Pollinator-mediated mating restriction between sympatric varieties of yellow lady’s slipper orchids (Cypripedium parviflorum Salisb.)

A predominant theme in the study of orchid evolution has been the importance of floral traits contributing to pollinator-mediated isolating barriers (i.e., floral isolation). However, few studies have quantified the contribution of floral isolation in sympatric orchid populations. Cypripedium parviflorum vars. makasin and pubescens are excellent taxa to test the strength of floral isolation because of their recent phylogenetic separation, overlapping flowering phenologies, and sympatric populations that can lack intermediate morphologies. In this paper, we use sympatric populations to (1) test for pre-mating and early-acting post-mating reproductive isolating barriers, (2) quantify genetic differentiation among populations using allozyme loci, and (3) document floral size differences between varieties. Pollen tracking experiments using fluorescent powders revealed minimal inter-varietal pollen movement. Across two sympatric sites, only 4 inter-varietal pollinations were observed among 52 var. makasin pollinations and 40 var. pubescens pollinations. All of these inter-varietal pollinations had var. makasin as the pollen donor. In contrast, artificial crosses within and between the varieties revealed no statistically significant differences in fruit set, seed weight, or embryo morphology. Allozyme data are consistent with restricted inter-varietal gene flow, showing strong allele frequency differences between the varieties across multiple loci. In a clustering analysis, these differences caused the varieties to group taxonomically and not by their geographic location. These data along with statistically significant morphological differences between the varieties strongly suggest the existence of a pollinator-mediated isolating barrier. The possible nature of the isolating barrier is discussed as well as the likelihood of other late acting post-zygotic barriers.     

Ethers and esters derived from apocynin avoid the interaction between p47phox and p22phox subunits of NADPH oxidase: evaluation in?vitro and in silico

NOX (NADPH oxidase) plays an important role during several pathologies because it produces the superoxide anion (O₂^•−), which reacts with NO (nitric oxide), diminishing its vasodilator effect. Although different isoforms of NOX are expressed in ECs (endothelial cells) of blood vessels, the NOX2 isoform has been considered the principal therapeutic target for vascular diseases because it can be up-regulated by inhibiting the interaction between its p47phox (cytosolic protein) and p22phox (transmembrane protein) subunits. In this research, two ethers, 4-(4-acetyl-2-methoxy-phenoxy)-acetic acid (1) and 4-(4-acetyl-2-methoxy-phenoxy)-butyric acid (2) and two esters, pentanedioic acid mono-(4-acetyl-2-methoxy-phenyl) ester (3) and heptanedioic acid mono-(4-acetyl-2-methoxy-phenyl) ester (4), which are apocynin derivatives were designed, synthesized and evaluated as NOX inhibitors by quantifying O₂^•− production using EPR (electron paramagnetic resonance) measurements. In addition, the antioxidant activity of apocynin and its derivatives were determined. A docking study was used to identify the interactions between the NOX2′s p47phox subunit and apocynin or its derivatives. The results showed that all of the compounds exhibit inhibitory activity on NOX, being 4 the best derivative. However, neither apocynin nor its derivatives were free radical scavengers. On the other hand, the in silico studies demonstrated that the apocynin and its derivatives were recognized by the polybasic SH3A and SH3B domains, which are regions of p47phox that interact with p22phox. Therefore this experimental and theoretical study suggests that compound 4 could prevent the formation of the complex between p47phox and p22phox without needing to be activated by MPO (myeloperoxidase), this being an advantage over apocynin.     

