Environmental and Molecular Mutagenesis - Legacy Tobacco ...

277 1989 EMS Abstracts 97
Notes
DEVELOPMENT OF A SENSITIVE HUMAN EPITHELIAL CELL LINE FOR MUTAGEN SCREENING . Y .S .
Jou, C .C . Chang, and J .E . Trosko, Department of Pediatrics and Human Development,
Michigan State University, East Lansing, MI 48824 .
An ideal assay for human mutagens should be relevant (related to mutations in human
cells), sensitive (able to detect low-dose mutagens) and informative (revealing genetic
alterations at the molecular level) . Toward developing a cell line with these attributes,
we have reactivated the hypoxanthine-guanine phosphoribosyl transferase
(HGPRT) gene on an inactive x-chromosome by 5-azacytidine treatment in a 6-TGr human
teratocarcinoma cell line (46 ch . ; xx ; t 15/20) . In contrast to the normal human cell
line, the reactivated HGPRT gene is on a non-essential x-chromosome . Therefore, deletions
or mutations of essential genes on the non-essential chromosome associated with
the HGPRT gene mutation would not affect the survival of a 6-TGr mutant . After exposure
to mutagnes, a higher frequency of induced 6-TGr mutants would be expected . After
treatment with 5-azacytidine, HATr colonies were readily recovered . Most of these
clones are revertible to 6-TGr cells at hi gh frequency . Few stable clones, however,
were also recovered . Our preliminary studies using one of these stable clones indicate
that the cell line had a 50-100 fold increase in x-ray induced 6-TGr mutant compared
to the parental HATr cell line . In conjunction with molecular analysis using
polymerase chain reaction amplification and DNA sequencing techniques, the cell line
might become an ideal assay for human mutagens . (Research supported by a NCI grant
CA21104-11) .
278
A CYTOGENcTIC STUDY ON SUBJECTS PRESENTING AIENORRNEA . STERILITY AND RPROOUCTIVE FAILURE .
A . Jvothv, G .S . Isaec, A,Shobhe Rani . C. Kususa Kumeri and P.P .Raddv .
Institute of Genetics . Hospital for Genetic Diseases . Owanie Universitv, Beouaoet . Hvderebad-S00 016.
A .P . India. '
A B s T R A C T
Chromosoae analysis plays a vital rola in spaculatinq the etioloqY of cases presanting s .enorrhsa . ster!-
litv and reproductive failure . The present study is tharsfore aieedrto lnvestipate the role and distribution
of chromosose abnormalities in causing thssa conditions . A total of 1575 twale subjects presenting
enenorrhea . sterility and reproductive fsilure usre investigated for .chrososae abnormalities . These
include cases of primary awenorrhea (37S) secondary wenorrhw ( 100), sterility (75) and reproductive
failure ( 325) .
The subjects were thoroughly examinsd and the history of the patient and her family rera recorded . Chroaosae
preparations wre ∎ade according to the ∎odified ∎sthod of Moorhead atal (1960 ) and banded
according to Seabright (1971) . Other staining techniques (CBG), Ag NOR etc .) wre employed wherever
necessary . The typs of abnormalities detected include 45X ; 4SX/46XX ; 45X/46XY; 43X/47X)0(i 4V/46X, frsgi
45X/46XX/46XY ; 46XX/46 XY ; 4SX/46xx/47XXX ; 46XY ( Phenotypic females) ; 47xXX ; 46XX, 13 p and 46 XX,
16p* The abnormalities ldentified suggest the need for routine chrososose survey among patients with
the above clinical syapta s . These studies will help !n the accurate diagnosis and eanapesent of such
clinical entities .
279
BOTRAN AND BLEOMYCIN INDUCED CROSSING OVER AND ANEUPLOIDY IN ASPERGILLUS NIDULANS
WHICH RESULTS IN DIFFERENT PATTERNS OF MITOTIC SEGRECANTS . E . Kifer, Department of
Biology, McGill University, 1205 Dr . Penfiald Ave ., Montreal, P .Q . Canada H3A 151 .
Botran and bleomycin reduce growth and increase mitotic segregation of recessive
colour markers in diploid heterozygous tester strains of Aspergillus . In both cases,
segregants are mainly diploid crossovers and haploids . The latter were especially
frequent on botran media, and at low concentration aneuploids, mainly disomics for
chromosome III, also formed discernible patches of coloured conidia . In addition,
diploid segregants showed high levels of coincidence of crossing over, segregation in
three or even four chromosome arms being not uncommon . On the other hand, treatment
of germinating conidia which were plated onto complete medium resulted in few large
crossover sectors but produced abnormal colonies in both cases . With increasing
concentrations of bleomycin, these were especially evident, increasing from 25 to 75%
among survivors . On replating, up to two thirds of them could be identified as
aneuploids, the majority being genuine trisomics . These results suggest that both
botran and bleomycin induce crossing over and malsegregation . (Supported by
Strategic Grant 0032242 from the Natural Science and Engineering Research Council of
Canada) .
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