Year: 1972
Type: article
Abstract: The first cleavage furrow in eggs of Arbacia (sea urchin) is accompanied by a uniform ring of aligned microfilaments, called the contractile ring. Individual contractile ring filaments measure 35-60 A and occasionally appear "hollow." The contractile ring exists from about 20 sec after anaphase to the end of furrowing activity, i.e., 6-7 min at 20 degrees C. It is closely associated with the plasma membrane at all times, and is probably assembled there. It is about 8 micro wide and 0.2 micro thick throughout cleavage. Its volume decreases, however, suggesting a contraction-related disassembly of contractile ring filaments, rather than a sliding-filament mechanism in the strict sense. Cytochalasin B (>10(-6)M) arrests cleavage within 60 sec, by which time contractile ring filaments are no longer visible ultrastructurally. The furrow may be seen to recede within this time. Karyokinesis is unaffected. Simultaneous disruption of furrowing activity and of the contractile ring largely confirms the vital role of the contractile ring as the organelle of cell cleavage.
Source: The Journal of Cell Biology
DOI: 10.1083/jcb.53.2.419
Author: Thomas E. Schroeder
Institutions: University of Washington, Friday Harbor Laboratories
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2087343300