and : Trajectories of Transposable Elements in Genomes.

During evolution, several types of sequences pass through genomes. Along with mutations and internal genetic tinkering, they are a useful source of genetic variability for adaptation and evolution. Most of these sequences are acquired by horizontal transfers (HT), but some of them may come from the genomes themselves.

The genome sequence of the grape phylloxera provides insights into the evolution, adaptation, and invasion routes of an iconic pest.

Background: Although native to North America, the invasion of the aphid-like grape phylloxera Daktulosphaira vitifoliae across the globe altered the course of grape cultivation. For the past 150 years, viticulture relied on grafting-resistant North American Vitis species as rootstocks, thereby limiting genetic stocks tolerant to other stressors such as pathogens and climate change. Limited understanding of the insect genetics resulted in successive outbreaks across the globe when rootstocks failed.

piRNA and Transposon Dynamics in Drosophila: A Female Story.

The germlines of metazoans contain transposable elements (TEs) causing genetic instability and affecting fitness. To protect the germline from TE activity, gonads of metazoans produce TE-derived PIWI-interacting RNAs (piRNAs) that silence TE expression. In Drosophila, our understanding of piRNA biogenesis is mainly based on studies of the Drosophila melanogaster female germline.

The somatic mobilization of transposable element mariner-Mos1 during the Drosophila lifespan and its biological consequences.

Transposable elements (TEs) are mobile DNA sequences on genomes. Some elements are able to transpose in somatic cells, a process known as somatic transposition (ST), which has been associated with detrimental biological effects. The mariner-Mos1 element of Drosophila promotes transposition in somatic and germline cells and is an excellent model for studies related to the biological consequence of somatic excision (SE).

Diversity and evolution of mariner-like elements in aphid genomes.

Background: Although transposons have been identified in almost all organisms, genome-wide information on mariner elements in Aphididae remains unknown. Genomes of Acyrthosiphon pisum, Diuraphis noxia and Myzus persicae belonging to the Macrosiphini tribe, actually available in databases, have been investigated.

Results: A total of 22 lineages were identified.

Transcriptional polymorphism of piRNA regulatory genes underlies the mariner activity in Drosophila simulans testes.

During colonization of new areas, natural populations have to deal with changing environments, and transposable elements (TEs) can be useful "tools" in the adaptation process as they are major contributor to the structural and functional evolution of genomes. In this general context, the activity (copy number, transcriptional and excision rate) of the mariner mos1 element was estimated in 19 natural populations of D. simulans.

Molecular Evolution of piggyBac Superfamily: From Selfishness to Domestication.

The piggyBac transposable element was originally isolated from the cabbage looper moth, Trichoplusia ni, in the 1980s. Despite its early discovery and specificity compared to the other Class II elements, the diversity and evolution of this superfamily have been only partially analyzed. Two main types of elements can be distinguished: the piggyBac-like elements (PBLE) with terminal inverted repeats, untranslated region, and an open reading frame encoding a transposase, and the piggyBac-derived sequences (PGBD), containing a sequence derived from a piggyBac transposase, and which correspond to domesticated elements.

Experimental evolution reveals hyperparasitic interactions among transposable elements.

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-paste mariner elements during experimental (short- and longer-term) evolution in Drosophila melanogaster Flies with autonomous and nonautonomous mariner copies were introduced in populations containing no active mariner, and TE accumulation was tracked by quantitative PCR for up to 100 generations.

Characterization of irritans mariner-like elements in the olive fruit fly Bactrocera oleae (Diptera: Tephritidae): evolutionary implications.

Genomic variation among species is commonly driven by transposable element (TE) invasion; thus, the pattern of TEs in a genome allows drawing an evolutionary history of the studied species. This paper reports in vitro and in silico detection and characterization of irritans mariner-like elements (MLEs) in the genome and transcriptome of Bactrocera oleae (Rossi) (Diptera: Tephritidae). Eleven irritans MLE sequences have been isolated in vitro using terminal inverted repeats (TIRs) as primers, and 215 have been extracted in silico from the sequenced genome of B.

VHICA, a New Method to Discriminate between Vertical and Horizontal Transposon Transfer: Application to the Mariner Family within Drosophila.

Transposable elements (TEs) are genomic repeated sequences that display complex evolutionary patterns. They are usually inherited vertically, but can occasionally be transmitted between sexually independent species, through so-called horizontal transposon transfers (HTTs). Recurrent HTTs are supposed to be essential in life cycle of TEs, which are otherwise destined for eventual decay.

Characterization of mariner-like transposons of the mauritiana Subfamily in seven tree aphid species.

Mariner-like elements (MLEs) are Class II transposons present in all eukaryotic genomes in which MLEs have been searched for. This article reports the detection of MLEs in seven of the main fruit tree aphid species out of eight species studied. Deleted MLE sequences of 916-919 bp were characterized, using the terminal-inverted repeats (TIRs) of mariner elements belonging to the mauritiana Subfamily as primers.

S-palmitoylation and s-oleoylation of rabbit and pig sarcolipin.

Sarcolipin (SLN) is a regulatory peptide present in sarcoplasmic reticulum (SR) from skeletal muscle of animals. We find that native rabbit SLN is modified by a fatty acid anchor on Cys-9 with a palmitic acid in about 60% and, surprisingly, an oleic acid in the remaining 40%. SLN used for co-crystallization with SERCA1a (Winther, A.

