Further observations on the nature of radiation-induced chromosomal interchanges recovered from Drosophila sperm

Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 847-855 ◽  
Author(s):  
Daniel F. Eberl ◽  
Arthur J. Hilliker ◽  
Cecil B. Sharp ◽  
Silvija N. Trusis-Coulter
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosomal Rearrangements ◽  
Strong Tendency ◽  
Chromosome 3 ◽  
Chromosome 2 ◽  
Mitotic Metaphase ◽  
Genetic Approach ◽  
Intercalary Heterochromatin ◽  
Chromosome Breaks ◽  
Radiation Induced

The induction and analysis of numerous translocations (identified genetically and characterized cytologically) between chromosomes 2 and 3 of Drosophila melanogaster have allowed us to reexamine three issues concerning the nature of radiation-induced interchanges in spermatozoa. First, our results support the idea that, relative to their mitotic metaphase length, all major chromosomal regions are similar in their breakability, whether euchromatic (proximal or distal) or heterochromatic. Second, analysis of all our reciprocal exchanges between the two chromosomes shows a statistically significant dependence of the position of the chromosome 2 breakpoint on that of the chromosome 3 breakpoint. Thirdly, our combined cytological and genetic approach strengthens the results of previous analyses, which suggested a strong tendency for chromosomal interchanges to be of the reciprocal type in multiple-break rearrangements. This indicates that if radiation induces chromosome breaks, then the resulting broken ends tend to rejoin in pairs rather than independently.Key words: Drosophila melanogaster, radiation mutagenesis, chromosomal rearrangements, heterochromatin, intercalary heterochromatin.

scholarly journals POST-TRANSLATIONAL MODIFICATION OF XANTHINE DEHYDROGENASE IN A NATURAL POPULATION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1981 ◽  
Vol 98 (4) ◽  
pp. 817-831
Author(s):  
George Johnson ◽  
Victoria Finnerty ◽  
Daniel Hartl
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Aldehyde Oxidase ◽  
Xanthine Dehydrogenase ◽  
Chromosome 3 ◽  
Chromosome 2 ◽  
Structural Genes ◽  
Post Translational Modification ◽  
Polymorphic Loci

ABSTRACT Second chromosomes of D. melanogaster were isolated from a single natural population, and 40 were analyzed by gel-sieving electrophoresis for the presence of polymorphic loci on chromosome 2 that act to modify xanthine dehydrogenase and/or aldehyde oxidase, whose structural genes map to chromosome 3. Clear evidence of polymorphism for one or more xanthine dehydrogenase modifier loci was obtained.

scholarly journals POSITION EFFECTS AT THE HAIRY LOCUS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1979 ◽  
Vol 91 (1) ◽  
pp. 105-125
Author(s):  
Duane E Jeffery
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosomal Rearrangements ◽  
Position Effect ◽  
Position Effects ◽  
Apparent Position ◽  
Clear Cut ◽  
Complex Interactions ◽  
Suppressor Effect ◽  
Radiation Induced ◽  
Polygenic System

ABSTRACT Radiation-induced chromosomal rearrangements of h+ have given rise to several Drosophila stocks that exhibit apparent position-effect inactivation; i.e., flies carrying the rearranged chromosomes heterozygously with h show varying degrees of hairiness. The numbers of hairy chaetae produce a quantifiable index of position effect. Six such "position-allele'' stocks are here discussed, both as to their basic expressions and in all possible pair-wise combinations with each other. Such crosses reveal complex interactions between the respective position alleles; little evidence is seen for clear-cut dominance or recessiveness. The stocks appear not to conform unequivocally to classical distinctions between variegated and stable types of position effects, nor to usual dicta relating the degree of inactivity to the proximity to heterochromatin. Indeed, these stocks appear to suggest additional dimensions to several of the principles to which position effects usually subscribe. The evidence additionally suggests that the hairy locus itself is associated with a tissue-specific suppressor effect on an otherwise polygenic system that produces the chaetae associated with the hairy phenotype.

scholarly journals Major Chromosomal Rearrangements Induced by T-DNA Transformation in Arabidopsis

Genetics ◽  
1998 ◽  
Vol 149 (2) ◽  
pp. 641-650 ◽  
Author(s):  
Philippe Nacry ◽  
Christine Camilleri ◽  
Béatrice Courtial ◽  
Michel Caboche ◽  
David Bouchez
Keyword(s):  
Chromosomal Rearrangements ◽  
The Other ◽  
Chromosome 3 ◽  
Head Orientation ◽  
Dna Transformation ◽  
Chromosome 2 ◽  
Dna Integration ◽  
Dna Insertion ◽  
Insertion Sites ◽  
Flanking Regions

