scholarly journals Reconstructing the Invasion Route of the P-Element in Drosophila melanogaster Using Extant Population Samples

2020 ◽  
Vol 12 (11) ◽  
pp. 2139-2152
Author(s):  
Lukas Weilguny ◽  
Christos Vlachos ◽  
Divya Selvaraju ◽  
Robert Kofler
Keyword(s):  
Drosophila Melanogaster ◽  
P Element ◽  
High Rate ◽  
Reasonable Accuracy ◽  
Dna Transposons ◽  
African Populations ◽  
Spatially Distributed ◽  
Invasion Routes ◽  
Extant Population ◽  
European Populations

Abstract The P-element, one of the best understood eukaryotic transposable elements, spread in natural Drosophila melanogaster populations in the last century. It invaded American populations first and later spread to the Old World. Inferring this invasion route was made possible by a unique resource available in D. melanogaster: Many strains sampled from different locations over the course of the last century. Here, we test the hypothesis that the invasion route of the P-element may be reconstructed from extant population samples using internal deletions (IDs) as markers. These IDs arise at a high rate when DNA transposons, such as the P-element, are active. We suggest that inferring invasion routes is possible as: 1) the fraction of IDs increases in successively invaded populations, which also explains the striking differences in the ID content between American and European populations, and 2) successively invaded populations end up with similar sets of IDs. This approach allowed us to reconstruct the invasion route of the P-element with reasonable accuracy. Our approach also sheds light on the unknown timing of the invasion in African populations: We suggest that African populations were invaded after American but before European populations. Simulations of TE invasions in spatially distributed populations confirm that IDs may allow us to infer invasion routes. Our approach might be applicable to other DNA transposons in different host species.

scholarly journals Reconstructing the invasion route of DNA transposons using extant population samples

2019 ◽  
Author(s):  
Lukas Weilguny ◽  
Christos Vlachos ◽  
Divya Selvaraju ◽  
Robert Kofler
Keyword(s):  
P Element ◽  
Model Organisms ◽  
Migration Patterns ◽  
Dna Transposons ◽  
Time Points ◽  
Wide Range ◽  
Invasion Routes ◽  
Geographic Regions ◽  
Extant Population ◽  
Shed Light

AbstractReconstructing invasion routes of transposable elements (TEs), so far, required capturing an ongoing invasion with population samples from different geographic regions and time points. Here, we propose a more accessible approach. Abundantly occurring internal deletions of DNA transposons allow to trace the direction as well as the path of an invasion, even hundreds of generations after the spread of a TE. We validated this hypothesis with computer simulations and by accurately reproducing the route of the P-element invasion in Drosophila melanogaster. Finally, we used our method to shed light on the controversial hobo invasion in D. melanogaster. Our approach solely requires sequenced samples from extant populations and sequences of TEs of interest. Hence, DNA transposons in a wide range of model and non-model organisms may be analyzed. Our approach will further our understanding of TE dynamics, migration patterns, and the ecology of species.

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 Temporal stability of P–M cytotype polymorphism in a natural population of Drosophila melanogaster

1987 ◽  
Vol 50 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Hassan Izaabel ◽  
Stephane Ronsseray ◽  
Dominique Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Natural Population ◽  
North Africa ◽  
Temporal Stability ◽  
Genetic Load ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
High Rate ◽  
Genetic Abnormalities

SummaryThe P–M system of hybrid dysgenesis in Drosophila melanogaster is a syndrome of genetic abnormalities which appears in the progeny of crosses between strains different with regard to their possession of ‘P’ transposable elements. Cytotype is an extrachromosomal property which regulates the mobility of the P element. We report here data showing that a cytotype polymorphism previously observed in a natural population from North-Africa is stable over a period of 5 years. A potentially high rate of mutation is associated with this cytotype polymorphism. Explanations of the appearance of a cytotype polymorphism are proposed and the consequences for the genetic load induced by transposable elements are discussed.

scholarly journals Early split between African and European populations of Drosophila melanogaster

2018 ◽  
Author(s):  
Adamandia Kapopoulou ◽  
Martin Kapun ◽  
Pavlos Pavlidis ◽  
Bjorn Pieper ◽  
Ricardo Wilches ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Divergence Time ◽  
Fruit Fly ◽  
European Population ◽  
Genetic Admixture ◽  
Demographic Models ◽  
African Populations ◽  
Adaptive Processes ◽  
European Populations

AbstractNatural populations of the fruit fly Drosophila melanogaster have been used extensively as a model system to investigate the effect of neutral and selective processes on genetic variation. The species expanded outside its Afrotropical ancestral range during the last glacial period and numerous studies have focused on identifying molecular adaptations associated with the colonization of northern habitats. The sequencing of many genomes from African and non-African natural populations has facilitated the analysis of the interplay between adaptive and demographic processes. However, most of the non-African sequenced material has been sampled from American and Australian populations that have been introduced within the last hundred years following recent human dispersal and are also affected by recent genetic admixture with African populations. Northern European populations, at the contrary, are expected to be older and less affected by complex admixture patterns and are therefore more appropriate to investigate neutral and adaptive processes. Here we present a new dataset consisting of 14 fully sequenced haploid genomes sampled from a natural population in Umeå, Sweden. We co-analyzed this new data with an African population to compare the likelihood of several competing demographic scenarios for European and African populations. We show that allowing for gene flow between populations in neutral demographic models leads to a significantly better fit to the data and strongly affects estimates of the divergence time and of the size of the bottleneck in the European population. Our results indicate that the time of divergence between cosmopolitan and ancestral populations is 30,000 years older than reported by previous studies.

