ISSN:
0886-1544
Keywords:
cell division
;
receptors
;
neurotransmitter
;
micronlaments
;
mitosis
;
cytokinesis
;
sea urchin eggs
;
microtubules
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Propranolol, a β-adrenergic receptor blocker, blocks the formation of the cleavage furrow, while karyokinesis is unaffected during first division in the sea urchins Paracentrotus lividus or Lytcchinus pictus. This effect is reversed by adrenalin, indicating that it is mediated by an adrenergic mechanism. The staining of F-actin microfilaments by rhodamine phalloidin in eggs in which the cleavage is blocked by the drug has revealed that propranolol affects both the distribution and the organization of actin microfilaments. A low-voltage scanning electron microscopy (LVSEM) study of microvilli in these eggs shows an extensive rearrangement of the egg surface. Anti-tubulin immunofluorescence microscopy of eggs treated with propranolol shows that they form normal mitotic asters. This indicates that while cleavage is affected, mitotic spindle formation is not. These results suggest that neurotransmitter monoamines known to be present in the sea urchin egg might be involved in the reorganization of the actin cytoskeleton underlying the formation of the cleavage furrow.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970160305
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