Localization of the gene for a third G protein β-subunit to mouse chromosome 6 near Raf-1

The large family of signal transducing proteins known as G proteins are heterotrimers that dissociate into an independent α-subunit and βγ-subunit complex after ligand binding or other stimulation. For Gα, at least 30 distinct sequences representing 10 different classes have been identified. On the other hand, cDNAs for only three Gβ-subunit genes have been isolated so far. All three of the Gβ genes have been chromosomally mapped in the human, but only two in the mouse. Using a human retinal cDNA for the third G protein β-subunit, we have mapped the corresponding gene, termed Gnb-3, to mouse Chromosome 6 with somatic cell hybrids and have positioned it distal to but near the marker Raf-1 by analysis of the progeny of three genetic crosses.     

Chemical Characterization and Phytotoxic Effects of the Aerial Parts of Ruzigrass (Urochloa ruziziensis)

Studies of the phytotoxic effects between plants can be a crucial tool in the discovery of innovative compounds with herbicide potential. In this sense, we can highlight ruzigrass (Urochloa ruziziensis), which is traditionally used in the crop rotation system in order to reduce weed emergence. The aim of this work was to characterize the secondary metabolites of ruzigrass and to evaluate its phytotoxic effects. In total, eight compounds were isolated: friedelin, oleanolic acid, α‐amyrin, 1‐dehydrodiosgenone, sitosterol and stigmasterol glycosides, tricin and p‐coumaric acid. Phytotoxic effects of the crude methanolic extract and fractions of ruzigrass were assessed using germination rate, initial seedling growth, and biomass of Bidens pilosa, Euphorbia heterophylla and Ipomoea grandifolia. Chemometric analysis discriminated the weed species into three groups, and B. pilosa was the most affected by fractions of ruzigrass. The phytotoxic activities of 1‐dehydrodiosgenone, tricin, and p‐coumaric acid are also reported, and p‐coumaric acid and 1‐dehydrodiosgenone were active against B. pilosa.     

Rosuvastatin protects isolated hearts against ischemia-reperfusion injury: role of Akt-GSK-3β, metabolic environment,and mitochondrial permeability transition pore

Journal of Physiology and Biochemistry - The cardioprotective activity of rosuvastatin (R) is yet to be known. The objective of this study was to research whether R perfusion before global ischemia...     

Cannot see the diversity for all the species: Evaluating inclusion criteria for local species lists when using abundant citizen science data

Abundant citizen science data on species occurrences are becoming increasingly available and enable identifying composition of communities occurring at multiple sites with high temporal resolution. However, for species displaying temporary patterns of local occurrences that are transient to some sites, biodiversity measures are clearly dependent on the criteria used to include species into local species lists. Using abundant opportunistic citizen science data from frequently visited wetlands, we investigated the sensitivity of α‐ and β‐diversity estimates to the use raw versus detection‐corrected data and to the use of inclusion criteria for species presence reflecting alternative site use. We tested seven inclusion criteria (with varying number of days required to be present) on time series of daily occurrence status during a breeding season of 90 days for 77 wetland bird species. We show that even when opportunistic presence‐only observation data are abundant, raw data may not produce reliable local species richness estimates and rank sites very differently in terms of species richness. Furthermore, occupancy model based α‐ and β‐diversity estimates were sensitive to the inclusion criteria used. Total species lists (all species observed at least once during a season) may therefore mask diversity differences among sites in local communities of species, by including vagrant species on potentially breeding communities and change the relative rank order of sites in terms of species richness. Very high sampling effort does not necessarily free opportunistic data from its inherent bias and can produce a pattern in which many species are observed at least once almost everywhere, thus leading to a possible paradox: The large amount of biological information may hinder its usefulness. Therefore, when prioritizing among sites to manage or preserve species diversity estimates need to be carefully related to relevant inclusion criteria depending on the diversity estimate in focus.     

The short‐ and long‐term fitness consequences of natal dispersal in a wild bird population

Dispersal is a key process in population and evolutionary ecology. Individual decisions are affected by fitness consequences of dispersal, but these are difficult to measure in wild populations. A long‐term dataset on a geographically closed bird population, the Mauritius kestrel, offers a rare opportunity to explore fitness consequences. Females dispersed further when the availability of local breeding sites was limited, whereas male dispersal correlated with phenotypic traits. Female but not male fitness was lower when they dispersed longer distances compared to settling close to home. These results suggest a cost of dispersal in females. We found evidence of both short‐ and long‐term fitness consequences of natal dispersal in females, including reduced fecundity in early life and more rapid aging in later life. Taken together, our results indicate that dispersal in early life might shape life history strategies in wild populations.     

