scholarly journals The relationship between P elements and male recombination in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 124 (2) ◽  
pp. 317-329
Author(s):  
A Duttaroy ◽  
M McCarron ◽  
K Sitaraman ◽  
G Doughty ◽  
A Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Hot Spot ◽  
The Other ◽  
P Element ◽  
Male Recombination ◽  
P Elements ◽  
Selective System ◽  
Element Mobilization ◽  
The Relationship ◽  
Initial Binding

Abstract P element dysgenesis associated male recombination in Drosophila was examined with a selective system focused upon 5% of the standard female genetic map divided into eight recombination segments. We found no correspondence between P element mobilization events and recombination in males in the intervals monitored. We defined two adjacent short genetic and molecular regions, one devoid of male recombination and the other acting as a "hot spot" for exchange in the absence of supporting P element insertion and excision activity. These data suggest that, even in the presence of mobilizing P elements, transposase may be active at non-P element sites, and that the genome may harbor sequences ranging from highly responsive to completely unresponsive to transposase action. A viewpoint is presented wherein P elements, with sequences that bind transposase, serve to focus the recombination action of transposase to encompass a region of DNA radiating outward from the initial binding site. We suggest that this region is measured in terms of chromosomal segments rather than limited to P element sequences.

scholarly journals P-element-induced control mutations at the r gene of Drosophila melanogaster.

1985 ◽  
Vol 5 (10) ◽  
pp. 2567-2574 ◽  
Author(s):  
S Tsubota ◽  
M Ashburner ◽  
P Schedl
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
P Element ◽  
Female Sterility ◽  
R Gene ◽  
Temporal Expression ◽  
Base Pairs ◽  
P Elements ◽  
Adult Females ◽  
Regulatory Mutations

The P-M hybrid dysgenesis system was used to produce five putative regulatory mutations at the rudimentary locus, r. All five mutations were the result of insertions at the 5' end of the gene, upstream of the proposed start of transcription. All of the mutants displayed a leaky wing phenotype, and four of the mutants showed an uncoupling of the wing and female-sterility phenotypes, suggesting that they altered the normal spatial and temporal expression of the r gene. Four of the insertions were P elements. The fifth insertion, which was larger than an intact P element, consisted of a small P element connected to non-P-element DNA. Two of the mutants produced very little r transcript in adult females and were clustered 80 to 150 base pairs upstream of the start of transcription. The other three mutants had higher levels of r transcript in adult females and were clustered 440 to 500 base pairs upstream of the start of transcription. All of the data suggest that the insertions are in a 5' noncoding region of the r gene involved in the control of its spatial and temporal expression.

scholarly journals Chromosome interactions in P-M dysgenic male recombination of Drosophila melanogaster

1992 ◽  
Vol 60 (3) ◽  
pp. 165-174
Author(s):  
P. Eggleston ◽  
K. A. Exley
Keyword(s):  
Drosophila Melanogaster ◽  
Recombination Breakpoint ◽  
P Element ◽  
Chromosome 2 ◽  
Male Recombination ◽  
P Elements ◽  
Element Array ◽  
Recombination Breakpoints ◽  
Map Distance

SummaryThe frequency, distribution and structure of P elements on the second and third chromosomes of Texas 1, a wild-type inbred strain of Drosophila melanogaster, were investigated by in situ hybridization. These autosomes were isolated individually and used as P-element donors to study the frequency and distribution of male recombination events generated on recipient chromosomes which were originally devoid of P sequences. The P-element array of chromosome 2 was shown to generate higher male recombination frequencies on chromosome 3 than vice versa, despite having fewer P factors and fewer P elements in general. This is likely to be due to the presence and distribution of specific P-deletion derivatives, which vary in their ability to repress P mobility. The male recombination generated on recipient chromosomes is associated with the insertion of donated P sequences, but only in a small minority of cases could a novel P-element site be detected at, or near, the recombination breakpoint. The majority of such breakpoints appear to be associated either with unsuccessful P insertion, or with the action of P transposase attracted by P elements newly inserted elsewhere on the recipient chromosome. Recent evidence also suggests that a small proportion of the breakpoints may be associated with the action of P transposase alone. Male recombination breakpoints appear to be distributed effectively at random along the recipient autosomes, and their frequency of occurrence was shown to correlate with the physical length of DNA available between markers, as revealed by the polytene map distance.

scholarly journals Germ-line and somatic recombination induced by in vitro modified P elements in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 124 (2) ◽  
pp. 331-337 ◽  
Author(s):  
J A Sved ◽  
W B Eggleston ◽  
W R Engels
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Somatic Cells ◽  
Chromosome Breakage ◽  
P Element ◽  
Male Germ Line ◽  
Male Recombination ◽  
P Elements ◽  
Somatic Recombination

Abstract The P element insertion delta 2-3(99B) has previously been shown to activate incomplete P elements elsewhere in the genome. We show that this element, in conjunction with a second incomplete P element, P[CaSpeR], also induces recombination in the male germ line. The recombination is induced preferentially in the region of the P[CaSpeR] element. Recombinant chromosomes contain the P[CaSpeR] element in more than 50% of cases, and alternative models of transposon replication and preferential chromosome breakage are put forward to explain this finding. As is the case with male recombination induced by P-M dysgenic crosses, recombination appears to be premeiotic in a high proportion of cases. The delta 2-3(99B) element is known to act in somatic cells. Correspondingly, we show that the delta 2-3(99B)-P[CaSpeR] combination elevates the incidence of somatic recombination.

scholarly journals Genetic Transformation of Drosophila melanogaster with an Autonomous P Element: Phenotypic and Molecular Analyses of Long-Established Transformed Lines

Genetics ◽  
1987 ◽  
Vol 115 (4) ◽  
pp. 711-723
Author(s):  
Stephen B Daniels ◽  
Stephen H Clark ◽  
Margaret G Kidwell ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
P Element ◽  
Stable Configuration ◽  
Phenotypic Properties ◽  
Molecular Analyses ◽  
P Elements ◽  
Regulatory Ability ◽  
Rate Of Increase

ABSTRACT Following transformation of a Drosophila melanogaster true M strain with an autonomous P element, six lines were established and monitored for their molecular and phenotypic properties during a 4-yr period. The number of P elements increased with time in all the lines but the rate of increase differed among lines. Furthermore, degenerate elements arose in each of the lines during propagation. By the end of the 4th yr, the total number of elements in every line was similar to that of a very strong P strain.—At the phenotypic level, all of the transformed lines evolved high P activity, but only three developed complete or nearly complete regulatory ability. The other three lines attained only intermediate levels of regulation over the 4-yr period. One of these lines was particularly noteworthy. Although it contained as many as 55 P elements per genome (20 of which were potentially complete) and had extremely high P activity potential, it continued to exhibit limited regulatory ability. In addition, when females of this line were maintained at high temperatures, the ability to suppress P activity was even further diminished. A strain with this combination of molecular and phenotypic properties, in an apparently stable configuration, has not been previously described.—The results are discussed in the context of the possible role of degenerate elements in regulating P element expression.

scholarly journals P-element transposase induces male recombination in Drosophila melanogaster

1989 ◽  
Vol 54 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Margaret Y. McCarron ◽  
Atanu Duttaroy ◽  
Glenn A. Doughty ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
P Element ◽  
Chromosomal Dna ◽  
Background Rate ◽  
Male Recombination ◽  
Selective System

SummaryMale recombination in P–M dysgenic crosses has been viewed as a reflection of P-element transposase interacting with P elements. However, recent studies suggest that the transposase may catalyse double-stranded breaks in chromosomal DNA. We have, therefore, introduced P(Δ2–3 ry+) (99B), a single non-mobile P-element transposase source, into the long-standing laboratory true M strains of a flanking lethal crossover selective system, thus facilitating the examination of rare male recombination events as an assay for transposase activity. We find that the rate of male recombination in the presence of this non-mobile P element is greater than twenty times the background rate of male recombination in the control examined prior to introduction of the transposase source.

scholarly journals P element insertions and rearrangements at the singed locus of Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 119 (1) ◽  
pp. 75-83
Author(s):  
H Roiha ◽  
G M Rubin ◽  
K O'Hare
Keyword(s):  
Drosophila Melanogaster ◽  
High Frequency ◽  
The Other ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Wild Type ◽  
Tandem Arrangement ◽  
P Elements

Abstract DNA from the singed gene of Drosophila melanogaster was isolated using an inversion between a previously cloned P element at cytological location 17C and the hypermutable allele singed-weak. Five out of nine singed mutants examined have alterations in their DNA maps in this region. The singed locus is a hotspot for mutation during P-M hybrid dysgenesis, and we have analyzed 22 mutations induced by P-M hybrid dysgenesis. All 22 have a P element inserted within a 700-bp region. The precise positions of 10 P element insertions were determined and they define 4 sites within a 100-bp interval. During P-M hybrid dysgenesis, the singed-weak allele is destabilized, producing two classes of phenotypically altered derivatives at high frequency. In singed-weak, two defective P elements are present in a "head-to-head" or inverse tandem arrangement. Excision of one element results in a more extreme singed bristle phenotype while excision of the other leads to a wild-type bristle phenotype.

P-element-induced control mutations at the r gene of Drosophila melanogaster

1985 ◽  
Vol 5 (10) ◽  
pp. 2567-2574
Author(s):  
S Tsubota ◽  
M Ashburner ◽  
P Schedl
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
P Element ◽  
Female Sterility ◽  
R Gene ◽  
Temporal Expression ◽  
Base Pairs ◽  
P Elements ◽  
Adult Females ◽  
Regulatory Mutations

The P-M hybrid dysgenesis system was used to produce five putative regulatory mutations at the rudimentary locus, r. All five mutations were the result of insertions at the 5' end of the gene, upstream of the proposed start of transcription. All of the mutants displayed a leaky wing phenotype, and four of the mutants showed an uncoupling of the wing and female-sterility phenotypes, suggesting that they altered the normal spatial and temporal expression of the r gene. Four of the insertions were P elements. The fifth insertion, which was larger than an intact P element, consisted of a small P element connected to non-P-element DNA. Two of the mutants produced very little r transcript in adult females and were clustered 80 to 150 base pairs upstream of the start of transcription. The other three mutants had higher levels of r transcript in adult females and were clustered 440 to 500 base pairs upstream of the start of transcription. All of the data suggest that the insertions are in a 5' noncoding region of the r gene involved in the control of its spatial and temporal expression.

scholarly journals Modified P elements that mimic the P cytotype in Drosophila melanogaster.

Genetics ◽  
1989 ◽  
Vol 123 (4) ◽  
pp. 815-824 ◽  
Author(s):  
H M Robertson ◽  
W R Engels
Keyword(s):  
Drosophila Melanogaster ◽  
Reciprocal Cross ◽  
Somatic Mosaicism ◽  
The Other ◽  
P Element ◽  
Cross Effect ◽  
P Elements ◽  
Somatic Tissues ◽  
Insertion Mutations ◽  
Cellular Condition

Abstract Activity of the P family of transposable elements in Drosophila melanogaster is regulated primarily by a cellular condition known as P cytotype. It has been hypothesized that P cytotype depends on a P element-encoded repressor of transposition and excision. We provide evidence in support of this idea by showing that two modified P elements, each with lesions affecting the fourth transposase exon, mimic most of the P cytotype effects. These elements were identified by means of two sensitive assays capable of detecting repression by a single P element. One assay makes use of cytotype-dependent gene expression of certain P element insertion mutations at the singed bristle locus. The other measures suppression of transposase activity from the unusually stable genomic P element, delta 2-3(99B), that normally produces transposase in both germinal and somatic tissues. The P cytotype-like effects include suppression of snw germline hypermutability, snw somatic mosaicism, pupal lethality, and gonadal dysgenic sterility. Unlike P cytotype, however, there was no reciprocal cross effect in the inheritance of repression.

scholarly journals Structure, frequency and distribution of P elements in relation to P—M hybrid dysgenic male recombination in Drosophila melanogaster

1989 ◽  
Vol 53 (3) ◽  
pp. 163-171 ◽  
Author(s):  
K. A. Exley ◽  
P. Eggleston
Keyword(s):  
Drosophila Melanogaster ◽  
Egg Production ◽  
Polytene Chromosomes ◽  
Element Distribution ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Male Recombination ◽  
P Elements ◽  
Egg Hatchability ◽  
The Third

SummaryThe frequency and distribution of P elements were investigated in the third chromosomes of two wild-type strains of Drosophila melanogaster using in situ hybridization of biotinylated probes to the polytene chromosomes. The relationship between these data and the extent of hybrid dysgenesis was determined through assays of egg production, egg hatchability (F2 embryo lethality), snw destabilization and male recombination along the third chromosome. The results suggest that P-element distribution, frequency and structure are all contributory factors in the regulation of hybrid dysgenesis. Texas 6 was shown consistently to be a stronger P strain than Texas 1, eliciting greater reductions in fertility, more extensive snw destabilization and higher frequencies of male recombination. Clustering of male recombination events, arising from pre-meiotic crossing over, was evident among the dysgenic progeny of each strain. Male recombination and snw destabilization were independently distributed among the dysgenic males studied, suggesting that these traits represent separate P-mediated functions. The third chromosome male recombination maps produced by the two strains differed significantly from each other and from the published female meiotic and polytene chromosome maps. Male recombination breakpoints were associated with the original distribution of P sequences in the two strains and the results suggest that this relationship may be closer for potentially complete P factors than for P sequences in general. An analysis of sub-lines derived from individual recombinant males revealed that chromosomal breakpoints could also be associated with novel insertions following P-element transposition.

scholarly journals P-element-induced male recombination can be produced in Drosophila melanogaster by combining end-deficient elements in trans.

Genetics ◽  
1995 ◽  
Vol 139 (4) ◽  
pp. 1601-1610 ◽  
Author(s):  
Y H Svoboda ◽  
M K Robson ◽  
J A Sved
Keyword(s):  
Drosophila Melanogaster ◽  
P Element ◽  
Male Recombination ◽  
P Elements ◽  
In Trans

Abstract Male recombination, not normally present in Drosophila melanogaster, can be produced at high rates when target P elements at homologous sites are combined in the presence of transposase protein. We have produced a set of elements by in situ deletion of a particular insertion and have found elements that have deletions stretching into either end. Elements were tested in pairs to see whether they complement each other in their ability to induce recombination. The combination of elements that are deficient for the same end produces very little recombination, but the combination of a right-end and a left-end element can generate recombination values higher than given by two complete P[CaSpeR] elements at homologous sites. This strongly suggests that "hybrid" P elements, containing ends from two different elements, can be recognized by transposase protein. We have also examined genotypes containing a normal and an end-deficient element and found that they yield reasonably high levels of recombination. We interpret the resultant gametes from such genotypes as showing that the majority of events in this genotype derive from the association of complementary ends from the same element, whereas the complementary ends from elements in trans associate in only a minority of cases.

Sign in / Sign up

Export Citation Format

Share Document