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.

scholarly journals Accumulation of P elements in minority inversions in natural populations of Drosophila melanogaster

1992 ◽  
Vol 59 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Walter F. Eanes ◽  
Cedric Wesley ◽  
Brian Charlesworth
Keyword(s):  
Mathematical Model ◽  
Drosophila Melanogaster ◽  
Copy Number ◽  
Natural Populations ◽  
P Element ◽  
P Elements ◽  
Chromosomal Inversions ◽  
Associated Production ◽  
African Populations ◽  
Parameter Values

SummaryThe accumulation of a transposable element inside chromosomal inversions is examined theoretically by a mathematical model, and empirically by counts of P elements associated with inversion polymorphisms in natural populations of Drosophila melanogaster. The model demonstrates that, if heterozygosity for an inversion effectively reduces element associated production of detrimental chromosome rearrangements, a differential accumulation of elements is expected, with increased copy number inside the minority inversion. Several-fold differential accumulations are possible with certain parameter values. We present data on P element counts for inversion polymorphisms on all five chromosome arms of 157 haploid genomes from two African populations. Our observations show significantly increased numbers of elements within the regions associated with the least common, or minority arrangements, in natural inversion polymorphisms.

scholarly journals The P-element strikes again: the recent invasion of naturalDrosophila simulanspopulations

2015 ◽  
Author(s):  
Robert Kofler ◽  
Tom Hill ◽  
Viola Nolte ◽  
Andrea Betancourt ◽  
Christian Schlötterer
Keyword(s):  
Drosophila Melanogaster ◽  
Defense Mechanisms ◽  
Natural Populations ◽  
Genomic Data ◽  
P Element ◽  
Expression Data ◽  
Transfer Event ◽  
P Elements ◽  
Origins Of Replication ◽  
Close Relatives

The P-element is one of the best understood eukaryotic transposable elements. It invadedDrosophila melanogasterpopulations within a few decades, but was thought to be absent from close relatives, includingD. simulans. Five decades after the spread inD. melanogaster, we provide evidence that the P-element has also invadedD. simulans. P-elements inD. simulansappear to have been acquired recently fromD. melanogasterprobably via a single horizontal transfer event. Expression data indicate that the P-element is processed in the germline ofD. simulans, and genomic data show an enrichment of P-element insertions in putative origins of replication, similar to that seen inD. melanogaster. This ongoing spread of the P-element in natural populations provides an unique opportunity to understand the dynamics of transposable element spreads and the associated piRNA defense mechanisms.

scholarly journals Transposable element-induced fitness mutations in Drosophila melanogaster

1986 ◽  
Vol 48 (2) ◽  
pp. 77-87 ◽  
Author(s):  
Trudy F. C. Mackay
Keyword(s):  
Drosophila Melanogaster ◽  
Extraction Procedure ◽  
Natural Populations ◽  
P Element ◽  
Recessive Lethal ◽  
P Elements ◽  
Fitness Traits ◽  
Mutational Effect ◽  
Evolution Of Transposable Elements ◽  
Mutational Variance

SummaryP element mutagenesis was used to contaminate M strain second chromosomes with P elements. The contaminated lines were compared to uncontaminated control lines for homozygous and heterozygous fitness and its components. Mean homozygous fitness, viability and fertility of chromosome lines contaminated with P elements is decreased relative to the uncontaminated control lines by, respectively, 55, 28 and 40%. Variance among contaminated homozygous lines of total fitness increases by a factor of 1·5, variance of viability by a factor of 5·9, and variance of fertility by a factor of 1·9, compared to variance of these traits among the population of uncontaminated homozygous chromosomes. Estimates of P-element-induced mutational variance among second chromosome lines for homozygous fitness, viability and fertility are, respectively, 2 × 10−2, 5 × 10−2 and 2 × 10−2. This magnitude of mutational effect is equivalent, in terms of incidence of induced recessive lethal chromosomes and D:L ratio, to a dose of approximately 1·0–2·5 × 10−3 m EMS. The distributions of fitness traits among M-derived second chromosome homozygous lines contaminated with P elements are remarkably similar in many regards to distributions of fitness and viability of chromosomal homozygotes derived from natural Drosophila populations. It is possible that a proportion of the fitness variation previously observed (reviewed by Simmons & Crow, 1977) following homozygosis of wild chromosomes was not present in the natural populations, but was generated by P-element transposition during the chromosome extraction procedure. P-element-induced fitness mutations appear to be completely recessive. Implications for models of evolution of transposable elements are discussed.