Resolution Doubling in 3D-STORM Imaging through Improved Buffers

Super-resolution imaging methods have revolutionized fluorescence microscopy by revealing the nanoscale organization of labeled proteins. In particular, single-molecule methods such as Stochastic Optical Reconstruction Microscopy (STORM) provide resolutions down to a few tens of nanometers by exploiting the cycling of dyes between fluorescent and non-fluorescent states to obtain a sparse population of emitters and precisely localizing them individually. This cycling of dyes is commonly induced by adding different chemicals, which are combined to create a STORM buffer. Despite their importance, the composition of these buffers has scarcely evolved since they were first introduced, fundamentally limiting what can be resolved with STORM. By identifying a new chemical suitable for STORM and optimizing the buffer composition for Alexa-647, we significantly increased the number of photons emitted per cycle by each dye, providing a simple means to enhance the resolution of STORM independently of the optical setup used. Using this buffer to perform 3D-STORM on biological samples, we obtained images with better than 10 nanometer lateral and 30 nanometer axial resolution.     

Effect of metabolic syndrome risk factors and MMP-2 genetic variations on circulating MMP-2 levels in childhood obesity

Matrix metalloproteinase-2 is involved in the development of the adipose tissue, and associated with cardiovascular diseases. Metabolic risk factors (MRFs) and functional polymorphisms in the MMP-2 gene may affect its expression and activity. We investigated whether traditional MRFs and two MMP-2 gene polymorphisms (C^?1306T; rs243865, and C^?735T; rs2285053) affect circulating MMP-2 levels in children and adolescents, and whether MMP-2 polymorphisms and/or haplotype are associated with susceptibility to childhood obesity. We studied 114 healthy controls, 43 obese, and 83 obese with ≥3 MRFs children and adolescents. Genotypes were determined by Taqman allele discrimination assay and real-time PCR. Plasma MMP-2 was measured using zymography. We found positive correlations between MMP-2 concentrations and mean blood pressure in all children and adolescents group (r = 0.132; P < 0.05) and in obese children and adolescents (r = 0.247; P < 0.01). We found that the CC genotype for the C^?1306T polymorphism was more common in subjects with higher MMP-2 concentrations in controls (P = 0.003) and in the obese group (P = 0.013). The CT genotype (OR = 0.40; P < 0.01) and the T allele (OR = 0.48; P < 0.01) for the C^?735T polymorphism were less common in obese children and adolescents than in controls. The haplotypes distribution did not show significant differences between control and obese (P > 0.05). Ours findings show that blood pressure is associated with circulating MMP-2 concentrations, and that the CC genotype for the C^?1306T polymorphism was more common subjects (controls and obese) with higher MMP-2 concentrations, whereas the CT genotype and the T allele for the C^?735T polymorphism are less common in obesity.     

Scribble is required for normal epithelial cell–cell contacts and lumen morphogenesis in the mammalian lung

During lung development, proper epithelial cell arrangements are critical for the formation of an arborized network of tubes. Each tube requires a lumen, the diameter of which must be tightly regulated to enable optimal lung function. Lung branching and lumen morphogenesis require close epithelial cell–cell contacts that are maintained as a result of adherens junctions, tight junctions and by intact apical–basal (A/B) polarity. However, the molecular mechanisms that maintain epithelial cohesion and lumen diameter in the mammalian lung are unknown. Here we show that Scribble, a protein implicated in planar cell polarity (PCP) signalling, is necessary for normal lung morphogenesis. Lungs of the Scrib mouse mutant Circletail (Crc) are abnormally shaped with fewer airways, and these airways often lack a visible, ‘open’ lumen. Mechanistically we show that Scrib genetically interacts with the core PCP gene Vangl2 in the developing lung and that the distribution of PCP pathway proteins and Rho mediated cytoskeletal modification is perturbed in Scrib^Crc/Crc lungs. However A/B polarity, which is disrupted in Drosophila Scrib mutants, is largely unaffected. Notably, we find that Scrib mediates functions not attributed to other PCP proteins in the lung. Specifically, Scrib localises to both adherens and tight junctions of lung epithelia and knockdown of Scrib in lung explants and organotypic cultures leads to reduced cohesion of lung epithelial cells. Live imaging of Scrib knockdown lungs shows that Scrib does not affect bud bifurcation, as previously shown for the PCP protein Celsr1, but is required to maintain epithelial cohesion. To understand the mechanism leading to reduced cell–cell association, we show that Scrib associates with β-catenin in embryonic lung and the sub-cellular distribution of adherens and tight junction proteins is perturbed in mutant lung epithelia. Our data reveal that Scrib is required for normal lung epithelial organisation and lumen morphogenesis by maintaining cell–cell contacts. Thus we reveal novel and important roles for Scrib in lung development operating via the PCP pathway, and in regulating junctional complexes and cell cohesion.