RESUMO
Ochratoxin A (OTA) is a mycotoxin with nephrotoxic, genotoxic, teratogenic and carcinogenic properties, produced by several species of Aspergillus, mainly those belonging to the A. section Circumdati and A. section Nigri. Although this toxin has been detected in spices and condiments, in black pepper (Piper nigrum L.) few studies have investigated the mycobiota (based on a molecular approach) and the presence of OTA in this food. The aim of this study was to investigate the presence of potentially ochratoxigenic species and ochratoxin A in black pepper marketed in Brazil, one of the largest producers in the world. A total of 60 samples of black pepper (29 in powder and 31 in grain) were collected in markets. The presence of OTA was investigated in black pepper samples using High-Performance Liquid Chromatography (HPLC), OTA was detected in 55% of the samples, with levels ranging from 0.05 to 13.15 µg/kg, all of which were below the Brazilian legal tolerances. A. section Nigri and A. section Circumdati were found in 80% of the samples, but the species of A. section Nigri were significantly more frequent than those of A. section Circumdati. The potential for OTA production by fungal isolates was tested using the agar plug technique and confirmed by HPLC. Among the isolates belonging to A. section Nigri (n = 1,083) and A. section Circumdati (n = 129), 3.7% and 3.8%, respectively, were able to produce OTA in Yeast Extract Sucrose Agar (YESA). A total of 25 strains from A. section Circumdati and 64 from A. section Nigri were identified using molecular data. The following potentially ochratoxigenic species were found in black pepper: A. niger, A. welwitschiae, A. carbonarius, A. westerdijkiae and A. ochraceus. The occurrence of these species denotes the need for continuous monitoring of black pepper by regulatory bodies in order to safeguard consumers' health.
Assuntos
Ocratoxinas , Piper nigrum , Aspergillus , BrasilRESUMO
The aim of this study was to isolate Aspergillus section Nigri from onion samples bought in supermarkets and to analyze the fungal isolates by means of molecular data in order to differentiate A. niger and A. welwitschiae species from the other non-toxigenic species of black aspergilli, and detect genes involved in the biosynthesis of ochratoxin A and fumonisin B2. Aspergillus section Nigri were found in 98% (94/96) of the onion samples. Based on the results of multiplex PCR (performed on 500 randomly selected strains), 97.4% of the Aspergillus section Nigri strains were recognized as A. niger/A. welwitschiae. Around half of them were subjected to partial sequencing of the CaM gene to distinguish one from the other. A total of 97.9% of the isolates were identified as A. welwitschiae and only 2.1% as A. niger. The fum8 gene, involved in fumonisin B2 biosynthesis, was found in 36% of A. welwitschiae isolates, but radH and pks genes, involved in ochratoxin A biosynthesis, were found in only 2.8%. The presence/absence of fum8 gene in the A. welwitschiae genome is closely associated with ability/inability of the isolates to produce fumonisin in vitro. Based on these results, we suggest that in-depth studies are conducted to investigate the presence of fumonisins in onion bulbs.
Assuntos
Aspergillus niger/genética , Microbiologia de Alimentos , Genoma Bacteriano , Micotoxinas/metabolismo , Cebolas/microbiologia , Aspergillus niger/classificação , Aspergillus niger/isolamento & purificação , Vias Biossintéticas/fisiologia , Contaminação de Alimentos/análise , Fumonisinas/metabolismo , Micotoxinas/classificação , Ocratoxinas/biossíntese , Filogenia , PrevalênciaRESUMO
The occurrence of black aspergilli in onions has been reported as frequent, and this group of fungi harbors potentially toxigenic species. In addition, Aspergillus niger has been reported as the causative agent of black mold rot, an important postharvest disease that causes damage throughout the world. Brazil stands out as one of the world's largest onion producers. However, few studies have been conducted to investigate the mycobiota in Brazilian onions. For this reason, we investigated the mycobiota of 48 market (n = 25) and field (n = 23) onion bulb samples. Nineteen soil samples were collected from the same fields and evaluated. In field onions and soil samples, Penicillium spp. was the prevalent fungal group, whereas in market samples A. section Nigri was the most frequent group. Due to the taxonomic complexity of this group, species identification was supported by phylogenetic data (CaM gene). A. welwitschiae was the most prevalent species in market samples. Black aspergillus strains were evaluated for fumonisin B2 (FB2) and ochratoxin A (OTA) production. Overall, 53% and 2.2% of the strains produced FB2 and OTA, respectively. The occurrence of FB2 and OTA was also investigated in onion bulb samples but none showed contamination with these mycotoxins.