scholarly journals The Transmission of Fragmented Chromosomes in Drosophila melanogaster

Genetics ◽  
1998 ◽  
Vol 148 (2) ◽  
pp. 775-792
Author(s):  
Kami Ahmad ◽  
Kent G Golic
Keyword(s):  
Drosophila Melanogaster ◽  
Sister Chromatid ◽  
Strand Break ◽  
P Element ◽  
High Rate ◽  
P Elements ◽  
Dicentric Chromosomes ◽  
Male Germline ◽  
Chromosome Fragments ◽  
And Behavior

Abstract We investigated the fate of dicentric chromosomes in the mitotic divisions of Drosophila melanogaster. We constructed chromosomes that were not required for viability and that carried P elements with inverted repeats of the target sites (FRTs) for the FLP site-specific recombinase. FLP-mediated unequal sister-chromatid exchange between inverted FRTs produced dicentric chromosomes at a high rate. The fate of the dicentric chromosome was evaluated in the mitotic cells of the male germline. We found that dicentric chromosomes break in mitosis, and the broken fragments can be transmitted. Some of these chromosome fragments exhibit dominant semilethality. Nonlethal fragments were broken at many sites along the chromosome, but the semilethal fragments were all broken near the original site of sister-chromatid fusion, and retained P element sequences near their termini. We discuss the implications of the recovery and behavior of broken chromosomes for checkpoints that detect double-strand break damage and the functions of telomeres in Drosophila.

scholarly journals Introduction of the transposable element mariner into the germline of Drosophila melanogaster.

Genetics ◽  
1991 ◽  
Vol 128 (2) ◽  
pp. 303-310 ◽  
Author(s):  
D Garza ◽  
M Medhora ◽  
A Koga ◽  
D L Hartl
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Element ◽  
High Efficiency ◽  
P Element ◽  
High Rate ◽  
Position Effects ◽  
Eye Color ◽  
Dosage Effects ◽  
High Level ◽  
Pole Plasm

Abstract A chimeric white gene (wpch) and other constructs containing the transposable element mariner from Drosophila mauritiana were introduced into the germline of Drosophila melanogaster using transformation mediated by the P element. In the absence of other mariner elements, the wpch allele is genetically stable in both germ cells and somatic cells, indicating that the peach element (i.e., the particular copy of mariner inserted in the wpch allele) is inactive. However, in the presence of the active element Mos1, the wpch allele reverts, owing to excision of the peach element, yielding eye-color mosaics and a high rate of germline reversion. In strains containing Mos1 virtually every fly is an eye-color mosaic, and the rate of wpch germline reversion ranges from 10 to 25%, depending on temperature. The overall rates of mariner excision and transposition are approximately sixfold greater than the rates in comparable strains of Drosophila simulans. The activity of the Mos1 element is markedly affected by position effects at the site of Mos1 insertion. In low level mosiac lines, dosage effects of Mos1 are apparent in the heavier level of eye-color mosaicism in Mos1 homozygotes than in heterozygotes. However, saturation occurs in high level mosaic lines, and then dosage effects are not observed. A pBluescribe M13+ plasmid containing Mos1 was injected into the pole plasm of D. melanogaster embryos, and the Mos1 element spontaneously integrated into the germline at high efficiency. These transformed strains of D. melanogaster presently contain numerous copies of mariner and may be useful in transposon tagging and other applications.

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 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 hobo enhancer trapping mutagenesis in Drosophila reveals an insertion specificity different from P elements.

Genetics ◽  
1993 ◽  
Vol 135 (4) ◽  
pp. 1063-1076 ◽  
Author(s):  
D Smith ◽  
J Wohlgemuth ◽  
B R Calvi ◽  
I Franklin ◽  
W M Gelbart
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Element ◽  
Enhancer Trap ◽  
P Element ◽  
Present Evidence ◽  
P Elements ◽  
Element Insertion ◽  
Enhancer Trapping ◽  
Indispensable Tool

Abstract P element enhancer trapping has become an indispensable tool in the analysis of the Drosophila melanogaster genome. However, there is great variation in the mutability of loci by these elements such that some loci are relatively refractory to insertion. We have developed the hobo transposable element for use in enhancer trapping and we describe the results of a hobo enhancer trap screen. In addition, we present evidence that a hobo enhancer trap element has a pattern of insertion into the genome that is different from the distribution of P elements in the available database. Hence, hobo insertion may facilitate access to genes resistant to P element insertion.

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