Phylogeography of the cactophilic species Drosophila gouveai: demographic events and divergence timing in dry vegetation enclaves in eastern Brazil

Aim  The aim of this study was to assess the causal mechanisms underlying populational subdivision in Drosophila gouveai , a cactophilic species associated with xeric vegetation enclaves in eastern Brazil. A secondary aim was to investigate the genetic effects of Pleistocene climatic fluctuations on these environments.
Location  Dry vegetation enclaves within the limits of the Cerrado domain in eastern Brazil.
Methods  We determined the mitochondrial DNA haplotypes of 55 individuals (representing 12 populations) based on sequence data of a 483-bp fragment from the cytochrome c oxidase subunit II (COII) gene. Phylogenetic and coalescent analyses were used to test for the occurrence of demographic events and to infer the time of divergence amongst genetically independent groups.
Results  Our analyses revealed the existence of two divergent subclades (G1 and G2) plus an introgressed clade restricted to the southernmost range of D. gouveai . Subclades G1 and G2 displayed genetic footprints of range expansion and segregated geographical distributions in south-eastern and some central highland regions, east and west of the Paraná River valley. Molecular dating indicated that the main demographic and diversification events occurred in the late to middle Pleistocene.
Main conclusions  The phylogeographical and genetic patterns observed for D. gouveai in this study are consistent with changes in the distribution of dry vegetation in eastern Brazil. All of the estimates obtained by molecular dating indicate that range expansion and isolation pre-dated the Last Glacial Maximum, occurring during the late to middle Pleistocene, and were probably triggered by climatic changes during the Pleistocene. The current patchy geographical distribution and population subdivision in D. gouveai is apparently closely linked to these past events.     

Cellular localization of bovine pancreatic trypsin inhibitor and related molecular forms in bovine lung

Summary In addition to bovine pancreatic trypsin inhibitor (BPTI), three BPTI-related molecular forms (isoinhibitors I, II and III) were isolated from bovine lung by affinity chromatography on immobilized trypsin and subsequently purified by Fast Protein Liquid Chromatography. These inhibitors are identical to the isoinhibitors previously isolated from bovine spleen. Their localization in bovine lung was studied by immunohistochemical techniques, using two different immunoglobulin preparations, selectively recognizing BPTI or the other molecular forms.BPTI-related immunoreactivity was found to be restricted to isolated cells, often identified as mast cells by Toluidine Blue staining. In contrast, isoinhibitor-related immunoreactivity, which also occurs in the mast cells, is present in a number of other cell types. These types include: (i) the smooth muscle cells of different calibre vessels, (ii) the ciliated cells of the bronchial epithelium and the related mucus, and (iii) many cells at alveolar level.Comparison of these data with previous results obtained for bovine spleen suggest multiple physiological roles for these inhibitors.     

High-performance liquid chromatographic separation of aprotinin-like inhibitors and their determination in very small amounts

A reversed-phase high-performance liquid chromatographic method for the determination and quantitative recovery of fully active aprotinin (the basic pancreatic trypsin inhibitor or Kunitz inhibitor) and aprotinin-like inhibitors in amounts down to 0.5 μg is reported. The method, which allows separation of aprotinin isoinhibitors characterized by small differences in the primary structure with respect to aprotinin itself, appears to be suitable for the quantitation and identification of aprotinin-like inhibitors in human biological fluids, in which they appear to be present at very low levels.     

Pierce into the Native Structure of Ata,a Trimeric Autotransporter of Acinetobacter baumannii ATCC 17978

International Journal of Peptide Research and Therapeutics - Acinetobacter baumannii is an important pathogen responsible for nosocomial infections worldwide. Trimeric autotransporters, the...     

