosis do not coalesce but remain as individual blebs just outside the oocyte; and, second, about a fourth of the cortical granule population does not undergo exo‐cytosis and remains in the cortical cytoplasm. Of the cortical granules remaining in the oocyte, some have unreacted contents and others have morphologically modified contents. Fine structures are compared among unreacted cortical granules, internally‐reacted cortical granules, extracellular blebs of cortical granule material and normal fertilization membranes. The comparison strongly suggests that the outer dense layer and inner fibrous layer of the normal fertilization membrane are derived, respectively, from the dense patches and from the matrices of the cortical granules.