Histone removal in sperm protects paternal chromosomes from premature division at fertilization.

The global replacement of histones with protamines in sperm chromatin is widespread in animals, including insects, but its actual function remains enigmatic. We show that in the paternal effect mutant (), sperm chromatin retains germline histones H3 and H4 genome wide without impairing sperm viability. However, after fertilization, sperm chromosomes are targeted by the egg chromosomal passenger complex and engage into a catastrophic premature division in synchrony with female meiosis II.

Paternal genome elimination: patterns and mechanisms of drive and silencing.

In thousands of arthropod species, males inherit, but subsequently eliminate the entire haploid genome of their father. However, why this peculiar reproductive strategy evolved repeatedly across diverse species and what mechanisms are involved in paternal genome elimination (PGE) remains largely unknown. In this review, we summarize what we know about the patterns of paternal chromosome elimination during various stages of development in the diverse taxa that have been studied.

Distinct spermiogenic phenotypes underlie sperm elimination in the Segregation Distorter meiotic drive system.

Segregation Distorter (SD) is a male meiotic drive system in Drosophila melanogaster. Males heterozygous for a selfish SD chromosome rarely transmit the homologous SD+ chromosome. It is well established that distortion results from an interaction between Sd, the primary distorting locus on the SD chromosome and its target, a satellite DNA called Rsp, on the SD+ chromosome.

A Role for COMPASS in Germline Chromatin Organization.

Deposition of histone H3 lysine 4 (H3K4) methylation at promoters is catalyzed by the SET1/COMPASS complex and is associated with context-dependent effects on gene expression and local changes in chromatin organization. The role of SET1/COMPASS in shaping chromosome architecture has not been investigated. Here we used to address this question through a live imaging approach and genetic analysis.

Association of lumbosacral transitional vertebra and sacroiliitis in patients with inflammatory back pain suggesting axial spondyloarthritis.

Objective: Lumbosacral transitional vertebras (LSTVs) are common in the general population, but their potential impact on the sacroiliac joints is unclear. We aimed to determine the prevalence of LSTVs and to assess their associations with sacroiliitis by standard radiography and MRI in a population with suspected axial spondyloarthritis.

Methods: The data were from the DESIR cohort of 688 patients aged 18-50 years with inflammatory low back pain for ⩾3 months but <3 years suggesting axial spondyloarthritis.

Physical and functional interaction between SET1/COMPASS complex component CFP-1 and a Sin3S HDAC complex in C. elegans.

The CFP1 CXXC zinc finger protein targets the SET1/COMPASS complex to non-methylated CpG rich promoters to implement tri-methylation of histone H3 Lys4 (H3K4me3). Although H3K4me3 is widely associated with gene expression, the effects of CFP1 loss vary, suggesting additional chromatin factors contribute to context dependent effects. Using a proteomics approach, we identified CFP1 associated proteins and an unexpected direct link between Caenorhabditis elegans CFP-1 and an Rpd3/Sin3 small (SIN3S) histone deacetylase complex.

Spinal-pelvic orientation: potential effect on the diagnosis of spondyloarthritis.

Objective: To assess associations of spinal-pelvic orientation with clinical and imaging-study findings suggesting axial SpA (axSpA) in patients with recent-onset inflammatory back pain.

Methods: Spinal-pelvic orientation was assessed in DESIR cohort patients with recent-onset inflammatory back pain and suspected axSpA, by using lateral lumbar-spine radiographs to categorize sacral horizontal angle (<40° vs ⩾40°), lumbosacral angle (<15° vs ⩾15°) and lumbar lordosis (LL, <50° vs ⩾50°). Associations between these angle groups and variables collected at baseline and 2 years later were assessed using the χ2 test (or Fisher's exact) and the Mann-Whitney test.

Peripheral-blood b-cell subset disturbances in inflammatory joint diseases induced by Tropheryma whipplei.

Objective: To look for abnormalities in circulating B-cell subsets in patients with rheumatic symptoms of Whipple's disease (WD).

Method: Consecutive patients seen between 2010 and 2016 for suspected inflammatory joint disease were identified retrospectively. Results of standardized immunological and serological tests and of peripheral-blood B-cell and T-cell subset analysis by flow cytometry were collected.

Usefulness of polymerase chain reaction for diagnosing Whipple's disease in rheumatology.

Objectives: To determine when Tropheryma whipplei polymerase chain reaction (PCR) is appropriate in patients evaluated for rheumatological symptoms.

Methods: In a retrospective observational study done in rheumatology units of five hospitals, we assessed the clinical and radiological signs that prompted T. whipplei PCR testing between 2010 and 2014, the proportion of patients diagnosed with Whipple's disease, the number of tests performed and the number of diagnoses according to the number of tests, the patterns of Whipple's disease, and the treatments used.

The C. elegans SET-2/SET1 histone H3 Lys4 (H3K4) methyltransferase preserves genome stability in the germline.

Maintaining the integrity of genetic information across generations is essential for both cell survival and reproduction, and requires the timely repair of DNA damage. Histone-modifying enzymes play a central role in the DNA repair process through the deposition and removal of post-translational modifications on the histone tails. Specific histone modification act in the DNA repair process through the recruitment of proteins and complexes with specific enzymatic activities, or by altering the chromatin state at the site of DNA lesions.

Mobility of cesium through the Callovo-Oxfordian claystones under partially saturated conditions.

The diffusion of cesium was studied in an unsaturated core of Callovo-Oxfordian claystone, which is a potential host rock for retrievable disposal of high-level radioactive wastes. In-diffusion laboratory experiments were performed on rock samples with water saturation degrees ranging from 81% to 100%. The analysis of both cesium concentration monitoring in the source reservoir and post-mortem cesium rock concentration profile of the samples was carried out using a chemical-transport code where the sorption of cesium was described by a multisite ion-exchange model.

Effect of temperature on the containment properties of argillaceous rocks: The case study of Callovo-Oxfordian claystones.

Heat generated by high level radioactive wastes could alter the performance of a clay repository. It was intended to investigate the effect of such a thermal period on the diffusive properties of Callovo-Oxfordian claystones. Thus, through-diffusion experiments with HTO, Cl-36, Na-22 and Cs-137 were performed before, during and after stages of heating at 80°C that lasted for up to one year.