scholarly journals Regulation of P-Element Transposase Activity in Drosophila melanogaster by hobo Transgenes That Contain KP Elements

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 205-215 ◽  
Author(s):  
Michael J Simmons ◽  
Kevin J Haley ◽  
Craig D Grimes ◽  
John D Raymond ◽  
Joseph C L Fong
Keyword(s):  
Drosophila Melanogaster ◽  
P Element ◽  
Drosophila Genome ◽  
Maternal Transmission ◽  
Alternate Splicing ◽  
Hsp70 Promoter ◽  
P Elements ◽  
Naturally Occurring ◽  
Element Activity ◽  
Transformation Vectors

Abstract Fusions between the Drosophila hsp70 promoter and three different incomplete P elements, KP, SP, and BP1, were inserted into the Drosophila genome by means of hobo transformation vectors and the resulting transgenic stocks were tested for repression of P-element transposase activity. Only the H(hsp/KP) transgenes repressed transposase activity, and the degree of repression was comparable to that of a naturally occurring KP element. The KP transgenes repressed transposase activity both with and without heat-shock treatments. Both the KP element and H(hsp/KP) transgenes repressed the transposase activity encoded by the modified P element in the P(ry+, Δ2-3)99B transgene more effectively than that encoded by the complete P element in the H(hsp/CP)2 transgene even though the P(ry+, Δ2-3)99B transgene was the stronger transposase source. Repression of both transposase sources appeared to be due to a zygotic effect of the KP element or transgene. There was no evidence for repression by a strictly maternal effect; nor was there any evidence for enhancement of KP repression by the joint maternal transmission of H(hsp/KP) and H(hsp/CP) transgenes. These results are consistent with the idea that KP-mediated repression of P-element activity involves a KP-repressor polypeptide that is not maternally transmitted and that KP-mediated repression is not strengthened by the 66-kD repressor produced by complete P elements through alternate splicing of their RNA.

scholarly journals A hobo Transgene That Encodes the P-Element Transposase in Drosophila melanogaster: Autoregulation and Cytotype Control of Transposase Activity

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Michael J Simmons ◽  
Kevin J Haley ◽  
Craig D Grimes ◽  
John D Raymond ◽  
Jarad B Niemi
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
P Element ◽  
Hsp70 Gene ◽  
Alternate Splicing ◽  
Male And Female ◽  
P Elements ◽  
Male Germline ◽  
Female Germline ◽  
Transposase Expression

Abstract Drosophila were genetically transformed with a hobo transgene that contains a terminally truncated but otherwise complete P element fused to the promoter from the Drosophila hsp70 gene. Insertions of this H(hsp/CP) transgene on either of the major autosomes produced the P transposase in both the male and female germlines, but not in the soma. Heat-shock treatments significantly increased transposase activity in the female germline; in the male germline, these treatments had little effect. The transposase activity of two insertions of the H(hsp/CP) transgene was not significantly greater than their separate activities, and one insertion of this transgene reduced the transposase activity of P(ry+, Δ2-3)99B, a stable P transgene, in the germline as well as in the soma. These observations suggest that, through alternate splicing, the H(hsp/CP) transgene produces a repressor that feeds back negatively to regulate transposase expression or function in both the somatic and germline tissues. The H(hsp/CP) transgenes are able to induce gonadal dysgenesis when the transposase they encode has P-element targets to attack. However, this ability and the ability to induce P-element excisions are repressed by the P cytotype, a chromosomal/cytoplasmic state that regulates P elements in the germline.

scholarly journals Localization of P elements, copy number regulation, and cytotype determination in Drosophila melanogaster

1990 ◽  
Vol 56 (1) ◽  
pp. 3-14 ◽  
Author(s):  
C. Biémont ◽  
S. Ronsseray ◽  
D. Anxolabéhère ◽  
H. Izaabel ◽  
C. Gautier
Keyword(s):  
Drosophila Melanogaster ◽  
Copy Number ◽  
Chromosomal Location ◽  
Inbred Lines ◽  
P Element ◽  
P Elements ◽  
Left And Right ◽  
Element Activity ◽  
Copy Number Regulation

