Ethylene stimulates growth and affects fatty acid content of Synechocystis sp. PCC 6803

This set of results shows that the growth of wild type Synechocystis sp. PCC 6803 was enhanced by exogenous ethylene and inhibited by 1-methylcyclopropene (1-MCP), a specific inhibitor of ethylene receptors. The fact that the growth of a Synechocystis sp. PCC 6803 strain with the ethylene receptor deleted was unaffected by exogenous ethylene, brings additional proof that this is a specific effect of ethylene. The results also confirm previous observations regarding the positive impact of ethylene on the photochemical efficiency of PSII. Additionally, it was observed that exogenous ethylene enhanced accumulation of C16:0 and C18:0 and C18:1 in the wild type strain. Finally, observations were performed regarding the capacity of the wild type strain to biosynthesize ethylene in the culture medium in the presence of methionine. These results and the recent description of an ethylene receptor in Synechocystis should lead to new areas of research in the field of microalgae

Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

The Intra- and Inter-Rater Reliability of a Variety of Testing Methods to Measure Shoulder Range of Motion, Hand-behind-Back and External Rotation Strength in Healthy Participants

This study determined the intra- and inter-rater reliability of various shoulder testing methods to measure flexion range of motion (ROM), hand-behind-back (HBB), and external rotation (ER) strength. Twenty-four healthy adults (mean age of 31.2 and standard deviation (SD) of 10.9 years) without shoulder or neck pathology were assessed by two examiners using standardised testing protocols to measure shoulder flexion with still photography, HBB with tape measure, and isometric ER strength in two abduction positions with a hand-held dynamometer (HHD) and novel stabilisation device. Intraclass correlation coefficient (ICC) established relative reliability. Standard error of measurement (SEM) and minimum detectable change (MDC) established absolute reliability. Differences between raters were visualised with Bland–Altman plots. A paired t-test assessed for differences between dominant and non-dominant sides. Still photography demonstrated good intra- and inter-rater reliability (ICCs 0.75–0.86). HBB with tape measure demonstrated excellent inter- and intra-rater reliability (ICCs 0.94–0.98). Isometric ER strength with HHD and a stabilisation device demonstrated excellent intra-rater and inter-rater reliability in 30° and 45° abduction (ICCs 0.96–0.98). HBB and isometric ER at 45° abduction differed significantly between dominant and non-dominant sides. Standardised shoulder ROM and strength tests provide good to excellent reliability. HBB with tape measure and isometric strength testing with HHD stabilisation are clinically acceptable

Comparaison franco-canadienne du développement des Cercles de soutien et de responsabilité (CSR) pour la prévention du risque de récidive des délinquants sexuels

International audienc

Expanding the phenotypic spectrum associated with OPHN1 variants

Genomic sequencing has allowed for the characterization of new gene-to-disease relationships, as well as the identification of variants in established disease genes in patients who do not fit the classically-described phenotype. This is especially true in rare syndromes where the clinical spectrum is not fully known. After a lengthy and costly diagnostic odyssey, patients with atypical presentations may be left with many questions even after a genetic diagnosis is identified. We present a 22-year old male with hypotonia, developmental delay, seizure disorder, and dysmorphic facial features who enrolled in our rare disease research center at 18 years of age, where exome sequencing revealed a novel, likely pathogenic variant in the OPHN1 gene. Through efforts by the study team and collaborations with the larger genetics community, contacts with other families with OPHN1 variants were eventually made, and outreach by these families expanded the patient network. This partnership between families and researchers facilitated the gathering of phenotypic information, allowing for comparison of clinical presentations among three new patients and those previously reported in the literature. These comparisons found previously unreported commonalities between the newly identified patients, such as the presence of otitis media and the lack of genitourinary abnormalities (i.e. hypoplastic scrotum, microphallus, cryptorchidism), which had been noted to be classic features of patients with OPHN1 variants. As genomic sequencing becomes more common, connecting patients with novel variants in the same gene will facilitate phenotypic analysis and continue to refine the clinical spectrum associated with that gene

Molecular biology: chromosome guardians on duty

Segregation of homologous maternal and paternal centromeres to opposite poles during meiosis I depends on post-replicative crossing over between homologous non-sister chromatids, which creates chiasmata and therefore bivalent chromosomes. Destruction of sister chromatid cohesion along chromosome arms due to proteolytic cleavage of cohesin's Rec8 subunit by separase resolves chiasmata and thereby triggers the first meiotic division. This produces univalent chromosomes, the chromatids of which are held together by centromeric cohesin that has been protected from separase by shugoshin (Sgo1/MEI-S332) proteins. Here we show in both fission and budding yeast that Sgo1 recruits to centromeres a specific form of protein phosphatase 2A (PP2A). Its inactivation causes loss of centromeric cohesin at anaphase I and random segregation of sister centromeres at the second meiotic division. Artificial recruitment of PP2A to chromosome arms prevents Rec8 phosphorylation and hinders resolution of chiasmata. Our data are consistent with the notion that efficient cleavage of Rec8 requires phosphorylation of cohesin and that this is blocked by PP2A at meiosis I centromeres