Inflammatory effects of particulate matter air pollution

Environmental Science and Pollution Research - Air pollution is an important cause of non-communicable diseases globally with particulate matter (PM) as one of the main air pollutants. PM is...     

Sexual selection on alleles that determine body size in the swordtail Xiphophorus nigrensis

Summary In a natural population, we document changes in the frequencies of alleles influencing body size and size-correlated alternative male reproductive tactics, and we examine the possible role of sexual selection in producing these changes. Male swordtails (Xiphophorus nigrensis, Rio Choy) exhibit three body size classes (small, intermediate, and large) that primarily derive from allelic variation (s, I, L) at the Y-linked pituitary (P) locus. Some XX individuals are male. They are small and can be fathered either by XX or XY males. We compared the frequencies of Y-linked P alleles across two generations in a natural population. There was a significant decrease in the Y-s genotype relative to Y-I and Y-L genotypes. Laboratory experiments suggest that the disadvantage of Y-s resulted, at least in part, from female preference for larger courting males relative to small chasing males. All larger courting males are of the Y-I or Y-L genotypes. Although the frequency of Y-linked P alleles changed across generations, there was no change in the distribution of male body size classes. The stability of the phenotypic distribution across generations, despite changes in P allele frequencies, was maintained by the production of small XX sons by Y-I and Y-L males. Offprint requests to: M.J. Ryan     

How <Emphasis Type="Italic">Doratomyces stemonitis</Emphasis> copes with Benzoxazolin-2(3<Emphasis Type="Italic">H</Emphasis>)-one (BOA), its derivatives and detoxification products

Summary. Doratomyces stemonitis (Hyphomycetales, Dematiaceae) is a saprotrophic fungus belonging to the mycobiota of the cereal rhizosphere. The fungus is able to metabolize benzoxazolin-2-(3H)-one and a variety of its derivatives including higher plant detoxification products, microbial degradation products and the chemically rather stable 2-amino-(3H)-phenoxazin-3-one. D. stemonitis can use all of these compounds as sole C-sources but their utilization, especially that of microbial degradation products and 2-amino-(3H)-phenoxazin-3-one, seems to be highly energy consuming, resulting in slow mycelium growth and a change of colony morphology. Benzoxazolin-2-(3H)-one derived compounds induce the synthesis of different isoforms of a glycosylated protein with sequence homologies to the endo-1,3-β-glucanase Asp f2, an allergen from Aspergillus fumigatus and other Asp f2-like proteins e.g., from Verticillium dahliae or PRA1 antigen from Candida albicans. The induction of the protein is regarded as a stress response.     

Demonstration of spontaneously dividing male fetal cells in maternal blood by negative magnetic cell sorting and fish

We investigated a case of massive feto-maternal bleeding by using negative magnetic cell sorting (MACS) and fluorescent in situ hybridization (FISH). A 37-year-old pregnant woman had an uncomplicated amniocentesis for advanced maternal age at 16 weeks' gestation. The fetal karyotype was 46, XY. At 19 weeks' gestation, she had a minor car accident and slight vaginal bleeding. A subsequent Kleihauer-Betke test showed a 140 ml feto-maternal haemorrhage. Serial sonographic examinations indicated a normal fetus and placenta. We performed FISH analysis on maternal peripheral blood at 25 weeks. Anti-CD45 and MACS were used to deplete maternal leucocytes, enriching the proportion of fetal nucleated erythrocytes present. The isolated cells were analysed by using dual-colour FISH with X and Y specific probes. Approximately 65 800 nucleated cells were obtained after MACS depletion. A total of 234 cells were analysed by FISH. The results revealed that 70 of the nucleated cells (30 per cent) were male with one X and one Y signal. Among these cells, six male metaphases were observed in spontaneously dividing cells.     

Noninvasive prenatal testing creates an opportunity for antenatal treatment of Down syndrome

Trisomy 21 (T21) is the most common autosomal aneuploidy that is associated with intellectual disability. It is the focus of many prenatal screening programs across the globe. Pregnant women who receive a prenatal diagnosis of T21 in their fetus currently have the option of continuing or terminating their pregnancy, but no fetal treatment is available. In this paper, we review compelling morphogenetic, cellular, and molecular studies that, taken together, suggest that there is an important window of opportunity during fetal life to positively impact brain development to improve postnatal neurocognition and behavior. Although substantial progress has been made in understanding the basic neurobiology of Down syndrome (DS), the majority of pre-clinical trials is currently focused on adults. There are a number of challenges in the identification and development of novel antenatal therapies for DS, including the lack of toxicity and teratogenicity for the pregnant woman and the fetus, evidence that the compounds can cross the placenta and achieve therapeutic levels, and the demonstration of clinical improvement. Preliminary experiments in mouse models suggest that prenatal treatment of DS is an achievable goal. © 2013 John Wiley & Sons, Ltd.     

Amazonian deforestation and soil biodiversity

Clearance and perturbation of Amazonian forests are one of the greatest threats to tropical biodiversity conservation of our times. A better understanding of how soil communities respond to Amazonian deforestation is crucially needed to inform policy interventions that effectively protect biodiversity and the essential ecosystem services it provides. We assessed the impact of deforestation and ecosystem conversion to arable land on Amazonian soil biodiversity through a meta-analysis. We analyzed 274 pairwise comparisons of soil biodiversity in Amazonian primary forests and sites under different stages of deforestation and land-use conversion: disturbed (wildfire and selective logging) and slash-and-burnt forests, pastures, and cropping systems. Overall, 60% and 51% of responses of soil macrofauna and microbial community attributes (i.e., abundance, biomass, richness, and diversity indexes) to deforestation were negative, respectively. We found few studies on mesofauna (e.g., microarthropods) and microfauna (e.g., protozoa and nematodes), so those groups could not be analyzed. Macrofauna abundance and biomass were more vulnerable to the displacement of forests by pastures than by agricultural fields, whereas microbes showed the opposite pattern. Effects of Amazonian deforestation on macrofauna were more detrimental at sites with mean annual precipitation >1900 mm, and higher losses of microbes occurred in highly acidic soils (pH < 4.5). Limited geographic coverage, omission of meso- and microfauna, and low taxonomic resolution were main factors impairing generalizations from the data set. Few studies assessed the impacts of within-forest disturbance (wildfires and selective logging) on soil species in Amazonia, where logging operations rapidly expand across public lands and more frequent severe dry seasons are increasing the prevalence of wildfires.