ISSN:
0886-1544
Keywords:
microtubules
;
fertilization
;
cell division
;
sea urchin
;
cytoskeleton
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The microtubule-containing structures that appear in eggs during fertilization and cell division in the sea urchins Lytechinus variegatus and Arbacia punctulata were detected by antitubulin immunofluorescence microscopy of detergent extracted cytoskeletal preparations. The extraction buffer, which is composed of 0.55 mM MgCl2, 10 mM EGTA, 25 mM MES, 25% glycerol, 1% Nonidet P-40, and 25 μM PMSF, pH 6.7, allows for dramatically improved fluorescent images compared to those obtained using conventional staining procedures, with residual background staining being reduced to near zero.The immunofluorescent images obtained using this technique provide information on several motile events that occur during the first cell cycle. This technique demonstrates that all of the cytoplasmic microtubules are associated with the incorporated sperm's centrioles during female pronuclear migration. This changes during the centration of the male and female pronuclei at which time a monastral array of microtubules forms in the egg's cytoplasm. A large proportion of the monastral microtubules do not appear to be associated with the centrioles. At prophase and early metaphase, the centrioles are the dominant microtubule organizing centers (MTOCs) consistent with mitotic theories that the kinetochore catches, but does not initiate, microtubules. Observations of intercentriolar distances show that there are three stages of pole separation during the first cell cycle. The initial separation occurs during pronuclear centration, the second during the streak stage, and the final one during the late stages of mitosis. At telophase, polar microtubules appear to extend into the cortex supporting the cell surface at all regions except the presumptive cleavage site.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970030303