Water deficit modulates growth,morphology, and the essential oil profile in Lippia alba L. (Verbenaceae) grown in vitro

Lippia alba (Miller) N.E. Brown is an aromatic plant species of great economic importance due to the medicinal properties of its essential oils, which provide stress relief, respiratory and gastrointestinal disease control, and anti-inflammatory and natural sedative effects. The plant is also effective in biological control against various pathogens and in food preservation. Water deficit is the most critical abiotic factor limiting plant growth and morpho-physiological development, as well as production of secondary metabolism compounds. The objective of this work was to evaluate the effect of water deficit on growth, photosynthesis, essential oil profile, and the expression of genes related to the biosynthesis of these compounds in L. alba grown in vitro. Nodal segments were cultured on medium supplemented with 0, 1, 2, and 3% (w/v) polyethylene glycol for 45 days. Water stress had a negative effect on primary metabolism indicators, such as growth, leaf area, and photosynthetic rate; but a positive effect on amino acid and total protein content. Similarly, secondary metabolism exhibited an increase in linalool but a reduction in germacrene levels under water deficit. These findings provide a deeper understanding of how water deficit affects primary and secondary metabolism in L. alba, showing the potential of this medicinal species to adapt to soils with low water availability, while still being able to grow and synthesize essential oils.

     

Homology modelling,virtual screening and molecular dynamics of the MARK3 KA1 domain for cancer drug design

Structural homology modelling was done with the software AMPS, MODELLER, PROCHECK, WHATIF AND VERIFY-3D to generate a quality model of human MARK3. Macromolecular docking simulations seem to confirm recent data in the literature and in MARK3 there does not occur intramolecular interactions between the associated kinase domain KA1 and the catalytic domain. Using virtual screening, we were able to identify and suggest the principal residues of MARK3 which interact with the ligands in addition to those reported in the literature. The pharmacophoric model obtained from Discovery Studio coincides with those obtained by molecular interaction fields, indicating the principal ligand residues of the MARK3 KA1 domain. Using virtual screening with pharmacophoric constraints as well as molecular dynamics, the most stable compounds in the ligand site as well as their potential toxicities were used to select potential inhibitors for further in vitro and in vivo investigations of human MARK3 KA1 domain, which could eventually pass to the market to be used for the treatment of head and neck cancer.     

Predation drives recurrent convergence of an interspecies mutualism

Mutualisms are important ecological interactions that underpin much of the world's biodiversity. Predation risk has been shown to regulate mutualism dynamics in species‐specific case studies; however, we lack studies which investigate whether predation can also explain broader patterns of mutualism evolution. We report that fish‐anemone mutualisms have evolved on at least 55 occasions across 16 fish families over the past 60 million years and that adult body size is associated with the ontogenetic stage of anemone mutualisms: larger‐bodied species partner with anemones as juveniles, while smaller‐bodied species partner with anemones throughout their lives. Field and laboratory studies show that predators target smaller prey, that smaller fishes associate more with anemones, and that these relationships confer protection to small fishes. Our results indicate that predation is likely driving the recurrent convergent evolution of fish‐anemone mutualisms and suggest that similar ecological processes may have selected convergence in interspecies interactions in other animal clades.     

A novel in vitro propagation system for West Indian elm [Guazuma ulmifolia Lam. (Malvaceae)]: a valuable medicinal woody species

In Vitro Cellular & Developmental Biology - Plant - The aim of this study was to establish a system of in vitro germination and propagation of Guazuma ulmifolia Lam. microcuttings (Malvaceae)....     

Structural characterization of cationic DODAB bilayers containing C24:1 β-glucosylceramide

The effect of 5 mol%, 9 mol%, and 16 mol% of C24:1 β-glucosylceramide (βGlcCer) on the structure of cationic DODAB bilayers was investigated by means of differential scanning calorimetry (DSC), electron spin resonance (ESR) spectroscopy and fluorescence microscopy. βGlcCer is completely miscible with DODAB at all fractions tested, since no domains were observed in fluorescence microscopy or ESR spectra. The latter showed that βGlcCer destabilized the gel phase of DODAB bilayers by decreasing the gel phase packing. As a consequence, βGlcCer induced a decrease in the phase transition temperature and cooperativity of DODAB bilayers, as seen in DSC thermograms. ESR spectra also showed that βGlcCer induced an increase in DODAB fluid phase order and/or rigidity. Despite their different structures, a similar effect of loosening the gel phase packing and turning the fluid phase more rigid/organized has also been observed when low molar fractions of cholesterol were incorporated in DODAB bilayers. The structural characterization of mixed membranes made of cationic lipids and glucosylceramides may be important for developing novel immunotherapeutic tools such as vaccine adjuvants.