Environmental and Molecular Mutagenesis - Legacy Tobacco ...

64 1989 EMS Abstracts
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
Note s 24 hour after treatment using 5 animals per group . The test compounds did not
increase the frequencies of MNFCEs . The preliminary in vivo CA-tests were
carried out at 6, 24, 48hours after administration . The frequencies of polyploid
were 0-3 .5% and were not different from control . Furthermore, the effect of
thes chemicals on polymerization of tubulin was examined . These compounds did
not inhibit specifically tubulin polymerization to microtubules . Therefore, in
vitro induced polyploid can not be mediated through the microtubular system .
(1)Ishidate,M . et a1(1988) Mutation Rea . 195 151-213 .
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MUTAGENIC ACTIVITY, DNA BREAKAGE AND SOMATIC MUTATION OF ARENEQUINONES .
H . Furukawa, K . Kavai, T . Miyazawa and T . Sato, Meijo University, Nagoya(Japan), Tohoku
University, Sendai(Japan), and Inaba Biophoton Project, Research Development
Corporation of Japan, Sendai(Japan) .
it was reported that arenequinone was synthesized photochemically by sunlight
irradiation from corresponding arenas . The mutagenic activity of 3,6-banzola)pyrenequlnone,
1,6-benzota]pyrenequinone, 1,6-pyranequinone and 1,8-pyrenequinone are 44, 77,
91 and 298 revertants on Salmonella typhimwrdun TA100 without S-9mix . . It was
considered there must be the other mechanism with the exception of epoxide formation .
Futhermore breakage of DNA such as pBR322 or A phage DNA by 1,6-pyrenequinone or 1,8pyrenequinone
were suppressed by active oxygen scavenger such as buthylhydroxytoluene,
glutathione, a-tocopherol, sorbitol and L-aacorbic acid in vitro . Therefore we
considered that both mutagenic activity and DNA breakage activity were caused by active
oxygen molecules and the like . Small single spot frequency in Drosophila wing spot test
by 1,6-pyrenequinone, 1,8-pyrenequinone, 1,6-bento(a]pyrenequinone and 3,6-benzo(aJpyrenequinone
were risen about two fold of control's frequency . Then it was considered
active oxygen molecules caused the somatic mutation of Droeoph{la melanOgaster . For the
reason above mentioned phenomena, we considered that the planar ring surface of arenequinone
molecules are x-electron deficient, and toxic arenequinones contain
considerable radical structures in the resonance formulae . And we would like to
emphasize the urbane airborn particulate containes a few arenequinones and toxic
arenequinones should be formed by sunlight irradiation from corresponding arenes .
TRANSPOSITION : EFFRCTg AND MECtlAMISMS
David J . Galas Molecular Biology, University of Southern California, Los Angeles, CA
90089
Transposition of mobile genetic elements is apparently a universal phenomenon
occurring in the genomes of all organisms . Certainly in all the experimental organisms
common to the genetics laboratory, they have been extensively characterized . The list
begins with maize, of course (McClintock, 1956), and includes Drosophila, 8aecharomyces
Caenorhabditis and several different types of bacteria . The genetic effects of mobile
elements are diverse and include the induction of insertion mutations, deletions,
inversions and other rearrangements, and the turning off and on of gene expression . In
this talk, I will discuss several examples of the ways in which the mobile elements can
cause these effects . I will draw examples from observations and experiments in several
systems, but will focus on bacterial systems in discussing specific mechanisms . The
bacterial insertion sequence, IS1, has been studied to determine the molecular
mechanisms of the transposition process, the component parts of the molecular
apparatus, and to dissect the specificity determinants of the protein and DNA
components .
GFW=CITY OF VANADIUM CCt1QC[[RNID6
A . GaLLI, L . GIHCKDR, R . DEL CARFA2WE, C . DELIA CPDCE and G . BI+DNZETTI
Instituto di Mutagenesi e DifferenziamenYa CIIIR PISA ITALY
181
182
Acmnnium Metavanadate and Vanadyl Sulfate were tested for their ability to induce mitotic
gene oonversion and point reverse uutatian in the D7 strain of S . oerevisiae . Metavanadate
increased the convertant and revertant frequencies and the highest ac v ty was observed
without metabolic activation . This indioates that S9 hepatic fraction and cells fron logphase
oantainirg a high level of cytochreme P-450 biotransform vanadate probably reducing
it to vanadyl . Vanadyl did not induce any genetic effects in the same experimental conditions
An increase of gene conversion and point mitation was induced by vanadyl in cells
fraa log-phase, suggesting that these cells are able to axidate vanadyl to vanadate . To
explain our results, we hypothized that matavanadate is the genetoxically active form and
the monooxygenase system is involved in biotransfotmntion of varadiun, particularly reduoing
vanadate or oxidatiry vanadyl . To confirm this hypothesis, years cells harvested fram
lod-phase with high level of cytochrane P-450 were treated with metavanadate and vanadyl
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