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.

Delimiting regulatory sequences of the Drosophila melanogaster Ddc gene

1986 ◽  
Vol 6 (12) ◽  
pp. 4548-4557
Author(s):  
J Hirsh ◽  
B A Morgan ◽  
S B Scholnick
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Regulatory Elements ◽  
P Element ◽  
Developmental Expression ◽  
Upstream Region ◽  
Regulatory Sequences ◽  
Flanking Sequences

We delimited sequences necessary for in vivo expression of the Drosophila melanogaster dopa decarboxylase gene Ddc. The expression of in vitro-altered genes was assayed following germ line integration via P-element vectors. Sequences between -209 and -24 were necessary for normally regulated expression, although genes lacking these sequences could be expressed at 10 to 50% of wild-type levels at specific developmental times. These genes showed components of normal developmental expression, which suggests that they retain some regulatory elements. All Ddc genes lacking the normal immediate 5'-flanking sequences were grossly deficient in larval central nervous system expression. Thus, this upstream region must contain at least one element necessary for this expression. A mutated Ddc gene without a normal TATA boxlike sequence used the normal RNA start points, indicating that this sequences is not required for start point specificity.

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 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.

Identification of a cis-acting sequence required for germ line-specific splicing of the P element ORF2-ORF3 intron

1991 ◽  
Vol 11 (3) ◽  
pp. 1538-1546
Author(s):  
A C Chain ◽  
S Zollman ◽  
J C Tseng ◽  
F A Laski
Keyword(s):  
Drosophila Melanogaster ◽  
Splice Site ◽  
Germ Line ◽  
Somatic Cells ◽  
Regulatory Region ◽  
Systematic Search ◽  
P Element ◽  
Regulatory Sequence ◽  
Cis Acting ◽  
The Third

P element transposition in Drosophila melanogaster is limited to the germ line because the third intron (the ORF2-ORF3 intron) of the P element transcript is spliced only in germ line cells. We describe a systematic search for P element sequences that are required to regulate the splicing of the ORF2-ORF3 intron. We have identified three adjacent mutations that abolish the germ line specificity and allow splicing of this intron in all tissues. These mutations define a 20-base regulatory region located in the exon, 12 to 31 bases from the 5' splice site. Our data show that this cis-acting regulatory sequence is required to inhibit the splicing of the ORF2-ORF3 intron in somatic cells.

scholarly journals Delimiting regulatory sequences of the Drosophila melanogaster Ddc gene.

1986 ◽  
Vol 6 (12) ◽  
pp. 4548-4557 ◽  
Author(s):  
J Hirsh ◽  
B A Morgan ◽  
S B Scholnick
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Regulatory Elements ◽  
P Element ◽  
Developmental Expression ◽  
Upstream Region ◽  
Regulatory Sequences ◽  
Flanking Sequences

We delimited sequences necessary for in vivo expression of the Drosophila melanogaster dopa decarboxylase gene Ddc. The expression of in vitro-altered genes was assayed following germ line integration via P-element vectors. Sequences between -209 and -24 were necessary for normally regulated expression, although genes lacking these sequences could be expressed at 10 to 50% of wild-type levels at specific developmental times. These genes showed components of normal developmental expression, which suggests that they retain some regulatory elements. All Ddc genes lacking the normal immediate 5'-flanking sequences were grossly deficient in larval central nervous system expression. Thus, this upstream region must contain at least one element necessary for this expression. A mutated Ddc gene without a normal TATA boxlike sequence used the normal RNA start points, indicating that this sequences is not required for start point specificity.

scholarly journals Identification of a cis-acting sequence required for germ line-specific splicing of the P element ORF2-ORF3 intron.

1991 ◽  
Vol 11 (3) ◽  
pp. 1538-1546 ◽  
Author(s):  
A C Chain ◽  
S Zollman ◽  
J C Tseng ◽  
F A Laski
Keyword(s):  
Drosophila Melanogaster ◽  
Splice Site ◽  
Germ Line ◽  
Somatic Cells ◽  
Regulatory Region ◽  
Systematic Search ◽  
P Element ◽  
Regulatory Sequence ◽  
Cis Acting ◽  
The Third

P element transposition in Drosophila melanogaster is limited to the germ line because the third intron (the ORF2-ORF3 intron) of the P element transcript is spliced only in germ line cells. We describe a systematic search for P element sequences that are required to regulate the splicing of the ORF2-ORF3 intron. We have identified three adjacent mutations that abolish the germ line specificity and allow splicing of this intron in all tissues. These mutations define a 20-base regulatory region located in the exon, 12 to 31 bases from the 5' splice site. Our data show that this cis-acting regulatory sequence is required to inhibit the splicing of the ORF2-ORF3 intron in somatic cells.

scholarly journals The maternally inherited regulation of P elements in Drosophila melanogaster can be elicited by two P copies at cytological site 1A on the X chromosome.

