Mutation Research, 29 (1975) 251-254 .D Elsevier Scientific Publishing Company, Amsterdam--Printed in The Netherlands
25I
39 GATTI, M., C. TANZARELLA,S. PIMPINELLI AND A. DE MARCO, Centro di Genetica Evoluzionistica del CNR, Istituto di Genetica, Rome (Italy)
Larval ganglia of Drosophila m. as a new test system for the study in vivo of induced chromosome aberrations With Drosophila m. it is now possible to use a series of quantitative procedures that enable nearly all types of genetic change to be noted. Point mutation, dominant and recessive lethal factors, chromosome aberrations, mitotic recombination, chromosome loss and non-disjunction are, in fact, types of damage that are readily detectable in this organism. Although m a n y studies have so far been carried out on induced chromosome rearrangements in the germ cells, there is no information on chromosome aberrations induced in somatic cells. Since somatic chromosome aberrations constitute the only type of genetic damage readily detectable in man, we feel that a study of somatic chromosome damage in Drosophila m. m a y serve to establish a useful model of correlation between the different types of damage (somatic and genetically transmittable) that can be induced in a given organism. For this reason we perfected a technique that enables good microscopic preparations to be obtained from larval ganglia of Drosophila. This system was tested with X-rays, and an extensive series of data has been collected on the type and frequency of the chromosome aberrations induced in various stages of the cell cycle. The small number oI chromosomes per cell and their easy recognition have made it possible to analyse the distribution of the aberrations among the chromosomes and on each individual chromosome. A difference of radio-sensitivity between the two sexes has also been observed (GATTI et al., Nature (London), in press), the damage found always being greater in females. Preliminary results obtained by using EMS and MMS as mutagens will also be reported. The data available to us, taken as a whole, indicate that the larval ganglia of Drosophila constitute a cell system that is highly suitable for studying induced chromosome aberrations in vivo. Moreover, the procedure required for it is fairly simple. Abbreviations: EMS. ethyl methanesulfonate; MMS. methyl methanesulfonate.
4O KRAMERS, P. G. N., AND A. G. A. C. KNAAP,Department of Radiation Genetics and Chemical Mutagenesis, University of Leiden, Leiden (The Netherlands)
Evaluation of the mutation spectrum induced by hycanthone in
Drosophila rnelanogaster; mutagenicity of hycanthone analogues In earlier work the antiscbistosomal agent hycanthone methanesulphonate (HMS) induced sex-linked recessive lethal mutations (late spermatids being the most sensitive stqge) but no I I - I I I translocations or dominant lethals (i.e. no chromosome breakage) (Mutation Res., 22 (1974) 55-62). Further results will be presented on four aspects.
252
4TH ANNUAI. MEETING, HEIDELBERG
(r) Chromosome breakage. To e x a m i n e whether the i n a b i l i t y ~l HMS t - induce c h r o m o s o m e b r e a k a g e as shown in previous e x p e r i m e n t s was al.~o true with respect to o t h e r b r e a k a g e events, we tested HMS for the induction of total a n d p a r t i a l sexchromosome loss. The t r e a t e d males carrmd a r i n g - X chromosome, a n d thrve differel~t t y p e s of female were used. A small b u t significaJ,t increase (nearly two-fold) of the incidence of t o t a l s e x - c h r o m o s o m e loss was found foc the HMS scrie.~. ( ' , , n t r a r v to w h a t these results would predict, p a r t i a l loss of the Y c h r o m o s o m e was riot increased. On the basis of these d a t a we c a n n o t exclude the possibility ~,f a \ ' e r r h,w lev,'¢ ~,f b r e a k a g e i n d u c t i o n b v HMS in Drosophila. (_~) Stage specifici(v. The highly specific sen:;itivitv ot late s p e r n m t i d s to thc illd u c t i o n of sex-linked recessive lethal m u t a t i o n s was a n a l y z e d using a m a t i n g scheme of 5 or 6 o n e - d a y broods. The results confirmed the incidence of a m a r k e d peak in the m u t a t i o n frequency on d a y 3 or 4 after injection. F u r t h e r , (a) in y o u n g males the l r e q u e n c y was 2-3 times higher t h a n in older one.~ a n d (b) s u b c u l t u r i n g the feluale~ after m a t i n g (storage of t h e sperm in the females) influenced the n m t a t i o n frequency. (3) Mechanism of mutation. It has been r e p o r t e d t h a t , in microorgani.mq, HMS acts as a frame-shift mutagen. Since the absence of t e m p e r a t u r e - s e n s i t i v e m u t a t i o n s (CARLSON el al. Genetzcs, 55 (Iq07) 295) can serve ,'ts a d e m o n s t r a t i . n of frame-shift n m t a t i o n s in Drosophila, a n u m b e r of H M S - i n d u c e d sex-linked recessive lethals were screened for t e m p e r a t u r e sensitivity. The results will be discussed. (4) Hvcanthone analogttes'. F o u r analogues of h y c a n t h o n e were tested tor t h e i r a b i l i t y to induce sex-linked recessive lethal m u t a t i o n s , in post-meiotic as well as in (pre)meiotic male germ cell stages. A p p l i c a t i o n of the c o m p o u n d s in doses at which HMS wa:s e v i d e n t l y n m t a g e n i c gave u m t a t i o n rates equal to ~r ~)ccasionallv higher t h a n control values. O n l y the indazole d e r i v a t i v e of l u c a n t h o n e increased the m u t a tion frequency just significantly, at the i°,, level. This work was s u p p o r t e d b v the N e t h e r l a n d s Ministry of Public H e a l t h a n d E n v i r o n m e n t a l Hygiene, a n d the U.S. National I n s t i t u t e ~f E n v i r o n m e n t a l H e a l t h Sciences, c o n t r a c t No. N I H 73-C-toIO. Abbreviation: HMS, hycarthone methane.~ulphonate.
