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Cytoplasmic rearrangements associated with amphibian egg symmetrizationCytoplasmic rearrangements which follow fertilization were mentioned in normal and inverted eggs. A set of yolk compartments was resolved by cytological analyses of both normally oriented and inverted eggs. Those compartments were characterized by their yolk platelet compositions and movement during egg inversion. It is found that during egg inversion the yolk compartments shift minor cytoplasmic compartments which line the egg cortex. Those yolk mass shifts occurred only after the inverted egg was activated. The direction of shift of the major yolk components, rather than the sperm entrance site, determines the dorsal/ventral polarity of the inverted egg. Among different spawnings the rate of shift varied. Eggs that displayed the fastest rate of shift exhibited the highest frequency of developmental abnormalities during organogenesis. Interpretation of novel observations on cytoplasmic organization provide criticism of some earlier models. A new density compartment model is presented as a coherent way to view the organization of the egg cytoplasm and the development of bilateral symmetry.
Document ID
19840010799
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Malacinski, G. M.
(Indiana Univ. Bloomington, IN, United States)
Date Acquired
August 12, 2013
Publication Date
February 1, 1984
Publication Information
Publication: NASA. Washington NASA Space Biol. Program
Subject Category
Life Sciences (General)
Accession Number
84N18867
Funding Number(s)
CONTRACT_GRANT: NAGW-60
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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