Metabolic products of soluble epoxide hydrolase are essential for monocyte chemotaxis to MCP-1 in vitro and in vivo

Monocyte chemoattractant protein-1 (MCP-1)-induced monocyte chemotaxis is a major event in inflammatory disease. Our prior studies have demonstrated that MCP-1-dependent chemotaxis requires release of arachidonic acid (AA) by activated cytosolic phospholipase A₂ (cPLA₂). Here we investigated the involvement of AA metabolites in chemotaxis. Neither cyclooxygenase nor lipoxygenase pathways were required, whereas pharmacologic inhibitors of both the cytochrome-P450 (CYP) and the soluble epoxide hydrolase (sEH) pathways blocked monocyte chemotaxis to MCP-1. To verify specificity, we demonstrated that the CYP and sEH products epoxyeiscosatrienoic acids (EETs) and dihydroxyeicosatrienoic acids (DHETs), respectively, restored chemotaxis in the presence of the inhibitors, indicating that sEH-derived products are essential for MCP-1-driven chemotaxis. Importantly, DHETs also rescued chemotaxis in cPLA₂-deficient monocytes and monocytes with blocked Erk1/2 activity, because Erk controls cPLA₂ activation. The in vitro findings regarding the involvement of CYP/sEH pathways were further validated in vivo using two complementary approaches measuring MCP-1-dependent chemotaxis in mice. These observations reveal the importance of sEH in MCP-1-regulated monocyte chemotaxis and may explain the observed therapeutic value of sEH inhibitors in treatment of inflammatory diseases, cardiovascular diseases, pain, and even carcinogenesis. Their effectiveness, often attributed to increasing EET levels, is probably influenced by the impairment of DHET formation and inhibition of chemotaxis.     

Diversity and abundance of wild host plants of lepidopteran stem borers in two different agroecological zones of Kenya

A survey was carried out between 2004 and 2005 in two ecologically different locations, Kakamega and Muhaka to assess diversity and abundance of wild host plants of lepidopteran stem borers as compared to maize plots during the cropping and non-cropping seasons. Kakamega in Western Kenya is characterized by a Guineo-Congolian rain forest mosaic and Muhaka at the Kenyan coast by a Zanzibar Inhambane mosaic with secondary grassy and woody vegetation. In Kakamega, wild host plants and maize covered 2 and 43% of the surveyed area. No variation in diversity and relative abundance of wild host plants was observed between both the cropping and non-cropping seasons. In Muhaka, the diversity and relative abundance of wild host plant species differed between seasons, with the Shannon Weaver Index (H) of 1.67 and 0.95 for cropping and non-cropping seasons, respectively. Similarly in this location, wild host plant cover varied between cropping (23%) and noncropping (17.9%). During both seasons, this was higher than the maize cover, with 10.7% and 0% for the cropping and non-cropping seasons, respectively. For both localities, the implication of the differences found in the abundance and diversity between the cropping and non-cropping seasons is discussed.     

Beaver dams maintain fish biodiversity by increasing habitat heterogeneity throughout a low‐gradient stream network

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Deforestation and Reforestation of Latin America and the Caribbean (2001–2010)

Forest cover change directly affects biodiversity, the global carbon budget, and ecosystem function. Within Latin American and the Caribbean region (LAC), many studies have documented extensive deforestation, but there are also many local studies reporting forest recovery. These contrasting dynamics have been largely attributed to demographic and socio‐economic change. For example, local population change due to migration can stimulate forest recovery, while the increasing global demand for food can drive agriculture expansion. However, as no analysis has simultaneously evaluated deforestation and reforestation from the municipal to continental scale, we lack a comprehensive assessment of the spatial distribution of these processes. We overcame this limitation by producing wall‐to‐wall, annual maps of change in woody vegetation and other land‐cover classes between 2001 and 2010 for each of the 16,050 municipalities in LAC, and we used nonparametric Random Forest regression analyses to determine which environmental or population variables best explained the variation in woody vegetation change. Woody vegetation change was dominated by deforestation (?541,835 km²), particularly in the moist forest, dry forest, and savannas/shrublands biomes in South America. Extensive areas also recovered woody vegetation (+362,430 km²), particularly in regions too dry or too steep for modern agriculture. Deforestation in moist forests tended to occur in lowland areas with low population density, but woody cover change was not related to municipality‐scale population change. These results emphasize the importance of quantitating deforestation and reforestation at multiple spatial scales and linking these changes with global drivers such as the global demand for food.     

