Molecular phylogeny and host-plant use (Lamiaceae) of the Thymogethes pollen beetles (Coleoptera)

The 24 members of the Euro-Asiatic genus Thymogethes are highly specialized pollen beetles associated as larvae with flowers of Lamiaceae Nepetoideae. All members of the genus were analysed in within the framework of an integrative taxonomy approach, which was aimed to reconstruct the phylogenetic relationships, as well as the possible pattern of evolution of their larval-host-plant association. Evidence from multiple molecular markers [COI; 16S; H3], combined with an estimation of divergence times using an average rate of 0.0177 substitutions/site/My among branches, placed the origin of the genus at a minimum of 9–10 Mya. This date of origin approximates the known evolution of the host plants in Euro-Mediterranean areas. Evidence from combined molecular and cladistic morphological analyses resulted in suitable agreement with the previously established morphology-based systematics of the genus, although members of the exilis species-group were split into three clades. The only disagreement between results of this new combined phylogeny and previous classification is in the exclusion of “Thymogethes” grenieri. This species is herein positioned outside the genus, based on molecular evidence. Our analysis depicts several Thymogethes species differentiating in the last few Mys, specifically those included in the T. lugubris species-group. Combined evidence from DNA, morphology and ancestral state parsimony reconstruction of larval-host-plant associations suggests that subtribe Menthinae likely represents the ancestral host plants, with a series of independent host shifts during the radiation of the clade, in association first with Menthinae and subsequently with Lavandulinae and Nepetinae. Steno-oligophagy is the most frequent (86%) condition, while strictly monophagous species are less numerous (14%).     

Phenotypic expression in Escherichia coli and nucleotide sequence of two Chinese hamster lung cell cDNAs encoding different dihydrofolate reductases.

Nucleotide sequence analysis of two cDNA clones, one shown to direct the synthesis in Escherichia coli of the pI 6.7 form of the 20,000-molecular-weight class of Chinese hamster lung cell dihydrofolate reductase, and the other shown to direct the synthesis of the pI 6.5 form of the 21,000-molecular-weight class of the enzyme, has revealed the following: (i) the differences in physical and enzymatic properties displayed by these two proteins are due to two variations in their respective amino acid sequences with the conversion of Leu to Phe at position 22 probably responsible for the differential sensitivity of these two enzymes to methotrexate and methasquin; (ii) the multiple mRNAs responsible for the synthesis of each of these proteins differ in size due, at least in part, to a length heterogeneity at their 3' ends; (iii) these two proteins are encoded by different genes; and (iv) the sequence AAATATA appears to be a major polyadenylation signal in one Chinese hamster lung cell dihydrofolate reductase gene and a minor signal in another.     

Conformational Analysis of a Synthetic Antimicrobial Peptide in Water and Membrane-Mimicking Solvents: A Molecular Dynamics Simulation Study

We have investigated structural and dynamic properties of the synthetic peptide hlF1-11 (GRRRSVQWCA, i.e., the first 11 N-terminal amino acids of the human lactoferrin protein) in water, 250 mM NaCl solution, 50% (V/V) water–trifluoroethanol mixture, and in the membrane mimetic 4:4:1 methanol–chloroform–water mixture. For comparison, we have also performed analogous simulations for the biologically inactive control peptide featuring Ala substitutions in the 2, 3, 6 and 9 positions of the hlF1-11 sequence. Statistical analyses of the trajectories indicate that only in the membrane-mimicking medium hlF1-11 adopts preferentially a conformation suitable to interact effectively with the membrane. In this conformation the peptide cationic region is rather flexible and elongated, while the C-terminal hydrophobic moiety appears as a more rigid hairpin-shaped loop approximately perpendicular to the cationic region. No such conformation is statistically relevant for the control peptide.     

Native woodland creation is associated with increase in a Black Grouse Lyrurus tetrix population

Capsule: Black Grouse population increases were greatest where new native woodland (NNW) within 1500?m of leks comprised approximately 30% of land area and averaged 5 years old.

Aims: To examine whether change in a population of Black Grouse Lyrurus tetrix in Scotland was associated with the creation of native woodland.

Methods: We examined whether lek location, size and change in size were associated with habitat and topography surrounding leks. We also examined vegetation differences in NNW and adjacent unplanted moorland.