Assuntos
Aspergillus/isolamento & purificação , Microbiologia de Alimentos , Cebolas/microbiologia , Microbiologia do Solo , Aspergillus/classificação , Aspergillus/genética , Aspergillus/metabolismo , Brasil , Humanos , Micobioma/genética , Micotoxinas/análise , Micotoxinas/metabolismo , Cebolas/química , Penicillium/classificação , Penicillium/genética , Penicillium/isolamento & purificação , FilogeniaRESUMO
The garlic contains sulfur bioactive compounds responsible for medicinal properties. The decrease of these compounds due to inadequate storage conditions reduces the beneficial properties and favors infection by microorganisms. Several studies have shown high frequency of garlic infected with Aspergillus section Nigri that potentially produce mycotoxin. Garlic samples were collected in markets of Brazil and a total of 32 samples (of 36) had the fungal infection with predominant genus Aspergillus (50.3%), Penicillium (34.7%), and Fusarium (11%). A total of 63% (649/1031) of infection with Aspergillus section Nigri, of which 60 isolates were selected for analysis of genetic variability that resulted in 4 clusters. Representatives of clusters were identified by the calmodulin gene. Isolates from cluster I were subdivided into A-I and identified as A. niger (16 isolates) and the isolates of clusters B-I, II, and III were identified as A. welwitschiae (43 isolates). Besides, an isolate of the IV-cluster was identified by A. luchuensis. Further, we used the multiplex PCR to verify genotypes of 59 isolates, and none of these had OTA production-associated genotype. Moreover, 19 A. welwitschiae and 15 A. niger were FB2 production-associated genotype. Our study is the first report to the incidence of garlic infection in Brazil and to show that A. welwitschiae causes most of these infections.
Assuntos
Aspergillus , Fumonisinas/metabolismo , Alho/microbiologia , Ocratoxinas/metabolismo , Aspergillus/genética , Aspergillus/metabolismo , Aspergillus/patogenicidade , Brasil , Microbiologia de Alimentos , GenótipoRESUMO
The presence of Aspergillus section Flavi and aflatoxins in sugarcane as well as in by-products, such as molasses, sugar, yeast cream and dried yeast, collected from different fields and processing plants in São Paulo state, were investigated throughout the sugarcane production chain. A total of 246 samples was collected and analyzed and 226 isolates of Aspergillus section Flavi were isolated. Aspergillus section Flavi strains were found in sugarcane juice, milled sugarcane, stalk, soil and dried yeast samples. Among the isolates of Aspergillus section Flavi submitted to polyphasic identification (nâ¯=â¯57), Aspergillus novoparasiticus and Aspergillus arachidicola were predominantly found. A significant proportion of the isolates (84.5%) were found to have morphological and physiological characteristics of A. novoparasiticus. Most samples, with the exception of sugar, showed some aflatoxin contamination. The highest level was in dried yeast with an average of 2.55⯵g/kg and maximum value of 10.19⯵g/kg. This is the first report of contamination of sugarcane by A. novoparasiticus.
