RESUMO
The main environmental problem in urban areas, especially in Brazil, is the discharge of untreated sewage. The in vivo Drosophila melanogaster Somatic Mutation and Recombination Test (SMART) was used to assess the genotoxicity of surface waters from three different sites in the Tocantins River, Brazil. The in silico approach was used to search for known and predicted interactions between environmental chemicals found in our samples and Drosophila and human proteins. The genotoxicity tests were performed in standard (ST) and high bioactivation (HB) crosses with samples collected at two periods, the rainy and dry seasons. Mutant spot frequencies found in treatments with unprocessed water from the test sites were compared with the frequencies observed in negative controls. The collection points were represented as sites A, B and C along Tocantins River. Sites A and B are located in Porto Nacional City, whereas site C is located in Palmas City. Considering the rainy season collection, positive responses in the ST cross were observed for sites A and C (89.47% and 85% of recombination, respectively) and in the HB cross for sites A, B and C (88.24%, 84.21% and 82.35% of recombination, respectively). The positive results in the dry season were restricted to sites A and B (88.89% and 85.71% of recombination, respectively) in the HB cross. In accordance with in vivo and in silico results, we hypothesize that ribosomal proteins (RPs) in fruit fly and humans are depleted in cells exposed to heavy metal causing DNA damage and chromosome instability, increasing homologous recombination.
Assuntos
Drosophila melanogaster , Rios , Animais , Brasil , Cidades , Dano ao DNA , Drosophila , Drosophila melanogaster/genética , Humanos , Água/metabolismo , Asas de Animais/metabolismoRESUMO
Bursicon is a heterodimeric neurohormone that acts through a G protein-coupled receptor named rickets (rk), thus inducing an increase in cAMP and the activation of tyrosine hydroxylase, the rate-limiting enzyme in the cuticular tanning pathway. In insects, the role of bursicon in the post-ecdysial tanning of the adult cuticle and wing expansion is well characterized. Here we investigated the roles of the genes encoding the bursicon subunits during the adult cuticle development in the honeybee, Apis mellifera. RNAi-mediated knockdown of AmBurs α and AmBurs ß bursicon genes prevented the complete formation and tanning (melanization/sclerotization) of the adult cuticle. A thinner, much less tanned cuticle was produced, and ecdysis toward adult stage was impaired. Consistent with these results, the knockdown of bursicon transcripts also interfered in the expression of genes encoding its receptor, AmRk, structural cuticular proteins, and enzymes in the melanization/sclerotization pathway, thus evidencing roles for bursicon in adult cuticle formation and tanning. Moreover, the expression of AmBurs α, AmBurs ß and AmRk is contingent on the declining ecdysteroid titer that triggers the onset of adult cuticle synthesis and deposition. The search for transcripts of AmBurs α, AmBurs ß and candidate targets in RNA-seq libraries prepared with brains and integuments strengthened our data on transcript quantification through RT-qPCR. Together, our results support our premise that bursicon has roles in adult cuticle formation and tanning, and are in agreement with other recent studies pointing for roles during the pharate-adult stage, in addition to the classical post-ecdysial ones.
Assuntos
Abelhas/genética , Ecdisteroides/genética , Hormônios de Invertebrado/genética , Metamorfose Biológica/genética , Animais , Abelhas/crescimento & desenvolvimento , AMP Cíclico/genética , Ecdisteroides/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Hormônios de Invertebrado/antagonistas & inibidores , Muda/genética , Interferência de RNA , Receptores Acoplados a Proteínas G/genética , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismoRESUMO
The main of this study was to evaluate the mutagenic and carcinogenic potential of (+) - usnic acid (UA), using Somatic Mutation and Recombination Test (SMART) and the test for detecting epithelial tumor clones (wts) in Drosophila melanogaster. Larvae from 72 ± 4 h from Drosophila were fed with UA (5.0, 10.0 or 20.0 mM); urethane (10.0 mM) (positive control); and solvent (Milli-Q water, 1% Tween-80 and 3% ethanol) (negative control). ST cross produced increase in total mutant spots in the individuals treated with 5.0, 10.0 or 20.0 mM of UA. HB cross produced spot frequencies in the concentration of 5.0 mM that were higher than the frequency for the same concentration in the ST cross. In the highest concentrations the result was negative, which means that the difference observed can be attributed, in part, to the high levels of P450, suggesting that increasing the metabolic capacity maximized the toxic effect of these doses. In the evaluation of carcinogenesis using the wts test, the results obtained for the same concentrations of UA show a positive result for the presence of tumors when compared to the negative control. We conclude that UA has recombinogenic, mutagenic and carcinogenic effects on somatic cells in D. melanogaster.