SummarySeventeen highly-inbred lines of Drosophila melanogaster extracted from an M′ strain (in the P/M system of hybrid dysgenesis) were studied for their cytotype and the number and chromosomal location of complete and defective P elements. While most lines were of M cytotype, three presented a P cytotype (the condition that represses P-element activity) and one was intermediate between M and P. All lines were found to possess K.P elements and only eight to bear full-sized P elements. Only the lines with full-sized P elements showed detectable changes in their P-insertion pattern over generations; their rates of gain and of loss of P-element sites were equal to 0·12 and 0·09 per genome, per generation, respectively. There was no correlation between these two rates within lines, suggesting independent transpositions and excisions in the inbred genomes. The results of both Southern blot analysis and in situ hybridization of probes made from left and right sides of the P element strongly suggested the presence of a putative complete P element in region 1A of the X chromosome in the three lines with a P cytotype; the absence of P copy in this 1A region in lines with an M cytotype, favours the hypothesis that the P element inserted in 1A could play a major role in the P-cytotype determination. Insertion of a defective 2 kb P element was also observed in region 93F in 9 of the 13 M lines. The regulation of the P-element copy number in our lines appeared not to be associated with the ratio of full-length and defective P elements.

scholarly journals Disgenesia do híbrido em populações naturais de Drosophila melanogaster.

1999 ◽  
Vol 21 (21) ◽  
pp. 51 ◽  
Author(s):  
Chirlei Cintia Klein ◽  
Liliana Essi ◽  
Ronaldo Medeiros Golombieski ◽  
Élgion Lúcio da Silva Loreto
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Analysis ◽  
Natural Populations ◽  
Rio Grande ◽  
P Element ◽  
Rio Grande Do Sul ◽  
Genetic Traits ◽  
P Elements ◽  
Regulatory Capacity ◽  
Element Activity

Hybrid dysgenesis has been defined as a remarkable syndrome of correlated genetic traits that are produced in some particular crosses between certain strains. The present study main objective was classify recently collected Drosophila melanogaster strains in relation to P element activity and regulatory capacity. Our results to natural populations trapped from Rio Grande do Sul, Brazil and Colombia shows that it fell on Q class, since all examinated strains has showed P elements by molecular analysis and low P activity. In the same way, these strains shows low susceptibility to P element action. The bigger values found in the colombian population are in agreement with the clinal hypothesis to P element activity.

scholarly journals Repression of Hybrid Dysgenesis in Drosophila melanogaster by Combinations of Telomeric P-Element Reporters and Naturally Occurring P Elements

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1857-1866 ◽  
Author(s):  
Stéphane Ronsseray ◽  
Laurent Marin ◽  
Monique Lehmann ◽  
Dominique Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Chromatin Structure ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Pericentromeric Heterochromatin ◽  
Combination Effect ◽  
P Elements ◽  
Naturally Occurring ◽  
Nuclear Location

Abstract In Drosophila melanogaster, hybrid dysgenesis occurs in the germline of flies produced by crosses between females lacking P elements and males carrying 25–55 P elements. We have previously shown that a complete maternally inherited repression of P transposition in the germline (P cytotype) can be elicited by only two autonomous P elements located at the X chromosome telomere (cytological site 1A). We have tested whether P transgenes at 1A, unable to code for a P-repressor, may contribute to the repression of P elements. Females carrying a P-lacZ transgene at 1A [“P-lacZ(1A)”], crossed with P males, do not repress dysgenic sterility in their progeny. However, these P-lacZ(1A) insertions, maternally or paternally inherited, contribute to P-element repression when they are combined with other regulatory P elements. This combination effect is not seen when the P-lacZ transgene is located in pericentromeric heterochromatin or in euchromatin; however a P-w,ry transgene located at the 3R chromosome telomere exhibits the combination effect. The combination effect with the P-lacZ(1A) transgene is impaired by a mutant Su(var)205 allele known to impair the repression ability of the autonomous P elements at 1A. We hypothesized that the combination effect is due to modification of the chromatin structure or nuclear location of genomic P elements.