Assuntos
Aflatoxinas/análise , Aspergillus/isolamento & purificação , Contaminação de Alimentos/análise , Saccharum/microbiologia , Aspergillus/classificação , Microbiologia de Alimentos , Microbiologia do SoloRESUMO
Fusarium verticillioides is a primary corn pathogen and fumonisin producer which is associated with toxic effects in humans and animals. The traditional methods for detection of fungal contamination based on morphological characteristics are time-consuming and show low sensitivity and specificity. Therefore, the objective of this study was to develop a PCR-ELISA based on the FUM21 gene for F. verticillioides detection. The DNA of the F. verticillioides, Fusarium sp., Aspergillus sp. and Penicillium sp. isolates was analyzed by conventional PCR and PCR-ELISA to determine the specificity. The PCR-ELISA was specific to F. verticillioides isolates, showed a 2.5â¯pg detection limit and was 100-fold more sensitive than conventional PCR. In corn samples inoculated with F. verticillioides conidia, the detection limit of the PCR-ELISA was 1â¯×â¯104 conidia/g and was also 100-fold more sensitive than conventional PCR. Naturally contaminated corn samples were analyzed by PCR-ELISA based on the FUM21 gene and PCR-ELISA absorbance values correlated positively (pâ¯<â¯0.05) with Fusarium sp. counts (CFU/g). These results suggest that the PCR-ELISA developed in this study can be useful for F. verticillioides detection in corn samples.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Proteínas Fúngicas/genética , Fusarium/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Zea mays/microbiologia , Contaminação de Alimentos/análise , Fusarium/classificação , Fusarium/genética , Especificidade da EspécieRESUMO
A total of 119 samples of peanut were collected throughout the peanut production chain in São Paulo State, Brazil. The peanut samples were directly plated for determination of percentages of infection and a polyphasic approach was used to identify Aspergillus section Flavi species. Further, the potential for aflatoxin production by the isolates was tested using the agar plug technique and the presence of aflatoxins in peanuts was assessed using an immunoaffinity column followed by quantification using HPLC with reverse phase column and fluorescence detection. The limit of detection and quantification were 0.05 and 0.17µg/kg for total aflatoxins, respectively. Four species of Aspergillus section Flavi were isolated: A. caelatus (11), A. flavus (515), A. parasiticus (17) and A. tamarii (13). All isolates of A. parasiticus were able to produce aflatoxin B and G whereas aflatoxin B was produced by 50% of A. flavus isolates. Aflatoxins were found in 12 samples at concentrations ranging from 0.3 to 100µg/kg. The data reported in this study add information on the occurrence and biodiversity of fungi in peanuts at several stages of the production chain. The occurrence of aflatoxins is also of major relevance for continuous monitoring and assessment of likely exposure of consumers to aflatoxins through consumption of peanuts.
Assuntos
Aflatoxinas/análise , Arachis/microbiologia , Aspergillus , Microbiologia de Alimentos , Abastecimento de Alimentos , Sementes/microbiologia , Aspergillus/genética , Aspergillus/metabolismo , Biodiversidade , Brasil , Cromatografia Líquida de Alta Pressão , Humanos , Especificidade da EspécieRESUMO
Maize is one of the most important commercial crops cultivated throughout the world, mostly in tropical and subtropical countries. It is highly susceptible to mycotoxins, toxic secondary metabolites produced by fungi. In this study, we assessed freshly harvested corn produced in Brazil for aflatoxin contamination and the presence of Aspergillus. B type aflatoxins (AFB1+AFB2) were detected in 56% of 16 grain samples, while G type aflatoxins (AFG1+AFG2) were detected in 25%. Of the total number of grains (n=1920) evaluated for the presence of fungi species, 4.7% were infected with Aspergillus species, 74.5% and 16.7% respectively with Fusarium and Penicillium species and 4.1% with other fungi genera. In total, 89 Aspergillus isolates were identified, most (86 isolates) characterized as belonging to Aspergillus section Flavi, and the remainder to Aspergillus section Cremei (2 isolates) and Aspergillus section Terrei (1 isolate). All the isolates of section Flavi were subjected to molecular analysis. They were found to belong to six species, including Aspergillus novoparasiticus, Aspergillus arachidicola and Aspergillus pseudocaelatus, all aflatoxins B and G producing species, which are herein described for the first time infecting corn kernels.
