Transcriptome Sequencing and Simple Sequence Repeat Marker Development for Three Macaronesian Endemic Plant Species

© 2016 White et al. Published by the Botanical Society of America. This work is licensed under a Creative Commons Attribution License (CC-BY-NC-SA). The attached file is the published version of the article

Patterns of genetic diversity in three plant lineages endemic to the Cape Verde Islands

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. The file attached is the published version of the article

Inflammation and hypoxia : novel regulators of mammalian copper homeostasis in macrophages

Title from PDF of title page (University of Missouri--Columbia, viewed on March 8, 2010).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Michael J. Petris.Vita.Ph. D. University of Missouri--Columbia 2008.Copper is an essential cofactor of enzymes involved in a variety of important metabolic processes including ATP production, iron transport, and antioxidant defense. The maintenance of copper homeostasis requires a balance of copper uptake and export, as well as the appropriate partitioning of copper between the cytoplasm, mitochondria and secretory compartments. Although many of the proteins involved in copper homeostasis have been identified, it is unknown whether specific pathophysiological conditions lead to compensatory changes in the intracellular copper distribution. In this study, we identify changes in copper homeostasis in response to pro-inflammatory mediators. We also show a novel role for the copper-transporting ATPase, ATP7A, in the bactericidal activity of RAW264.7 macrophage cell. We also identify striking alterations in copper homeostasis in response to hypoxia in RAW264.7 macrophage cells. In response to hypoxia, we observe a change in the hierarchy of intracellular distribution favoring delivery of copper to ATP7A and to the secretory pathway, as evidenced by enhanced activity of the ferroxidase, ceruloplasmin, and by copper-dependent trafficking of ATP7A in hypoxic macrophages in vitro and in vivo. Our study underscores the potential for pathophysiological conditions to regulate adaptive responses involving altered copper distribution to cuproenzymes.Includes bibliographical reference

Comparison of Small- and Large-Footprint Lidar Characterization of Tropical Forest Aboveground Structure and Biomass: A Case Study From Central Gabon

NASA's Global Ecosystem Dynamic Investigation (GEDI) mission has been designed to measure forest structure using lidar waveforms to sample the earth's vegetation while in orbit aboard the International Space Station. In this paper, we used airborne large-footprint (LF) lidar measurements to simulate GEDI observations from which we retrieved ground elevation, vegetation height, and aboveground biomass (AGB). GEDI-like product accuracy was then assessed by comparing them to similar products derived from airborne small-footprint (SF) lidar measurements. The study focused on tropical forests and used data collected during the NASA and European Space Agency (ESA) AfriSAR ground and airborne campaigns in the Lope National Park in Central Gabon. The measurements covered a gradient of successional stages of forest development with different height, canopy density, and topography. The comparison of the two sensors shows that LF lidar waveforms and simulated waveforms from SF lidar are equivalent in their ability to estimate ground elevation (RMSE = 0.5 m, bias = 0.29 m) and maximum forest height (RMSE = 2.99 m, bias = 0.24 m) over the study area. The difference in the AGB estimated from both lidar instruments at the 1-ha spatial scale is small over the entire study area (RMSE = 6.34 Mg·ha-1, bias = 11.27 Mg·ha-1) and the bias is attributed to the impact of ground slopes greater than 10–20° on the LF lidar measurements of forest height. Our results support the ability of GEDILF lidar to measure the complex structure of humid tropical forests and provide AGB estimates comparable to SF-derived ones

Scrophularia arguta, a widespread annual plant in the Canary Islands: a single recent colonization event or a more complex phylogeographic pattern?

Many studies have addressed evolution and phylogeography of plant taxa in oceanic islands, but have primarily focused on endemics because of the assumption that in widespread taxa the absence of morphological differentiation between island and mainland populations is due to recent colonization. In this paper, we studied the phylogeography of Scrophularia arguta, a widespread annual species, in an attempt to determine the number and spatiotemporal origins of dispersal events to Canary Islands. Four different regions, ITS and ETS from nDNA and psbA-trnH and psbJ-petA from cpDNA, were used to date divergence events within S. arguta lineages and determine the phylogenetic relationships among populations. A haplotype network was obtained to elucidate the phylogenetic relationships among haplotypes. Our results support an ancient origin of S. arguta (Miocene) with expansion and genetic differentiation in the Pliocene coinciding with the aridification of northern Africa and the formation of the Mediterranean climate. Indeed, results indicate for Canary Islands three different events of colonization, including two ancient events that probably happened in the Pliocene and have originated the genetically most divergent populations into this species and, interestingly, a recent third event of colonization of Gran Canaria from mainland instead from the closest islands (Tenerife or Fuerteventura). In spite of the great genetic divergence among populations, it has not implied any morphological variation. Our work highlights the importance of nonendemic species to the genetic richness and conservation of island flora and the significance of the island populations of widespread taxa in the global biodiversity.Trabajo financiado por: Ministerio de Ciencia e Innovación y Fondos FEDER. Proyecto CGL2011-24140 (I+D+i)peerReviewe