41 MAGNVSSON, J., AND C. RAMEI., W a l l e n b e r g I . a b o r a t o r y , Lilla Frescati, .c,-IO4 O5 S t o c k h o h n 50 (Sweden).
A variation in toxicity of heavy metal compounds in different strains of
Drosophila melanogaster I n v e s t i g a t i o n s were m a d e to test differences in s e n s i t i v i t y to h e a v v m e t a l comp o u n d s between different wild t y p e strains of Drosophila mela.nog*aster, a n d w h e t h e r there is a n y correlation in the l e a c t i o n to different c o m p o u n d s between strains. The test c o m p o u n d s were m i x e d in the s u b s t r a t e in suitable concentrations, which were d e t e r m i n e d for each c o m p o u n d on the basis of t o x i c i t y tests with a series ~f concentrations. Twelve w i l d - t y p e strains were tested, a n d for each strain 2oo larvae were used d i v i d e d a m o n g 8 vials. The percentage of flies h a t c h i n g after the t r e a t m e n t was
25I
39 GATTI, M., C. TANZARELLA,S. PIMPINELLI AND A. DE MARCO, Centro di Genetica Evoluzionistica del CNR, Istituto di Genetica, Rome (Italy)
Larval ganglia of Drosophila m. as a new test system for the study in vivo of induced chromosome aberrations With Drosophila m. it is now possible to use a series of quantitative procedures that enable nearly all types of genetic change to be noted. Point mutation, dominant and recessive lethal factors, chromosome aberrations, mitotic recombination, chromosome loss and non-disjunction are, in fact, types of damage that are readily detectable in this organism. Although m a n y studies have so far been carried out on induced chromosome rearrangements in the germ cells, there is no information on chromosome aberrations induced in somatic cells. Since somatic chromosome aberrations constitute the only type of genetic damage readily detectable in man, we feel that a study of somatic chromosome damage in Drosophila m. m a y serve to establish a useful model of correlation between the different types of damage (somatic and genetically transmittable) that can be induced in a given organism. For this reason we perfected a technique that enables good microscopic preparations to be obtained from larval ganglia of Drosophila. This system was tested with X-rays, and an extensive series of data has been collected on the type and frequency of the chromosome aberrations induced in various stages of the cell cycle. The small number oI chromosomes per cell and their easy recognition have made it possible to analyse the distribution of the aberrations among the chromosomes and on each individual chromosome. A difference of radio-sensitivity between the two sexes has also been observed (GATTI et al., Nature (London), in press), the damage found always being greater in females. Preliminary results obtained by using EMS and MMS as mutagens will also be reported. The data available to us, taken as a whole, indicate that the larval ganglia of Drosophila constitute a cell system that is highly suitable for studying induced chromosome aberrations in vivo. Moreover, the procedure required for it is fairly simple. Abbreviations: EMS. ethyl methanesulfonate; MMS. methyl methanesulfonate.
4O KRAMERS, P. G. N., AND A. G. A. C. KNAAP,Department of Radiation Genetics and Chemical Mutagenesis, University of Leiden, Leiden (The Netherlands)
Evaluation of the mutation spectrum induced by hycanthone in
Drosophila rnelanogaster; mutagenicity of hycanthone analogues In earlier work the antiscbistosomal agent hycanthone methanesulphonate (HMS) induced sex-linked recessive lethal mutations (late spermatids being the most sensitive stqge) but no I I - I I I translocations or dominant lethals (i.e. no chromosome breakage) (Mutation Res., 22 (1974) 55-62). Further results will be presented on four aspects.
