RESUMO
BACKGROUND: Loose anagen hair is a rare form of impaired hair anchorage in which anagen hairs that lack inner and outer root sheaths can be gently and painlessly plucked from the scalp. This condition usually occurs in children and is often self-limiting. A genetic basis for the disorder has been suggested but not proven. A better understanding the aetiology of loose anagen hair may improve prevention and treatment strategies. OBJECTIVES: To identify a possible genetic basis of loose anagen hair using next-generation DNA sequencing and functional analysis of variants identified. METHODS: In this case study, whole-exome sequencing analysis of a pedigree with one affected individual with features of loose anagen hair was performed. RESULTS: The patient was found to be compound heterozygous for two single-nucleotide substitutions in TKFC resulting in the following missense mutations: c.574G> C (p.Gly192Arg) and c.682C> T (p.Arg228Trp). Structural analysis of human TKFC showed that both mutations are located near the active site cavity. Kinetic assays of recombinant proteins bearing either of these amino acid substitutions showed almost no dihydroxyacetone kinase or D-glyceraldehyde kinase activity, and FMN cyclase activity reduced to just 10% of wildtype catalytic activity. CONCLUSIONS: TKFC missense mutations may predispose to the development of loose anagen hairs. Identification of this new biochemical pathobiology expands the metabolic and genetic basis of hypotrichosis.
Assuntos
Doenças do Cabelo , Hipotricose , Alopecia , Criança , Cabelo , Doenças do Cabelo/genética , Humanos , Hipotricose/genética , Mutação de Sentido IncorretoRESUMO
BACKGROUND: The horn fly (Haematobia irritans) is an obligate blood feeder that causes considerable economic losses in livestock industries worldwide. The control of this cattle pest is mainly based on insecticides; unfortunately, in many regions, horn flies have developed resistance. Vaccines or biological control have been proposed as alternative control methods, but the available information about the biology or physiology of this parasite is rather scarce. RESULTS: We present a comprehensive description of the salivary and midgut transcriptomes of the horn fly (Haematobia irritans), using deep sequencing achieved by the Illumina protocol, as well as exploring the virome of this fly. Comparison of the two transcriptomes allow for identification of uniquely salivary or uniquely midgut transcripts, as identified by statistically differential transcript expression at a level of 16 x or more. In addition, we provide genomic highlights and phylogenetic insights of Haematobia irritans Nora virus and present evidence of a novel densovirus, both associated to midgut libraries of H. irritans. CONCLUSIONS: We provide a catalog of protein sequences associated with the salivary glands and midgut of the horn fly that will be useful for vaccine design. Additionally, we discover two midgut-associated viruses that infect these flies in nature. Future studies should address the prevalence, biological effects and life cycles of these viruses, which could eventually lead to translational work oriented to the control of this economically important cattle pest.
Assuntos
Perfilação da Expressão Gênica , Mucosa Intestinal/metabolismo , Muscidae/genética , Muscidae/virologia , Glândulas Salivares/metabolismo , Animais , Sequenciamento de Nucleotídeos em Larga Escala , Proteínas de Insetos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Breast cancer (BC) under age 40 is a complex disease to manage due to the additionally fertility-related factors to be taken in consideration. More than 90% of young patients with BC are symptomatic. Women<40 years are more likely to develop BC with worse clinicopathological features and more aggressive subtype. This has been frequently associated with inferior outcomes. Recently, the prognostic significance of age<40 has been shown to differ according to the BC subtype, being associated with worst recurrence-free survival (RFS) and overall survival (OS) for luminal BC. The biology of BC<40 has also been explored through analysis of large genomic data set, and specific pathways overexpressed in these tumors have been identified which can lead to the development of targeted therapy in the future. A multidisciplinary tumor board should determine the optimal locoregional and systemic management strategies for every individual patient with BC before the start of any therapy including surgery. This applies to both early (early breast cancer (EBC)) and advanced (advanced breast cancer (ABC)) disease, before the start of any therapy. Mastectomy even in young patients confers no overall survival advantage when compared to breast-conserving treatment (BCT), followed by radiotherapy. Regarding axillary approach, indications are identical to other age groups. Young age is one of the most important risk factors for local recurrence after both breast-conserving surgery (BCS) and mastectomy, associated with a higher risk of distant metastasis and death. Radiation after BCS reduces local recurrence from 19.5 to 10.2% in BC patients 40 years and younger. The indications for and the choice of systemic treatment for invasive BC (both early and advanced disease) should not be based on age alone but driven by the biological characteristics of the individual tumor (including hormone receptor status, human epidermal growth factor receptor 2 (HER-2) status, grade, and proliferative activity), disease stage, and patient's comorbidities. Recommendations regarding the use of genomic profiles such as MammaPrint, Oncotype Dx, and Genomic grade index in young women are similar to the general BC population. Especially in the metastatic setting, patient preferences should always be taken into account, as the disease is incurable. The best strategy for these patients is the inclusion into well-designed, independent, prospective randomized clinical trials. Metastatic disease should always be biopsied whenever feasible for histological confirmation and reassessment of biology. Endocrine therapy is the preferred option for hormone receptor-positive disease (HR+ve), even in presence of visceral metastases, unless there is concern or proof of endocrine resistance or there is a need for rapid disease response and/or symptom control. Recommendations for chemotherapy (CT) should not differ from those for older patients with the same characteristics of the metastatic disease and its extent. Young age by itself should not be an indication to prescribe more intensive and combination CT regimens over the sequential use of monotherapy. Poly(ADP-ribose) polymerase inhibitors (PARP inhibitors) represent an important group of promising drugs in managing patients with breast cancer susceptibility gene (BRCA)-1- or BRCA-2-associated BC. Specific age-related side effects of systemic treatment (e.g., menopausal symptoms, change in body image, bone morbidity, cognitive function impairment, fertility damage, sexual dysfunction) and the social impact of diagnosis and treatment (job discrimination, taking care for children) should also be carefully addressed when planning systemic long-lasting therapy, such as endocrine therapy. Survivorship concerns for young women are different compared to older women, including issues of fertility, preservation, and pregnancy.
Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Adulto , Fatores Etários , Neoplasias da Mama/genética , Feminino , Humanos , Gravidez , Adulto JovemRESUMO
The saliva of bloodsucking animals contains dozens to hundreds of proteins that counteract their hosts' haemostasis, inflammation and immunity. It was previously observed that salivary proteins involved in haematophagy are much more divergent in their primary sequence than those of housekeeping function, when comparisons were made between closely related organisms. While this pattern of evolution could result from relaxed selection or drift, it could alternatively be the result of positive selection driven by the intense pressure of the host immune system. We investigated the polymorphism of five different genes associated with blood-feeding in the mosquito Anopheles gambiae and obtained evidence in four genes for sites with signatures of positive selection. These results add salivary gland genes from bloodsucking arthropods to the small list of genes driven by positive selection.
Assuntos
Evolução Molecular , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/biossíntese , Seleção Genética , Sequência de Aminoácidos , Animais , Anopheles/genética , Etiquetas de Sequências Expressas , Perfilação da Expressão Gênica , Proteínas de Insetos/genéticaRESUMO
The salivary glands of Rhodnius prolixus contain a nitrosyl-heme protein, named nitrophorin, that releases the vasodilatory and antiplatelet compound nitric oxide (NO). Because imidazole compounds such as histamine can interact with Fe(III) heme proteins, we investigated whether such substances could interact with Rhodnius nitrophorins. Both imidazole and histamine, but not histidine can produce full of the difference spectra of the Soret band in the 1-3 microM concentration range (at a heme protein concentration of 0.4 microM). The apparent K0.5 for the binding of histamine with the heme protein is below 1 microM. Furthermore, the complex histamine-heme protein does not dissociate after molecular sieving chromatography. To investigate whether histamine could displace NO from the native nitrosyl nitrophorins, histamine was added to the native heme proteins, leading to displacement of the bound NO as observed by changes in the absorption spectra as well as by the production of nitrite. Finally, the antihistamine effect of the heme protein was demonstrated by its inhibition of the histamine-provoked contractures of the guinea pig ileum. It is concluded that histamine, a common autacoid found at the site of injury and exposure to antigenic substances such as the site of feeding by hematophagous arthropods, can be scavenged by the nitrosyl nitrophorin of R. prolixus, which, in return, will release the vasodilatory and platelet inhibiting NO to counteract the host hemostatic response.
Assuntos
Hemeproteínas/metabolismo , Hemeproteínas/farmacologia , Antagonistas dos Receptores Histamínicos/farmacologia , Histamina/metabolismo , Rhodnius/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Proteínas e Peptídeos Salivares/farmacologia , Animais , Cromatografia em Gel , