ISSN:
1432-0878
Keywords:
Pomatoceros triqueter
;
Cytokinesis
;
Surface folding
;
New surface membrane
;
Ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The first cleavage division of Pomatoceros triqueter eggs is described. Time-lapse microcinematographic and electron microscopic studies revealed that, prior to division, the plasma membrane was folded into pleats. These were not present after division. This fact pointed to an unfolding of the plasma membrane which enabled it to cover the increased surface area resulting from cleavage. It is suggested that the pre-cleavage folds are derived from the membranes of the cortical granules, which continue releasing their contents into the perivitelline region following fertilization and first division. Filamentous material in the form of a band was present subjacent to the plasma membrane in the region of the furrow. The individual filaments of this band measure 5 to 7 nm in cross section, the dimensions being similar to those described for other kinds of dividing cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00335544
Permalink
