Ultraviolet microbeam irradiations of mitotic diatoms: investigation of spindle elongation.
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چکیده
منابع مشابه
Ultraviolet microbeam irradiations of mitotic diatoms: investigation of spindle elongation
Our simple instrumentation for generating a UV-microbeam is described UV microbeam irradiations of the central spindle in the pennate diatom Hantzschia amphioxys have been examined through correlated birefringence light microscopy and TEM. A precise correlation between the region of reduced birefringence and the UV-induced lesion in the microtubules (MTs) of the central spindle is demonstrated....
متن کاملUV microbeam irradiations of the mitotic spindle. II. Spindle fiber dynamics and force production
Metaphase and anaphase spindles in cultured newt and PtK1 cells were irradiated with a UV microbeam (285 nM), creating areas of reduced birefringence (ARBs) in 3 s that selectively either severed a few fibers or cut across the half spindle. In either case, the birefringence at the polewards edge of the ARB rapidly faded polewards, while it remained fairly constant at the other, kinetochore edge...
متن کاملPrometaphase forces towards opposite spindle poles are not independent: an on/off control system is identified by ultraviolet microbeam irradiations.
Individual spindle fibres in prometaphase spermatocytes of the cricket, Neocurtilla hexadactyla, were irradiated with an ultraviolet microbeam. The stretched heteromorphic bivalent (X2Y) contracted to about 75% of its pre-irradiation length after irradiation of either of its two oppositely directed spindle fibres (i.e., the X2 or Y spindle fibre). The X2Y bivalent also contracted after irradiat...
متن کاملStu2 Promotes Mitotic Spindle Elongation in Anaphase
During anaphase, mitotic spindles elongate up to five times their metaphase length. This process, known as anaphase B, is essential for correct segregation of chromosomes. Here, we examine the control of spindle length during anaphase in the budding yeast Saccharomyces cerevisiae. We show that microtubule stabilization during anaphase requires the microtubule-associated protein Stu2. We further...
متن کاملAction spectrum for changes in spindle fibre birefringence after ultraviolet microbeam irradiations of single chromosomal spindle fibres in crane-fly spermatocytes.
Single chromosomal spindle fibres in Nephrotoma suturalis (crane-fly) spermatocytes in metaphase and anaphase were irradiated with monochromatic ultraviolet light focussed to a 2 micrometer spot. In cells in both metaphase and anaphase either the birefringence of the irradiated spindle fibre was altered in the irradiated region, or there was no change, depending on the dose and wavelength of ul...
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ژورنال
عنوان ژورنال: Journal of Cell Biology
سال: 1983
ISSN: 0021-9525,1540-8140
DOI: 10.1083/jcb.96.2.548