Assuntos
Aflatoxina B1/análise , Aflatoxinas/análise , Aspergillus flavus/isolamento & purificação , Aspergillus flavus/metabolismo , Fusarium/isolamento & purificação , Penicillium/isolamento & purificação , Zea mays/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Aspergillus flavus/patogenicidade , Sequência de Bases , Brasil , DNA Fúngico/genética , Análise de Sequência de DNA , Tubulina (Proteína)/genéticaRESUMO
OBJECTIVES: To provide a review of published literature regarding genetic polymorphism of serotonin transporter gene, named as 5-HTTLPR, and its potential role as a susceptibility marker for ethanol abuse in childhood and adolescence. METHODS: A literature review of several databases was conducted with the following keywords: 5-HTTLPR, children or adolescents or teenagers, susceptibility, alcohol or ethanol, abuse or misuse. RESULTS: Alcohol interacts with serotonergic synaptic transmission in several ways, and the reduced availability of serotonin transporters might foster brain dysfunction, driving to alcohol abuse. The initial use of ethanol in children and adolescents is determined primarily by environmental influences, whereas the establishment of drinking patterns is strongly controlled by genetic factors. Functional polymorphic variants in the promoter region of the 5-HTTLPR gene have age-dependent effects in alcohol abuse. This polymorphism, mapped to the 5' region of the SLC6A4, is a variable number of tandem repeats (VNTR) and involves a direct repeat of 20-23 base pairs GC-rich sequences, comprising a short (S) allele, consisting of 14 repeats, and a long (L) allele, with 16 repeats. Additional variants have been described, although their influences on childhood and adolescence ethanol use are not clear. CONCLUSION: The influence of the 5-HTTLPR allelic variants in children and adolescent misuse of alcohol might be considered for clinical management, preventing long-term behavior problem. Identifying genetic markers associated to the potential alcohol misuse or abuse could be useful in guiding management and formulating effective coping strategies.
OBJECTIFS: Offrir une revue de la littérature publiée sur le polymorphisme génétique du gène transporteur de la sérotonine, nommé 5-HTTLPR, et son rôle potentiel de marqueur de la susceptibilité à l'abus d'éthanol dans l'enfance et l'adolescence. MÉTHODES: Une revue de la littérature dans plusieurs bases de données a été menée à l'aide des mots clés suivants: 5-HTTLPR, enfants ou adolescents ou teenagers, susceptibilité, alcool ou éthanol, abus ou excès. RÉSULTATS: L'alcool interagit de plusieurs façons avec la transmission synaptique sérotoninergique, et la disponibilité réduite des transporteurs de la sérotonine peut favoriser une dysfonction cérébrale, qui mène à l'abus d'alcool. L'utilisation initiale d'éthanol chez les enfants et les adolescents est déterminée principalement par des influences environnementales, alors que l'établissement de modèles de consommation d'alcool est fortement contrôlé par des facteurs génétiques. Les variantes polymorphiques fonctionnelles de la région promotrice du gène 5-HTTLPR ont des effets selon l'âge sur l'abus d'alcool. Ce polymorphisme, localisé à la région 5' de SLC6A4, est un nombre variable de répétitions en tandem (NVRT) et implique une répétition directe de séquences de 2023 paires de base riches en GC, comprenant un allèle court (C), consistant en 14 répétitions, et un allèle long (L), avec 16 répétitions. Les variantes additionnelles ont été décrites, bien que leurs influences sur l'utilisation d'éthanol dans l'enfance et l'adolescence ne soient pas définies. CONCLUSION: L'influence des variantes alléliques de 5-HTTLPR sur l'excès d'alcool chez les enfants et les adolescents pourrait être considérée pour la prise en charge clinique, et la prévention de problèmes de comportement à long terme, L'identification des marqueurs génétiques associés à l'excès ou l'abus d'alcool potentiel pourrait être utile pour guider la prise en charge et formuler des stratégies d'adaptation efficaces.
RESUMO
We present the multiplex PCR data for the presence/absence of genes involved in OTA and FB2 biosynthesis in Aspergillus niger/Aspergillus welwitschiae strains isolated from different food substrates in Brazil. Among the 175 strains analyzed, four mPCR profiles were found: Profile 1 (17%) highlights strains harboring in their genome the pks, radH and the fum8 genes. Profile 2 (3.5%) highlights strains harboring genes involved in OTA biosynthesis i.e. radH and pks. Profile 3 (51.5%) highlights strains harboring the fum8 gene. Profile 4 (28%) highlights strains not carrying the genes studied herein. This research content is supplemental to our original research article, "Prospecting for the incidence of genes involved in ochratoxin and fumonisin biosynthesis in Brazilian strains of A. niger and A. welwitschiae" [1].
RESUMO
Aspergillus niger "aggregate" is an informal taxonomic rank that represents a group of species from the section Nigri. Among A. niger "aggregate" species Aspergillus niger sensu stricto and its cryptic species Aspergillus welwitschiae (=Aspergillus awamori sensu Perrone) are proven as ochratoxin A and fumonisin B2 producing species. A. niger has been frequently found in tropical and subtropical foods. A. welwitschiae is a new species, which was recently dismembered from the A. niger taxon. These species are morphologically very similar and molecular data are indispensable for their identification. A total of 175 Brazilian isolates previously identified as A. niger collected from dried fruits, Brazil nuts, coffee beans, grapes, cocoa and onions were investigated in this study. Based on partial calmodulin gene sequences about one-half of our isolates were identified as A. welwitschiae. This new species was the predominant species in onions analyzed in Brazil. A. niger and A. welwitschiae differ in their ability to produce ochratoxin A and fumonisin B2. Among A. niger isolates, approximately 32% were OTA producers, but in contrast only 1% of the A. welwitschiae isolates revealed the ability to produce ochratoxin A. Regarding fumonisin B2 production, there was a higher frequency of FB2 producing isolates in A. niger (74%) compared to A. welwitschiae (34%). Because not all A. niger and A. welwitschiae strains produce ochratoxin A and fumonisin B2, in this study a multiplex PCR was developed for detecting the presence of essential genes involved in ochratoxin (polyketide synthase and radHflavin-dependent halogenase) and fumonisin (α-oxoamine synthase) biosynthesis in the genome of A. niger and A. welwitschiae isolates. The frequency of strains harboring the mycotoxin genes was markedly different between A. niger and A. welwitschiae. All OTA producing isolates of A. niger and A. welwitschiae showed in their genome the pks and radH genes, and 95.2% of the nonproducing isolates did not contain these genes. The α-oxoamine synthase gene was detected in 100% and 36% of the A. niger and A. welwitschiae isolates, respectively. The loss of ochratoxin A production in A. niger and A. welwitschiae is highly associated with gene deletions within the ochratoxin biosynthetic gene cluster. The loss of fumonisin production in A. welwitschiae is associated with gene deletions within the fumonisin biosynthetic gene cluster, but this is not the case with A. niger.
Assuntos
Aspergillus/genética , Microbiologia de Alimentos , Fumonisinas , Ocratoxinas , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Aspergillus niger/genética , Aspergillus niger/metabolismo , Brasil , Família Multigênica/genética , Reação em Cadeia da Polimerase Multiplex , Ocratoxinas/biossínteseRESUMO
We designed a primer pair (BtubNomF/BtubNomR) specifically for amplifying Aspergillus nomius DNA. In vitro assays confirmed BtubNomF/BtubNomR specificity, corroborating its usefulness in detecting and identifying A. nomius. We then investigated the occurrence of A. nomius in floral visitors of Bertholletia excelsa trees by means of PCR, and A. nomius was detected in the following bees: Xylocopa frontalis, Bombus transversalis, Centris denudans, C. ferruginea, and Epicharis flava. The presence of A. nomius in bees visiting Brazil nuts opens up new avenues for obtaining novel insights into the process whereby Brazil nuts are contaminated by aflatoxin-producing fungi.