252
4TH ANNUAI. MEETING, HEIDELBERG
(r) Chromosome breakage. To e x a m i n e whether the i n a b i l i t y ~l HMS t - induce c h r o m o s o m e b r e a k a g e as shown in previous e x p e r i m e n t s was al.~o true with respect to o t h e r b r e a k a g e events, we tested HMS for the induction of total a n d p a r t i a l sexchromosome loss. The t r e a t e d males carrmd a r i n g - X chromosome, a n d thrve differel~t t y p e s of female were used. A small b u t significaJ,t increase (nearly two-fold) of the incidence of t o t a l s e x - c h r o m o s o m e loss was found foc the HMS scrie.~. ( ' , , n t r a r v to w h a t these results would predict, p a r t i a l loss of the Y c h r o m o s o m e was riot increased. On the basis of these d a t a we c a n n o t exclude the possibility ~,f a \ ' e r r h,w lev,'¢ ~,f b r e a k a g e i n d u c t i o n b v HMS in Drosophila. (_~) Stage specifici(v. The highly specific sen:;itivitv ot late s p e r n m t i d s to thc illd u c t i o n of sex-linked recessive lethal m u t a t i o n s was a n a l y z e d using a m a t i n g scheme of 5 or 6 o n e - d a y broods. The results confirmed the incidence of a m a r k e d peak in the m u t a t i o n frequency on d a y 3 or 4 after injection. F u r t h e r , (a) in y o u n g males the l r e q u e n c y was 2-3 times higher t h a n in older one.~ a n d (b) s u b c u l t u r i n g the feluale~ after m a t i n g (storage of t h e sperm in the females) influenced the n m t a t i o n frequency. (3) Mechanism of mutation. It has been r e p o r t e d t h a t , in microorgani.mq, HMS acts as a frame-shift mutagen. Since the absence of t e m p e r a t u r e - s e n s i t i v e m u t a t i o n s (CARLSON el al. Genetzcs, 55 (Iq07) 295) can serve ,'ts a d e m o n s t r a t i . n of frame-shift n m t a t i o n s in Drosophila, a n u m b e r of H M S - i n d u c e d sex-linked recessive lethals were screened for t e m p e r a t u r e sensitivity. The results will be discussed. (4) Hvcanthone analogttes'. F o u r analogues of h y c a n t h o n e were tested tor t h e i r a b i l i t y to induce sex-linked recessive lethal m u t a t i o n s , in post-meiotic as well as in (pre)meiotic male germ cell stages. A p p l i c a t i o n of the c o m p o u n d s in doses at which HMS wa:s e v i d e n t l y n m t a g e n i c gave u m t a t i o n rates equal to ~r ~)ccasionallv higher t h a n control values. O n l y the indazole d e r i v a t i v e of l u c a n t h o n e increased the m u t a tion frequency just significantly, at the i°,, level. This work was s u p p o r t e d b v the N e t h e r l a n d s Ministry of Public H e a l t h a n d E n v i r o n m e n t a l Hygiene, a n d the U.S. National I n s t i t u t e ~f E n v i r o n m e n t a l H e a l t h Sciences, c o n t r a c t No. N I H 73-C-toIO. Abbreviation: HMS, hycarthone methane.~ulphonate.
41 MAGNVSSON, J., AND C. RAMEI., W a l l e n b e r g I . a b o r a t o r y , Lilla Frescati, .c,-IO4 O5 S t o c k h o h n 50 (Sweden).
A variation in toxicity of heavy metal compounds in different strains of
Drosophila melanogaster I n v e s t i g a t i o n s were m a d e to test differences in s e n s i t i v i t y to h e a v v m e t a l comp o u n d s between different wild t y p e strains of Drosophila mela.nog*aster, a n d w h e t h e r there is a n y correlation in the l e a c t i o n to different c o m p o u n d s between strains. The test c o m p o u n d s were m i x e d in the s u b s t r a t e in suitable concentrations, which were d e t e r m i n e d for each c o m p o u n d on the basis of t o x i c i t y tests with a series ~f concentrations. Twelve w i l d - t y p e strains were tested, a n d for each strain 2oo larvae were used d i v i d e d a m o n g 8 vials. The percentage of flies h a t c h i n g after the t r e a t m e n t was
