Cytochalasin induces abnormal anaphase in crane-fly spermatocytes and causes altered distribution of actin and centromeric antigens

Visualization of kinetochores and analysis of their refractility in crane-fly spermatocytes after aldehyde fixation

“…Only those autosomal chromosomes that are segregating to the poles have kinetochores with weakened refractility; kinetochores of lagging sex univalents remain strongly refractile. These findings parallel results from immunofluorescence studies on crane-fly spermatocytes using CREST antibodies [LaFountain, et al, 1992]. CREST fluorescence is diminished in autosomal kinetochores at late anaphase, but that of lagging sex univalents remains as bright as at metaphase.…”

“…The results reported in this paper are an outgrowth from an earlier immunofluorescence study that used CREST antibodies to investigate kinetochores in cranefly spermatocytes [LaFountain et al, 1992]. We have extended that work using higher concentrations of FA in an attempt to improve cytological preservation.…”

“…We previously used serum from a patient with the CREST (Calcinosis, Raynauds's phenomenon, Esophageal dysmotility, Sclerodactyly, Telangiectasia) variant of systemic sclerosis in our immunofluorescence studies of meiosis in crane-fly spermatocytes and reported altered CREST staining at centromere/kinetochore regions upon exposure to cytochalasin D [LaFountain et al, 1992]. We also used sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and protein blotting to demonstrate the presence of several peptides with molecular masses of approximately 56, 53, 35, and 23 kDa in spermatocyte homogenates.…”

The perpetual movements of anaphase

“…In a subsequent study, somewhat contradicting findings were reported in the same system where addition of latrunculin B before anaphase did not cause an effect on chromosome movement during anaphase [179]. Under these experimental conditions inhibition of myosin with two different drugs, [180]. Increasing cytochalasins to concentrations exceeding those needed to inhibit cytokinesis in this or other systems, caused alterations in kinetochore structure and lagging chromosomes during anaphase [180,181].…”

“…Under these experimental conditions inhibition of myosin with two different drugs, [180]. Increasing cytochalasins to concentrations exceeding those needed to inhibit cytokinesis in this or other systems, caused alterations in kinetochore structure and lagging chromosomes during anaphase [180,181]. Nevertheless, in a different set of studies, treatment of crane fly spermatocytes with calyculin A, which hyperactivates myosin, was shown to accelerate poleward chromosome movement [182].…”