Assuntos
Aspergillus/isolamento & purificação , Abelhas/microbiologia , Bertholletia/microbiologia , Flores/microbiologia , Animais , Aspergillus/genética , Abelhas/fisiologia , BrasilRESUMO
The exploitation of the Brazil nut is one of the most important activities of the extractive communities of the Amazon rainforest. However, its commercialization can be affected by the presence of aflatoxins produced by fungi, namely Aspergillus section Flavi. In the present study, we investigated a collection of Aspergillus nomius strains isolated from Brazil nuts using different approaches, including morphological characters, RAPD and AFLP profiles, partial ß-tubulin and calmodulin nucleotide sequences, aflatoxin patterns, as well as tolerance to low water activity in cultured media. Results showed that most of the isolates do belong to A. nomius species, but a few were re-identified as Aspergillus pseudonomius, a very recently described species. The results of the analyses of molecular variance, as well as the high pairwise FST values between A. nomius and A. pseudonomius suggested the isolation between these two species and the inexistence of gene flow. Fixed interspecific nucleotide polymorphisms at ß-tubulin and calmodulin loci are presented. All A. pseudonomius strains analyzed produced aflatoxins AFB1, AFB2, AFG1 and AFG2. This study contains the first-ever report on the occurrence in Brazil nuts of A. pseudonomius. The G-type aflatoxins and the mycotoxin tenuazonic acid are reported here for the first time in A. pseudonomius.
Assuntos
Aspergillus/fisiologia , Bertholletia/microbiologia , Microbiologia de Alimentos , Aflatoxinas/isolamento & purificação , Aspergillus/genética , Aspergillus/isolamento & purificação , Variação Genética , Ácido Tenuazônico/isolamento & purificaçãoRESUMO
Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Genetic polymorphisms in the 3'UTR region of the CXCL12 (rs1801157) and TP53 codon 72 (rs1042522) genes may contribute to susceptibility to childhood ALL because they affect some important processes, such as metastasis regulation and tumor suppression. Thus the objective of the present study was to detect the frequency of two genetic polymorphisms in ALL patients and controls and to add information their impact on genetic susceptibility and prognosis. The CXCL12 and TP53 polymorphisms were tested in 54 ALL child patients and in 58 controls by restriction fragment length polymerase chain reaction and allelic specific chain reaction techniques, respectively. The frequencies of both allelic variants were higher in ALL patients than in the controls and indicated a positive association: OR = 2.44; 95 % CI 1.05-5.64 for CXCL12 and OR = 2.20; 95 % CI 1.03-4.70 for TP53. Furthermore, when the two genetic variants were analyzed together, they increased significantly more than fivefold the risk of this neoplasia development (OR = 5.24; 95 % CI 1.39-19.75), indicating their potential as susceptibility markers for ALL disease and the relevance of the allelic variant combination to increased risk of developing malignant tumors. Future studies may indicate a larger panel of genes involved in susceptibility of childhood ALL and other hematological neoplasias.
Assuntos
Biomarcadores Tumorais , Quimiocina CXCL12/genética , Predisposição Genética para Doença , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteína Supressora de Tumor p53/genética , Adolescente , Brasil , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Humanos , Masculino , Razão de ChancesRESUMO
In silico comparison of 34 putative pks genes in Aspergillus niger strain CBS 513.88 versus A. niger strain ATCC 1015 genome revealed significant nucleotide identity (>95% covering a minimum of 99% of the gene sequence) for 31 of these genes (approximately 91%). A. niger CBS 513.88 harbors three putative pks genes (An01g01130, An11g05940, and An15g07920), for which nucleotide identity was not found in A. niger ATCC 1015. To compare the results of the in silico analysis with the in vivo situation, experimental data were obtained for a large number of A. niger strains obtained from different substrates and geographical regions. Three putative pks genes that were found to be variable between the two A. niger strains using bioinformatics tools were in fact strain-specific genes based on experimental data. The PCR amplification signals for the An01g01130, An11g05940, and An15g07920 pks genes were detected in only 97%, 71%, and 26% of the strains, respectively. Southern blot analyses confirmed the PCR data. Because one of the strain-specific pks genes (An15g07920) is located in a putative ochratoxin cluster, we focused our investigation on that region. We assessed the ochratoxin production capability of the 119 A. niger strains and found a positive association between the presence of this pks gene and the capability of the respective strain to produce ochratoxin.