Here today, here tomorrow: Beached timber in Gabon, a persistent threat to nesting sea turtles

notes:types: JOURThe African country of Gabon has seen decadal increases in commercial logging. An unforeseen consequence of this has been that many coastal areas, including several National Parks and Reserves, have suffered severe pollution from beached timber. This has the potential to adversely affect nesting sea turtles, particularly the leatherback turtle (Dermochelys coriacea) for which Gabon constitutes the world’s largest rookery. In this study, we analyse aerial survey data (2003, 2007 and 2011) to determine the temporal persistence and spatial extent of beached timber, and by integrating spatial data on nesting, ascertain regions where beached timber poses the greatest threat to nesting leatherback turtles. There was no marked difference in the number of beached logs recorded across the study area during the period, with 15,160, 13,528 and 17,262 logs recorded in the three years, respectively. There was, however, a significant difference in abundance of beached logs among geographical areas. Analysis highlighted two coastal areas where nesting leatherback turtles were likely to be at greatest risk from beached timber. At one such site, Kingere, within Pongara National Park, where both logs and turtle densities are high, monitoring in 2006/2007 and 2007/2008 suggested that between 1.6% and 4.4% of leatherback turtles could be entrapped at this site. Given the dynamic nature of Gabon’s coastal environment, and the potential limitations of aerial surveys, densities of beached timber could be greater than this analysis reveals. We also propose, that despite recent export restrictions of whole logs, their environmental persistence potentially represents a long-term problem

Functioning of the dimeric GABA(B) receptor extracellular domain revealed by glycan wedge scanning

The G-protein-coupled receptor (GPCR) activated by the neurotransmitter GABA is made up of two subunits, GABA(B1) and GABA(B2). GABA(B1) binds agonists, whereas GABA(B2) is required for trafficking GABA(B1) to the cell surface, increasing agonist affinity to GABA(B1), and activating associated G proteins. These subunits each comprise two domains, a Venus flytrap domain (VFT) and a heptahelical transmembrane domain (7TM). How agonist binding to the GABA(B1) VFT leads to GABA(B2) 7TM activation remains unknown. Here, we used a glycan wedge scanning approach to investigate how the GABA(B) VFT dimer controls receptor activity. We first identified the dimerization interface using a bioinformatics approach and then showed that introducing an N-glycan at this interface prevents the association of the two subunits and abolishes all activities of GABA(B2), including agonist activation of the G protein. We also identified a second region in the VFT where insertion of an N-glycan does not prevent dimerization, but blocks agonist activation of the receptor. These data provide new insight into the function of this prototypical GPCR and demonstrate that a change in the dimerization interface is required for receptor activation

Molecular epidemiology of DFNB1 deafness in France

BACKGROUND: Mutations in the GJB2 gene have been established as a major cause of inherited non syndromic deafness in different populations. A high number of sequence variations have been described in the GJB2 gene and the associated pathogenic effects are not always clearly established. The prevalence of a number of mutations is known to be population specific, and therefore population specific testing should be a prerequisite step when molecular diagnosis is offered. Moreover, population studies are needed to determine the contribution of GJB2 variants to deafness. We present our findings from the molecular diagnostic screening of the GJB2 and GJB6 genes over a three year period, together with a population-based study of GJB2 variants. METHODS AND RESULTS: Molecular studies were performed using denaturing High Performance Liquid Chromatograghy (DHPLC) and sequencing of the GJB2 gene. Over the last 3 years we have studied 159 families presenting sensorineural hearing loss, including 84 with non syndromic, stable, bilateral deafness. Thirty families were genotyped with causative mutations. In parallel, we have performed a molecular epidemiology study on more than 3000 dried blood spots and established the frequency of the GJB2 variants in our population. Finally, we have compared the prevalence of the variants in the hearing impaired population with the general population. CONCLUSION: Although a high heterogeneity of sequence variation was observed in patients and controls, the 35delG mutation remains the most common pathogenic mutation in our population. Genetic counseling is dependent on the knowledge of the pathogenicity of the mutations and remains difficult in a number of cases. By comparing the sequence variations observed in hearing impaired patients with those sequence variants observed in general population, from the same ethnic background, we show that the M34T, V37I and R127H variants can not be responsible for profound or severe deafness

An aPKC-Exocyst Complex Controls Paxillin Phosphorylation and Migration through Localised JNK1 Activation

The exocyst/aPKC complex controls the spatiotemporal activation of the kinases JNK and ERK at the leading edge of migrating cells and thereby controls the dynamic behaviour of the adhesion protein paxillin during cell migration