Results: From 2002 to 2012 the number of lekking male Black Grouse increased by 90%. Lek occurrence was positively associated with the amount of NNW edge habitat. Leks were larger where there was more adjacent NNW. Lek increases were greatest where NNW plots comprised approximately 30% land area, and were 5 years old, within a 1500?m radius. Plots aged more than approximately 20 years old were associated with Black Grouse population declines. NNW supported taller and denser important field-layer vegetation than adjacent moorland, likely due to grazing exclusion.

Conclusions: Subject to longer-term management commitments to stimulate continued regrowth of the important field layer and maintain benefits for Black Grouse, expansion of native woodland could contribute to landscape-scale recovery of Black Grouse after decades of decline.     

Heparin Dodecasaccharide Containing Two Antithrombin-binding Pentasaccharides: STRUCTURAL FEATURES AND BIOLOGICAL PROPERTIES

The antithrombin (AT) binding properties of heparin and low molecular weight heparins are strongly associated to the presence of the pentasaccharide sequence AGA*IA (A_NAc,6S-GlcUA-A_NS,3,6S-I_2S-A_NS,6S). By using the highly chemoselective depolymerization to prepare new ultra low molecular weight heparin and coupling it with the original separation techniques, it was possible to isolate a polysaccharide with a biosynthetically unexpected structure and excellent antithrombotic properties. It consisted of a dodecasaccharide containing an unsaturated uronate unit at the nonreducing end and two contiguous AT-binding sequences separated by a nonsulfated iduronate residue. This novel oligosaccharide was characterized by NMR spectroscopy, and its binding with AT was determined by fluorescence titration, NMR, and LC-MS. The dodecasaccharide displayed a significantly increased anti-FXa activity compared with those of the pentasaccharide, fondaparinux, and low molecular weight heparin enoxaparin.     

A High-Content Small Molecule Screen Identifies Sensitivity of Glioblastoma Stem Cells to Inhibition of Polo-Like Kinase 1

Glioblastoma multiforme (GBM) is the most common primary brain cancer in adults and there are few effective treatments. GBMs contain cells with molecular and cellular characteristics of neural stem cells that drive tumour growth. Here we compare responses of human glioblastoma-derived neural stem (GNS) cells and genetically normal neural stem (NS) cells to a panel of 160 small molecule kinase inhibitors. We used live-cell imaging and high content image analysis tools and identified JNJ-10198409 (J101) as an agent that induces mitotic arrest at prometaphase in GNS cells but not NS cells. Antibody microarrays and kinase profiling suggested that J101 responses are triggered by suppression of the active phosphorylated form of polo-like kinase 1 (Plk1) (phospho T210), with resultant spindle defects and arrest at prometaphase. We found that potent and specific Plk1 inhibitors already in clinical development (BI 2536, BI 6727 and GSK 461364) phenocopied J101 and were selective against GNS cells. Using a porcine brain endothelial cell blood-brain barrier model we also observed that these compounds exhibited greater blood-brain barrier permeability in vitro than J101. Our analysis of mouse mutant NS cells (INK4a/ARF^−/−, or p53^−/−), as well as the acute genetic deletion of p53 from a conditional p53 floxed NS cell line, suggests that the sensitivity of GNS cells to BI 2536 or J101 may be explained by the lack of a p53-mediated compensatory pathway. Together these data indicate that GBM stem cells are acutely susceptible to proliferative disruption by Plk1 inhibitors and that such agents may have immediate therapeutic value.     

Species of the genus Quercus in Italy: Characterization by means of leaf surface observation

Abstract

We propose a study of the main species belonging to the genus Quercus in Italy, characterized and identified by means of leaf surface observation, with special attention devoted to waxes, trichomes and stomata. Comparing our results with the classification proposed by SCHWARZ (1984), we find that species belonging to Schwarz's subgenus Quercus are recognizable because their waxes are structured in vertical scales; the two other subgenera (Sclerophyllodrys and Cerris) present smooth wax structures, their distinctive feature being the shape of the stomatal rima, which is roundish in Sclerophyllodrys and elliptical in Cerris. The study characterizes Quercus pubescens Willd. and Quercus petraea Liebl. by analyzing some morphometric traits; but the authors feel that further research is needed on these critical taxonomic entities. Lastly, the study examines forms of was degeneration correlated to the phenomenon known as oak decline.