Assuntos
Anti-Infecciosos/toxicidade , Benzofuranos/toxicidade , Carcinógenos/toxicidade , Drosophila melanogaster/efeitos dos fármacos , Larva/efeitos dos fármacos , Mutagênicos/toxicidade , Recombinação Genética/efeitos dos fármacos , Animais , Carcinogênese/induzido quimicamente , Drosophila melanogaster/genética , Larva/genética , Mutagênese/efeitos dos fármacos , Asas de Animais/efeitos dos fármacos , Asas de Animais/metabolismoRESUMO
Propolis is a resinous, complex mixture of compounds collected by the bee species Apis mellifera. This study investigated the genotoxicity of green and brown propolis collected in southeast Brazil using the somatic mutation and recombination test (SMART) in Drosophila melanogaster. The effect of five concentrations (0.5, 1.0, 2.0, 4.0, and 7.5 mg/mL) of both propolis types was analyzed in standard (ST) and high-bioactivation (HB) crosses, which have normal and high levels of cytochrome P450 enzymes, respectively. The results show that the types of propolis evaluated have no mutagenic action, in either cross. Moreover, chromatography findings revealed that the propolis types analyzed have different chemical compositions. Brown propolis had lower levels of polyphenols (â¼7.2 mg/mL), compared to the green type (34.9 mg/g). Taken together, the findings of the present study and literature reports point to the safety in consuming low amounts of propolis, considering the risk of genetic damage, and confirm the absence of mutagenic and recombinagenic actions of the propolis types investigated.
Assuntos
Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Larva/efeitos dos fármacos , Mutagênicos/toxicidade , Própole/toxicidade , Recombinação Genética/genética , Asas de Animais/efeitos dos fármacos , Animais , Anti-Infecciosos/toxicidade , Abelhas/química , Feminino , Larva/genética , Masculino , Asas de Animais/metabolismoRESUMO
Butterflies belonging to the nymphalid subfamily, Morphinae, are famous for their brilliant blue wing coloration and iridescence. These striking optical phenomena are commonly explained as to originate from multilayer reflections by the ridges of the wing scales. Because the lower lamina of the scales of related nymphalid butterflies, the Nymphalinae, plays a dominant role in the wing coloration, by acting as a thin film reflector, we investigated single blue scales of three characteristic Morpho species: M. epistrophus, M. helenor and M. cypris. The experimental data obtained by spectrophotometry, scatterometry and scanning electron microscopy demonstrated that also in the Morpho genus the lower lamina of both the cover and ground scales acts as an optical thin film reflector, contributing importantly to the blue structural coloration of the wings. Melanin pigment has a contrast-enhancing function in a sub-class of ground scales.
Assuntos
Borboletas/metabolismo , Borboletas/ultraestrutura , Iridescência , Asas de Animais/metabolismo , Asas de Animais/ultraestrutura , Animais , Microscopia Eletrônica de Varredura , Pigmentação , Especificidade da Espécie , EspectrofotometriaRESUMO
Genetic selection for production traits has resulted in a rapid improvement in animal performance and development. Previous studies have mapped quantitative trait loci for body weight at 35 and 41 days, and drum and thigh yield, onto chicken chromosome 4. We investigated this region for single nucleotide polymorphisms and their associations with important economic traits. Three positional candidate genes were studied: KLF3 (Krüeppel-like factor 3), SLIT2 (Slit homolog 2), and PPARGC1A (peroxisome proliferator-activated receptor gamma, coactivator 1 alpha). Fragment sequencing of these genes was conducted in 11 F1 animals, and one polymorphism in each gene was selected and genotyped in an F2 population (N = 276) and a paternal broiler line TT (N = 840). Associations were identified with growth, carcass, and fat traits in the F2 and the paternal line (P < 0.05). Using single markers in both the F2 and the TT line, KLF3 was associated with weight gain (P < 0.05), PPPARGC1A was associated with liver and wing-parts weights and yields (P < 0.05), and SLIT2 was associated with back yield (P < 0.05) and fat traits (P < 0.05). Using multiple markers, KLF3 lost its significance in both populations, and SLIT2 was associated with feed conversion only in the TT population (P < 0.05). The QTLs mapped in the F2 population could be partly explained by PPARGC1A and SLIT2, which were associated with body weight at 35 and 41 days, respectively, and with drum and thigh yield in the same population. The results of this study indicate the importance of these genes for production traits.
