European checkerspots (Melitaeini: Lepidoptera,Nymphalidae) are not aposematic – the point of view of great tits (Parus major)

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Bacterial Strain <Emphasis Type="Italic">Alcaligenes denitrificans</Emphasis> C-32 Containing Two Nitrilases with Different Substrate Specificities

Two genes encoding nitrilases with different properties have been found in an Alcaligenes denitrificans C-32 strain with high nitrilase activity that is currently used as a biocatalyst for commercial ammonium acrylate production. Both genes were expressed in E. coli, and the properties of the recombinant nitrilases were studied. One of these genes, which is designated as nitC1, controlled the formation of nitrilase that preferred aliphatic nitriles (acrylonitrile and butyronitrile) as best substrates. The nucleotide sequence of the gene nitC1 was almost (99%) identical to the gene sequence of an aliphatic nitrilase from Acidovorax facilis 72W (DQ4444267). In turn, nitC2 had a high level of homology (85%) with the arylacetonitrilase gene from Alcaligenes faecalis JM3 (D13419). Benzyl cyanide was shown to be the best substrate for nitC2-encoded nitrilase. In light of the results of DNA homology and differences in substrate specificity, the NitC2 and NitC1 nitrilases from Alcaligenes denitrificans C-32 were allocated to the groups of aliphatic nitrilases and arylacetonitrilases, respectively.     

ONTOGENETIC NICHE SHIFT IN THE BRACHIOPOD TEREBRATALIA TRANSVERSA: RELATIONSHIP BETWEEN THE LOSS OF ROTATION ABILITY AND ALLOMETRIC GROWTH

Abstract: Many articulated brachiopods experience marked life habit variations during ontogeny because they experience their fluid environment at successively higher Reynolds numbers, and they can change the configuration of their inhalant and exhalant flows as body size increases. We show that the extant brachiopod Terebratalia transversa undergoes a substantial ontogenetic change in reorientation governed by rotation around the pedicle. T. transversa′s reorientation angle (maximum ability to rotate on the pedicle) decreases during ontogeny, from 180 degrees in juveniles to 10–20 degrees in individuals exceeding 5 mm, to complete cessation of rotation in individuals larger than 10 mm. Rotation ability is substantially reduced after T. transversa achieves the adult lophophore configuration and preferred orientation with respect to ambient water currents at a length of 2.5–5 mm. We hypothesize that the rotation angle of T. transversa is determined mainly by the position of ventral and dorsal points of attachment of dorsal pedicle muscles relative to the pedicle. T. transversa shows a close correlation between the ontogenetic change in reorientation angle and ontogeny of morphological traits that are related to points of attachment of dorsal pedicle muscles, although other morphological features can also limit rotation in the adult stage. The major morphological change in cardinalia shape and the observed reduction of rotation affect individuals 2.5–10 mm in length. The position of ventral insertions of dorsal pedicle muscles remains constant, but contraction of dorsal pedicle muscles is functionally handicapped because dorsal insertions shift away from the valve midline, rise above the dorsal valve floor, and become limited by a wide cardinal process early in ontogeny (<5 mm). The rate of increase of cardinal process width and of distance between dorsal pedicle muscle scars substantially decreases in the subadult stage (5–10 mm), and most of the cardinalia shell traits grow nearly isometrically in the adult stage (>10 mm). T. transversa attains smaller shell length in crevices than on exposed substrates. The proportion of small‐sized individuals and population density is lower on exposed substrates than in crevices, indicating higher juvenile mortality on substrates prone to grazing and physical disturbance. The loss of reorientation ability can be a consequence of morphological changes that strengthen substrate attachment and maximize protection against biotic or physical disturbance (1) by minimizing torques around the pedicle axis and/or (2) by shifting energy investments into attachment strength at the expense of the cost involved in reorientation.     

