Scorpion Biodiversity and Interslope Divergence at “Evolution Canyon”, Lower Nahal Oren Microsite, Mt. Carmel, Israel

BACKGROUND: Local natural laboratories, designated by us as the "Evolution Canyon" model, are excellent tools to study regional and global ecological dynamics across life. They present abiotic and biotic contrasts locally, permitting the pursuit of observations and experiments across diverse taxa sharing sharp microecological subdivisions. Higher solar radiation received by the "African savannah-like" south-facing slopes (AS) in canyons north of the equator than by the opposite "European maquis-like" north-facing slopes (ES) is associated with higher abiotic stress. Scorpions are a suitable taxon to study interslope biodiversity differences, associated with the differences in abiotic factors (climate, drought), due to their ability to adapt to dry environments. METHODOLOGY/PRINCIPAL FINDINGS: Scorpions were studied by the turning stone method and by UV light methods. The pattern observed in scorpions was contrasted with similar patterns in several other taxa at the same place. As expected, the AS proved to be significantly more speciose regarding scorpions, paralleling the interslope patterns in taxa such as lizards and snakes, butterflies (Rhopalocera), beetles (families Tenebrionidae, Dermestidae, Chrysomelidae), and grasshoppers (Orthoptera). CONCLUSIONS/SIGNIFICANCE: Our results support an earlier conclusion stating that the homogenizing effects of migration and stochasticity are not able to eliminate the interslope intra- and interspecific differences in biodiversity despite an interslope distance of only 100 m at the "EC" valley bottom. In our opinion, the interslope microclimate selection, driven mainly by differences in insolance, could be the primary factor responsible for the observed interslope pattern

Children’s experiences following a CBT intervention to reduce dental anxiety: one year on

Objective: To investigate children’s ongoing experiences of dental care and use of strategies to manage their dental anxiety following cognitive behavioural therapy (CBT). Design: A child self-completed postal questionnaire. Settings: Hospital, community and general dental practice. Subjects: Questionnaires were sent to 44 children, aged 10-17 years who had been referred to specialist services due to their dental anxiety. Intervention: Children had all previously received a guided CBT self-help intervention to reduce their dental anxiety and, on completion of treatment, had been discharged to their referring dentist. Questionnaires were sent out 12-18 months later to ascertain dental attendance patterns and application of any strategies learnt from the previous CBT intervention. Results: 22 responses (50%) were received from 16 girls and 6 boys. 82% had subsequently accessed follow up care with a general dental practitioner and over half of these had undergone a dental procedure, other than a check-up. 91% reported feeling less worried about dental visits, than previously, and described a change in cognition, behaviours, and feelings that allowed them to manage their anxiety better. Conclusions: CBT has positive immediate and longitudinal effects in reducing children’s dental anxiety. The challenge of adopting this evidence-based approach within primary care settings remains

Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population

Mineral nutrient malnutrition, and particularly deficiency in zinc and iron, afflicts over 3 billion people worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, genepool harbors a rich allelic repertoire for mineral nutrients in the grain. The genetic and physiological basis of grain protein, micronutrients (zinc, iron, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulfur) concentration was studied in tetraploid wheat population of 152 recombinant inbred lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Wide genetic variation was found among the RILs for all grain minerals, with considerable transgressive effect. A total of 82 QTLs were mapped for 10 minerals with LOD score range of 3.2–16.7. Most QTLs were in favor of the wild allele (50 QTLs). Fourteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. Significant positive correlation was found between grain protein concentration (GPC), Zn, Fe and Cu, which was supported by significant overlap between the respective QTLs, suggesting common physiological and/or genetic factors controlling the concentrations of these mineral nutrients. Few genomic regions (chromosomes 2A, 5A, 6B and 7A) were found to harbor clusters of QTLs for GPC and other nutrients. These identified QTLs may facilitate the use of wild alleles for improving grain nutritional quality of elite wheat cultivars, especially in terms of protein, Zn and Fe

A Tradeoff Drives the Evolution of Reduced Metal Resistance in Natural Populations of Yeast

Various types of genetic modification and selective forces have been implicated in the process of adaptation to novel or adverse environments. However, the underlying molecular mechanisms are not well understood in most natural populations. Here we report that a set of yeast strains collected from Evolution Canyon (EC), Israel, exhibit an extremely high tolerance to the heavy metal cadmium. We found that cadmium resistance is primarily caused by an enhanced function of a metal efflux pump, PCA1. Molecular analyses demonstrate that this enhancement can be largely attributed to mutations in the promoter sequence, while mutations in the coding region have a minor effect. Reconstruction experiments show that three single nucleotide substitutions in the PCA1 promoter quantitatively increase its activity and thus enhance the cells' cadmium resistance. Comparison among different yeast species shows that the critical nucleotides found in EC strains are conserved and functionally important for cadmium resistance in other species, suggesting that they represent an ancestral type. However, these nucleotides had diverged in most Saccharomyces cerevisiae populations, which gave cells growth advantages under conditions where cadmium is low or absent. Our results provide a rare example of a selective sweep in yeast populations driven by a tradeoff in metal resistance

Light Perception in Two Strictly Subterranean Rodents: Life in the Dark or Blue?

BACKGROUND: The African mole-rats (Bathyergidae, Rodentia) are strictly subterranean, congenitally microphthalmic rodents that are hardly ever exposed to environmental light. Because of the lack of an overt behavioural reaction to light, they have long been considered to be blind. However, recent anatomical studies have suggested retention of basic visual capabilities. In this study, we employed behavioural tests to find out if two mole-rat species are able to discriminate between light and dark, if they are able to discriminate colours and, finally, if the presence of light in burrows provokes plugging behaviour, which is assumed to have a primarily anti-predatory function. METHODOLOGY/PRINCIPAL FINDING: We used a binary choice test to show that the silvery mole-rat Heliophobius argenteocinereus and the giant mole-rat Fukomys mechowii exhibit a clear photoavoidance response to full-spectrum ("white"), blue and green-yellow light, but no significant reaction to ultraviolet or red light during nest building. The mole-rats thus retain dark/light discrimination capabilities and a capacity to perceive short to medium-wavelength light in the photopic range of intensities. These findings further suggest that the mole-rat S opsin has its absorption maximum in the violet/blue part of the spectrum. The assay did not yield conclusive evidence regarding colour discrimination. To test the putative role of vision in bathyergid anti-predatory behaviour, we examined the reaction of mole-rats to the incidence of light in an artificial burrow system. The presence of light in the burrow effectively induced plugging of the illuminated tunnel. CONCLUSION/SIGNIFICANCE: Our findings suggest that the photopic vision is conserved and that low acuity residual vision plays an important role in predator avoidance and tunnel maintenance in the African mole-rats

Pro-inflammatory profile of preeclamptic placental mesenchymal stromal cells: new insights into the etiopathogenesis of preeclampsia.

The objective of the present study was to evaluate whether placental mesenchymal stromal cells (PDMSCs) derived from normal and preeclamptic (PE) chorionic villous tissue presented differences in their cytokines expression profiles. Moreover, we investigated the effects of conditioned media from normal and PE-PDMSCs on the expression of pro-inflammatory Macrophage migration Inhibitory Factor (MIF), Vascular Endothelial Growth Factor (VEGF), soluble FMS-like tyrosine kinase-1 (sFlt-1) and free β-human Chorionic Gonadotropin (βhCG) by normal term villous explants. This information will help to understand whether anomalies in PE-PDMSCs could cause or contribute to the anomalies typical of preeclampsia. METHODS: Chorionic villous PDMSCs were isolated from severe preeclamptic (n = 12) and physiological control term (n = 12) placentae. Control and PE-PDMSCs’s cytokines expression profiles were determined by Cytokine Array. Control and PE-PDMSCs were plated for 72 h and conditioned media (CM) was collected. Physiological villous explants (n = 48) were treated with control or PE-PDMSCs CM for 72 h and processed for mRNA and protein isolation. MIF, VEGF and sFlt-1 mRNA and protein expression were analyzed by Real Time PCR and Western Blot respectively. Free βhCG was assessed by immunofluorescent. RESULTS: Cytokine array showed increased release of pro-inflammatory cytokines by PE relative to control PDMSCs. Physiological explants treated with PE-PDMSCs CM showed significantly increased MIF and sFlt-1 expression relative to untreated and control PDMSCs CM explants. Interestingly, both control and PE-PDMSCs media induced VEGF mRNA increase while only normal PDMSCs media promoted VEGF protein accumulation. PE-PDMSCs CM explants released significantly increased amounts of free βhCG relative to normal PDMSCs CM ones. CONCLUSIONS: Herein, we reported elevated production of pro-inflammatory cytokines by PE-PDMSCs. Importantly, PE PDMSCs induced a PE-like phenotype in physiological villous explants. Our data clearly depict chorionic mesenchymal stromal cells as central players in placental physiopathology, thus opening to new intriguing perspectives for the treatment of human placental-related disorders as preeclampsia

Genetic Population Structure in the Antarctic Benthos: Insights from the Widespread Amphipod, Orchomenella franklini

Currently there is very limited understanding of genetic population structure in the Antarctic benthos. We conducted one of the first studies of microsatellite variation in an Antarctic benthic invertebrate, using the ubiquitous amphipod Orchomenella franklini (Walker, 1903). Seven microsatellite loci were used to assess genetic structure on three spatial scales: sites (100 s of metres), locations (1–10 kilometres) and regions (1000 s of kilometres) sampled in East Antarctica at Casey and Davis stations. Considerable genetic diversity was revealed, which varied between the two regions and also between polluted and unpolluted sites. Genetic differentiation among all populations was highly significant (FST = 0.086, RST = 0.139, p<0.001) consistent with the brooding mode of development in O. franklini. Hierarchical AMOVA revealed that the majority of the genetic subdivision occurred across the largest geographical scale, with Nem≈1 suggesting insufficient gene flow to prevent independent evolution of the two regions, i.e., Casey and Davis are effectively isolated. Isolation by distance was detected at smaller scales and indicates that gene flow in O. franklini occurs primarily through stepping-stone dispersal. Three of the microsatellite loci showed signs of selection, providing evidence that localised adaptation may occur within the Antarctic benthos. These results provide insights into processes of speciation in Antarctic brooders, and will help inform the design of spatial management initiatives recently endorsed for the Antarctic benthos

Rapid linkage disequilibrium decay in the Lr10 gene in wild emmer wheat (Triticum dicoccoides) populations

INTRODUCTION: Recombination is a key evolutionary factor enhancing diversity. However, the effect of recombination on diversity in inbreeding species is expected to be low. To estimate this effect, recombination and diversity patterns of Lr10 gene were studied in natural populations of the inbreeder species, wild emmer wheat (Triticum dicoccoides). Wild emmer wheat is the progenitor of most cultivated wheats and it harbors rich genetic resources for disease resistance. Lr10 is a leaf rust resistance gene encoding three domains: a coiled-coil, nucleotide-binding site, and leucine-rich repeat (CC-NBS-LRR). RESULTS: Lr10 was sequenced from 58 accessions representing 12 diverse habitats in Israel. Diversity analysis revealed a high rate of synonymous and non-synonymous substitutions (d (S) = 0.029, d (N) = 0.018, respectively) in the NBS-LRR domains. Moreover, in contrast to other resistance genes, in Lr10 the CC domain was more diverse than the NBS-LRR domains (d (S) = 0.069 vs. 0.029, d (N) = 0.094 vs. 0.018) and was subjected to positive selection in some of the populations. Seventeen recombination events were detected between haplotypes, especially in the CC domain. Linkage disequilibrium (LD) analysis has shown a rapid decay from r (2) = 0.5 to r (2) = 0.1 within a 2-kb span. CONCLUSION: These results suggest that recombination is a diversifying force for the R-gene, Lr10, in the selfing species T. dicoccoides. This is the first report of a short-range LD decay in wild emmer wheat