Environmental and Molecular Mutagenesis - Legacy Tobacco ...

'ne oencentromer c region of the Tchromosome : 011123. complementarv to a DNA sequence repeated 50 times in thee
penrentromenc region of chromosome 9 : pNlt}it, honwiogous to the N-Myc oncogene and specific for chromosome 1 in the
Neuroblastoma cell line LAN-1, wheWthe oncogene is amplified 50 times . /e situ hybridization experiments have been
cerrred out on human lymphocytes with Y97 and Op23 and on Neuroblastoma cell hnes with oNb19-21 . Preliminary
exper ments, performed on untreated cultures, to test the efficiency of the probes . showed an exceedingly high proportion of
hvpodiplo,d nuclei due to technical artifacts . Therefore hyperdiploiov has been taken as a reliable index of induced sneuploidv .
In order to check the validity of the assay we analyzed four known aneuploidy inducers, iumely fknomyl (8E), 6rieeofulvln
!nF 1 . Chloral hydrate (CH), Diethvlstiibestroi (DES) and a putative carcinogenic agent NitrilTnacebcAcid INTAI . A significant
increase in the percentage of hyperdiploid nuclei has been found with 8E . 6F, CH and DES ; a dose-related effect has been
revealed w,ti` CH and DES . NTA did not show any effect in the induction of aneuplmdv . To improve the efficiency of the method
we have compared the conventional aRO'f ddiographlc proCeDUre with that based on immunofluorescence . To this purpose
parallel experiments heve been carried out with radioactive and biotmvlated probes using DES as a test compound . The nonrIclioaCtlve
technique turned Out to be more sensitive and therefore more suitable for screening new compounds . The positive
response obtained with agents that induce chromosome number variation by different mechanisms of action indicates that the
rriethod we have devroloped may be of general application for testing aneuploidy Inducers is riua Moreover, the possibility of
scoring large cell samples makes interphase analysis suitable for tne cytogenetic monitoring of exposed populations .
595
APPRAISAL OF GENOTOXIC EFFECTS OF AGROCHEMICALS IN HIGHER PLANTS USING IN VIVO AND
IN VITRO END POINTS .
K .Vaidyanath and T .Suryakumari, Department of Genetics, Osmania University,
Hyderabad - 500 007 (A .P .) India .
The use of different agrochemicals to control diseases, pests and weeds is
an essential component of the modern agricultural technology . Though economic advantages
of such practice is appreciated, it is belived that exposure to agrochemicals
has many genetic consequences . To have a realistic appraisal of genotoxicity, three
commonly used Chemicals viz ., Ethylene dibromide, Phenyl mercury acetate and Ekalux,
have been studied using multiple end points like, somatic chromosomal aberrations,
heritable germinal mutations at specific and non-specific locus, and in vitro growth
of callus cultures . Significant frequency of chromosomal aberrations, -c-h1orophyll
deficient seedlings in M. generation, specific locus mutations at waxy locus
(Wx - wx), pollen sterility, polygenic variability in H3 generation and iphibition
of callus growth have been observed . The overall results of the study suggests that
any one or combination of genetic end points could be employed for the effective
screening of environmental mutagens .
596
ACRYLAMIDE-1NDUCED CHROMOSONE-T1iPE ABBRRAT'IONS IN SPERMiOGENIC STAGES EVALUATED
IN THE FIRST CLEAVAGE ME'1'AYHASES IN '1'Hh MOUSI : . N .Y . Vald>lvia, N .M . Lafuente and
M . Katoh, Fac . Odontoloqia, U . de Chile, bTGO (CHILIi) and Hatano Research Instztute,
F .D .S .C ., Kanagawa (JAPAN) .
Because of the evidences reported by Seqa, et al . (19`" Annual Meeting BMS) that acr7laaide (AA)
binding to protasine of speraioqenic stages in the souse appears to be correlated with the pattern
of genetic dasage oroduced by this cneaical in late speraatids and early speraatoza stages (Shelby,
et a1 ., 1986) cytogenatic evaluation of these sase sensitive stages was perforaed in sarlir cleavage
of souse eabryos . Adult sale M sice were intraperitoneally (i .p.) injected with 150 sq AA/kq and
aated to untreated fesales at intervals ranging fros 6 to 9 and 10 to 13 days after tratsent . The
plugged fesales sere i .p . injected with colchicine and the fert:lized ova were collected to the first
cleavage aitosis, at sich tiae the male chroaosou cosplesent su analyzed for strsctaral ohrosososal
da.age . The chroaosose-t)