A new species of Characidium (Characiformes: Crenuchidae) from the rio Madeira basin,Brazil

This study describes Characidium nambiquara, a new species from the upper rio Guaporé, rio Madeira basin, Brazil. The new species differs from most congeners by the presence of isthmus and area between the contralateral pectoral-fin bases completely naked. From congeners with some degree of scaleless ventral surface of the body C. nambiquara differs by having 10 circumpeduncular scales. The new species is also distinguished from congeners by the spotted colour pattern on body of the large-sized specimens and by having black dashes on all fins and conspicuous midlateral longitudinal dark stripe or conspicuous vertical bars absent. Characidium nambiquara further differs from most congeners by the presence of 34–36 pored scales on the lateral line, 3 horizontal scale rows above the lateral line and 3 horizontal scale rows from the lateral line to the midventral scale series. Remarks on intraspecific colour variation within the genus, not related to sexual dimorphism, are also provided.     

Better to Be in Bad Company than to Be Alone? Aedes Vectors Respond Differently to Breeding Site Quality in the Presence of Others

This study focuses on two competing species, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), both invasive mosquitoes of the New World. Context-specific competition between immature forms inside containers seems to be an important determinant of the coexistence or displacement of each species in different regions of the world. Here, competition experiments developed at low density (one, two or three larvae) and receiving four different resource food concentration, were designed to test whether Ae. albopictus and Ae. aegypti respond differently to competition, and whether competition can be attributed to a simple division of resources. Three phenotypic traits - larval development, adult survival under starvation and wing length - were used as indicators of performance. Larvae of neither species were limited by resource concentration when they were alone, unlike when they developed with competitors. The presence of conspecifics affected Ae. aegypti and Ae. albopictus, inducing slower development, reduced survival and wing length. The response to resource limitation was different when developing with heterospecifics: Ae. aegypti developing with one heterospecific showed faster development, producing smaller adults with shorter lives, while in the presence of two competitors, development increased and adults lived longer. Aedes albopictus demonstrated a better performance when developing with heterospecifics, with no loss in their development period and improved adult survival. Overall, our results suggest that response to competition can not simply be attributed to the division of resources, and that larvae of both species presented large phenotypic plasticity in their response to the presence or absence of heterospecifics and conspecifics.     

The role of nutrition on epigenetic modifications and their implications on health

Nutrition plays a key role in many aspects of health and dietary imbalances are major determinants of chronic diseases including cardiovascular disease, obesity, diabetes and cancer. Adequate nutrition is particularly essential during critical periods in early life (both pre- and postnatal). In this regard, there is extensive epidemiologic and experimental data showing that early sub-optimal nutrition can have health consequences several decades later.     

Genomic Characterization of Novel Circular ssDNA Viruses from Insectivorous Bats in Southern Brazil

Circoviruses are highly prevalent porcine and avian pathogens. In recent years, novel circular ssDNA genomes have recently been detected in a variety of fecal and environmental samples using deep sequencing approaches. In this study the identification of genomes of novel circoviruses and cycloviruses in feces of insectivorous bats is reported. Pan-reactive primers were used targeting the conserved rep region of circoviruses and cycloviruses to screen DNA bat fecal samples. Using this approach, partial rep sequences were detected which formed five phylogenetic groups distributed among the Circovirus and the recently proposed Cyclovirus genera of the Circoviridae. Further analysis using inverse PCR and Sanger sequencing led to the characterization of four new putative members of the family Circoviridae with genome size ranging from 1,608 to 1,790 nt, two inversely arranged ORFs, and canonical nonamer sequences atop a stem loop.     

Trypanosoma cruzi glycoprotein 72: Immunological analysis and cellular localization

Two monoclonal antibodies were used to biochemically characterize glycoprotein 72 (GP72) from Trypanosoma cruzi and to localize the protein in live and fixed parasites by indirect immunofluorescence and in thin section of parasites by immunogold electron microscopy. GP72 was shown in immunoblots to be specific for the epimastigote stage; the protein could not be detected in trypomastigotes. Each antibody reacted with a different epitope on the glycoprotein and deglycosylation of GP72 ablated reactivity with one of the antibodies. Indirect immunofluorescence and electron microscopic evaluation of parasite associated gold particles showed the presence of GP72 in the cell surface membrane including the flagellar pocket and the cytostome. In addition, cytoplasmic membrane vesicles of the endosomal-lysosomal system stained intensely.     

Cloning of the replication region on the bacteriocinogenic plasmid pRJ9 of Staphylococcus aureus

Abstract A 5.8-kb Cla I fragment of pRJ9, a bacteriocinogenic plasmid of Sphylococcus aureus , was cloned in the unique Cla I site of pRJ5. The recombinant plasmid obtained, pRJ23, failed to confer bacteriocin production and immunity to bacteriocin on host cells. The cloned fragment was shown to contain the complete replicon of pRJ9. Attempts to clone the 4.4-kb Cla I fragment of pRJ9 were unsuccessful, apparently due to the inactivation of the basic replicon of the cloning vector. Therefore, plasmid pRJ5 cut at its Cla I site appears to be a suitable vector for cloning replication regions of plasmids that cab replicate in S. aureus .     

Chemical Composition and Cytotoxic Evaluation of the Essential Oil of Phyllogonium viride (Phyllogoniaceae,Bryophyta)

The present study aimed to determine the chemical composition and biological activity of the essential oil obtained from Phyllogonium viride Brid. (Phyllogoniaceae, Bryophyta), whose samples were collected in southern Brazil. For the first time, the cytotoxic activity of the essential oil of P. viride in breast and colorectal tumor cells (MCF-7 and HCT-116) was evaluated, as well as the cytotoxic potential of this oil in non-tumoral cells of human immortalized keratinocytes (HaCaT) via MTT assay. The compounds majorly found in P. viride essential oil were β-bazzanene (20.30 %), β-caryophyllene (17.06 %), β-chamigrene (14.02), and germacrene B (11.72 %). Treatment with P. viride essential oil in the different tested cell lines did not induce any toxicity in most of the tested concentrations. These data contribute to generating new scientific information about this understudied plant species. Furthermore, the chemical characterization of the compounds present in the essential oil of P. viride can lead to greater elucidation of its biotechnological potential.