Environmental and Molecular Mutagenesis - Legacy Tobacco ...

136 1989 EMS Abstracts
Notes based descriptors that focus on details of the molecular structures . The descriptors were analyzed
statistically in order to develop a minimal set to characterize the compounds . Pattern recognition
techniques were used to classify the compounds as active or inactive based on the structural
descriptors. A training set of 80 compounds (40 active and 40 inactive) was classified almost perfectly
using 15 descriptors, and the remaining compounds formed a prediction set of unknowns . Studies in
progress are aimed at refining our SAR model for PAH mutagenicity .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
CLONING ILLID PARTIAL C11WCP6RIZATION OF RftE H(A7)1N IXCISION RLPAIR GENB ERCC-5 .
J .S . Mudgett, G .F . Strniste, and ri .A. MacInnes, Genetics Group, LS-3, M886, Los
A,lamos National Laboratory, Los Alamos, t39 87545 (iJSA) .
The human excision repair gene DtCC-5 was identified and isolated by complementation
of the W-sensitive Chiness hamster ovary cell mtutant UV-135 and
subsequent cosmid library construction and analysis . Genomic DtA from repair
proficient human skin fibroblasts was ligated to pSV2gpt and transferred into
W-sensitive Ctq cells of complementation group 5(W-135) . DNA from a primary
MAX (aycophenolic acid, adenine, xanthine) resistant, W-resistant cell line was
transferred into W-135 cells to isolate a secondary Mhe, W cell line, from
which tertiary MaX`, i)V' cell lines were isolated by gene transfer . Cotuid
clones which contained inserted human sequences wsre obtained from a 20X genumic
library of the secondary transformant . None of thse individual (101) cosmid
clones isolated and tested were able to ca .plement the repair defect, but
specific overlapping pairs of cosmids co-transfected into UV-135 cells yielded
transformnnts at high frequency which exhibited wild-type W resistance, suggestit~g
that the repair gene is as large or greater than the cosmid insert size
(-40 kb) . The overlap between the appropriate cosmid clones, and the coaplete
contiguous human genomic insert, will be napped to identify the sise and functional
boundaries of the human nNA repair gene . Unique huswt sequence probes
derived from these specific cosmid clones were used to : 1) demonstrate a positive
hybridization correlation with genomic tx4A from independent UV-resistant
transformants and human cell hybrids ; 2) to confirm the previous assignment of
ERCC-5 on chromosome 13 ; and 3) to screen c0Nuh libraries . (Supported by the
U .S . Department of Snerqy under c^ntract W-7405-lN".-36)
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IN VIVO GENOTOXICITY OF TERTIARY BUTYL HYDROQUINONE IN GERM CELLS OP MALB
NICE . A . Mukher,)ee and A . Sharma, Centre for Advanced Study in Cell and Chromosome
Research, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road,
Calcutta 700 019 (INDIA)
Effect of tertiary butyl hydroQuinone (doses of 10, 20 and 100 mg/kg/day during
14 days) on germ cells of male mice were investigated . The mode of application was
stomach intubation . The germ cell stages analysed were spermatids (for the heritable
effects) and differentiating and stem-cell spermatogonia (for direct effects) . A lack
of heritable translocations, sperm abnormalities was demonstrated in F males originating
from treated P males . Significant effects in treated males were found with respect
to . (1) sex-chromosomal univalency in the diakinesis-metaphase I stage after the
treatment of stem spermatogonia, (2) sperm-head abnormalities after treatment of
differentiating spermatogonia and (3) fertility after treatment of spermatids .
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MICRONUCLEI INDUCED BY TERTIARY BUTYL HYDROQUINONE (AN ANTIOXIDANT) IN BONE MARROW
CELLS OF MICE . Anita Mukherjee . Human Genetics Unit, Centre for Advanced Study
in Cell and Chromosome Research, Department of Botany, University of Calcutta,
35 Ballygunge Circular Road, Calcutta 700 019 . India .
Tertiary butyl hydroquinone (TBHQ) a phenolic antioxidant was administered to
Swiss albino male mice of 20, 50, 100 and 200 mg/kg as a single (i .p .) injection .
Corn oil and cyclophosphamide were used as the vehicle (negative) and reference
(positive) control respectively . Samples of bone marrow were examined for the
incidence of micronuclei in the poiychromatie erythrocytes at 24 hours after dosing .
A positive dose response effect in the micronuclei freQuency was observed following
the Cochran Armitage Trend Test . 50, 100 and 200 mg/kg of TBHQ caused an increase
in the incidence of micronuclei compared to the negative vehicle control . Cycl,ophoephamide
caused a significant increase in the incidence of micronuclei .
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