Abstract We show that major chromosomal rearrangements can occur upon T-DNA transformation of Arabidopsis thaliana. In the ACL4 line, two T-DNA insertion loci were found; one is a tandem T-DNA insert in a head-to-head orientation, and the other is a truncated insert with only the left part of the T-region. The four flanking DNA regions were isolated and located on the Arabidopsis chromosomes; for both inserts, one side of the T-DNA maps to chromosome 2, whereas the other side maps to chromosome 3. Both chromosome 3 flanking regions map to the same location, despite a 1.4-kb deletion at this point, whereas chromosome 2 flanking regions are located 40 cM apart on the bottom arm of chromosome 2. These results strongly suggest a reciprocal translocation between chromosomes 2 and 3, with the breakpoints located at the T-DNA insertion sites. The interchanged fragments roughly correspond to the 20-cM distal ends of both chromosomes. Moreover, a large inversion, spanning 40 cM on the genetic map, occurs on the bottom arm of chromosome 2. This was confirmed by genetic analyses that demonstrated a strong reduction of recombination in the inverted region. Models for T-DNA integration and the consequences for T-DNA tagging are discussed in light of these results.

FURTHER CHARACTERIZATION OF GENETIC ELEMENTS ASSOCIATED WITH THE SEGREGATION DISTORTER PHENOMENON IN DROSOPHILA MELANOGASTER

Genetics ◽  
1985 ◽  
Vol 110 (4) ◽  
pp. 671-688
Author(s):  
Cecil B Sharp ◽  
Arthur J Hilliker ◽  
David G Holm
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome 2 ◽  
Major Focus ◽  
Genetic Components ◽  
Segregation Distorter ◽  
Crossover Analysis ◽  
Radiation Induced ◽  
Definition Of ◽  
The Right

ABSTRACT Segregation Distorter, SD, associated with the second chromosome of Drosophila melanogaster, is known to cause sperm bearing the non-SD homologue to dysfunction in heterozygous males. In earlier studies, using different, independently derived, SD chromosomes, three major loci were identified as contributing to the distortion of segregation ratios in males. In this study the genetic components of the SD-5 chromosome have been the subjects of further investigation, and our findings offer the following information. Crossover analysis confirms the mapping of the Sd locus to a position distal to but closely linked with the genetic marker pr. Spontaneous and radiation-induced recombinational analyses and deficiency studies provide firm support to the notion that the Rsp(Responder) locus lies within the proximal heterochromatin of chromosome 2, between the genetic markers lt and rl and most likely in the heterochromatin of the right arm. The major focus of this study, however, has been on providing a better definition of the genetic properties of the Enhancer of SD [E(SD)]. Our findings place this locus within the region of the two most proximal essential genes in the heterochromatin of the left arm of chromosome 2. Moreover, our analysis reveals a probable association of the E(SD) locus with a meiotic drive independent of that caused by Sd.

Genes controlling malathion resistance in a laboratory-selected population of Drosophila melanogaster

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 844-853 ◽  
Author(s):  
D. R. Houpt ◽  
J. C. Pursey ◽  
R. A. Morton
Keyword(s):  
Drosophila Melanogaster ◽  
Oxidase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chromosome 3 ◽  
Population Exposure ◽  
Relative Molecular Mass ◽  
Chromosome 2 ◽  
Mixed Function Oxidase ◽  
Cytochrome P 450 ◽  
Mixed Function Oxidase Activity

The chromosomal locations of several genes responsible for increased malathion resistance in a laboratory-selected population of Drosophila melanogaster have been determined. These genes appear to be involved in the regulation of microsomal cytochrome P-450. A major gene on chromosome 2 (2-64) and at least two genes on chromosome 3 (near 3-58) control increased mixed function oxidase activity, and both larval and adult malathion resistance. Although the chromosome 2 locus was not associated with a significant increase in cytochrome P-450 content, SDS polyacrylamide gel electrophoresis of microsomal proteins detected increased silver staining of a polypeptide having a relative molecular mass (Mr) of about 52 000. Microsomes from strains carrying the chromosome 3 factors for resistance contained more cytochrome P-450 and increased amounts of two heme-staining protein bands (Mr = 50 000 and 54 000). The genes regulating these proteins were closely linked to striped at 3-62 and probably identical to the loci responsible for malathion resistance and increased mixed function oxidase activity. Other R genes on both chromosomes 2 and 3 as well as target resistance were required for the full expression of malathion resistance in the selected Drosophila population. Exposure of this Drosophila melanogaster population to malathion selected a polygenic system for the oxidative metabolism of insecticide.Key words: insecticide resistance, mixed-function oxidase, cytochrome P-450, Drosophila melanogaster.

scholarly journals Chromosome breakage by pairs of closely linked transposable elements of the Ac-Ds family in maize.