Therapeutic implications of GIPC1 silencing in cancer

GIPC1 is a cytoplasmic scaffold protein that interacts with numerous receptor signaling complexes, and emerging evidence suggests that it plays a role in tumorigenesis. GIPC1 is highly expressed in a number of human malignancies, including breast, ovarian, gastric, and pancreatic cancers. Suppression of GIPC1 in human pancreatic cancer cells inhibits in vivo tumor growth in immunodeficient mice. To better understand GIPC1 function, we suppressed its expression in human breast and colorectal cancer cell lines and human mammary epithelial cells (HMECs) and assayed both gene expression and cellular phenotype. Suppression of GIPC1 promotes apoptosis in MCF-7, MDA-MD231, SKBR-3, SW480, and SW620 cells and impairs anchorage-independent colony formation of HMECs. These observations indicate GIPC1 plays an essential role in oncogenic transformation, and its expression is necessary for the survival of human breast and colorectal cancer cells. Additionally, a GIPC1 knock-down gene signature was used to interrogate publically available breast and ovarian cancer microarray datasets. This GIPC1 signature statistically correlates with a number of breast and ovarian cancer phenotypes and clinical outcomes, including patient survival. Taken together, these data indicate that GIPC1 inhibition may represent a new target for therapeutic development for the treatment of human cancers.     

Recombinant glutamate carboxypeptidase II (prostate specific membrane antigen--PSMA)--cellular localization and bioactivity analyses

Glutamate Carboxypeptidase II (also known as Prostate Specific Membrane Antigen—PSMA) is an important marker in the diagnosis of prostate cancer, however, relatively little is known about its biochemical and structure-function characteristics. We have expressed mutant forms of PSMA and have started to address the roles of three putative domains of PSMA in its cellular localization and peptidase activity. Three mutants, a full-length recombinant PSMA (rPSMA-FL), one expressing only the proposed extracellular domain of PSMA (rPSMA-ECD) and one form omitting the proposed transmembrane domain (rPSMA-TMD) have been produced in human cells via a mammalian expression vector system. We show that rPSMA-FL is associated with the cell surface membrane; so too is rPSMA-TMD even though it lacks the proposed transmembrane domain, whereas rPSMA-ECD has a cytosolic localization. Only rPSMA-FL retains functional hydrolytic activity and is similarly glycosylated to PSMA found in the cultured prostate cancer cell line LNCaP.     

MDA-MB-435 human breast carcinoma cell homo- and heterotypic adhesion under flow conditions is mediated in part by Thomsen-Friedenreich antigen-galectin-3 interactions

The importance of Thomsen-Friedenreich antigen (T antigen)-galectin-3 interactions in adhesion of human breast carcinoma cells to the endothelium under conditions of flow was studied. Highly metastatic cells (MDA-MB-435) expressing high levels of both galectin-3 and T antigen demonstrated significantly increased adhesion to monolayers of endothelial cells compared with their non-metastatic counterpart (MDA-MB-468) in vitro. Within minutes of adhesion, the highly metastatic cells acquire the ability of enhanced homotypic adhesion, leading to the formation of multicellular aggregates at sites of attachment to endothelial cells in vitro. Treatment of cells with lactulosyl-l-leucine, a synthetic T antigen antagonist that targets galectin-3 by mimicking T antigen, caused a 60-80% inhibition of both homo- and heterotypic adhesion of MDA-MB-435 cells. Confocal microscopy and fluorescence-activated cell sorter analysis revealed redistribution of endothelial galectin-3 to the site of heterotypic intercellular contacts, whereas galectin-3 in MDA-MB-435 cells accumulated at sites of homotypic interaction. MDA-MB-435 cells also exhibited increased adhesion and intravascular retention within the microvessels of transplanted lung allografts in nude mice. T antigen and galectin-3-mediated interactions of metastatic cancer cells with endothelium under conditions of flow are characterized by a unique adhesion mechanism that qualitatively distinguishes their homo- and heterotypic adhesive behavior from other cell types such as leukocytes.     

