Body-weight and chromosome aberrations induced by X-rays in somatic cells of Drosophila melanogaster

1976 ◽  
Vol 146 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Antonio De Marco ◽  
Maria Pia Belloni
Keyword(s):  
Body Weight ◽  
Drosophila Melanogaster ◽  
Chromosome Aberrations ◽  
Somatic Cells ◽  
X Rays

scholarly journals ANALYSIS OF THE CHROMOSOME ABERRATIONS INDUCED BY X-RAYS IN SOMATIC CELLS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1974 ◽  
Vol 77 (4) ◽  
pp. 701-719
Author(s):  
M Gatti ◽  
C Tanzarella ◽  
G Olivieri
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome Aberrations ◽  
High Frequency ◽  
Low Frequency ◽  
X Rays ◽  
Somatic Pairing ◽  
Chromatid Aberrations ◽  
Radio Sensitivity ◽  
Two Peaks ◽  
Chromatid Exchanges

ABSTRACT A technique has been perfected for enabling good microscope preparations to be obtained from the larval ganglia of Drosophila melanogaster. This system was then tested with X-rays and an extensive series of data was obtained on the chromosome aberrations induced in the various stages of the cell cycle.—The analysis of the results obtained offers the following points of interest: (1) There exists a difference in radio-sensitivity between the two sexes. The females constantly display a greater frequency of both chromosome and chromatid aberrations. They also display a greater frequency of spontaneous aberrations. (2) In both sexes the overall chromosome damage is greater in cells irradiated in stages G2 and G1. These two peaks of greater radiosensitivity are produced by a high frequency of terminal deletions and chromatid exchanges and by a high frequency of dicentrics, respectively. (3) The aberrations are not distributed at random among the various chromosomes. On the average, the Y chromosome is found to be more resistant and the breaks are preferentially localized in the pericentromeric heterochromatin of the X chromosome and of the autosomes. (4) Somatic pairing influences the frequency and type of the chromosome aberrations induced. In this system, such an arrangement of the chromosomes results in a high frequency of exchanges and dicentrics between homologous chromosomes and a low frequency of scorable translocations. Moreover, somatic pairing, probably by preventing the formation of looped regions in the interphase chromosomes, results in the almost total absence of intrachanges at both chromosome and chromatid level.

scholarly journals MUTAGEN SPECIFICITY IN THE INDUCTION OF CHROMOSOMAL ABERRATIONS IN SOMATIC CELLS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1977 ◽  
Vol 85 (2) ◽  
pp. 249-257
Author(s):  
S Pimpinelli ◽  
D Pignone ◽  
G Santini ◽  
M Gatti ◽  
G Olivieri
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Chromosomal Aberrations ◽  
Somatic Cells ◽  
X Rays ◽  
Aberration Frequency ◽  
Mutagen Specificity ◽  
Methane Sulphonate

ABSTRACT The distribution of chromosomal aberrations between and within chromosomes of male D. melanogaster somatic cells after treatment with UV has been analyzed.—Distribution of the breaks between chromosomes was largely nonrandom since we found a higher aberration frequency than that expected on the Y chromosome. Moreover, within the chromosomes the aberrations are clustered in the pericentromeric heterochromatic regions. The above distribution is compared with that of the breaks induced by X rays and methyl-methane-sulphonate (MMS) which were distributed in a different pattern.

scholarly journals THE INTERCELLULAR DISTRIBUTION OF MUTATIONS INDUCED IN OOCYTES OF DROSOPHILA MELANOGASTER BY CHEMICAL AND PHYSICAL MUTAGENS

Genetics ◽  
1979 ◽  
Vol 92 (1) ◽  
pp. 151-160
Author(s):  
H Traut
Keyword(s):  
Drosophila Melanogaster ◽  
Mitomycin C ◽  
Mutation Frequency ◽  
Lethal Mutation ◽  
X Rays ◽  
Mutagenic Treatment ◽  
X Chromosomes ◽  
Recessive Lethal ◽  
Lethal Mutations ◽  
X Irradiation

ABSTRACT When females of Drosophila melanogaster are treated with chemical or physical mutagens, not only in one but also in both of the two homologous X chromosomes of a given oocyte, a recessive sex-linked lethal mutation may be induced. A method is described that discriminates between such "single" and "double mutations." A theory is developed to show how a comparison between the expected and the observed frequency of double mutations yields an indication of the intercellular distribution (random or nonrandom) of recessive lethal mutations induced by mutagenic agents in oocytes and, consequently, of the distribution (homogeneous or nonhomogeneous) of those agents.—Three agents were tested: FUdR (12.5, 50.0 and 81.0,μg/ml), mitomycin C (130.0 μg/ml) and X rays (2000 R, 150 kV). After FUdR feeding, no increase in the mutation frequency usually observed in D. melanogaster without mutagenic treatment was obtained (u=0.13%, namely three single mutations among 2332 chromosomes tested). After mitomycin C feeding, 104. single and three double mutations were obtained. All of the 50 mutations observed after X irradiation were single mutations. The results obtained in the mitomycin C and radiation experiments favor the assumption of a random intercellular distribution of recessive lethal mutations induced by these two agents in oocytes of D. melanogaster. Reasons are discussed why for other types of mutagenic agents nonrandom distributions may be observed with our technique.

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