Biological weighting functions for DNA damage in sea urchin embryos exposed to ultraviolet radiation

Laboratory experiments examining the effects of ultraviolet radiation (UVR, 290-400 nm) on DNA damage were carried out using the embryos of three species of sea urchins from different habitats; Strongylocentrotus droebachiensis from the Gulf of Maine, Sterechinus neumayeri from the Antarctic, and Evechinus chloroticus from New Zealand. All three species exhibited significant amounts of accumulated DNA damage, measured as cyclobutane pyrimidine dimers (CPD) photoproducts, when exposed to UVR in the laboratory. Biological weighting functions (BWFs) revealed that S. neumayeri has significantly higher sensitivity to UVR-induced DNA damage across most of the UVR spectrum compared to the other two species, and all species were observed to have weightings in the ultraviolet-A (UVA, 320-400 nm) portion of the spectrum. The increased sensitivity to ultraviolet-B (290-320 nm) and UVA in S. neumayeri is correlated with the lowest concentration of UVR absorbing compounds observed in the embryos of the three species of urchin used in this study. Sea urchin embryos and larvae in the respective habitats of the species tested are known to occur within 5 m of the surface of the ocean where both UVB and UVA wavelengths occur. Solar irradiances of UVR at a depth of 5 m, weighted using the urchin DNA damage BWFs, show that E. chloroticus receives the greatest amount of biologically effective UVR despite having the lowest wavelength dependent weightings for DNA damage when compared to the other two species.     

Wengen,the Sole Tumour Necrosis Factor Receptor in Drosophila,Collaborates with Moesin to Control Photoreceptor Axon Targeting during Development

Photoreceptor neurons (R cells) in the Drosophila eye define a map of visual space by connecting to targets in distinct layers of the optic lobe, with R1-6 cells connecting to the lamina (the first optic ganglion) and R7 and R8 cells connecting to the medulla (the second optic ganglion). Here, we show that Wengen (Wgn) directly binds Moesin (Moe) through a cytosolic membrane proximal domain and this interaction is important for mediating two distinct aspects of axonal targeting. First, we show that loss of wgn or moe function disrupts cell autonomous R8 axon targeting. Second, we report that wgn or moe mutants show defects in R2–R5 targeting that result from disruption of non-cell autonomous effects, which are secondary to the cell autonomous R8 phenotype. Thus, these studies reveal that the Wgn-Moe signaling cascade plays a key role in photoreceptor target field innervations through cell autonomous and non-cell autonomous mechanisms.     

Competition over Personal Resources Favors Contribution to Shared Resources in Human Groups

Members of social groups face a trade-off between investing selfish effort for themselves and investing cooperative effort to produce a shared group resource. Many group resources are shared equitably: they may be intrinsically non-excludable public goods, such as vigilance against predators, or so large that there is little cost to sharing, such as cooperatively hunted big game. However, group members'' personal resources, such as food hunted individually, may be monopolizable. In such cases, an individual may benefit by investing effort in taking others'' personal resources, and in defending one''s own resources against others. We use a game theoretic “tug-of-war” model to predict that when such competition over personal resources is possible, players will contribute more towards a group resource, and also obtain higher payoffs from doing so. We test and find support for these predictions in two laboratory economic games with humans, comparing people''s investment decisions in games with and without the options to compete over personal resources or invest in a group resource. Our results help explain why people cooperatively contribute to group resources, suggest how a tragedy of the commons may be avoided, and highlight unifying features in the evolution of cooperation and competition in human and non-human societies.     

Discovery and development of exome‐based,co‐dominant single nucleotide polymorphism markers in hexaploid wheat (Triticum aestivum L.)

Globally, wheat is the most widely grown crop and one of the three most important crops for human and livestock feed. However, the complex nature of the wheat genome has, until recently, resulted in a lack of single nucleotide polymorphism (SNP)‐based molecular markers of practical use to wheat breeders. Recently, large numbers of SNP‐based wheat markers have been made available via the use of next‐generation sequencing combined with a variety of genotyping platforms. However, many of these markers and platforms have difficulty distinguishing between heterozygote and homozygote individuals and are therefore of limited use to wheat breeders carrying out commercial‐scale breeding programmes. To identify exome‐based co‐dominant SNP‐based assays, which are capable of distinguishing between heterozygotes and homozygotes, we have used targeted re‐sequencing of the wheat exome to generate large amounts of genomic sequences from eight varieties. Using a bioinformatics approach, these sequences have been used to identify 95 266 putative single nucleotide polymorphisms, of which 10 251 were classified as being putatively co‐dominant. Validation of a subset of these putative co‐dominant markers confirmed that 96% were true polymorphisms and 65% were co‐dominant SNP assays. The new co‐dominant markers described here are capable of genotypic classification of a segregating locus in polyploid wheat and can be used on a variety of genotyping platforms; as such, they represent a powerful tool for wheat breeders. These markers and related information have been made publically available on an interactive web‐based database to facilitate their use on genotyping programmes worldwide.     

KCa3.1 Channel-Blockade Attenuates Airway Pathophysiology in a Sheep Model of Chronic Asthma

Background

The Ca²⁺-activated K⁺ channel K_Ca3.1 is expressed in several structural and inflammatory airway cell types and is proposed to play an important role in the pathophysiology of asthma. The aim of the current study was to determine whether inhibition of K_Ca3.1 modifies experimental asthma in sheep.

Methodology and Principal Findings

Atopic sheep were administered either 30 mg/kg Senicapoc (ICA-17073), a selective inhibitor of the K_Ca3.1-channel, or vehicle alone (0.5% methylcellulose) twice daily (orally). Both groups received fortnightly aerosol challenges with house dust mite allergen for fourteen weeks. A separate sheep group received no allergen challenges or drug treatment. In the vehicle-control group, twelve weeks of allergen challenges resulted in a 60±19% increase in resting airway resistance, and this was completely attenuated by treatment with Senicapoc (0.25±12%; n = 10, P = 0.0147). The vehicle-control group had a peak-early phase increase in lung resistance of 82±21%, and this was reduced by 58% with Senicapoc treatment (24±14%; n = 10, P = 0.0288). Senicapoc-treated sheep also demonstrated reduced airway hyperresponsiveness, requiring a significantly higher dose of carbachol to increase resistance by 100% compared to allergen-challenged vehicle-control sheep (20±5 vs. 52±18 breath-units of carbachol; n = 10, P = 0.0340). Senicapoc also significantly reduced eosinophil numbers in bronchoalveolar lavage taken 48 hours post-allergen challenge, and reduced vascular remodelling.

Conclusions

These findings suggest that K_Ca3.1-activity contributes to allergen-induced airway responses, inflammation and vascular remodelling in a sheep model of asthma, and that inhibition of K_Ca3.1 may be an effective strategy for blocking allergen-induced airway inflammation and hyperresponsiveness in humans.     

Early Life Stress and Physical and Psychosocial Functioning in Late Adulthood

Background

Severe stress experienced in early life may have long-term effects on adult physiological and psychological health and well-being. We studied physical and psychosocial functioning in late adulthood in subjects separated temporarily from their parents in childhood during World War II.

Methods

The 1803 participants belong to the Helsinki Birth Cohort Study, born 1934–44. Of them, 267 (14.8%) had been evacuated abroad in childhood during WWII and the remaining subjects served as controls. Physical and psychosocial functioning was assessed with the Short Form 36 scale (SF-36) between 2001 and 2004. A test for trends was based on linear regression. All analyses were adjusted for age at clinical examination, social class in childhood and adulthood, smoking, alcohol intake, physical activity, body mass index, cardiovascular disease and diabetes.

Results

Physical functioning in late adulthood was lower among the separated men compared to non-separated men (b = −0.40, 95% confidence interval [95% CI]: −0.71 to −0.08). Those men separated in school age (>7 years) and who were separated for a duration over 2 years had the highest risk for lower physical functioning (b = −0.89, 95% CI: −1.58 to −0.20) and (b = −0.65, 95% CI: −1.25 to −0.05), respectively). Men separated for a duration over 2 years also had lower psychosocial functioning (b = −0.70, 95% CI: −1.35 to −0.06). These differences in physical and psychosocial functioning were not observed among women.

Conclusion

Early life stress may increase the risk for impaired physical functioning in late adulthood among men. Timing and duration of the separation influenced the physical and psychosocial functioning in late adulthood.     

Automated,High Accuracy Classification of Parkinsonian Disorders: A Pattern Recognition Approach

Progressive supranuclear palsy (PSP), multiple system atrophy (MSA) and idiopathic Parkinson’s disease (IPD) can be clinically indistinguishable, especially in the early stages, despite distinct patterns of molecular pathology. Structural neuroimaging holds promise for providing objective biomarkers for discriminating these diseases at the single subject level but all studies to date have reported incomplete separation of disease groups. In this study, we employed multi-class pattern recognition to assess the value of anatomical patterns derived from a widely available structural neuroimaging sequence for automated classification of these disorders. To achieve this, 17 patients with PSP, 14 with IPD and 19 with MSA were scanned using structural MRI along with 19 healthy controls (HCs). An advanced probabilistic pattern recognition approach was employed to evaluate the diagnostic value of several pre-defined anatomical patterns for discriminating the disorders, including: (i) a subcortical motor network; (ii) each of its component regions and (iii) the whole brain. All disease groups could be discriminated simultaneously with high accuracy using the subcortical motor network. The region providing the most accurate predictions overall was the midbrain/brainstem, which discriminated all disease groups from one another and from HCs. The subcortical network also produced more accurate predictions than the whole brain and all of its constituent regions. PSP was accurately predicted from the midbrain/brainstem, cerebellum and all basal ganglia compartments; MSA from the midbrain/brainstem and cerebellum and IPD from the midbrain/brainstem only. This study demonstrates that automated analysis of structural MRI can accurately predict diagnosis in individual patients with Parkinsonian disorders, and identifies distinct patterns of regional atrophy particularly useful for this process.     

Development of a sequence-specific real-time PCR to the melon thrips Thrips palmi (Thysan., Thripidae)

Abstract:  In recent years, the polyphagous pest Thrips palmi Karny has become a species of major quarantine concern, often intercepted on plant material in international trade. The ability to rapidly identify the species is a critical factor that will determine the success of any campaign to prevent its establishment in Europe or elsewhere. However, the immature stages cannot currently be identified to the species level with certainty by morphological methods. In this study, random amplified polymorphic DNA analysis was performed to identify putative markers, which were then screened by Southern blot analysis. One marker was sequenced and a real-time polymerase chain reaction assay developed. The assay was screened against 21 thrips species including 10 other species of the genus Thrips and were found to be specific to T. palmi . The assay is rapid, could be completed in as little as 45 min and can be used to aid the identification of T. palmi .     

Identification of a uniquely southern African clade of coastal pipefishes Syngnathus spp

The taxonomic status of two southern African coastal pipefish species, Syngnathus temminckii and Syngnathus watermeyeri, was investigated using a combination of morphological and genetic data. Morphological data showed that S. temminckii is distinct from the broadly distributed European pipefish Syngnathus acus, and a molecular phylogeny reconstructed using mitochondrial DNA recovered S. temminckii and S. watermeyeri as sister taxa. The southern African species share an evolutionary origin with north‐eastern Atlantic Ocean and Mediterranean Sea species, including S. acus. These data support the existence of a distinct southern African clade of Syngnathus pipefishes that has diverged in situ to form the two species present in the region today.