A single staining solution was made by compounding it in the following order (dyes were from British Drug Houses): ethanol, 10 ml; 1% malachite green in 95% ethanol, 1 ml; distilled water, 50 ml; glycerol 25 ml; phenol, 5 gm; chloral hydrate, 5 gm; acid fuchsin 1% in water, 5 ml; orange G, 1% in water 0.5 ml; and glacial acetic acid, 1–4 ml. For best results in differentiation to give green pollen walls and red protoplasm, the staining solution should be acidified with glacial acetic acid. The amount of acid to be added depends upon thickness of the pollen walls: for very thin-walled pollen, 1 ml; for moderately thin walls, 2 ml; and for thick-walled or spiny-walled pollen, 3 ml of acid. For pollen inside non-dehiscent anthers, 4 ml of acid should be used. Staining is hastened by flaming the slide (for loose thin-walled pollen) or by immersing thick-walled pollen or anthers for 24–48 hr at 50 C. In the typical stain, aborted pollen grains are green; nonaborted, red. The method is useful for pollen inside ...

Differential Staining of Aborted and Nonaborted Pollen

The Allium test is suggested as a standard in environmental monitoring, e. g. as a part of a test battery. Background, the method including suggested parameters for standard use, results from various application areas and comparisons with a number of other test systems are presented. The Allium test is a short-term test with many advantages: low cost, ease to handle, good chromosome conditions for the study of chromosome damage or disturbance of cell division including the evaluation of risks of aneuploidy. The ability of the root cells to activate promutagens (the MFO-system) further widens the application areas of the Allium test. The use of series of onions for each concentration of the test chemical allows statistical considerations, and from growth curves Effect-Concentration values are obtained. The Allium test is, lastly, a sensitive test showing good correlation to other test systems. Thus, positive results in the Allium test should be considered as a warning and also an indication that the tested chemical may be a risk to human health and to our environment.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-5223.1985.tb00471.x

The Allium test as a standard in environmental monitoring

Inhibition of mitosis by many drugs that bind to tubulin has been attributed to depolymerization of microtubules. However, we found previously that low concentrations of vinblastine and vincristine blocked mitosis in HeLa cells with little or no depolymerization of spindle microtubules, and spindles appeared morphologically normal or nearly normal. In the present study, we characterized the effects of vinblastine, podophyllotoxin and nocodazole over broad concentration ranges on mitotic spindle organization in HeLa cells. These three drugs are known to affect the dynamics of microtubule polymerization in vitro and to depolymerize microtubules in cells. We wanted to probe further whether mitotic inhibition by these drugs is brought about by a more subtle effect on the microtubules than net microtubule depolymerization. We compared the effects of vinblastine, podophyllotoxin and nocodazole on the organization of spindle microtubules, chromosomes and centrosomes, and on the total mass of microtubules. Spindle organization was examined by immunofluorescence microscopy, and microtubule polymer mass was assayed on isolated cytoskeletons by a quantitative enzyme-linked immunoadsorbence assay for tubulin. As the drug concentration was increased, the organization of mitotic spindles changed in the same way with all three drugs. The changes were associated with mitotic arrest, but were not necessarily accompanied by net microtubule depolymerization. With podophyllotoxin, mitotic arrest was accompanied by microtubule depolymerization. In contrast, with vinblastine and nocodazole, mitotic arrest occurred in the presence of a full complement of spindle microtubules. All three drugs induced a nearly identical rearrangement of spindle microtubules, an increasingly aberrant organization of metaphase chromosomes, and fragmentation of centrosomes. The data suggest that these anti-mitotic drugs block mitosis primarily by inhibiting the dynamics of spindle microtubules rather than by simply depolymerizing the microtubules.

Effects of vinblastine, podophyllotoxin and nocodazole on mitotic spindles. Implications for the role of microtubule dynamics in mitosis.

Publisher Summary This chapter discusses chromosome aberrations induced by ionizing radiations. Chromosome aberrations are used as general indices of cellular damage or as cell markers in studying cell-population kinetics in irradiated or tumor tissues. Of primary importance are the mechanisms involved in aberration induction and in the action of modifying agents that alter the overall frequency or relative frequencies of the different aberration types. The types of aberrations that are induced following irradiation or treatment with certain radiomimetic chemicals are classified according to the unit of breakage or exchange that is involved. The types of structural changes that can occur within or between chromosomes and chromatids are of two kinds: the simple deletion and the exchange. The simple deletion appears to be the result of a single break in the chromosome or chromatid and the exchange is a new rearrangement following the joining of breakage ends that result from separate breaks. Comparisons among different types of ionizing radiations and among similar radiation types having different energies for their capacity for producing chromosome aberrations are of considerable fundamental importance in the study of aberration production.

Chromosome Aberrations Induced by Ionizing Radiations

Periwinkle alkaloids in very low concentrations cause an intracytoplasmic sequestration of microtubule protein in the form of symmetrical, microtubular bodies. These crystals, which may measure up to 8 µ in length, appear within 30 min in L-strain fibroblasts in vitro, but they increase in incidence and size with time of exposure to the alkaloids. Similarly, if exposed to these compounds, human leukocytes in vitro contain identical crystalline structures. Neither colchicine nor puromycin prevents the formation of these bodies; the latter compound, however, retards crystal growth.

https://rupress.org/jcb/article-pdf/40/1/95/1069010/95.pdf

Microtubular crystals in mammalian cells

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-5223.1944.tb02739.x

Colchicine mitosis, chromosome contraction, narcosis and protein chain folding

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-5223.1962.tb01820.x

Measles‐Associated Chromosome Breakage. Preliminary Communication

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-5223.1962.tb01817.x

A squash technique for chromosome morphological studies

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-5223.1943.tb03297.x

Gunnar Östergren

Papers

Colchicine mitosis, chromosome contraction, narcosis and protein chain folding

Measles‐Associated Chromosome Breakage. Preliminary Communication

A squash technique for chromosome morphological studies

The mechanism of c-mitotic action observations on the naphthalene series

Behaviour on the spindle of the actively mobile chromosome ends of rye.