WSB1 and IL21R Genetic Variants Are Involved in Th2 Immune Responses to Ascaris lumbricoides.

Genetic and epigenetic factors are considered to be critical for host-parasite interactions. There are limited data on the role of such factors during human infections with Ascaris lumbricoides. Here, we describe the potential role of genetic factors as determinants of the Th2 immune response to A. lumbricoides in Brazilian children. Stool samples were collected from the children to detect A. lumbricoides by microscopy and peripheral blood leukocytes (PBLs) were cultured in whole blood cultures for detection of cytokines (IL-5, IL-10, and IL-13) in vitro. Levels of anti-A. lumbricoides IgE and IgG4 were measured in plasma. DNA was extracted from PBLs and genotyped using Illumina 2.5 Human Omni Beadchip. Candidate genes associated with A. lumbricoides responses were identified and SNVs in these selected genes associated with the Th2 immune response to A. lumbricoides. Haplotype, gene expression, and epigenetic analyses were done to identify potential associations with Th2 immune responses. GWAS on samples from 1,189 children identified WSB1 as a candidate gene, and IL-21R was selected as a biologically relevant linked gene for further analysis. Variants in WSB1 and IL21R were associated with markers of Th2 immune responses: increased A. lumbricoides-specific IgE and IL-5/IL-13 by PBLs from infected compared to uninfected individuals. In infected children, WSB1 but not IL21R gene expression was suppressed and increased methylation was observed in the WSB1 promoter region. This is the first study to show an association between genetic variants in WSB1 and IL21R and Th2 immune responses during A. lumbricoides infections in children. WSB1/IL21R pathways could provide a potential target for the treatment of Th2-mediated diseases

FUNCTIONAL POLYGYNY, AGONISTIC INTERACTIONS AND REPRODUCTIVE DOMINANCE IN THE NEOTROPICAL ANT ODONTOMACHUS-CHELIFER (HYMENOPTERA, FORMICIDAE, PONERINAE)

Intracolony aggression among dealated queens of the ponerine ant Odontomachus chelifer leads to a dominance order within the colony. Behavioral domination between queens entails an array of stereotyped displays which may escalate from vigorous antennation bouts to full mandibular strikes. In extreme situations a dominant queen may also suspend her subordinate opponent, who remains in pupal posture while being lifted up. As a rule the individual initiating a contest normally wins it. Subordinate queens may assume a crouching posture at the approach of a dominant nestmate from behind, a fact suggesting that chemical cues may also play a role in the establishment of the dominance order. Behavioral performances during domination contests and the rank position of different dealated queens correlated well with the data on individual egg production, ovarian development and other parameters of division of labor within the colony. Therefore, highly-ranked queens laid more eggs, had better developed ovaries and engaged less frequently in foraging activities outside the nest. Inseminated queens occupied the top positions in the dominance structure of the colony, and accounted for most of the aggressive interactions recorded within the nest tubes. Aggression toward egg-laying queens and the destruction of newly-laid eggs were conspicuous behavioral traits in the reproductive dominance of the O. chelifer colony. High ranking dealated queens were also the ones more frequently seen attacking alate females. The latter were observed to lay eggs, and some of them had developed ovaries. Our results with Odontomachus chelifer are in accordance with the data obtained elsewhere for other ponerine ants, and provide the first demonstration of a dominance structure linked to reproductive status among queens in a functionally polygynous ant colony.91213414

Advances in the graphitization protocol at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil

© 2015 Elsevier B.V. In this paper, we summarize the sample preparation methods currently used at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil. We also report on a series of results with regards to the graphitization protocol. Tests with different temperatures and baking times were performed, and carbon stable isotope ratios of graphite were measured by an EA-IRMS (elemental analyzer coupled with an isotopic ratio mass spectrometer) to infer the completeness of the graphitization reaction. We monitored the muffle furnace temperature using an independent thermocouple and found a -60°C offset, which may have caused the lower graphitization yields (detected from the large isotopic fractionation on several reference materials targets). At a temperature of 520°C, the isotopic fractionation in the graphitization reaction was systematically lower (-5‰ in average) and the overall scattering was reduced. As long as isotopic fractionation corrections are made using the online stable isotopes ratios provided by the AMS system, the accuracy of the 14C results should be maintained