Avaliação dos parâmetros ambientais e fisiológicos para frangos de corte linhagem caipira em diferentes fases de criação na Amazônia Ocidental / Evaluation of environmental and physiological parameters for free-range broilers in different productive phases in the Western Amazon

Objetivou-se com este trabalho avaliar a influência do ambiente em diferentes períodos do dia sobre os parâmetros fisiológicos de frangos caipira da linhagem Label Rouge em diferentes fases de criação (inicial, crescimento e terminação) na Amazônia Ocidental. Foram utilizados 300 pintinhos da linhagem Caipira Label Rouge, distribuídos em vinte cinco boxes de 12 animais cada. Semanalmente foram coletados dados de temperatura de bulbo seco, temperatura de ponto de orvalho, temperatura de globo negro e umidade relativa no interior do galpão, em três pontos (início, meio e fim) e em diferentes horários, 09:00, 15:00 e 21:00 horas. A partir da coleta das variáveis climáticas foram calculados os índices de conforto térmico: índices de temperatura e umidade e o índice de temperatura de globo e umidade. Os parâmetros fisiológicos foram avaliados em cada fase de criação (inicial, crescimento e final), nas idades de 21, 42 e 63 dias, considerando as variáveis, temperatura cloacal, temperaturas superficiais (cabeça, pescoço, dorso, asa e pernas) e frequência respiratória. Os resultados dos índices bioclimáticos demonstraram que em todas fases de criação os animais se encontravam fora da faixa de conforto térmico de temperatura e umidade relativa, sendo os maiores índices (p<0,05) observados no período da tarde. Para os parâmetros fisiológicos, foi possível observar que houve incremento (p<0,05) em todas as temperaturas mensuradas, como também, na frequência respiratória (p<0,05) no período da tarde nas fases inicial e crescimento. Sendo assim, conclui-se que as altas temperaturas associadas a alta umidade no período da tarde aumentaram os índices bioclimáticos e o desconforto dos animais, alterando as temperaturas superficiais e frequência respiratória de frangos caipiras Label Rouge criados na Amazônia Ocidental. 

Novel immunomodulators from hard ticks selectively reprogramme human dendritic cell responses

Hard ticks subvert the immune responses of their vertebrate hosts in order to feed for much longer periods than other blood-feeding ectoparasites; this may be one reason why they transmit perhaps the greatest diversity of pathogens of any arthropod vector. Tick-induced immunomodulation is mediated by salivary components, some of which neutralise elements of innate immunity or inhibit the development of adaptive immunity. As dendritic cells (DC) trigger and help to regulate adaptive immunity, they are an ideal target for immunomodulation. However, previously described immunoactive components of tick saliva are either highly promiscuous in their cellular and molecular targets or have limited effects on DC. Here we address the question of whether the largest and globally most important group of ticks (the ixodid metastriates) produce salivary molecules that specifically modulate DC activity. We used chromatography to isolate a salivary gland protein (Japanin) from Rhipicephalus appendiculatus ticks. Japanin was cloned, and recombinant protein was produced in a baculoviral expression system. We found that Japanin specifically reprogrammes DC responses to a wide variety of stimuli in vitro, radically altering their expression of co-stimulatory and co-inhibitory transmembrane molecules (measured by flow cytometry) and their secretion of pro-inflammatory, anti-inflammatory and T cell polarising cytokines (assessed by Luminex multiplex assays); it also inhibits the differentiation of DC from monocytes. Sequence alignments and enzymatic deglycosylation revealed Japanin to be a 17.7 kDa, N-glycosylated lipocalin. Using molecular cloning and database searches, we have identified a group of homologous proteins in R. appendiculatus and related species, three of which we have expressed and shown to possess DC-modulatory activity. All data were obtained using DC generated from at least four human blood donors, with rigorous statistical analysis. Our results suggest a previously unknown mechanism for parasite-induced subversion of adaptive immunity, one which may also facilitate pathogen transmission

High Levels of Diversity Uncovered in a Widespread Nominal Taxon: Continental Phylogeography of the Neotropical Tree Frog

Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered