Structural Maintenance of Chromosome (SMC) Proteins Link Microtubule Stability to Genome Integrity

Structural maintenance of chromosome (SMC) proteins are key organizers of chromosome architecture and are essential for genome integrity. They act by binding to chromatin and connecting distinct parts of chromosomes together. Interestingly, their potential role in providing connections between chromatin and the mitotic spindle has not been explored. Here, we show that yeast SMC proteins bind directly to microtubules and can provide a functional link between microtubules and DNA. We mapped the microtubule-binding region of Smc5 and generated a mutant with impaired microtubule binding activity. This mutant is viable in yeast but exhibited a cold-specific conditional lethality associated with mitotic arrest, aberrant spindle structures, and chromosome segregation defects. In an in vitro reconstitution assay, this Smc5 mutant also showed a compromised ability to protect microtubules from cold-induced depolymerization. Collectively, these findings demonstrate that SMC proteins can bind to and stabilize microtubules and that SMC-microtubule interactions are essential to establish a robust system to maintain genome integrity.     

Long‐term temporal and spatial trends in eutrophication status of the Baltic Sea

Much of the Baltic Sea is currently classified as ‘affected by eutrophication’. The causes for this are twofold. First, current levels of nutrient inputs (nitrogen and phosphorus) from human activities exceed the natural processing capacity with an accumulation of nutrients in the Baltic Sea over the last 50–100 years. Secondly, the Baltic Sea is naturally susceptible to nutrient enrichment due to a combination of long retention times and stratification restricting ventilation of deep waters. Here, based on a unique data set collated from research activities and long‐term monitoring programs, we report on the temporal and spatial trends of eutrophication status for the open Baltic Sea over a 112‐year period using the HELCOM Eutrophication Assessment Tool (HEAT 3.0). Further, we analyse variation in the confidence of the eutrophication status assessment based on a systematic quantitative approach using coefficients of variation in the observations. The classifications in our assessment indicate that the first signs of eutrophication emerged in the mid‐1950s and the central parts of the Baltic Sea changed from being unaffected by eutrophication to being affected. We document improvements in eutrophication status that are direct consequences of long‐term efforts to reduce the inputs of nutrients. The reductions in both nitrogen and phosphorus loads have led to large‐scale alleviation of eutrophication and to a healthier Baltic Sea. Reduced confidence in our assessment is seen more recently due to reductions in the scope of monitoring programs. Our study sets a baseline for implementation of the ecosystem‐based management strategies and policies currently in place including the EU Marine Strategy Framework Directives and the HELCOM Baltic Sea Action Plan.     

Diagnosis of urogenital Chlamydia trachomatis infection in women based on mailed samples obtained at home: multipractice comparative study.

OBJECTIVE: To compare urine and vaginal flush samples collected by women at home with endocervical and urethral swabs obtained by general practitioners for their efficacy in the diagnosis of urogenital Chlamydia trachomatis infection. DESIGN: Multipractice comparative study. SETTING: 33 general practices and a central department of clinical microbiology in Aarhus County, Denmark. SUBJECTS: 222 women aged 18-25 years who for any reason had a gynaecological examination. INTERVENTIONS: Endocervical and urethral swabs were obtained by the women''s general practitioners. The same women when at home then collected a first void urine sample, a midstream urine sample, and a vaginal flush sample (using a vaginal pipette) and mailed them to the laboratory. MAIN OUTCOME MEASURES: C trachomatis defected by the polymerase chain reaction and the ligase chain reaction. Eight tests for C trachomatis were performed for every woman. When two of the eight yielded positive results the patient was considered infected. RESULTS: The overall prevalence of C trachomatis infection was 11.2% (23/205 women). Test sensitivities in samples obtained by general practitioners, samples obtained at home subjected to polymerase chain reaction, and samples obtained at home subjected to ligase chain reaction were 91%, 96%, and 100% respectively. The corresponding specificities were 100%, 92.9%, and 99.5%. CONCLUSIONS: The diagnostic efficacy of samples obtained by women at home and mailed to the laboratory was as good as for samples obtained by a general practitioner when using the ligase chain reaction. This may have important implications for the practicability of screening for this common, often asymptomatic, and treatable infection.     

Venom Alkaloid Chemistry of Australian Species of the Monomorium rothsteini Complex,with Particular Reference to Taxonomic Implications

A comparison of the morphology and of the venom alkaloids of the Australian Monomorium rothsteini complex was undertaken. These ants were collected in Australia from western New South Wales, northern Queensland, and northern Northern Territory. Additionally, samples from the M. sordidum complex and M. carinatum complex were examined. Thirteen previously described trans‐2,5‐dialkylpyrrolidines were detected in these ants, along with the novel trans‐2‐ethyl‐5‐[(Z)‐tridec‐4‐enyl]pyrrolidine ( 6 ), whose structure was confirmed by synthesis. The extent of variation and the correlation observed in the morphology and venom chemistry in M. rothsteini samples is very strongly indicative of multiple species in this complex. The presence and location of the C?C bond in 6 reinforces the remarkable structural similarity of the 2‐ethylpyrrolidines in these Monomorium species to the 2‐methylpiperidines in the venoms of many Solenopsis species, and may represent convergent evolution of biosynthetic processes in different genera of solenopsidine ants.     

Maximal oxygen uptake in Danish adolescents 16-19 years of age

A random sample of schoolchildren, 119 boys and 153 girls, was tested in the fall of 1983. The data presented here are anthropometric data (height, weight, fat % and vital capacity) and oxygen uptake directly measured on a bicycle ergometer. The mean height and weight for boys were 179.1 cm and 67.7 kg, and those for girls were 168.0 cm and 59.6 kg. The mean fat content was 9.1% for boys and 19.1% for girls, and their mean vital capacities were 4.91 and 3.61 respectively. The boys had a high maximal oxygen uptake (51.7 ml X kg-1 X min-1) showing no reduction over the age span studied. The girls' maximal oxygen uptake was lower (overall mean 40.0 ml X kg-1 X min-1) with a small reduction from 16 to 19 years of age. When comparing maximal oxygen uptake per kg lean body mass in the two sexes, the boys had 18.4% higher values than the girls, indicating that girls of this age have the lower fitness level. The results of maximal aerobic power measurement in the boys compare well with findings from other investigations using direct measurements, indicating that the fitness of teenage boys is kept at a high level. Comparable data from various countries for girls show different pictures, but it appears that in general they have a low fitness level.     

Photoaffinity spin-labeling of the Ca2+ ATPase in sarcoplasmic reticulum : Evidence for oligomeric structure

A spin labeled fatty acid (16-doxylstearic acid) was linked to a photochemical reacting group (azido derivative). When the molecule is introduced, at a low concentration, into rabbit sarcoplasmic reticulum membranes, the spectrum before illumination is identical to the spectrum obtained with the corresponding spin labeled fatty acid. After illumination, a large immobilized components is seen. It corresponds to about 70% of the ESR signal of the effectively bound label, at room temperature. The fraction of immobilized component varies with temperature, from 100% at 0°C to 50% at 35°C. Addition of a small amount of detergent (dodecyl octaethylene glycol monoether), under non solubilizing conditions, decreases the fraction of signal due to a strongly immobilized probe. A possible interpretation is that the immobilized signal reflects protein bound spin labels trapped in Ca²⁺ ATPase oligomers, which are partially dissociated by detergent addition or temperature increase.