Chromosome instability induced by agrochemicals among farm workers in Passo Fundo, Rio Grande do Sul, Brazil

A major share of the grain farming (wheat and soybeans) in the State of Rio Grande do Sul is in the Passo Fundo area. For crop pest control, large amounts of agrochemicals (fungicides, insecticides, and herbicides) are used. To evaluate the genotoxicity of these products, the micronucleus test was performed in farm workers directly exposed to these chemicals. Heparinized blood samples were drawn by venipuncture from 30 exposed workers and 30 non-exposed controls. Micronuclei frequency was evaluated by counting 1,000 binucleated cells per individual in both groups. Smoking habits, age, and duration of exposure showed no effect on the frequency of micronuclei in both groups. However, statistical analysis showed significantly higher mean numbers of binucleated cells with micronuclei in exposed individuals (14.3/1,000 cells) as compared to controls (7.1/1,000 cells), allowing the authors to conclude that the micronucleus test is an efficient biological assay for monitoring population exposure to mixtures of agrochemicals.A região de Passo Fundo no Planalto Médio do Rio Grande do Sul, caracteriza-se pela produção de grãos (trigo, soja), nas quais grandes quantidades de agroquímicos (fungicidas, inseticidas e herbicidas) são utilizadas. Para avaliar a atividade genotóxica desses produtos em seres humanos, utilizou-se a técnica de micronúcleos, através de amostras de sangue periférico de trinta trabalhadores expostos e de trinta indivíduos controles não expostos. A freqüência de micronúcleos foi avaliada em 1.000 células binucleadas por indivíduo em ambos os grupos. Fatores como tabagismo, idade e tempo de exposição não exerceram qualquer efeito sobre a freqüência de micronúcleos em ambos os grupos. No entanto, a análise estatística revelou números significativamente mais elevados de micronúcleos em expostos (14,3/1.000 células) do que em não expostos (7,1/1.000 células), indicando que o teste do micronúcleo é um ensaio biológico eficiente para monitorar populações expostas a misturas de agroquímicos.1675168

[genes Involved In Sex Determination And Differentiation].

Chromosomal sex is established at fertilization by the presence of an X or Y chromosome. The first step of male and female development is gonadal specialization in testes or ovaries; all other processes that follow result from secondary effects produced by testis and ovary hormones. Gonadal determination and differentiation and the development of external genitalia involve time- and tissue-specific expression of genes forming a gene cascade. Those genes, their expression profile and their role in the pathological manifestations related to gonadal and external genitalia development will be discussed in this review.4914-2

Um caso de possível predisposição genética à síndrome mielodisplástica

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Metabolite transport and associated sugar signalling systems underpinning source/ sink interactions

Metabolite transport between organelles, cells and source and sink tissues not only enables pathway co-ordination but it also facilitates whole plant communication, particularly in the transmission of information concerning resource availability. Carbon assimilation is co-ordinated with nitrogen assimilation to ensure that the building blocks of biomass production, amino acids and carbon skeletons, are available at the required amounts and stoichiometry, with associated transport processes making certain that these essential resources are transported from their sites of synthesis to those of utilization. Of the many possible posttranslational mechanisms that might participate in efficient co-ordination of metabolism and transport only reversible thiol-disulphide exchange mechanisms have been described in detail. Sucrose and trehalose metabolism are intertwined in the signalling hub that ensures appropriate resource allocation to drive growth and development under optimal and stress conditions, with trehalose-6-phosphate acting as an important signal for sucrose availability. The formidable suite of plant metabolite transporters provides enormous flexibility and adaptability in inter-pathway coordination and source-sink interactions. Focussing on the carbon metabolism network, we highlight the functions of different transporter families, and the important of thioredoxins in the metabolic dialogue between source and sink tissues. In addition, we address how these systems can be tailored for crop improvement

Madagascar’s extraordinary biodiversity: Evolution, distribution, and use

Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique living laboratory for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth's biodiversity

Madagascar’s extraordinary biodiversity: Threats and opportunities

Madagascar's unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar's terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as themost prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar

Instabilidade cromossômica induzida por agroquímicos em trabalhadores rurais na região de Passo Fundo, Rio Grande do Sul, Brasil Chromosome instability induced by agrochemicals among farm workers in Passo Fundo, Rio Grande do Sul, Brazil

A região de Passo Fundo no Planalto Médio do Rio Grande do Sul, caracteriza-se pela produção de grãos (trigo, soja), nas quais grandes quantidades de agroquímicos (fungicidas, inseticidas e herbicidas) são utilizadas. Para avaliar a atividade genotóxica desses produtos em seres humanos, utilizou-se a técnica de micronúcleos, através de amostras de sangue periférico de trinta trabalhadores expostos e de trinta indivíduos controles não expostos. A freqüência de micronúcleos foi avaliada em 1.000 células binucleadas por indivíduo em ambos os grupos. Fatores como tabagismo, idade e tempo de exposição não exerceram qualquer efeito sobre a freqüência de micronúcleos em ambos os grupos. No entanto, a análise estatística revelou números significativamente mais elevados de micronúcleos em expostos (14,3/1.000 células) do que em não expostos (7,1/1.000 células), indicando que o teste do micronúcleo é um ensaio biológico eficiente para monitorar populações expostas a misturas de agroquímicos.A major share of the grain farming (wheat and soybeans) in the State of Rio Grande do Sul is in the Passo Fundo area. For crop pest control, large amounts of agrochemicals (fungicides, insecticides, and herbicides) are used. To evaluate the genotoxicity of these products, the micronucleus test was performed in farm workers directly exposed to these chemicals. Heparinized blood samples were drawn by venipuncture from 30 exposed workers and 30 non-exposed controls. Micronuclei frequency was evaluated by counting 1,000 binucleated cells per individual in both groups. Smoking habits, age, and duration of exposure showed no effect on the frequency of micronuclei in both groups. However, statistical analysis showed significantly higher mean numbers of binucleated cells with micronuclei in exposed individuals (14.3/1,000 cells) as compared to controls (7.1/1,000 cells), allowing the authors to conclude that the micronucleus test is an efficient biological assay for monitoring population exposure to mixtures of agrochemicals