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.

Physical exercise rescues defective neural stem cells and neurogenesis in the adult subventricular zone of Btg1 knockout mice.

Adult neurogenesis occurs throughout life in the dentate gyrus (DG) and the subventricular zone (SVZ), where glia-like stem cells generate new neurons. Voluntary running is a powerful neurogenic stimulus triggering the proliferation of progenitor cells in the DG but, apparently, not in the SVZ. The antiproliferative gene Btg1 maintains the quiescence of DG and SVZ stem cells.

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.

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.

Diversity of cytosolic HSP70 Heat Shock Protein from decapods and their phylogenetic placement within Arthropoda.

The 70kDa heat shock proteins (HSP70) are considered the most conserved members of the HSP family. These proteins are primordial to the cell, because of their implications in many cellular pathways (e. g.

Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates.

The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit.

Mariner transposons are sailing in the genome of the blood-sucking bug Rhodnius prolixus.

Background: The Triatomine bug Rhodnius prolixus is a vector of Trypanosoma cruzi, which causes the Chagas disease in Latin America. R. prolixus can also transfer transposable elements horizontally across a wide range of species.

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.

First evidence of mariner-like transposons in the genome of the marine microalga Amphora acutiuscula (Bacillariophyta).

Mariner-like elements (MLEs) are transposable elements able to move in the host genomes by a "cut and paste" mechanism. They have been found in numerous organisms. We succeeded in amplifying complete and truncated MLEs in the marine diatom Amphora acutiuscula.

The RNA-binding protein Mex3b regulates the spatial organization of the Rap1 pathway.

The four related mammalian MEX-3 RNA-binding proteins are evolutionarily conserved molecules for which the in vivo functions have not yet been fully characterized. Here, we report that male mice deficient for the gene encoding Mex3b are subfertile. Seminiferous tubules of Mex3b-deficient mice are obstructed as a consequence of the disrupted phagocytic capacity of somatic Sertoli cells.

Running rescues defective adult neurogenesis by shortening the length of the cell cycle of neural stem and progenitor cells.

Physical exercise increases the generation of new neurons in adult neurogenesis. However, only few studies have investigated the beneficial effects of physical exercise in paradigms of impaired neurogenesis. Here, we demonstrate that running fully reverses the deficient adult neurogenesis within the hippocampus and subventricular zone of the lateral ventricle, observed in mice lacking the antiproliferative gene Btg1.

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.

CDX2 regulation by the RNA-binding protein MEX3A: impact on intestinal differentiation and stemness.

The homeobox transcription factor CDX2 plays a crucial role in intestinal cell fate specification, both during normal development and in tumorigenic processes involving intestinal reprogramming. The CDX2 regulatory network is intricate, but it has not yet been fully uncovered. Through genome-wide screening of a 3D culture system, the RNA-binding protein MEX3A was identified as putatively involved in CDX2 regulation; therefore, its biological relevance was addressed by setting up cell-based assays together with expression studies in murine intestine.

Btg1 is Required to Maintain the Pool of Stem and Progenitor Cells of the Dentate Gyrus and Subventricular Zone.

Btg1 belongs to a family of cell cycle inhibitory genes. We observed that Btg1 is highly expressed in adult neurogenic niches, i.e.

Regulation of mariner transposition: the peculiar case of Mos1.

Background: Mariner elements represent the most successful family of autonomous DNA transposons, being present in various plant and animal genomes, including humans. The introduction and co-evolution of mariners within host genomes imply a strict regulation of the transposon activity. Biochemical data accumulated during the past decade have led to a convergent picture of the transposition cycle of mariner elements, suggesting that mariner transposition does not rely on host-specific factors.

Direct cooperation between androgen receptor and E2F1 reveals a common regulation mechanism for androgen-responsive genes in prostate cells.

We have studied the regulation of ATAD2 gene expression by androgens in prostate cells. ATAD2 is a coactivator of the androgen receptor (AR) and the MYC protein. We showed that ATAD2 expression is directly regulated by AR via an AR binding sequence (ARBS) located in the distal enhancer of its regulatory region.

Evolution of cuticular hydrocarbons of Hawaiian Drosophilidae.

Hawaiian Drosophila offer an excellent model for adaptive evolution. More than 500 species are reported in Hawaiian islands, and there is considerable diversity in behavior and morphology. Such diversity is mainly driven by sexual selection.

Role of miR-34c microRNA in the late steps of spermatogenesis.

Spermatogenesis is a cyclic process in which diploid spermatogonia differentiate into haploid spermatozoa. This process is highly regulated, notably at the post-transcriptional level. MicroRNAs (miRNAs), single-stranded noncoding RNA molecules of about 20-25 nucleotides, are implicated in the regulation of many important biological pathways such as proliferation, apoptosis, and differentiation.

Transcriptional activation of hTERT, the human telomerase reverse transcriptase, by nuclear factor of activated T cells.

Telomerase is essential for telomere maintenance, and its activation is thought to be a critical step in cellular immortalization and tumorigenesis. Human telomerase reverse transcriptase (hTERT) is a major component of telomerase activity. We show here that hTERT is expressed soon after lymphocyte activation and that its expression is inhibited by rapamycin, wortmannin, and FK506, which was the most potent inhibitor.

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.

Vinorelbine induces beta3-tubulin gene expression through an AP-1 Site.

Although the correlation between beta3-tubulin expression level in tumors has been well correlated with clinical outcome in patients receiving microtubule-targeted agents, the regulation of this protein remains poorly understood. Recently, new insight of regulatory processes was offered with the cloning of the gene promoter. In this study beta3-tubulin gene expression was induced in response to exposure to various antimicrotubule agents such as vinorelbine and paclitaxel.

Two new miR-16 targets: caprin-1 and HMGA1, proteins implicated in cell proliferation.

Background Information: miRNAs (microRNAs) are a class of non-coding RNAs that inhibit gene expression by binding to recognition elements, mainly in the 3' UTR (untranslated region) of mRNA. A single miRNA can target several hundred mRNAs, leading to a complex metabolic network. miR-16 (miRNA-16), located on chromosome 13q14, is involved in cell proliferation and apoptosis regulation; it may interfere with either oncogenic or tumour suppressor pathways, and is implicated in leukaemogenesis.