Assuntos
Aspergillus niger/enzimologia , Genes Fúngicos , Ocratoxinas/biossíntese , Policetídeo Sintases/genética , Aspergillus niger/genética , Biologia Computacional , DNA Fúngico/genética , Variação Genética , Família Multigênica , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
Data suggest that the serotonin (5-hydroxytryptamine, 5-HT) system is implicated in the pathogenesis of multiple neuropsychiatric disorders and may also be involved in smoking behaviour since nicotine increases brain serotonin secretion. It is known that smoking behaviour is influenced by both genetic and environmental factors. The present review examines the role of the serotonin transporter gene (5-HTT) in smoking behaviour and investigating studies that showed association of 5-HTT gene with smoking. This study discusses a polymorphism which has been investigated by many researchers, as the bi-allelic insertion/deletion polymorphism in the 5'- flanking promoter region (5-HTTLPR). This gene has received considerable attention in attempts to understand the molecular determinants of smoking. Therefore, in the present study, the relationship between genetic polymorphism of serotonin transporter in smoking behaviour is reviewed considering the interactive effect of genetic factors.
Assuntos
Comportamento Aditivo/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Fumar/genética , Regiões 5' não Traduzidas/genética , Estudos de Associação Genética , Humanos , Mutação INDEL , Neurônios/metabolismo , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Serotonina/genética , Transmissão Sináptica/genéticaRESUMO
In this study a total of 16 Fusarium verticillioides strains isolated from corn feed samples were characterized by fumonisin (FB) production and random amplified polymorphic DNA (RAPD). All the strains produced FB1 and FB2 with levels ranging from 2.41 to 3996.36 µg/g, and from 1.18 to 1209.91 µg/g, respectively. From the 16 F. verticillioides strains, four were identified as low (3.59 to 1289.84 µg/g), eight as intermediate (>1289.84 to 3772.44 µg/g) and four strains as high (>3772.44 µg/g) fumonisin producers. From the total of 105 loci amplified, 60 (57.14 percent) were polymorphic. RAPD analysis showed very similar patterns among low, moderate and high fumonisin-producing strains. Although RAPD markers were capable of discriminating the different F. verticillioides strains, there was no clear association between these makers and fumonisin production.
Neste estudo, 16 cepas de F. verticillioides isoladas de amostras de ração de milho foram caracterizadas com base na produção de fumonisinas (FB) e em marcadores de polimorfismos de DNA amplificado ao acaso (RAPD). Todas as cepas produziram FB1 e FB2, com níveis variando, respectivamente, de 2,41 a 3996,36 µg/g e 1,18 a 1209,91 µg/g. De acordo com a produção de fumonisinas totais (FB1 + FB2) e a distribuição por análise de quartis, do total de 16 cepas de F. verticillioides, quatro foram identificadas como baixas produtoras de fumonisinas (3,59 a 1289,84 µg/g), oito como intermediárias (>1289,84 a 3772,44 µg/g) e quatro como altas produtoras de fumonisinas (>3772,44 µg/g). Os 10 primers utilizados amplificaram 105 locos, 60 (57,14 por cento) dos quais foram polimórficos. As análises de RAPD mostraram padrões muito similares entre as cepas baixas, médias e altas produtoras de fumonisinas. Embora os marcadores RAPD tenham se mostrado capazes de discriminar as diferentes cepas de F. verticillioides, não foi detectada nenhuma associação entre estes marcadores e a produção de fumonisinas.