Changes in fatty acids contents and growth characteristics in transformed oilseed rape (Brassica napus)

Spring oilseed rapeBrassica napus L. ssp.oleifera cv. HM-81 was transformed with T_L-DNA of the Ri plasmid of the agropine strainAgrobacterium rhizogenes 15834. Selfed progenies (R₂ and R₃ generations) were studied for changes in values of growth characteristics and fatty acids contents. Transformants are ‘homozygous’ for T_L-DNA. Both generations of transformants differed significantly from the nontransformed control plants in reduced length, lower number of pods per plant, lower total mass of seeds and the higher number of branches. The contents of palmitic, linoleic and linolenic acids were significantly higher in transformants when compared with the control. On the contrary, the contents of both stearic and oleic acids were in most of transformants significantly lower. Only traces of erucic acid (less than 0.05 % ) were found, both in transformed and nontransformed plants.     

Diversity and ecology of algae from the Nahal Qishon river,northern Israel

In 59 samples of periphyton and phytoplankton collected in 2002 - 2003 from the Nahal Qishon (Qishon River), northern Israel, we found 178 species from seven divisions of algae and cyanoprocaryotes. Diatoms, clorophytes, and cyanoprocaryotes prevail. Nitzschia and Navicula (Bacillariophyta) are the most abundant. Most of the species are cosmopolitan or widespread, except Lagynion janei (Chrysophyta), which is endemic for the Mediterranean Realm. About 17% of species (26) are new for Israel and five of them represent the first recorded genera: Crinalium endophyticum Crow, Actinocyclus normanii (Gregory) Hustedt, Rhizoclonium hieroglyphicum (Agardh) Kütz (Chlorophyta), Lagynion janei Bourelly, and Stylococcus aureus Chodat. Most of them come from a rare riverine assemblage with red alga Audouinella pygmea, as well as from the estuarine assemblage. Alkaliphiles predominate among the indicators of acidity, with few acidophiles confined to the communities under the impact of industrial wastes. Among the indicators of salinity, most numerous are the oligohalobien-indifferents and species adapted to a moderate salinity level. The relative species richness of ecological groups and the indices of saprobity are correlated with changes in conductivity, pH, and N-nitrate concentration. Indicators of organic pollution fall in the range of betameso- to alfamesosaprobic self-purification grades. Our studies show ecological significance of the Nahal Qishon as a model for a strongly disturbed aquatic ecosystem in the coastal zone of eastern Mediterranean.     

Pulsed Estrogen Therapy Prevents Post-OVX Porcine Dura Mater Microvascular Network Weakening via a PDGF-BB-Dependent Mechanism

In postmenopausal women, estrogen (E2) deficiencies are frequently associated with higher risk of intracranial hemorrhage, increased incidence of stroke, cerebral aneurysm, and decline in cognitive abilities. In younger postpartum women and those using oral contraceptives, perturbations in E2 are associated with higher risk of cerebral venous thrombosis. A number of serious intracranial pathologic conditions linked to E2 deficiencies, such as dural sinus thrombosis, dural fistulae, non-parenchymal intracranial hemorrhages, migraines, and spontaneous cerebrospinal fluid leaks, involve the vessels not of the brain itself, but of the outer fibrous membrane of the brain, the dura mater (DM). The pathogenesis of these disorders remains mysterious and how estrogen regulates structural and functional integrity of DM vasculature is largely unknown. Here, we demonstrate that post ovariectomy (OVX) DM vascular remodeling is manifested by microvessel destabilization, capillary rarefaction, increased vascular permeability, and aberrant angio-architecture, and is the result of disrupted E2-regulated PDGF-BB signaling within dura microvasculature. These changes, associated with the reduction in systemic PDGF-BB levels, are not corrected by a flat-dose E2 hormone replacement therapy (HRT), but are largely prevented using HRT schedules mimicking physiological E2 fluctuations. We demonstrate that 1) E2 regulates PDGF-BB production by endothelial cells in a dose-dependent manner and 2) optimization of PDGF-BB levels and induction of robust PDGF-mediated endothelial cell-vascular pericyte interactions require high (estrous) E2 concentrations. We conclude that high (estrous) levels of E2 are important in controlling PDGF-mediated crosstalk between endothelial cells and pericytes, a fundamental mechanism governing microvessel stability and essential for preserving intracranial homeostasis.