RESUMO
The adult females of Aedes aegypti mosquitoes are facultative hematophagous insects but they are unable to feed on blood right after pupae emergence. The maturation process that takes place during the first post-emergence days, hereafter named hematophagic and gonotrophic capacitation, comprises a set of molecular and physiological changes that prepare the females for the first gonotrophic cycle. Notwithstanding, the molecular bases underlying mosquito hematophagic and gonotrophic capacitation remain obscure. Here, we investigated the molecular and biochemical changes in adult Ae. aegypti along the first four days post-emergence, prior to a blood meal. We performed a RNA-Seq analysis of the head and body, comparing male and female gene expression time courses. A total of 811 and 203 genes were differentially expressed, respectively in the body and head, and both body parts showed early, mid, and late female-specific expression profiles. Female-specific up-regulation of genes involved in muscle development and the oxidative phosphorylation pathway were remarkable features observed in the head. Functional assessment of mitochondrial oxygen consumption in heads showed a gradual increase in respiratory capacity and ATP-linked respiration as a consequence of induced mitochondrial biogenesis and content over time. This pattern strongly suggests that boosting oxidative phosphorylation in heads is a required step towards blood sucking habit. Several salivary gland genes, proteases, and genes involved in DNA replication and repair, ribosome biogenesis, and juvenile hormone signaling were up-regulated specifically in the female body, which may reflect the gonotrophic capacitation. This comprehensive description of molecular and biochemical mechanisms of the hematophagic and gonotrophic capacitation in mosquitoes unravels potentially new targets for vector control.
Assuntos
Aedes/fisiologia , Comportamento Alimentar/fisiologia , Transcriptoma , Animais , Replicação do DNA , Feminino , Expressão Gênica , Humanos , Masculino , Mitocôndrias/metabolismo , Mosquitos Vetores/fisiologia , Oxigênio/metabolismo , FosforilaçãoRESUMO
The aim of this report is to describe general and methodological characteristics of a cohort study in southern Brazil (Coorte Brasil Sul), aimed at understanding the impact of the first 1,000 days of life on children's health. It is a cohort study involving all children born in 2009 and their families living in the municipality of Palhoça, State of Santa Catarina, Brazil. Face-to-face interviews with parents at home using a structured questionnaire and children's physical and clinical examinations at schools have been carried out. Cross-sectional analyzes, longitudinal comparisons and hierarquical regression analysis will allow understanding if the first 1,000 days of life can influence on 6-year-old children's health. The Coorte Brasil Sul is in its retrospective phase together with the children's physical data collection. Preliminary data (n=1270) related to nutritional status point to a high prevalence of overweight (16.4%) and obesity (15.5%). With the continuity of the study, it is expected to evaluate if the first phases of life can influence health during adolescence and in adult life, mainly in relation to chronic diseases.
Assuntos
Comportamento Infantil/fisiologia , Saúde da Criança , Doença Crônica , Adulto , Índice de Massa Corporal , Criança , Pré-Escolar , Estudos de Coortes , Comportamento Alimentar , Previsões , Humanos , Lactente , Pais , Estudos Retrospectivos , Inquéritos e QuestionáriosRESUMO
In the midgut of the mosquito Aedes aegypti, a vector of dengue and yellow fever, an intense release of heme and iron takes place during the digestion of a blood meal. Here, we demonstrated via chromatography, light absorption and mass spectrometry that xanthurenic acid (XA), a product of the oxidative metabolism of tryptophan, is produced in the digestive apparatus after the ingestion of a blood meal and reaches milimolar levels after 24 h, the period of maximal digestive activity. XA formation does not occur in the White Eye (WE) strain, which lacks kynurenine hydroxylase and accumulates kynurenic acid. The formation of XA can be diminished by feeding the insect with 3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl] benzenesulfonamide (Ro-61-8048), an inhibitor of XA biosynthesis. Moreover, XA inhibits the phospholipid oxidation induced by heme or iron. A major fraction of this antioxidant activity is due to the capacity of XA to bind both heme and iron, which occurs at a slightly alkaline pH (7.5-8.0), a condition found in the insect midgut. The midgut epithelial cells of the WE mosquito has a marked increase in occurrence of cell death, which is reversed to levels similar to the wild type mosquitoes by feeding the insects with blood supplemented with XA, confirming the protective role of this molecule. Collectively, these results suggest a new role for XA as a heme and iron chelator that provides protection as an antioxidant and may help these animals adapt to a blood feeding habit.
Assuntos
Aedes/fisiologia , Antioxidantes/metabolismo , Quelantes/metabolismo , Digestão/fisiologia , Trato Gastrointestinal/fisiologia , Xanturenatos/metabolismo , Aedes/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Feminino , Trato Gastrointestinal/metabolismo , Heme/metabolismo , Concentração de Íons de Hidrogênio , Ferro/metabolismo , Quinurenina 3-Mono-Oxigenase/antagonistas & inibidores , Espectrometria de Massas , Estrutura Molecular , Sulfonamidas/farmacologia , Tiazóis/farmacologia , Xanturenatos/químicaRESUMO
Once mosquito midgut barrier was crossed malaria parasite faces a extensive metabolic developmental program in order to ensure its transmission. In the hemolymph of the mosquito the dynamics of lipid metabolism is conducted by a major lipoprotein, lipophorin (Lp). It was recently shown that Lp is engaged in the mosquito immune response to parasite infection. However, it is not clear if Lp is uptaken by the parasite. Here, we show that oocysts are able to uptake mosquito Lp. The uptake of FITC-labeled Lp was demonstrated in midgut-associated oocysts. Alternatively, to confirm Lp incorporation by oocysts we have conducted another set of experiments with iodinated Lp ((125)I-Lp). Oocysts were able to incorporate (125)I-Lp and the process is both time and temperature dependent. This set of results indicated that no matter oocysts are attached to mosquito midgut wall they bear a lipid sequestering machinery from its surroundings. Phospholipid transfer to sporozoites was also demonstrated. In conclusion, these results demonstrate for the first time that malaria parasite undergoes lipid uptake while in the invertebrate host.