Eukaryote DIRS1-like retrotransposons: an overview

<p>Abstract</p> <p>Background</p> <p>DIRS1-like elements compose one superfamily of tyrosine recombinase-encoding retrotransposons. They have been previously reported in only a few diverse eukaryote species, describing a patchy distribution, and little is known about their origin and dynamics. Recently, we have shown that these retrotransposons are common among decapods, which calls into question the distribution of DIRS1-like retrotransposons among eukaryotes.</p> <p>Results</p> <p>To determine the distribution of DIRS1-like retrotransposons, we developed a new computational tool, ReDoSt, which allows us to identify well-conserved DIRS1-like elements. By screening 274 completely sequenced genomes, we identified more than 4000 DIRS1-like copies distributed among 30 diverse species which can be clustered into roughly 300 families. While the diversity in most species appears restricted to a low copy number, a few bursts of transposition are strongly suggested in certain species, such as <it>Danio rerio </it>and <it>Saccoglossus kowalevskii</it>.</p> <p>Conclusion</p> <p>In this study, we report 14 new species and 8 new higher taxa that were not previously known to harbor DIRS1-like retrotransposons. Now reported in 61 species, these elements appear widely distributed among eukaryotes, even if they remain undetected in streptophytes and mammals. Especially in unikonts, a broad range of taxa from Cnidaria to Sauropsida harbors such elements. Both the distribution and the similarities between the DIRS1-like element phylogeny and conventional phylogenies of the host species suggest that DIRS1-like retrotransposons emerged early during the radiation of eukaryotes.</p

Description, évolution et facteurs pronostiques des infections pulmonaires à pneumocystis jirovecii en réanimation (comparaison selon le statut VIH au sein d une cohorte rétrospective)

PARIS7-Xavier Bichat (751182101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Le Palais d’Amathonte : bilan des fouilles des dix dernières années (2004-2014)

Blandin Béatrice, Petit Thierry, Marangou Antigone, Tassignon Isabelle. Le Palais d’Amathonte : bilan des fouilles des dix dernières années (2004-2014). In: Dialogues d'histoire ancienne, vol. 41, n°2, 2015. pp. 187-201

Ebola: should we consider influenza vaccination?

International audienc

Metals and radionuclides (MaR) in the Alum Shale of Denmark: Identification of MaR-bearing phases for the better management of hydraulic fracturing waters

International audienc

Hepatitis C Virus Proteins Induce Lipogenesis and Defective Triglyceride Secretion in Transgenic Mice*

Chronic hepatitis C virus (HCV) infection is associated with altered lipid metabolism and hepatocellular steatosis. Virus-induced steatosis is a cytopathic effect of HCV replication. The goal of this study was to examine the mechanisms underlying HCV-induced lipid metabolic defects in a transgenic mouse model expressing the full HCV protein repertoire at levels corresponding to natural human infection. In this model, expression of the HCV full-length open reading frame was associated with hepatocellular steatosis and reduced plasma triglyceride levels. Triglyceride secretion was impaired, whereas lipogenesis was activated. Increased lipogenic enzyme transcription was observed, resulting from maturational activation and nuclear translocation of sterol regulatory element-binding protein 1c (SREBP1c). However, endoplasmic reticulum (ER) stress markers were expressed at similar levels in both HCV transgenic mice and their wild type counterparts, suggesting that SREBP1c proteolytic cleavage in the presence of HCV proteins was independent of ER stress. In conclusion, transgenic mice expressing the HCV full-length polyprotein at low levels have decreased plasma triglyceride levels and develop hepatocellular steatosis in the same way as HCV-infected patients. In these mice, SREBP1c activation by one or several HCV proteins induces de novo triglyceride synthesis via the lipogenic pathway, in a manner independent of ER stress, whereas triglyceride secretion is simultaneously reduced

Rapid emergence of Mycobacterium tuberculosis bedaquiline resistance: lessons not to repeat past errors

On behalf of the CNR MyRMA and the Tuberculosis Consilium of the CNR MyRMAInternational audienceBedaquiline (BDQ) has demonstrated potent clinical activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis complex strains [1–3]. It has now been used in >50 countries, and it is estimated that ∼2500 patients had been treated with BDQ by the end of 2015. In spite of its recent clinical use, there are few reports of BDQ-resistant strains [4, 5]. Mutations in the rv0678 gene encoding the MmpL5 efflux pump repressor generate low-level BDQ resistance and clofazimine (CFZ) cross-resistance [6]. To our knowledge, this is the sole mechanism of BDQ resistance described in clinical strains [4, 5]. Despite its introduction in France in 2011 for XDR- and MDR-tuberculosis (TB) treatment, we report herein four BDQ-resistant cases, and discuss strategies to avoid a surge of BDQ resistance