Hybrid dysgenesis in Drosophila melanogaster: the elimination of P elements through repeated backcrossing to an M-type strain

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 195-200 ◽  
Author(s):  
Allen G. Good ◽  
Donal A. Hickey
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Hybridization ◽  
Copy Number ◽  
Natural Populations ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
P Elements ◽  
Element Activity ◽  
Equivalent Reduction ◽  
Replicative Transposition

The rapid increase in the frequency of P elements in natural populations of Drosophila melanogaster has led to the suggestion that these elements can spread in nature through replicative transposition. In an attempt to model the introduction of a small number of P flies into an M population we backcrossed P flies and their offspring to M flies. Two components of dysgenesis, P element activity and P element copy number (measured by DNA hybridization), were monitored each generation. In these experiments P elements were not capable of spreading rapidly enough to maintain 30–50 copies per fly and were rapidly lost from the population. We also found that the reduction in a fly's ability to induce gonadal dysgenesis was matched by an equivalent reduction in P element copy number as measured by DNA hybridization. These results are discussed in terms of the conventional mechanisms of selection or segregation; the conclusion is that there are conditions under which P elements can be lost from a population. Key words: hybrid dysgenesis, P element, transposable elements, Drosophila.

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 P-Element Repression in Drosophila melanogaster by a Naturally Occurring Defective Telomeric P Copy

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1841-1854 ◽  
Author(s):  
Laurent Marin ◽  
Monique Lehmann ◽  
Danielle Nouaud ◽  
Hassan Izaabel ◽  
Dominique Anxolabéhère ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Tunisian Population ◽  
P Elements ◽  
Naturally Occurring ◽  
Dependent Component ◽  
Associated Sequences ◽  
Element Sequence

Abstract In Drosophila melanogaster, hybrid dysgenesis occurs in progeny from crosses between females lacking P elements and males carrying P elements scattered throughout the genome. We have genetically isolated a naturally occurring P insertion at cytological location 1A, from a Tunisian population. The Nasr'Allah-P(1A) element [NA-P(1A)] has a deletion of the first 871 bp including the P promoter. It is flanked at the 3′ end by telomeric associated sequences and at the 5′ end by a HeT-A element sequence. The NA-P(1A) element strongly represses dysgenic sterility and P transposition. However, when testing P-promoter repression, NA-P(1A) was unable to repress a germinally expressed P-lacZ construct bearing no 5′-homology with it. Conversely, a second P-lacZ construct, in which the fusion with lacZ takes place in exon 3 of P, was successfully repressed by NA-P(1A). This suggests that NA-P(1A) repression involves a homology-dependent component.

scholarly journals P-Element Insertion Alleles of Essential Genes on the Third Chromosome of Drosophila melanogaster Correlation of Physical and Cytogenetic Maps in Chromosomal Region 86E-87F

Genetics ◽  
1997 ◽  
Vol 147 (4) ◽  
pp. 1697-1722 ◽  
Author(s):  
Peter Deák ◽  
Mahmoud M Omar ◽  
Robert D C Saunders ◽  
Margit Pál ◽  
Orbán Komonyi ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Maps ◽  
P Element ◽  
Drosophila Genome ◽  
Induced Mutations ◽  
Lethal Mutant ◽  
P Elements ◽  
Element Insertion ◽  
The Third ◽  
Complementation Groups

