Spatial genetic patterns of Octopus vulgaris Mediterranean populations support the hypothesis of a transitional zone across the Siculo-Tunisian Strait

Hydrobiologia - Recent research hypothesised that the Siculo-Tunisian Strait might fit, at least for some species, the picture of a genetic transitional zone instead of a sharp genetic break...     

Ecological and geological processes impacting speciation modes drive the formation of wide-range disjunctions within tribe Putorieae (Rubiaceae)

Wide-range geographically discontinuous distributions have long intrigued scientists. We explore the role of ecology, geology, and dispersal in the formation of these large-scale disjunctions, using the angiosperm tribe Putorieae (Rubiaceae) as a case study. From DNA sequences of nuclear ITS and six plastid markers, we inferred a phylogeny with 65% of all known Putorieae species. Divergence times, ancestral ranges, and diversification rate shifts were then estimated using Bayesian inference. We further explored species climatic tolerances and performed ancestral niche reconstruction to discriminate among alternative speciation modes, including geographical and ecological vicariance, and ecogeographical, ecological, and dispersal-mediated speciation. As a result, we identified seven major clades in Putorieae, some of which exhibit striking geographical disjunctions, matching the Rand Flora pattern, with sister species in the Canary Islands andeastern and southern Africa. Initial diversification within the tribe occurred in the early Miocene, coincident with a period of climate warming; however, most clades diverged within the last 10 Myr. Aridification and high extinction rates, coupled with ecological vicariance, explain the oldest disjunctions. Adaptation to new environmental conditions, after allopatry, is observed in several clades. Dispersal, either long-distance or via corridors made available by mountain uplift, is behind the most recent disjunctions. Some of these events were followed by ecological speciation and rapid diversification, with species becoming adapted to xeric or increasingly colder continental climates. We show that an integrative approach may help discriminate among speciation modes invoked to explain disjunctions at macroevolutionary time scales, even when extinction has erased the signature of past events.     

Chemopreventive and Antioxidant Activity of the Chamazulene‐Rich Essential Oil Obtained from Artemisia arborescens L. Growing on the Isle of La Maddalena,Sardinia, Italy

The essential oils of Artemisia arborescens growing in Sardinia (Italy), collected during three plant growth stages, i.e., from the vegetative stage to post‐blooming time, were characterized. Moreover, the in vitro antiproliferative and antioxidant activities of the oil isolated from aerial parts collected in February were evaluated. The essential oils belonged to the β‐thujone/chamazulene chemotype, notably with the highest amount of chamazulene (ca. 52%) ever detected up to now in the genus Artemisia and, in general, in essential oils. Quantitative variations in the oil composition were observed as the plant passes from the vegetative to the blooming stage. The oil was tested for its potential tumor cell growth‐inhibitory effect on T98G, MDA‐MB 435S, A375, and HCT116 human cell lines, using the MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) assay. The highest activity was observed on A375 and HCT116 cell lines, with IC₅₀ values of 14 μg/ml. Moreover, the in vitro antioxidant and free radical‐scavenging assays revealed the oil to be an effective scavenger of the ABTS radical cation, with an activity comparable to that of Trolox^®. These results support the use of A. arborescens oil for the treatment of inflamed skin conditions. Finally, the composition of the polar fraction of the A. arborescens aerial parts was also examined, and the main component detected was 5‐O‐caffeoylquinic acid, which was identified for the first time in this plant.     

Etiology and Audiological Outcomes at 3 Years for 364 Children in Australia

Hearing loss is an etiologically heterogeneous trait with differences in the age of onset, severity and site of lesion. It is caused by a combination of genetic and/or environmental factors. A longitudinal study to examine the efficacy of early intervention for improving child outcomes is ongoing in Australia. To determine the cause of hearing loss in these children we undertook molecular testing of perinatal “Guthrie” blood spots of children whose hearing loss was either detected via newborn hearing screening or detected later in infancy. We analyzed the GJB2 and SLC26A4 genes for the presence of mutations, screened for the mitochondrial DNA (mtDNA) A1555G mutation, and screened for congenital CMV infection in DNA isolated from dried newborn blood spots. Results were obtained from 364 children. We established etiology for 60% of children. One or two known GJB2 mutations were present in 82 children. Twenty-four children had one or two known SLC26A4 mutations. GJB2 or SLC26A4 changes with unknown consequences on hearing were found in 32 children. The A1555G mutation was found in one child, and CMV infection was detected in 28 children. Auditory neuropathy spectrum disorder was confirmed in 26 children whose DNA evaluations were negative. A secondary objective was to investigate the relationship between etiology and audiological outcomes over the first 3 years of life. Regression analysis was used to investigate the relationship between hearing levels and etiology. Data analysis does not support the existence of differential effects of etiology on degree of hearing loss or on progressiveness of hearing loss.     

Social Class,Social Mobility and Risk of Psychiatric Disorder - A Population-Based Longitudinal Study

Objectives

This study explored how adult social class and social mobility between parental and own adult social class is related to psychiatric disorder.

Material and Methods

In this prospective cohort study, over 1 million employed Swedes born in 1949-1959 were included. Information on parental class (1960) and own mid-life social class (1980 and 1990) was retrieved from the censuses and categorised as High Non-manual, Low Non-manual, High Manual, Low Manual and Self-employed. After identifying adult class, individuals were followed for psychiatric disorder by first admission of schizophrenia, alcoholism and drug dependency, affective psychosis and neurosis or personality disorder (N=24 659) from the Swedish Patient Register. We used Poisson regression analysis to estimate first admission rates of psychiatric disorder per 100 000 person-years and relative risks (RR) by adult social class (treated as a time-varying covariate). The RRs of psychiatric disorder among the Non-manual and Manual classes were also estimated by magnitude of social mobility.

Results

The rate of psychiatric disorder was significantly higher among individuals belonging to the Low manual class as compared with the High Non-manual class. Compared to High Non-manual class, the risk for psychiatric disorder ranged from 2.07 (Low Manual class) to 1.38 (Low Non-manual class). Parental class had a minor impact on these estimates. Among the Non-manual and Manual classes, downward mobility was associated with increased risk and upward mobility with decreased risk of psychiatric disorder. In addition, downward mobility was inversely associated with the magnitude of social mobility, independent of parental class.

Conclusions

Independently of parental social class, the risk of psychiatric disorder increases with increased downward social mobility and decreases with increased upward mobility.     

Predator faunas past and present: quantifying the influence of waterborne cues in divergent ecotypes of the isopod Asellus aquaticus

Waterborne chemical cues are an important source of information for many aquatic organisms, in particular when assessing the current risk of predation. The ability to use chemical cues to detect and respond to potential predators before an actual encounter can improve prey chances of survival. We investigated predator recognition and the impact of chemical cues on predator avoidance in the freshwater isopod Asellus aquaticus. This isopod has recently colonised a novel habitat and diverged into two distinct ecotypes, which encounter different predator communities. Using laboratory-based choice experiments, we have quantified behavioural responses to chemical cues from predators typical of the two predator communities (larval dragonflies in the ancestral habitat, perch in the newly colonised habitat) in wild-caught and lab-reared Asellus of the two ecotypes. Individuals with prior experience of predators showed strong predator avoidance to cues from both predator types. Both ecotypes showed similar antipredator responses, but sexes differed in terms of threat-sensitive responses with males avoiding areas containing predator cues to a larger extent than females. Overall, chemical cues from fish elicited stronger predator avoidance than cues from larval dragonflies. Our results indicate that in these isopods, prior exposure to predators is needed to develop antipredator behaviour based on waterborne cues. Furthermore, the results emphasise the need to analyse predator avoidance in relation to waterborne cues in a sex-specific context, because of potential differences between males and females in terms of vulnerability and life history strategies.     

Phylogenetic position and delimitation of the moss family Plagiotheciaceae in the order Hypnales

The phylogenetic position and generic composition of the moss family Plagiotheciaceae were explored using DNA sequence data from three genomes: plastid trnL‐F and rps4, mitochondrial nad5 intron and nuclear ITS1‐5.8S‐ITS2. Our phylogenetic analyses included 35 terminals from Plagiotheciaceae and 71 outgroup taxa from a representative set of hypnalean moss families. The family Plagiotheciaceae is resolved in the early‐diverging Hypnales grade, together with Fontinalaceae, Habrodontaceae and several genera which are mainly distributed in the area of the former Gondwanan supercontinent. However, monophyly of the family can only be attained if the three Southern Hemisphere genera, Acrocladium, Catagonium and Rhizofabronia, are excluded. Ancestral state reconstruction for eight morphological characters reveals that many characters used to delimit the family, such as a lack of pseudoparaphyllia and rhizoids inserted in the leaf axils, were already present in the ancestor of Hypnales. Dispersal–vicariance analysis suggests that Plagiotheciaceae and Fontinalaceae have their ancestral distributions in the area of the former Laurasian supercontinent. As the analyses also reveal a Gondwanan distribution for the ancestor of Hypnales in general, Plagiotheciaceae and Fontinalaceae represent the first diverging Laurasian lineages in the order. © 2013 The Linnean Society of London     

Small molecules interacting with α-synuclein: antiaggregating and cytoprotective properties

Curcumin, a dietary polyphenol, has shown a potential to act on the symptoms of neurodegenerative disorders, including Alzheimer’s and Parkinson’s diseases, as a consequence of its antioxidant, anti-inflammatory and anti-protein aggregation properties. Unfortunately, curcumin undergoes rapid degradation at physiological pH into ferulic acid, vanillin and dehydrozingerone, making it an unlikely drug candidate. Here, we evaluated the ability of some curcumin by-products: dehydrozingerone (1), its O-methyl derivative (2), zingerone (3), and their biphenyl analogues (4–6) to interact with α-synuclein (AS), using CD and fluorescence spectroscopy. In addition, the antioxidant properties and the cytoprotective effects in rat pheochromocytoma (PC12) cells prior to intoxication with H₂O₂, MPP+ and MnCl₂ were examined while the Congo red assay was used to evaluate the ability of these compounds to prevent aggregation of AS. We found that the biphenyl zingerone analogue (6) interacts with high affinity with AS and also displays the best antioxidant properties while the biphenyl analogues of dehydrozingerone (4) and of O-methyl-dehydrozingerone (5) are able to partially inhibit the aggregation process of AS, suggesting the potential role of a hydroxylated biphenyl scaffold in the design of AS aggregation inhibitors.