Genetics ◽  
1991 ◽  
Vol 129 (2) ◽  
pp. 501-512 ◽  
Author(s):  
S Ronsseray ◽  
M Lehmann ◽  
D Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
P Element ◽  
P Elements ◽  
Element Activity ◽  
High Level ◽  
Regulatory Properties ◽  
Cellular Condition

Abstract Two P elements, inserted at the cytological site 1A on an X chromosome from an Drosophila melanogaster natural population (Lerik, USSR), were isolated by genetic methods to determine if they are sufficient to cause the P cytotype, the cellular condition that regulates the P family of transposable element. The resulting "Lerik P(1A)" line (abbreviated "Lk-P(1A)") carries only one P element in situ hybridization site but genomic Southern analysis indicates that this site contains two, probably full length, P copies separated by at least one EcoRI cleavage site. Because the Lk-P(1A) line shows some transposase activity, at least one of these two P elements is autonomous. The Lk-P(1A) line fully represses germline P element activity as judged by the GD sterility and snw hypermutability assays; this result shows that the P cytotype can be elicited by only two P element copies. However, the Lk-P(1A) line does not fully repress delta 2-3(99B) transposase activity in the soma, although it fully represses delta 2-3(99B) transposase activity in the germline (delta 2-3(99B) is an in vitro modified P element that produces a high level of transposase activity in both the germline and the soma). The germline regulatory properties of the Lk-P(1A) line are maternally transmitted, even when the delta 2-3(99B) element is used as the source of transposase. By contrast, the partial regulation of delta 2-3(99B) somatic activity is chromosomally inherited. These results suggest that the regulatory P elements of the Lk-P(1A) line are inserted near a germline-specific enhancer.

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 Somatic Effects of P Element Activity in Drosophila melanogaster: Pupal Lethality

Genetics ◽  
1987 ◽  
Vol 117 (4) ◽  
pp. 745-757
Author(s):  
William R Engels ◽  
Wendy K Benz ◽  
Christine R Preston ◽  
Patricia L Graham ◽  
Randall W Phillis ◽  
...  
Keyword(s):  
Strong Dependence ◽  
Somatic Cells ◽  
Pupal Stage ◽  
Lethal Effect ◽  
Chromosome Breakage ◽  
P Element ◽  
Transposase Gene ◽  
P Elements ◽  
Larval Stages ◽  
Disc Cells

ABSTRACT Nonautonomous P elements normally excise and transpose only when a source of transposase is supplied, and only in the germline. The germline specificity depends on one of the introns of the transposase gene which is not spliced in somatic cells. To study the effects of somatic P activity, a modified P element (Δ2-3) lacking this intron was used as a source of transposase. Nonautonomous P elements from a strain called Birmingham, when mobilized in somatic cells by Δ2-3, were found to cause lethality, although neither component was lethal by itself. The three major Birmingham chromosomes acted approximately independently in producing the lethal effect. This lethality showed a strong dependence on temperature. Although temperature sensitivity was limited to larval stages, the actual deaths occurred at the pupal stage. Survivors, which could be recovered by decreasing the temperature or by reducing the proportion of the Birmingham genome present, often showed multiple developmental anomalies and reduced longevity reminiscent of the effects of cell death from radiation damage. Although the genetic damage occurred in dividing imaginal disc cells, the phenotypic manifestations—death and abnormalities—are not observed until later. The survivors also showed gonadal dysgenic (GD) sterility, a well-known characteristic of P-M hybrid dysgenesis. To explain these findings, we suggest that pupal lethality and GD sterility are both caused by massive chromosome breakage in larval cells, resulting from excision and transposition of genomic P elements acting as substrate for the transposase.

P element mediated germ line transformation of Drosophila melanogaster with the Tc1 transposable DNA element from Caenorhabditis elegans

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 356-366 ◽  
Author(s):  
A. Alex Szekely ◽  
R. C. Woodruff ◽  
R. Mahendran
Keyword(s):  
Drosophila Melanogaster ◽  
Caenorhabditis Elegans ◽  
Germ Line ◽  
Molecular Data ◽  
P Element ◽  
P Elements ◽  
Line Transfer ◽  
Genomic Locations ◽  
Tc1 Element ◽  
Germ Line Transformation

Questions relating to the origin and regulation of mobile genetic elements are currently of considerable interest. Since it is now possible to address more precisely issues concerning the entry, dispersion, and regulation of elements within a virgin genome, one approach that may afford a better understanding of transposable elements in general could be provided by interspecific DNA transformation. Therefore, the Tc1 transposable DNA element from Caenorhabditis elegans was chosen as a proposed invading element of the Drosophila melanogaster genome. The basis for this selection resided in the inherent structural and functional similarities, as well as sequence identities, between the Caenorhabditis element and elements innate to Drosophila (e.g., P, HB1, and Uhu). Initial investigations were carried out to define a clone carrying an intact Tc1 element. This Tc1 element was inserted into a P transposon vector and two P–Tc1–ry+ constructs, differing only in insert orientation, were identified. P element mediated germ line transfer was then used to generate a transformant that was genetically and molecularly identified as containing a single, structurally intact Tc1 element at cytological location 64C4-5 on the third chromosome. The single P[(Tc1, ry+)]SAS-B insertion was thereafter mobilized by using a P[ry+Δ2-3] element as a transposase source, and the genetic and molecular data suggested that the insertion had been successfully reintegrated to a variety of genomic locations. On the basis of genetic and molecular analyses, the Tc1 element in the P[(Tc1, ry+)] transformed stock is not highly unstable in germ line and somatic tissues.Key words: Tc1 transposable element, transformation, Drosophila melanogaster, Caenorhabditis elegans, P elements.

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