RESUMO
Copaifera langsdorffii possesses 2n = 24 large meta- and submetacentric chromosomes (5.97-2.60 microm) in comparison with other Caesalpinioideae trees. Chromosome banding revealed an abundance of GC-rich blocks with a few differences in the size and location of bands between different populations. Polymerase chain reaction and digestion with restriction enzyme RsaI were carried out in order to isolate repetitive DNAs, yielding three fragments of different size: (1) cp-rDNA-like, 109 bp (pCl03 clone); (2) Ty1-copia-like retroelement, 185 bp (pCl23 clone); and (3) Ty3-gypsy-like retroelement, 269 bp (pCl08 clone). The first clone produced unmistakable hybridization signals at subterminal and intercalary positions, coinciding with or adjacent to most of the GC-rich bands. The second clone (pCl23 clone) showed dispersed signals distributed throughout several chromosomes, while the pCl08 clone exhibited hybridization signals scattered and organized in blocks in all chromosomes of the complement. Fluorescent in situ hybridization and chromosome banding results allowed the detection of translocation events and unequal crossing-over involving 45S rDNA regions (pairs 7, 8, and 11). However, the most intriguing result was the insertion and subsequent overamplification of a cp-rDNA-like fragment and its distribution over the chromosomes of C. langsdorffii. Additionally, the results suggest that this segment behaves like satellite DNA. These different chromosome markers produced by cytomolecular techniques show that samples from different locations, although isolated, retain more karyotypic similarities than differences.
Assuntos
Cromossomos de Plantas/genética , Fabaceae/genética , Sequências Repetitivas de Ácido Nucleico , Retroelementos , Sequência de Bases , Clonagem Molecular , Marcadores Genéticos , Hibridização in Situ FluorescenteRESUMO
Microsatellites and gene-derived markers are still underrepresented in the core molecular linkage map of common bean compared to other types of markers. In order to increase the density of the core map, a set of new markers were developed and mapped onto the RIL population derived from the 'BAT93' x 'Jalo EEP558' cross. The EST-SSR markers were first characterized using a set of 24 bean inbred lines. On average, the polymorphism information content was 0.40 and the mean number of alleles per locus was 2.7. In addition, AFLP and RGA markers based on the NBS-profiling method were developed and a subset of the mapped RGA was sequenced. With the integration of 282 new markers into the common bean core map, we were able to place markers with putative known function in some existing gaps including regions with QTL for resistance to anthracnose and rust. The distribution of the markers over 11 linkage groups is discussed and a newer version of the common bean core linkage map is proposed.
RESUMO
The common occurrence of multiple papillomavirus infections has been shown in several studies involving the human host. However, investigations with the aim of identifying mixed papillomavirus infections in cattle have been conducted only recently. In the current work we describe a co-infection with two different bovine papillomavirus (BPV) types that was identified in a bovine teat papilloma. The skin wart was obtained from a cow belonging to a Brazilian beef herd. A PCR assay was carried out with the FAP primer pair, which amplifies a partial segment of the L1 gene (approximately 478 bp), and the amplicon was submitted to direct sequencing. Because nucleotide sequences with satisfactory quality scores were not obtained, the amplicon was cloned and further sequencing, involving ten selected clones, was performed. The sequence analysis of the cloned inserts revealed the presence of two different BPV types. BPV-1 (Deltapapillomavirus genus) was detected in six clones, while BPV-6 (Xipapillomavirus genus) was detected in four clones. This finding confirms the presence of BPV co-infection associated with cutaneous papillomatosis in cattle.
Em seres humanos, as infecções múltiplas pelo papilomavírus têm sido demonstradas em vários estudos. Em bovinos, somente recentemente foram conduzidas investigações com o objetivo de avaliar infecções mistas pelo papilomavírus. O presente trabalho teve como objetivo descrever a co-infecção por dois tipos de papilomavírus bovino (BPV) em um papiloma de teto. A amostra clínica foi obtida de uma vaca pertencente a um rebanho de corte localizado na região norte do estado do Paraná, Brasil. Inicialmente, a técnica de PCR foi realizada com o par de oligonucleotídeos iniciadores FAP, que amplificam um segmento do gene L1, sendo que o amplicon gerado foi submetido ao sequenciamento direto. Entretanto, como as sequências obtidas não apresentaram qualidade aceitável, o amplicon foi clonado e dez clones foram selecionados para um novo sequenciamento. A análise das sequências dos insertos revelou a presença de dois diferentes tipos de BPV. O BPV-1 (gênero Deltapapillomavirus) foi detectado em seis clones, enquanto o BPV-6 (gênero Xipapillomavirus) foi detectado em quatro clones. Esse resultado confirma a ocorrência da co-infecção pelo BPV associada a papilomas cutâneos em bovinos.