Genomic landscape and evolutionary dynamics of mariner transposable elements within the Drosophila genus.

Background: The mariner family of transposable elements is one of the most widespread in the Metazoa. It is subdivided into several subfamilies that do not mirror the phylogeny of these species, suggesting an ancient diversification. Previous hybridization and PCR studies allowed a partial survey of mariner diversity in the Metazoa.

Internal deletions of transposable elements: the case of Lemi elements.

Mobile elements using a "cut and paste" mechanism of transposition (Class II) are frequently prone to internal deletions and the question of the origin of these copies remains elusive. In this study, we looked for copies belonging to the Lemi Family (Tc1-mariner-IS630 SuperFamily) in the plant genomes, and copies within internal deletions were analyzed in detail. Lemi elements are found exclusively in Eudicots, and more than half of the copies have been deleted.

Genomic parasites or symbionts? Modeling the effects of environmental pressure on transposition activity in asexual populations.

Transposable elements are DNA segments capable of persisting in host genomes by self-replication in spite of deleterious mutagenic effects. The theoretical dynamics of these elements within genomes has been studied extensively, and population genetic models predict that they can invade and maintain as a result of both intra-genomic and inter-individual selection in sexual species. In asexuals, the success of selfish DNA is more difficult to explain.

How does selfing affect the dynamics of selfish transposable elements?

Background: Many theoretical models predicting the dynamics of transposable elements (TEs) in genomes, populations, and species have already been proposed. However, most of them only focus on populations of sexual diploid individuals, and TE dynamics in populations partly composed by autogamous individuals remains poorly investigated. To estimate the impact of selfing on TE dynamics, the short- and long-term evolution of TEs was simulated in outcrossing populations with various proportions of selfing individuals.

Fossil rhabdoviral sequences integrated into arthropod genomes: ontogeny, evolution, and potential functionality.

Retroelements represent a considerable fraction of many eukaryotic genomes and are considered major drives for adaptive genetic innovations. Recent discoveries showed that despite not normally using DNA intermediates like retroviruses do, Mononegaviruses (i.e.

The struggle for life of the genome's selfish architects.

Unlabelled: Transposable elements (TEs) were first discovered more than 50 years ago, but were totally ignored for a long time. Over the last few decades they have gradually attracted increasing interest from research scientists. Initially they were viewed as totally marginal and anecdotic, but TEs have been revealed as potentially harmful parasitic entities, ubiquitous in genomes, and finally as unavoidable actors in the diversity, structure, and evolution of the genome.

Copia retrotransposon in the Zaprionus genus: another case of transposable element sharing with the Drosophila melanogaster subgroup.

Copia is a retrotransposon that appears to be distributed widely among the Drosophilidae subfamily. Evolutionary analyses of regulatory regions have indicated that the Copia retrotransposon evolved through both positive and purifying selection, and that horizontal transfer (HT) could also explain its patchy distribution of the among the subfamilies of the melanogaster subgroup. Additionally, Copia elements could also have transferred between melanogaster subgroup and other species of Drosophilidae-D.

The evolutionary history of mariner-like elements in Neotropical drosophilids.

The evolutionary history of mariner-like elements (MLEs) in 49 mainly Neotropical drosophilid species is described. So far, the investigations about the distribution of MLEs were performed mainly using hybridization assays with the Mos1 element (the first mariner active element described) in a widely range of drosophilid species and these sequences were found principally in species that arose in Afrotropical and Sino-Indian regions. Our analysis in mainly Neotropical drosophilid species shows that twenty-three species presented MLEs from three different subfamilies in their genomes: eighteen species had MLEs from subfamily mellifera, fifteen from subfamily mauritiana and three from subfamily irritans.

Multiple invasions of Gypsy and Micropia retroelements in genus Zaprionus and melanogaster subgroup of the genus Drosophila.

Background: The Zaprionus genus shares evolutionary features with the melanogaster subgroup, such as space and time of origin. Although little information about the transposable element content in the Zaprionus genus had been accumulated, some of their elements appear to be more closely related with those of the melanogaster subgroup, indicating that these two groups of species were involved in horizontal transfer events during their evolution. Among these elements, the Gypsy and the Micropia retroelements were chosen for screening in seven species of the two Zaprionus subgenera, Anaprionus and Zaprionus.

Automatic classification within families of transposable elements: application to the mariner Family.

The higher levels of the classification of transposable elements (TEs) from Classes to Superfamilies or Families, is regularly updated, but the lower levels (below the Family) have received little investigation. In particular, this applies to the Families that include a large number of copies. In this article we propose an automatic classification of DNA sequences.

Evolutionary genetics of Zaprionus. II. Mitochondrial DNA and chromosomal variation of the invasive drosophilid Zaprionus indianus in Egypt.

Zaprionus indianus is an Afrotropical drosophilid species that has expanded its geographical range in the Palearctic region and the Americas during the second half of the last century. It has invaded Egypt within the past two decades from East Africa or Asia and became a dominant species in the drosophilid fauna therein, but the exact date of introduction and source of the propagule remain unknown. Here, we investigate the genetic structure of eight geographical populations within and around the Nile Delta using mitochondrial DNA sequences of the cox2 gene and chromosomal inversion polymorphism.