scholarly journals Experimental evolution reveals hyperparasitic interactions among transposable elements

2016 ◽  
Vol 113 (51) ◽  
pp. 14763-14768 ◽  
Author(s):  
Émilie Robillard ◽  
Arnaud Le Rouzic ◽  
Zheng Zhang ◽  
Pierre Capy ◽  
Aurélie Hua-Van
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Dna Sequences ◽  
Experimental Evolution ◽  
Substantial Part ◽  
Repeated Dna ◽  
Selfish Dna ◽  
Transposition Rate ◽  
Term Evolution ◽  
Major Interest

Transposable elements (TEs) are repeated DNA sequences that can constitute a substantial part of genomes. Studying TEs’ activity, interactions, and accumulation dynamics is thus of major interest to understand genome evolution. Here, we describe the transposition dynamics of cut-and-pastemarinerelements during experimental (short- and longer-term) evolution inDrosophila melanogaster. Flies with autonomous and nonautonomousmarinercopies were introduced in populations containing no activemariner, and TE accumulation was tracked by quantitative PCR for up to 100 generations. Our results demonstrate that (i) activemarinerelements are highly invasive and characterized by an elevated transposition rate, confirming their capacity to spread in populations, as predicted by the “selfish-DNA” mechanism; (ii) nonautonomous copies act as parasites of autonomousmarinerelements by hijacking the transposition machinery produced by activemariner, which can be considered as a case of hyperparasitism; (iii) this behavior resulted in a failure of active copies to amplify which systematically drove the whole family to extinction in less than 100 generations. This study nicely illustrates how the presence of transposition-competitive variants can deeply impair TE dynamics and gives clues to the extraordinary diversity of TE evolutionary histories observed in genomes.

scholarly journals Coevolution of the Telomeric Retrotransposons Across Drosophila Species

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1113-1124 ◽  
Author(s):  
Elena Casacuberta ◽  
Mary-Lou Pardue
Keyword(s):  
Drosophila Melanogaster ◽  
Nucleotide Sequence ◽  
Transposable Elements ◽  
Dna Sequences ◽  
Nucleotide Sequence Identity ◽  
Sequence Evolution ◽  
Repeated Dna ◽  
Repeated Dna Sequences ◽  
Sequence Identity ◽  
Species Complexes

AbstractAs in other eukaryotes, telomeres in Drosophila melanogaster are composed of long arrays of repeated DNA sequences. Remarkably, in D. melanogaster these repeats are produced, not by telomerase, but by successive transpositions of two telomere-specific retrotransposons, HeT-A and TART. These are the only transposable elements known to be completely dedicated to a role in chromosomes, a finding that provides an opportunity for investigating questions about the evolution of telomeres, telomerase, and the transposable elements themselves. Recent studies of D. yakuba revealed the presence of HeT-A elements with precisely the same unusual characteristics as HeT-Amel although they had only 55% nucleotide sequence identity. We now report that the second element, TART, is also a telomere component in D. yakuba; thus, these two elements have been evolving together since before the separation of the melanogaster and yakuba species complexes. Like HeT-Ayak, TART yak is undergoing concerted sequence evolution, yet they retain the unusual features TART mel shares with HeT-Amel. There are at least two subfamilies of TART yak with significantly different sequence and expression. Surprisingly, one subfamily of TART yak has >95% sequence identity with a subfamily of TART mel and shows similar transcription patterns. As in D. melanogaster, other retrotransposons are excluded from the D. yakuba terminal arrays studied to date.

Methylation of repeated DNA sequences and genome stability in Ascobolus immersus

1995 ◽  
Vol 73 (S1) ◽  
pp. 221-225 ◽  
Author(s):  
Vincent Colot ◽  
Christophe Goyon ◽  
Godeleine Faugeron ◽  
Jean-Luc Rossignol
Keyword(s):  
Transposable Elements ◽  
Dna Sequences ◽  
Genome Stability ◽  
Methylation Status ◽  
Biological Significance ◽  
Dna Repeats ◽  
Repeated Dna ◽  
Key Words Dna ◽  
Ectopic Recombination ◽  
Ascobolus Immersus

In the ascomycete Ascobolus immersus, artificially repeated DNA fragments are subject to a process of methylation induced premeiotically (MIP). Artificially repeated genes are inactivated as a consequence of this methylation. Once established, both methylation and inactivation are stably maintained (although they can be reversed) through vegetative as well as sexual reproduction, even after the different copies of the repeat have segregated from each other. Therefore, MIP constitutes a process of epimutation. The biological significance of MIP remains unknown. Two likely hypotheses, which are not mutually exclusive, are that MIP acts to limit the spread of transposable elements throughout the genome or that it acts to reduce ectopic recombination between dispersed sequences. In this second hypothesis, targets for MIP are also likely to be mainly transposable elements. For these reasons, we have recently started a search for such elements in Ascobolus. Results obtained so far indicate that several types of transposable elements or remnants of them are present in Ascobolus. Analysis of their methylation status suggests that they are indeed likely targets of MIP and in one case points to a possible strategy that transposons might use to escape MIP, simply by reducing their size. Key words: DNA repeats, methylation, genome stability, Ascobolus immersus.

The Organization of Highly Repeated DNA Sequences in Drosophila melanogaster Chromosomes

1974 ◽  
Vol 38 (0) ◽  
pp. 405-416 ◽  
Author(s):  
W. J. Peacock ◽  
D. Brutlag ◽  
E. Goldring ◽  
R. Appels ◽  
C. W. Hinton ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Sequences ◽  
Repeated Dna ◽  
Repeated Dna Sequences ◽  
Highly Repeated Dna

Repetitive DNA and chromosome evolution in plants

1986 ◽  
Vol 312 (1154) ◽  
pp. 227-242 ◽  
Keyword(s):  
Transposable Elements ◽  
Repetitive Dna ◽  
Dna Sequences ◽  
Dna Content ◽  
Molecular Mechanisms ◽  
Chromosome Structure ◽  
Species Turnover ◽  
Inverted Terminal Repeat ◽  
Repeated Dna ◽  
Higher Plant

Most higher plant genomes contain a high proportion of repeated sequences. Thus repetitive DNA is a major contributor to plant chromosome structure. The variation in total DNA content between species is due mostly to variation in repeated DNA content. Some repeats of the same family are arranged in tandem arrays, at the sites of heterochromatin. Examples from the Secale genus are described. Arrays of the same sequence are often present at many chromosomal sites. Heterochromatin often contains arrays of several unrelated sequences. The evolution of such arrays in populations is discussed. Other repeats are dispersed at many locations in the chromosomes. Many are likely to be or have evolved from transposable elements. The structures of some plant transposable elements, in particular the sequences of the terminal inverted repeats, are described. Some elements in soybean, antirrhinum and maize have the same inverted terminal repeat sequences. Other elements of maize and wheat share terminal homology with elements from yeast, Drosophila , man and mouse. The evolution of transposable elements in plant populations is discussed. The amplification, deletion and transposition of different repeated DNA sequences and the spread of the mutations in populations produces a turnover of repetitive DNA during evolution. This turnover process and the molecular mechanisms involved are discussed and shown to be responsible for divergence of chromosome structure between species. Turnover of repeated genes also occurs. The molecular processes affecting repeats imply that the older a repetitive DNA family the more likely it is to exist in different forms and in many locations within a species. Examples to support this hypothesis are provided from the Secale genus.

scholarly journals Mapping simple repeated DNA sequences in heterochromatin of Drosophila melanogaster.

Genetics ◽  
1993 ◽  
Vol 134 (4) ◽  
pp. 1149-1174 ◽  
Author(s):  
A R Lohe ◽  
A J Hilliker ◽  
P A Roberts
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Dna Sequences ◽  
Repeated Sequences ◽  
Chromosome 2 ◽  
Repeated Dna ◽  
Mitotic Chromosomes ◽  
Satellite Dnas ◽  
Repeated Dna Sequences ◽  
Chromosome Map

Abstract Heterochromatin in Drosophila has unusual genetic, cytological and molecular properties. Highly repeated DNA sequences (satellites) are the principal component of heterochromatin. Using probes from cloned satellites, we have constructed a chromosome map of 10 highly repeated, simple DNA sequences in heterochromatin of mitotic chromosomes of Drosophila melanogaster. Despite extensive sequence homology among some satellites, chromosomal locations could be distinguished by stringent in situ hybridizations for each satellite. Only two of the localizations previously determined using gradient-purified bulk satellite probes are correct. Eight new satellite localizations are presented, providing a megabase-level chromosome map of one-quarter of the genome. Five major satellites each exhibit a multi-chromosome distribution, and five minor satellites hybridize to single sites on the Y chromosome. Satellites closely related in sequence are often located near one another on the same chromosome. About 80% of Y chromosome DNA is composed of nine simple repeated sequences, in particular (AAGAC)n (8 Mb), (AAGAG)n (7 Mb) and (AATAT)n (6 Mb). Similarly, more than 70% of the DNA in chromosome 2 heterochromatin is composed of five simple repeated sequences. We have also generated a high resolution map of satellites in chromosome 2 heterochromatin, using a series of translocation chromosomes whose breakpoints in heterochromatin were ordered by N-banding. Finally, staining and banding patterns of heterochromatic regions are correlated with the locations of specific repeated DNA sequences. The basis for the cytochemical heterogeneity in banding appears to depend exclusively on the different satellite DNAs present in heterochromatin.

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