scholarly journals CORRIGENDA

Genetics ◽  
1996 ◽  
Vol 144 (3) ◽  
pp. 1329C-1329C
Keyword(s):  
Drosophila Melanogaster ◽  
P Element ◽  
P Elements ◽  
Regulatory Properties

Abstract In the paper by S. Ronsseray, M. Lehmann, D. Nouaud and D. Anxolabéhère (Genetics  143:  1663–1674; August, 1996) entitled “The regulatory properties of autonomous subtelomeric P elements are sensitive to a Suppresor of variegation in Drosophila melanogaster,” on page 1668 in the legend to Figure 2, line 4 should begin “representing the P element is oriented as follows: 5′◀3′.

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 Transposable element-induced polygenic mutations in Drosophila melanogaster

1987 ◽  
Vol 49 (3) ◽  
pp. 225-233 ◽  
Author(s):  
Trudy F. C. Mackay
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Element ◽  
Quantitative Traits ◽  
Natural Populations ◽  
P Element ◽  
Environmental Variance ◽  
X Ray ◽  
P Elements ◽  
Very High ◽  
Mutational Variance

SummaryP-element mutagenesis was used to contaminate M-strain second chromosomes with P elements. The effect of P-element transposition on abdominal and sternopleural bristle scores and on female productivity was deduced by comparing the distributions of these quantitative traits among the contaminated second-chromosome lines with a control population of M-strain second-chromosome lines free of P elements. Estimates of P-element-induced mutational variance, Vm, for these characters are very high, and mutational ‘heritabilities’ (Vm/Ve, the ratio of mutational variance to environmental variance) are of the same order as heritabilities of these traits from natural populations. P-element-induced mutational variance of abdominal bristle score is roughly two orders of magnitude greater than spontaneous and X-ray-induced Vm/Ve for this trait.

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 Rapid spread of transposable p elements in experimental populations of Drosophila melanogaster.

Genetics ◽  
1989 ◽  
Vol 122 (2) ◽  
pp. 387-396 ◽  
Author(s):  
A G Good ◽  
G A Meister ◽  
H W Brock ◽  
T A Grigliatti ◽  
D A Hickey
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
Natural Populations ◽  
P Element ◽  
P Elements ◽  
Rapid Spread ◽  
Laboratory Populations ◽  
Experimental Populations

Abstract The invasion of P elements in natural populations of Drosophila melanogaster was modeled by establishing laboratory populations with 1%, 5% and 10% P genomes and monitoring the populations for 20 generations. In one experiment, the ability of flies to either induce or suppress gonadal sterility in different generations was correlated with the amount of P element DNA. In a second experiment, the percentage of genomes that contained P elements, and the distribution of P elements among individual flies was monitored. The ability to induce gonadal dysgenesis increased rapidly each generation. However, the increase in P cytotype lagged behind by five to ten generations. The total amount of P element DNA and the frequency of flies containing P elements increased each generation. The number of P elements within individual genomes decreased initially, but then increased. Finally, the distribution of P elements within the genomes of individuals from later generations varied considerably, and this pattern differed from the parental P strain. These results suggest that the interaction between the assortment and recombination of chromosomal segments, and multiplicative transposition could result in the rapid spread of P elements in natural populations.

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 STERILITY AND HYPERMUTABILITY IN THE P-M SYSTEM OF HYBRID DYSGENESIS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 114 (4) ◽  
pp. 1147-1163
Author(s):  
Gordon J Kocur ◽  
Eric A Drier ◽  
Michael J Simmons
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Insertion Mutation ◽  
Eastern United States ◽  
X Chromosomes ◽  
P Elements ◽  
Y Chromosomes ◽  
Wild Strains

ABSTRACT Inbred wild strains of Drosophila melanogaster derived from the central and eastern United States were used to make dysgenic hybrids in the P-M system. These strains possessed P elements and the P cytotype, the condition that represses P element transposition. Their hybrids were studied for the mutability of the P element insertion mutation, snw, and for the incidence of gonadal dysgenesis (GD) sterility. All the strains tested were able to induce hybrid dysgenesis by one or both of these assays; however, high levels of dysgenesis were rare. Sets of X chromosomes and autosomes from the inbred wild strains were more effective at inducing GD sterility than were sets of Y chromosomes and autosomes. In two separate analyses, GD sterility was positively correlated with snw mutability, suggesting a linear relationship. However, one strain appeared to induce too much GD sterility for its level of snw destabilization, indicating an uncoupling of these two manifestations of hybrid dysgenesis.

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