Assuntos
Cromossomos/química , Peptídeos e Proteínas de Sinalização Intercelular/genética , Carne , Proteínas do Tecido Nervoso/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Fatores de Transcrição/genética , Tecido Adiposo/anatomia & histologia , Tecido Adiposo/metabolismo , Animais , Peso Corporal/genética , Galinhas , Mapeamento Cromossômico , Feminino , Expressão Gênica , Genótipo , Fatores de Transcrição Kruppel-Like/genética , Fígado/anatomia & histologia , Fígado/metabolismo , Masculino , Tamanho do Órgão/genética , Fenótipo , Característica Quantitativa Herdável , Asas de Animais/anatomia & histologia , Asas de Animais/metabolismoRESUMO
BACKGROUND: In Brazil, the autochthonous transmission of extra-Amazonian malaria occurs mainly in areas of the southeastern coastal Atlantic Forest, where Anopheles cruzii is the primary vector. In these locations, the population density of the mosquito varies with altitude (5-263 m above sea level), prompting us to hypothesise that gene flow is also unevenly distributed. Describing the micro-geographical and temporal biological variability of this species may be a key to understanding the dispersion of malaria in the region. We explored the homogeneity of the An. cruzii population across its altitudinal range of distribution using wing shape and mtDNA gene analysis. We also assessed the stability of wing geometry over time. METHODS: Larvae were sampled from lowland (5-20 m) and hilltop (81-263 m) areas in a primary Atlantic Forest region, in the municipality of Cananéia (State of São Paulo, Brazil). The right wings of males and females were analysed by standard geometric morphometrics. Eighteen landmarks were digitised for each individual and a discriminant analysis was used to compare samples from the hilltop and lowland. A 400-bp DNA fragment of the mitochondrial cytochrome oxidase gene subunit I (CO-I) was PCR-amplified and sequenced. RESULTS: Wing shapes were distinct between lowland and hilltop population samples. Results of cross-validated tests based on Mahalanobis distances showed that the individuals from both micro-environments were correctly reclassified in a range of 54-96%. The wings of hilltop individuals were larger. The CO-I gene was highly polymorphic (haplotypic diversity = 0.98) and altitudinally structured (Фst = 0.085 and Jaccard = 0.033). We found 60 different haplotypes but only two were shared by the lowland and hilltop populations. Wing shape changed over the brief study period (2009-2013). CONCLUSIONS: Wing geometry and CO-I gene analysis indicated that An. cruzii is vertically structured. Wing shape varied rapidly, but altitude structure was maintained. Future investigations should identify the biotic/abiotic causes of these patterns and their implications in the local epidemiology of malaria.
Assuntos
Anopheles/crescimento & desenvolvimento , Insetos Vetores/crescimento & desenvolvimento , Altitude , Animais , Anopheles/genética , Anopheles/metabolismo , Evolução Biológica , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Proteínas de Insetos/genética , Insetos Vetores/genética , Insetos Vetores/metabolismo , Masculino , Densidade Demográfica , Dinâmica Populacional , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismoRESUMO
The Rhodnius Pacific group is composed of three species: Rhodnius pallescens, R. colombiensis and R. ecuadoriensis, which are considered important vectors of trypanosomes (Trypanosoma cruzi and T. rangeli) infecting humans. This group is considered as a recent trans-Andean lineage derived from the widespread distributed sister taxa R. pictipes during the later uplift of northern Andes mountain range. The widest spread species R. pallescens may be a complex of two divergent lineages with different chromosomal attributes and a particular biogeographical distribution across Central America and Colombia with several southern populations in Colombia occupying the same sylvatic habitat as its sister species R. colombiensis. Although the taxonomy of Rhodnius Pacific group has been well studied, the unresolved phylogenetic and systematic issues are the target of this paper. Here we explore the molecular phylogeography of this species group analyzing two mitochondrial (ND4 and cyt b) and one nuclear (D2 region of ribosomal 28S gene) gene sequences. The molecular analyses suggest an early divergence of the species R. ecuadoriensis and R. colombiensis, followed by a recent expansion of R. pallescens lineages. The phylogenetic relationship between sympatric R. pallescens Colombian lineage and R. colombiensis was further explored using wing morphometry, DNA genome size measurements, and by analyzing chromosomal behavior of hybrids progeny obtained from experimental crosses. Our results suggest that the diversification of the two R. pallescens lineages was mainly influenced by biogeographical events such as (i) the emergence of the Panama Isthmus, while the origin and divergence of R. colombiensis was associated with (ii) the development of particular genetic and chromosomal features that act as isolation mechanisms from its sister species R. pallescens (Colombian lineage). These findings provide new insights into the evolution of the Rhodnius Pacific group and the underlying biological processes that occurred during its divergence.
