Environmental and Molecular Mutagenesis - Legacy Tobacco ...

98 1989 EMS Abstracts 280
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
Notes MOLECULAR SPECfRUM ANALYSIS OF FRAMESHIFT MUTATIONS IN YEAST D . Kalirawcki,
KM. Mottus, M.J. Plewa, and RW. Larimer', Institute for Environmental Studiea, University of Illiaois,
Urbana, IL 61801, 'Biology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 .
The purpose of this study is to recover sequence information at the HIS4A region on chromosome III
from a large number of independently arising, htr• spontaneous and 4 nitroquinoline-N-oAde (4NQ0)
induced revertants of Saccharomyces temirk+e . We constructed a shuttle vector, pMP4, that contains a
438 bp deletion encompassing the +G framahift mutation, hls4 :38 . A large number of hit4- .38 spontaneous
revertants were obtained ; a random sample of 200 spontaneous and 4NQO induoed revertants
were screened for suppressor mutations and are being analpsed . Each revertant is separately transformed
with linear pMP4 that contains the 438 bp gap and the Infocmation from the yeast chromosome is copied
onto the plasmid by a gene conversion process known as double,strand gap repair. Since the gap extends
3' beyond the original +1 frameshift mutation, a new 1.3 kb SaII restriction site appears in the repaired
pMP4 . We have recovered and sequenced chromosomal information from over 40 spontaneous his4-38
revertants . The 4NQO induced revertants were produced at a concentration of 2.3 µghnl and are being
screened using the same procedure . This approach permits the isolation of DNA sequence information
of a mutation from an unmodified eukaryotic chromosome. We will define the distribution of bases
involved in mutation leading to reversion at his4- .Id The use of double strand gap repair allows the
analysis of the molecular spectrum of these revertants and will provide insight to the mechanisms
underlying spontaneous and 4NQO•induced frameshift mutation In eukaryotes . Funded by the
Interdisciplinary Program in Environmental 7bbcology .
281
S'PuLY UiV 1'cir . .:c.. .dJiOk OF MUTA(3ENS FROM MJNICIPAL INCINP:RATORS BY MhnfiS
OF AMES ASSAY .
A~.Ka~miya,:~agoya City Environmental Pollution Research Institute,Chudochc
nNTiamiku, Nagoya City(Japan), Y .Ose and T .Sato,Gifu Pharmaceutical
University,Mitahira-higashi, 3ifu City(Japan)
The mutagenicity and mutagens of fly ash,emission gas and wastewater
in municipal incinerators have been investigated by Ames assay and chem•ical
analysis . A negative relationship was obtained for complete combustion
and a positive one for incomplete combustion . About 90% of all
mutagens produced in a incinerator are released into atmosphere as emission
gas,and 10% are disposed in the electrostatic precipitator and
wastewater treatment plants . 1,6-Dinitropyrene(DNP) as direct acting
mutagen was detected in emission gas from incomplete combustion . The gac
phase photochemical reaction of oyrene with (vOs gas was examined in a
quartz vessel with various reaction times and temperature . 1-NP was
readily formed from pyrene in the absence of light irradiation and low
temperature, but the formation of 1,6-DNP is dependent on light irradiation,
temperature and nitric acid . Most of mutagens in wastewater
treatment olants are not decomposed by normal aeration times, but are
removed by adsorption onto suspendid solid . Total revertants per minute
from the emitted gases corresoonded to that from the exhaust of 1700 -
3000 motor vehicles . The mutagens emitted from total municipal incinerators
in Japan 1985 were estimated to be 16 .3ton as benzo(a)pyrene .
282
ON THE VALIDATION OF TME SYSTFM OF ASPER(iILLUS FOR TESTING IINIFAM1FNfAL ANEIIGIIdS
A . Kappas
National Research Center "Aeaacritus", Athens, Greece .
Chemically-induced malsegregation of chranosones is detected in two types of diploid
strains of the ascamycete As r illus nidulans . One detects euploid mitotic
segregants as products of either ma segregat on non-disjunction) or mitotic crossing-
-over . The other detects aneuploids as unstable abnormal segregants and can distinguish
between primary aneuploidy of whole chrat,oscmes and secondary spontaneous aneuploidy
resulting from primary chrotaosome breakage . We developed a system which
belongs to the first type of strains in which we can also detect chromosome breakage
and it is possible to identify whether segregants can be the result of secondary spon
taneous malsegregation of chraaosemes with terminal deletions . In this system we have
been able to use the metabolic activation technique with an S9 mix with microsamal
fraction from rats . In a coordinated progratmne of the EBC countries with the aim of
developing and validating proper test system(s) for the regulation of environmental
chemicals which can induce genaaic mutations, a variety of chemicals selected on the
basis of their ability to interact with several cellular targets have been investigated
in A . nidulans and many of them, including chloral hydrate, hydroquinone, thiabendazole
grise'o uTvin, benomyl, were detected as aneugens .
Supported by Grant EV4V-003S-GR from the EBC .
50869 3610