Transposable elements and fitness in Drosophila melanogaster

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 284-295 ◽  
Author(s):  
Trudy F. C. Mackay
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Insertional Mutagenesis ◽  
Natural Populations ◽  
P Element ◽  
Induced Mutations ◽  
P Elements ◽  
Copy Numbers ◽  
Genomic Locations

Transposable elements constitute a significant fraction of the Drosophila melanogaster genome. The five families of moderately repeated transposable elements identified to date occupy dispersed and variable genomic locations, but have relatively constant copy numbers per individual. What effect to these elements have on the fitness of the individuals harboring them? Experimental evidence relating to this question is reviewed. The relevant data fall into two broad categories. The first involves the determination of the distribution of transposable elements in natural populations, by restriction mapping or in situ hybridization, and the comparison of the observed distribution with different theoretical expectations. The second approach is to study directly the effects of new transposable element-induced mutations on fitness. The P family of transposable elements is a particularly efficient mutagen, and the results of experiments in which initially P-free chromosomes are contaminated with P elements are discussed with regard to P-induced fitness mutations.Key words: transposable elements, Drosophila melanogaster, insertional mutagenesis, fitness, P element mutagenesis, hybrid dysgenesis.

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.

Restriction of P-element insertions at the Notch locus of Drosophila melanogaster

1987 ◽  
Vol 7 (4) ◽  
pp. 1545-1548
Author(s):  
M R Kelley ◽  
S Kidd ◽  
R L Berg ◽  
M W Young
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Sequences ◽  
Consensus Sequence ◽  
P Element ◽  
Induced Mutations ◽  
P Elements ◽  
Target Dna ◽  
Complex Locus ◽  
Additional Level ◽  
Derivatives Of

P elements move about the Drosophila melanogaster genome in a nonrandom fashion, preferring some chromosomal targets for insertion over others (J. C. J. Eeken, F. H. Sobels, V. Hyland, and A. P. Schalet, Mutat. Res. 150:261-275, 1985; W. R. Engels, Annu. Rev. Genet. 17:315-344, 1983; M. D. Golubovsky, Y. N. Ivanov, and M. M. Green, Proc. Natl. Acad. Sci. USA 74:2973-2975, 1977; M. J. Simmons and J. K. Lim, Proc. Natl. Acad. Sci. USA 77:6042-6046, 1980). Some of this specificity may be due to recognition of a particular DNA sequence in the target DNA; derivatives of an 8-base-pair consensus sequence are occupied by these transposable elements at many different chromosomal locations (K. O'Hare and G. M. Rubin, Cell 34:25-36, 1983). An additional level of specificity of P-element insertions is described in this paper. Of 14 mutations induced in the complex locus Notch by hybrid dysgenesis, 13 involved P-element insertions at or near the transcription start site of the gene. This clustering was not seen in other transposable element-induced mutations of Notch. DNA sequences homologous to the previously described consensus target for P-element insertion are not preferentially located in this region of the locus. The choice of a chromosomal site for integration appears to be based on more subtle variations in chromosome structure that are probably associated with activation or expression of the target gene.

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.

Aberrant splicing and transcription termination caused by P element insertion into the intron of a Drosophila gene.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 327-335 ◽  
Author(s):  
H Horowitz ◽  
C A Berg
Keyword(s):  
Insertional Mutagenesis ◽  
Transcription Termination ◽  
P Element ◽  
Untranslated Regions ◽  
Induced Mutations ◽  
Aberrant Splicing ◽  
P Elements ◽  
Dominant Mutant ◽  
Varied Function ◽  
Mutant Lines

Abstract Insertional mutagenesis screens using the P[lacZ, rosy+] (PZ) transposable element have provided thousands of mutant lines for analyzing genes of varied function in the fruitfly, Drosophila melanogaster. As have been observed with other P elements, many of the PZ-induced mutations result from insertion of the P element into the promoter or 5' untranslated regions of the affected gene. We document here a novel mechanism for mutagenesis by this element. We show that sequences present within the element direct aberrant splicing and termination events that produce a mRNA composed of 5' sequences from the mutated gene (in this case, pipsqueak) and 3' sequences from within the P[lacZ, rosy+] element. These truncated RNAs could yield proteins with dominant mutant effects.

scholarly journals Restriction of P-element insertions at the Notch locus of Drosophila melanogaster.

1987 ◽  
Vol 7 (4) ◽  
pp. 1545-1548 ◽  
Author(s):  
M R Kelley ◽  
S Kidd ◽  
R L Berg ◽  
M W Young
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Sequences ◽  
Consensus Sequence ◽  
P Element ◽  
Induced Mutations ◽  
P Elements ◽  
Target Dna ◽  
Complex Locus ◽  
Additional Level ◽  
Derivatives Of

P elements move about the Drosophila melanogaster genome in a nonrandom fashion, preferring some chromosomal targets for insertion over others (J. C. J. Eeken, F. H. Sobels, V. Hyland, and A. P. Schalet, Mutat. Res. 150:261-275, 1985; W. R. Engels, Annu. Rev. Genet. 17:315-344, 1983; M. D. Golubovsky, Y. N. Ivanov, and M. M. Green, Proc. Natl. Acad. Sci. USA 74:2973-2975, 1977; M. J. Simmons and J. K. Lim, Proc. Natl. Acad. Sci. USA 77:6042-6046, 1980). Some of this specificity may be due to recognition of a particular DNA sequence in the target DNA; derivatives of an 8-base-pair consensus sequence are occupied by these transposable elements at many different chromosomal locations (K. O'Hare and G. M. Rubin, Cell 34:25-36, 1983). An additional level of specificity of P-element insertions is described in this paper. Of 14 mutations induced in the complex locus Notch by hybrid dysgenesis, 13 involved P-element insertions at or near the transcription start site of the gene. This clustering was not seen in other transposable element-induced mutations of Notch. DNA sequences homologous to the previously described consensus target for P-element insertion are not preferentially located in this region of the locus. The choice of a chromosomal site for integration appears to be based on more subtle variations in chromosome structure that are probably associated with activation or expression of the target gene.

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 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.

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