Assuntos
Evolução Molecular , Variação Genética , Insetos Vetores/genética , Rhodnius/genética , Animais , Núcleo Celular/genética , América Central , Colômbia , Citocromos b/classificação , Citocromos b/genética , Análise Citogenética , DNA Mitocondrial/química , DNA Mitocondrial/genética , Feminino , Geografia , Haplótipos , Humanos , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Masculino , Dados de Sequência Molecular , NADH Desidrogenase/classificação , NADH Desidrogenase/genética , Filogenia , RNA Ribossômico 28S/classificação , RNA Ribossômico 28S/genética , Rhodnius/anatomia & histologia , Rhodnius/classificação , Análise de Sequência de DNA , Tripanossomíase/transmissão , Asas de Animais/anatomia & histologia , Asas de Animais/metabolismoRESUMO
Mammalian insulin-degrading enzyme (IDE) cleaves insulin, among other peptidic substrates, but its function in insulin signaling is elusive. We use the Drosophila system to define the function of IDE in the regulation of growth and metabolism. We find that either loss or gain of function of Drosophila IDE (dIDE) can restrict growth in a cell-autonomous manner by affecting both cell size and cell number. dIDE can modulate Drosophila insulin-like peptide 2 levels, thereby restricting activation of the phosphatidylinositol-3-phosphate kinase pathway and promoting activation of Drosophila forkhead box, subgroup O transcription factor. Larvae reared in high sucrose exhibit delayed developmental timing due to insulin resistance. We find that dIDE loss of function exacerbates this phenotype and that mutants display increased levels of circulating sugar, along with augmented expression of a lipid biosynthesis marker. We propose that dIDE is a modulator of insulin signaling and that its loss of function favors insulin resistance, a hallmark of diabetes mellitus type II.
Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Insulisina/genética , Transdução de Sinais , Animais , Tamanho Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Insulisina/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Neuropeptídeos , Fenótipo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Asas de Animais/citologia , Asas de Animais/metabolismoRESUMO
Recent studies indicate that relatively few genomic regions are repeatedly involved in the evolution of Heliconius butterfly wing patterns. Although this work demonstrates a number of cases where homologous loci underlie both convergent and divergent wing pattern change among different Heliconius species, it is still unclear exactly how many loci underlie pattern variation across the genus. To address this question for Heliconius erato, we created fifteen independent crosses utilizing the four most distinct color pattern races and analyzed color pattern segregation across a total of 1271 F2 and backcross offspring. Additionally, we used the most variable brood, an F2 cross between H. himera and the east Ecuadorian H. erato notabilis, to perform a quantitative genetic analysis of color pattern variation and produce a detailed map of the loci likely involved in the H. erato color pattern radiation. Using AFLP and gene based markers, we show that fewer major genes than previously envisioned control the color pattern variation in H. erato. We describe for the first time the genetic architecture of H. erato wing color pattern by assessing quantitative variation in addition to traditional linkage mapping. In particular, our data suggest three genomic intervals modulate the bulk of the observed variation in color. Furthermore, we also identify several modifier loci of moderate effect size that contribute to the quantitative wing pattern variation. Our results are consistent with the two-step model for the evolution of mimetic wing patterns in Heliconius and support a growing body of empirical data demonstrating the importance of major effect loci in adaptive change.