Environmental and Molecular Mutagenesis - Legacy Tobacco ...

232 1989 EMS Abstracts
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NOtE'S immunosuppresive agents . Two to three drops of blood were taken from the ear lobes of
examined persons . TM&,blood was then incubated with 1 .0-2 .0 ml Tris-ammonium chloride
buffer solution 'to'renxTlyze red blood cells . Monolayer cell smears were made with
cytocentrifuge and Feulgen stain was applied to detect DNA content . The morphological
observation and micronuclei counting were done with light microscope . We found that
the frequencies of micronuclei of lymphocytes in healthy persons were 0 .82 per
thousand cells but in patients with esophageal carcinoma were 2 .88 per thousand . The
difference of frequencies of micronuclei of lymphocytes between healthy persons and
patients with esophageal carcinoma was statastically significant (PA0 .001) . The
method we used to detect micronuclei of lymphocytes was fast and reliable and easily
accepted by patients examined .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
674
4IT' STU7Y i :+CCU' ; L :^_ IO° OF 2.L' :1 .. . . : IN Gr'.Rh: CSLLS ON INDUCTIi . :i
OF ~.lDICG-_? ;~TC7.L^.OLCGICAL 3F :^r:CT .
Zhu Bhoup n~, heov Siyinq, -ad lP-n :^- Liuyi, Suzhou Nedical College, Suzhou(China)
T~j purpose of the present study is to ascertain r,omp,?~rative retontion of 147Pn
o„- Cs in qerm cells on induction of chromnsome aberraM ns of sparmatogonium and
eb :iormall+.i .e in sperm . Results it .dicated that after iv Pm throu,h 50 d observstion
. The rEtr.nt~oPC~~a~s in tastis were well describad by an exponential expression
13~(t)=0 .1872xe- , where the retention ^=1C5 ( : . 'lhlle th3 .fat~~ntion data of
Cs in t•?stiF w•er^ described by e-n expreswlofi : =tlt).O,OC15za , where the
retention T, was on}X75 .2 d, 3xperimsnts indicated that the retention value aQJ4thc
abs.irption ose of Pn i?A°a is ree sirnificantly high in comparism with C s .
Internal conta.nins!ion of ?~ or Ce can be induced chromosome aberrations in
germ cells and abnormalltiT17in spaj~b Atnona the type of chromosome aberrations of
apermato-onium induc,~d bv _m or Ce includin- ^a~, chromatid breakage, chromosome
brea ::age, and tranalocation, as woll as poly :'-oid spermatogonium . },oreover,
the chromosoma aberrft3on rctt*s and pol,T,:loid cells were elevated when the periods
of conta^:ination of Pm :rora prolon,? !d . ,1t th : semt_ t#" ehromoso:ae fragment and
If~nalocations of primary spermatocyte also induced by Pm . By compaTign with
:m, ho-ver, the induction of cytogenetic effects on germ cells by a wke
quite low.
675
INDUC'TION OF MUTATION IN F-'aihcrichin cofi BY DIMETHYISULFATE IS INFLUENCED BY SOS :
OBSERVA'11ONS OF THE MUTATIONAL SPF.C IFICI'IY OF DMS AND E7HYL ETHANESULFONATE
IN WILD-TYPE AND UmuC STRAINS . Maria Zieknaka, Janet Smylie, Jiso Iian Li and Barry W . Olickman .
Dept . of Biology. York llniversity, Toronto Canada M3J 1P3 .
In this study we have undertaken to examine how mutagenesis resulting from EMS and DMS is
influenced by the error-prone misrepair pathway of E. rofi . We Investigated the mutational specificity of
these alkylating agents by DNA sequencing and oligonucleotide probing methodologies In the first 180
base pairs of the Inrl gene of F. rnfi in wild-type and UmuC strains . Consistent with the established
alkylating ability of these agents, the O :C _> A :T transition dominated the resulting spedra . EMS
elicited an identical mutagenic response in the two strairo ; after treatment with 3mM KMS there was a
15-fold increase in mutation frequency at 57% survivaL Mutational specificity of EMS in the l1muC
background was identical to that found in the wild-type strain ; O:C - > A :T transitions accounted for
over 96% of the mutational events in each spectrum and their distribution was identical . DMS
mutagenicity decreased in the UmuC background from a 128-fold increase in mutation frequency at 14%
survival (wild-typel to a 26-fokl increase at 6O/o sunival. The influence of UmuC function was also
apparent at the DNA sequence level . In the wild-type background t3 :C - > A:T transitions accounted for
74% of the mutations, which were alan characterised by a significant contribution of additional
mutatiomd events including Ai r=- (hC' trnnsitkms, all classes of transverskms and framoshifu . In
eontrast, after DMS treatntent in a UmuC strain 82% of all mutational events were (t :C .• > A:T
transitions with a different site specificity from that recovered in the wild-type background. The other
claases of events found consisted of A :T => T :A and C; :C - > T:A tramversions, frameshUts and a
duplication. We conclude that mutagenesis by EMS Is independent of the UmuC function in contrast to
mutagenesis by 1)MS which shrn.s a marked Umu inhtence .
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DETERMINATION OF SPONTANEOUS AND ENU-INDUCED MUTANT FREQUENCIES IN
CYNOMOLOGOUS MONKEYS . D .M .Zimmer, C .S.Aaron, R .J .Albertini, and J .P.O'NeiII. The
Upjohn Co. and University of Vermont, USA .
We have undertaken a study of mutagenesis In primates (cynomologous monkeys) to
determine whether such an assay offers better means of risk assessment than currently
used in vitro and rodent tests. Using methods similar to those described by Albertini
(Mutat . Res. 150 (1985), 411-422J, mutation at the HPRT locus was monitored by
determining the ability of PHA stimulated peripheral T- lymphocytes to form clones In the
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