Publication of descriptions of novel bacterial taxa in <Emphasis Type="Italic">Antonie van Leeuwenhoek</Emphasis>

The species from the order Neisseriales are currently distinguished from other bacteria on the basis of branching in 16S rRNA gene trees. For this order containing a single family, Neisseriaceae, no distinctive molecular, biochemical, or phenotypic characters are presently known. We report here detailed phylogenetic and comparative analyses on the 27 genome sequenced species of the order Neisseriales. Our comparative genomic analyses have identified 54 conserved signature indels (CSIs) in widely distributed proteins that are specific for either all of the sequenced Neisseriales species or a number of clades within this order that are also supported by phylogenetic analyses. Of these CSIs, 11 are specifically present in all of the sequenced species from this order, but are not found in homologous proteins from any other bacteria. These CSIs provide novel molecular markers specific for, and delimiting, this order. Twenty-one CSIs in diverse proteins are specific for a group comprised of the genera Neisseria, Eikenella, Kingella, and Simonsiella (Clade I), which are obligate host-associated organisms, lacking flagella and exhibiting varied morphology. The species from these genera also formed a strongly supported clade in phylogenetic trees based upon concatenated protein sequences; a monophyletic grouping of these genera and other genera displaying similar morphological characteristics was also observed in the 16S rRNA gene tree. A second clade (Clade II), supported by seven of the identified CSIs and phylogenetic trees based upon concatenated protein sequences, grouped together species from the genera Chromobacterium, Laribacter, and Pseudogulbenkiania that are rod-shaped bacteria, which display flagella-based motility and are capable of free living. The remainder of the CSIs were uniquely shared by smaller groups within these two main clades. Our analyses also provide novel insights into the evolutionary history of the Neisseriales and suggest that the CSIs that are specific for the Clade I species may play an important role in the evolution of obligate host-association within this order. On the basis of phylogenetic analysis, the identified CSIs, and conserved phenotypic characteristics of different Neisseriales genera, we propose a division of this order into two families: an emended family Neisseriaceae (corresponding to Clade I) containing the genera Alysiella, Bergeriella, Conchiformibius, Eikenella, Kingella, Neisseria, Simonsiella, Stenoxybacter, Uruburuella and Vitreoscilla and a new family, Chromobacteriaceae fam. nov., harboring the remainder of the genera from this order (viz. Andreprevotia, Aquaspirillum, Aquitalea, Chitinibacter, Chitinilyticum, Chitiniphilus, Chromobacterium, Deefgea, Formivibrio, Gulbenkiania, Iodobacter, Jeongeupia, Laribacter, Leeia, Microvirgula, Paludibacterium, Pseudogulbenkiania, Silvimonas, and Vogesella).     

Kinetic and anion inhibition studies of a β-carbonic anhydrase (FbiCA 1) from the C4 plant Flaveria bidentis

Several β-carbonic anhydrases (CAs, EC 4.2.1.1) are present in all land plants examined thus far. Here we report the first detailed biochemical characterization of one such isoform, FbiCA 1, from the C₄ plant Flaveria bidentis, which was cloned, purified and characterized as recombinant protein. FbiCA 1 has an interesting CO₂ hydrase catalytic activity (k_cat of 1.2 × 10⁵ and k_cat/K_m of 7.5 × 10⁶ M^?1 × s^?1) and was moderately inhibited by most simple/complex inorganic anions. Potent FbiCA 1 inhibitors were also detected, such as trithiocarbonate, diethyldithiocarbamate, sulfamide, sulfamic acid, phenylboronic acid and phenylarsonic acid (K_Is in the range of 4–60 μM). Such inhibitors may be used as tools to better understand the role of various β-CA isoforms in photosynthesis.