ISSN:0192-2521    

DOI:10.1002/em.2860010102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0192-2521    

DOI:10.1002/em.2860010103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0192-2521    

DOI:10.1002/em.2860010104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0192-2521    

DOI:10.1002/em.2860010105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractAntimutagenic radioprotective compounds have been reported to decrease the yield of chemically induced chromosome aberrations even when administered long before the chemical mutagen thio‐TEPA. Because thio‐TEPA can induce aberrations in all parts of the cell cycle, it seemed likely that the apparent decrease in aberrations was the result of an effect of the antimutagen on the progression of cells through the cell cycle so that cells treated in the more sensitive stage would be scored. To test this possibility human lymphocytes were treated with the protective compound WR2721 and then thio‐TEPA. The cells were grown in the presence of 5‐bromodeoxyuridine, which allows the definitive determination of metaphases from cells that divided once, twice, or three times after treatment. The yield of aberrations observed in first division cells was the same whether or not the protector was present. A decrease in aberration yields appeared only in rapidly cycling cells that were in the second division at the time of fixation. Labeling experiments showed that in this rapidly dividing population fewer of the metaphase cells had been in G2when thio‐TEPA was added. The results indicate that part of the decrease in aberration yields obtained by treatment with an antimutagen several hours before the addition of a mutagen is an artifact of cell

ISSN:0192-2521    

DOI:10.1002/em.2860010106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractDrosophila melanogaster males were exposed to gaseous 1, 2‐dibromoethane at concentrations lower than those used in aerosol treatments of suspected mutagens by other investigators. Premeiotic stages appear to be more sensitive than postmeiotic stages to gaseous mutagens. At an exposure of 125 ppm.hr, significant numbers of mutations were induced in spermatids, spermatocytes, and spermatogonia. Since this exposure increased the mutation rate in spermatogonial stages by a factor of 20–40 over the spontaneous rate, it appears that the lowest detectable exposures may be much lower than 125 ppm.hr for 1, 2‐dibromoe

ISSN:0192-2521    

DOI:10.1002/em.2860010107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractStrain DBA/2J male mice were treated with triethylenemelamine (TEM) and subsequently mated to strain C57BL/6J females. Tissues from F1progeny produced in these crosses were then examined using starch gel electrophoresis for the presence of presumed induced mutations at a series of 11 specific enzyme loci. In the course of this study, four heritable mutations were identified at the following loci:Es‐1, Ldh‐1, Pgm‐1, andGpi‐1. Of these four, the first two were apparently segregating in parental males and were not TEM‐induced. Both of these are viable and fertile in the heterozygous and homozygous condition, and neither confers any readily apparent deleterious effect to the animal. The latter mutations(Pgm‐1andGpi‐1)are presumably induced. Although viable and fertile in the heterozygous state, we have not yet recovered any offspring homozygous for either of these

ISSN:0192-2521    

DOI:10.1002/em.2860010108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractWe have surveyed the clastogenic potential of 12 different groups of stains and dyes totalling 48 compounds. We observed that 18 compounds induced significant increase in chromosome damage. Most of them were also found to be mutagenic, carcinogenic, or toxic in other reported studies. However, no significant studies were reported on six of them. It is concluded that these agents are potentially hazardous and should be studied further in detail.

ISSN:0192-2521    

DOI:10.1002/em.2860010109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractWhen mutation or recombination events occur premeiotically, the distribution of exceptional individuals among the offspring will be “clustered” as opposed to binomial. Even though the exact nature of the clustering is usually unknown, unbiased methods for measuring mutation rate and determining the precision of these measurements are given to replace a biased method now frequently used. When clustering is pronounced, the unweighted average mutation rate is found to be a more efficient estimator than the usual average weighted by family size. Methods of statistical inference and optimal experimental design in the absence of specific knowledge of the mechanism of clustering are also discus

ISSN:0192-2521    

DOI:10.1002/em.2860010110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe genetic activity of PR toxin, a mycotoxin from Penicillium roqueforti, was studied in Saccharomyces cerevisiae and Neurospora crassa. The results show that PR toxin, without enzymic activation, causes gene conversion in S. cerevisiae strains D4 and D7, reverse mutation in S. cerevisiae strain D7 and N. crassa strain N24, and mitotic crossing‐over in S. cerevisiae strain D7, In the log phase cells of S. cerevisiae the effects are more pronounced at alkaline than at acid pH. The active site responsible for the genetic activity and toxicity is known. The carbonyl groups appear to play an important role in the biologic activity of this molecul

ISSN:0192-2521    

DOI:10.1002/em.2860010111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY