Selective sweeps on novel and introgressed variation shape mimicry loci in a butterfly adaptive radiation.

Natural selection leaves distinct signatures in the genome that can reveal the targets and history of adaptive evolution. By analysing high-coverage genome sequence data from 4 major colour pattern loci sampled from nearly 600 individuals in 53 populations, we show pervasive selection on wing patterns in the Heliconius adaptive radiation. The strongest signatures correspond to loci with the greatest phenotypic effects, consistent with visual selection by predators, and are found in colour patterns with geographically restricted distributions. These recent sweeps are similar between co-mimics and indicate colour pattern turn-over events despite strong stabilising selection. Using simulations, we compare sweep signatures expected under classic hard sweeps with those resulting from adaptive introgression, an important aspect of mimicry evolution in Heliconius butterflies. Simulated recipient populations show a distinct 'volcano' pattern with peaks of increased genetic diversity around the selected target, characteristic of sweeps of introgressed variation and consistent with diversity patterns found in some populations. Our genomic data reveal a surprisingly dynamic history of colour pattern selection and co-evolution in this adaptive radiation

Ancient and historical DNA in conservation policy

Although genetic diversity has been recognized as a key component of biodiversity since the first Convention on Biological Diversity (CBD) in 1993, it has rarely been included in conservation policies and regulations. Even less appreciated is the role that ancient and historical DNA (aDNA and hDNA, respectively) could play in unlocking the temporal dimension of genetic diversity, allowing key conservation issues to be resolved, including setting baselines for intraspecies genetic diversity, estimating changes in effective population size (N-e), and identifying the genealogical continuity of populations. Here, we discuss how genetic information from ancient and historical specimens can play a central role in preserving biodiversity and highlight specific conservation policies that could incorporate such data to help countries meet their CBD obligations.Peer reviewe

MicroRNA-96 Directly Inhibits γ-Globin Expression in Human Erythropoiesis

Fetal hemoglobin, HbF (α2γ2), is the main hemoglobin synthesized up to birth, but it subsequently declines and adult hemoglobin, HbA (α2β2), becomes predominant. Several studies have indicated that expression of the HbF subunit γ-globin might be regulated post-transcriptionally. This could be confered by ∼22-nucleotide long microRNAs that associate with argonaute proteins to specifically target γ-globin mRNAs and inhibit protein expression. Indeed, applying immunopurifications, we found that γ-globin mRNA was associated with argonaute 2 isolated from reticulocytes that contain low levels of HbF (<1%), whereas association was significantly lower in reticulocytes with high levels of HbF (90%). Comparing microRNA expression in reticulocytes from cord blood and adult blood, we identified several miRNAs that were preferentially expressed in adults, among them miRNA-96. The overexpression of microRNA-96 in human ex vivo erythropoiesis decreased γ-globin expression by 50%, whereas the knock-down of endogenous microRNA-96 increased γ-globin expression by 20%. Moreover, luciferase reporter assays showed that microRNA-96 negatively regulates expression of γ-globin in HEK293 cells, which depends on a seedless but highly complementary target site located within the coding sequence of γ-globin. Based on these results we conclude that microRNA-96 directly suppresses γ-globin expression and thus contributes to HbF regulation

Azide and sulfonylazide functionalized fluorophores for the selective and sensitive detection of hydrogen sulfide

[EN] Three fluorescent probes (1–3) for the selective and sensitive detection of hydrogen sulfide have been synthesized and characterized. Probe 1 is a coumarin derivative functionalized with an azide moiety whereas 2 contain the azide reactive group into a naphthalene fluorophore backbone. Probe 3 is composed also by a naphthalene fluorophore but, in this case, functionalized with a sulfonylazide reactive moiety. Probes 1 and 3 are non-fluorescent whereas 2 is weakly emissive in HEPES (10 mM, pH 7.4)–DMSO 99:1 (v/v). The emission behavior of the three probes was tested against selected anions, bio-thiols and oxidant molecules. Of all the chemical species tested, only HS− is able to induce an enhancement in the emission intensity (50, 11 and 20-fold for 1, 2 and 3, respectively). The observed emission in the presence of hydrogen sulfide is ascribed, in the case of probes 1 and 2, to an azide–amine reduction induced by HS− anion, whereas for probe 3 the sensing mechanism is related with a sulfonylazide–sulfonamide conversion. The three probes are very sensitive to HS− anion with limits of detection of 0.17, 0.20 and 0.40 mM for 1, 2 and 3 respectively. Cell viability studies demonstrated that 1–3 probes are essentially non-toxic at concentrations 10–50 μM and are well suited for in vivo studies. Finally, probe 1 was used for the detection on intracellular HS− anion in HeLa cells by means of confocal microscopy.Financial support from the Spanish Government (Project MAT2012-38429-004-01) and the Generalitat Valenciana (Project PROMETEO/2009/016) is gratefully acknowledged. S.E. is grateful to the Generalitat Valenciana for his Santiago Grisolia fellow. C.T. also thanks the Ministerio de Ciencia e Innovacion for her FPU grant. L.E.S.F. thanks the Carolina Foundation and UPNFM-Honduras for his doctoral grant.El Sayed Shehata Nasr, S.; De La Torre Paredes, C.; Santos Figueroa, LE.; Marín Hernández, C.; Martínez Mañez, R.; Sancenón Galarza, F.; Costero Nieto, AM.... (2015). Azide and sulfonylazide functionalized fluorophores for the selective and sensitive detection of hydrogen sulfide. Sensors and Actuators B: Chemical. 207(B):987-994. https://doi.org/10.1016/j.snb.2014.04.047S987994207

Dental treatment on a German warship during a three-month deployment

Introduction: Despite routine dental screenings and treatments before military deployments, dental emergencies may arise due to acute infections, trauma or failed restorations. The purpose of this study is to evaluate the dental service during a three-month deployment on a German warship. Methods: A retrospective analysis of dental attendances and treatments in a German naval task group of three ships with an average total of 650 soldiers. Diagnosis, treatments performed, percentage of emergencies, routine procedures and numbers of appointments were recorded. Results: Out of 650 soldiers, there were 71 patients (10.92%) with a mean age of 25.1±5.3 years. Out of 136 treatments, 17.65% were for emergency treatment, which is equivalent to 3.69% of all servicemen of the task group. Combining the reasons for dental emergencies, 95.84% were caused by caries. Conclusions: The pre-screening of sailors before an overseas deployment is necessary to avoid severe dental treatments. Caries remains the main cause for dental emergencies, and medical doctors should be trained to treat caries lesions if a dentist is not on board

Gingiva thickening with a porcine collagen matrix in a preclinical dog model: Histological outcomes

Aim To compare 10‐month histological and immunohistological outcomes after soft tissue thickening around teeth with a porcine collagen matrix (CM) versus a subepithelial connective tissue graft (SCTG). Material and Methods In eight beagle dogs, soft tissue thickening of the buccal gingiva of upper canines was performed with the SCTG or the CM. Connective tissue thickness (CTT) was histomorphometrically measured in the augmented regions. The augmented connective tissues were also histologically characterized and the collagen I and vascular endothelial growth factor (VEGF) expressions immunohistologically quantified. Results CTT significantly differed between groups (SCTG: 1.32 mm ± 0.44 mm; CM: 1.06 mm ± 0.27 mm; p = .008). Descriptive histological analyses revealed mature connective tissue that did not differ between groups. Immunohistological quantification of collagen I and VEGF expressions in the connective tissue also revealed no significant inter‐group differences (collagen I: SCTG, 32.64% ± 7.09% vs. CM, 30.57% ± 7.83%; VEGF: SCTG, 39.06% ± 7.27% vs. CM, 37.15% ± 9.80%). Conclusion SCTG is superior to CM with regard to CTT in this experimental model. The CM and the SCTG lead to comparable connective tissue quality ten months after connective tissue thickening

Hidden diversity in the freshwater planktonic diatom Asterionella formosa

Many freshwater and marine algal species are described as having cosmopolitan distributions. Whether these widely distributed morphologically similar algae also share a similar gene pool remains often unclear. In the context of island biogeography theory, stronger spatial isolation deemed typical of freshwater lakes should restrict gene flow and lead to higher genetic differentiation among lakes. Using nine microsatellite loci, we investigate the genetic diversity of a widely distributed freshwater planktonic diatom, Asterionella formosa, across different lakes in Switzerland and the Netherlands. We applied a hierarchical spatial sampling design to determine the geographical scale at which populations are structured. A subset of the isolates was additionally analysed using amplified fragment length polymorphism (AFLP) markers. Our results revealed complex and unexpected population structure in A. formosa with evidence for both restricted and moderate to high gene flow at the same time. Different genetic markers (microsatellites and AFLPs) analysed with a variety of multivariate methods consistently revealed that genetic differentiation within lakes was much stronger than among lakes, indicating the presence of cryptic species within A. formosa. We conclude that the hidden diversity found in this study is expected to have implications for the further use of A. formosa in biogeographical, conservation and ecological studies. Further research using species-level phylogenetic markers is necessary to place the observed differentiation in an evolutionary context of speciation

Deep sequencing and proteomic analysis of the microRNA-induced silencing complex in human red blood cells

During maturation, erythropoietic cells extrude their nuclei but retain their ability to respond to oxidant stress by tightly regulating protein translation. Several studies have reported microRNA-mediated regulation of translation during terminal stages of erythropoiesis, even after enucleation. In the present study, we performed a detailed examination of the endogenous microRNA machinery in human red blood cells using a combination of deep sequencing analysis of microRNAs and proteomic analysis of the microRNA-induced silencing complex. Among the 197 different microRNAs detected, miR-451a was the most abundant, representing more than 60% of all read sequences. In addition, miR-451a and its known target, 14-3-3ζ mRNA, were bound to the microRNA-induced silencing complex, implying their direct interaction in red blood cells. The proteomic characterization of endogenous Argonaute 2-associated microRNA-induced silencing complex revealed 26 cofactor candidates. Among these cofactors, we identified several RNA-binding proteins, as well as motor proteins and vesicular trafficking proteins. Our results demonstrate that red blood cells contain complex microRNA machinery, which might enable immature red blood cells to control protein translation independent of de novo nuclei information

Morphology and composition of Au films on Si(100)

Spot profile analysis low-energy electron diffraction, low-energy ion scattering and Auger electron spectroscopy were employed to study the morphology and composition of Au films on Si(100). After annealing, two distinct surface reconstructions were observed: a two-domain c(8×2) phase and a four-domain incommensurate (5×3.2)R5.7° phase. During the transition from the c(8×2) to the (5×3.2)R5.7° phase, the subsurface composition changes drastically from Au-rich to Si-rich, whereas the outermost layer composition remains almost constant (about 65 at.% Au). Detailed information concerning the domain structure for the two phases is subtracted from the profiles of the LEED spots