Genetics ◽  
1991 ◽  
Vol 129 (3) ◽  
pp. 855-862 ◽  
Author(s):  
H K Dooner ◽  
A Belachew
Keyword(s):  
Transposable Elements ◽  
Chromosomal Rearrangements ◽  
Chromosome Breakage ◽  
Endosperm Development ◽  
Strong Tendency ◽  
Chromosome Breaks ◽  
Chromosome Breaking ◽  
Ac Transposition

Abstract Chromosome breaks and hence chromosomal rearrangements often occur in maize stocks harboring transposable elements (TEs), yet it is not clear what types of TE structures promote breakage. We have shown previously that chromosomes containing a complex transposon structure consisting of an Ac (Activator) element closely linked in direct orientation to a terminally deleted or fractured Ac (fAc) element have a strong tendency to break during endosperm development. Here we show that pairs of closely linked transposons with intact ends, either two Ac elements--a common product of Ac transposition--or an Ac and a Ds (Dissociation) element, can constitute chromosome-breaking structures, and that the frequency of breakage is inversely related to intertransposon distance. Similar structures may also be implicated in chromosome breaks in other eukaryotic TE systems known to produce chromosomal rearrangements. The present findings are discussed in light of a model of chromosome breakage that is based on the transposition of a partially replicated macrotransposon delimited by the outside ends of the two linked TEs.

scholarly journals CYTOGENETIC LOCALIZATION OF THE ACID PHOSPHATASE-1 GENE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1978 ◽  
Vol 88 (3) ◽  
pp. 487-497
Author(s):  
William J Morrison ◽  
Ross J MacIntyre
Keyword(s):  
Drosophila Melanogaster ◽  
Acid Phosphatase ◽  
Y Chromosome ◽  
Chromosomal Rearrangements ◽  
Position Effect ◽  
Chromosome 3 ◽  
Position Effect Variegation ◽  
Effect Variegation

ABSTRACT A translocation in which a segment of chromosome 3 is inserted into the Y chromosome was found to contain the acid phosphatase-1 gene (Acph-1). In flies hyperploid for that gene, acid phosphatase-1 levels are proportional to the dose of the gene. The locus is placed within the salivary chromosome subdivisions 99D and 99E on the basis of its inclusion in the translocated segment and on the previous placement of the claret locus. Several chromosomal rearrangements involving heterochromatic breakpoints and euchromatic breakpoints adjacent to 99D-99E were tested for possible position-effect variegation of acid phosphatase-1. No decrease in the synthesis of the electrophoretic subunit encoded by the relocated gene was observed within any of the rearrangements.

scholarly journals Genetic Analysis of the Heterochromatin of Chromosome 3 in Drosophila Melanogaster. II. Vital Loci Identified through Ems Mutagenesis.

Genetics ◽  
1988 ◽  
Vol 120 (2) ◽  
pp. 519-532
Author(s):  
G E Marchant ◽  
D G Holm
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Single Copy ◽  
Chromosome 3 ◽  
Temperature Sensitive ◽  
Chromosome 2 ◽  
Complementation Groups ◽  
Sensitive Allele ◽  
Interallelic Complementation ◽  
The Right

Abstract Chromosome 3 of Drosophila melanogaster contains the last major blocks of heterochromatin in this species to be genetically analyzed. Deficiencies of heterochromatin generated through the detachment of compound-3 chromosomes revealed the presence of vital loci in the heterochromatin of chromosome 3, but an extensive complementation analysis with various combinations of lethal and nonlethal detachment products gave no evidence of tandemly repeated vital genes in this region. These findings indicate that the heterochromatin of chromosome 3 is genetically similar to that of chromosome 2. A more thorough genetic analysis of the heterochromatic regions has been carried out using the chemical mutagen ethyl methanesulfonate (EMS). Seventy-five EMS-induced lethals allelic to loci uncovered by detachment-product deficiencies were recovered and tested for complementation. In total, 12 complementation groups were identified, ten in the heterochromatin to the left of the centromere and two to the right. All but two complementation groups in the left heterochromatic block could be identified as separate loci through deficiency mapping. The interallelic complementation observed between some EMS-induced lethals, as well as the recovery of a temperature-sensitive allele for each of the two loci, provided further evidence that single-copy, transcribed vital genes reside in the heterochromatin of chromosome 3. Cytological analysis of three detachment-product deficiencies provided evidence that at least some of the genes uncovered in this study are located in the most distal segments of the heterochromatin in both arms. This study provides a detailed genetic analysis of chromosome 3 heterochromatin and offers further information on the genetic nature and heterogeneity of Drosophila heterochromatin.

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