Abstract We have established a collection of 2460 lethal or semi-lethal mutant lines using a procedure thought to insert single P elements into vital genes on the third chromosome of Drosophila melanogaster. More than 1200 randomly selected lines were examined by in situ hybridization and 90% found to contain single insertions at sites that mark 89% of all lettered subdivisions of the Bridges' map. A set of chromosomal deficiencies that collectively uncover ~25% of the euchromatin of chromosome 3 reveal lethal mutations in 468 lines corresponding to 145 complementation groups. We undertook a detailed analysis of the cytogenetic interval 86E-87F and identified 87 P-element-induced mutations falling into 38 complementation groups, 16 of which correspond to previously known genes. Twenty-one of these 38 complementation groups have at least one allele that has a P-element insertion at a position consistent with the cytogenetics of the locus. We have rescued P elements and flanking chromosomal sequences from the 86E-87F region in 35 lines with either lethal or genetically silent P insertions, and used these as probes to identify cosmids and P1 clones from the Drosophila genome projects. This has tied together the physical and genetic maps and has linked 44 previously identified cosmid contigs into seven “super-contigs” that span the interval. STS data for sequences flanking one side of the P-element insertions in 49 lines has identified insertions in the αγ element at 87C, two known transposable elements, and the open reading frames of seven putative single copy genes. These correspond to five known genes in this interval, and two genes identified by the homology of their predicted products to known proteins from other organisms.

scholarly journals P-Element Repression in Drosophila melanogaster by Variegating Clusters of P-lacZ-white Transgenes

Genetics ◽  
2001 ◽  
Vol 159 (4) ◽  
pp. 1631-1642 ◽  
Author(s):  
Stéphane Ronsseray ◽  
Antoine Boivin ◽  
Dominique Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Maternal Effect ◽  
P Element ◽  
Lacz Reporter ◽  
X Ray ◽  
Subtelomeric Heterochromatin ◽  
P Elements ◽  
In Trans ◽  
Element Activity

Abstract In Drosophila, clusters of P transgenes (P-lac-w) display a variegating phenotype for the w marker. In addition, X-ray-induced rearrangements of chromosomes bearing such clusters may lead to enhancement of the variegated phenotype. Since P-lacZ transgenes in subtelomeric heterochromatin have some P-element repression abilities, we tested whether P-lac-w clusters also have the capacity to repress P-element activity in the germline. One cluster (T-1), located on a rearranged chromosome (T2;3) and derived from a line bearing a variegating tandem array of seven P-lac-w elements, partially represses the dysgenic sterility (GD sterility) induced by P elements. This cluster also strongly represses in trans the expression of P-lacZ elements in the germline. This latter suppression shows a maternal effect. Finally, the combination of variegating P-lac-w clusters and a single P-lacZ reporter inserted in subtelomeric heterochromatic sequences at the X chromosome telomere (cytological site 1A) leads to strong repression of dysgenic sterility. These results show that repression of P-induced dysgenic sterility can be elicited in the absence of P elements encoding a polypeptide repressor and that a transgene cluster can repress the expression of a single homologous transgene at a nonallelic position. Implications for models of transposable element silencing are discussed.

scholarly journals The Regulatory Properties of Autonomous Subtelomeric P Elements Are Sensitive to a Suppressor of variegation in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 143 (4) ◽  
pp. 1663-1674 ◽  
Author(s):  
Stéphane Ronsseray ◽  
Monique Lehmann ◽  
Danielle Nouaud ◽  
Dominique Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Recombination ◽  
Natural Populations ◽  
P Element ◽  
Single Element ◽  
Heterochromatin Protein 1 ◽  
X Chromosomes ◽  
P Elements ◽  
Associated Sequences ◽  
Regulatory Properties

Abstract Genetic recombination was used in Drosophila melanogaster to isolate P elements, inserted at the telomeres of X chromosomes (cytological site 1A) from natural populations, in a genetic background devoid of other P elements. We show that complete maternally inherited P repression in the germline (P cytotype) can be elicited by only two autonomous P elements at 1A and that a single element at this site has partial regulatory properties. The analysis of the surrounding chromosomal regions of the P elements at 1A shows that in all cases these elements are flanked by Telomeric Associated Sequences, tandemly repetitive noncoding sequences that have properties of heterochromatin. In addition, we show that the regulatory properties of P elements at 1A can be inhibited by some of the mutant alleles of the Su(var)205 gene and by a deficiency of this gene. However, the regulatory properties of reference P strains (Harwich and Texas 007) are not impaired by Su(var)205 mutations. Su(var)205 encodes Heterochromatin Protein 1 (HP1). These results suggest that the HP1 dosage effect on the P element properties is sitedependent and could involve the structure of the chromatin.

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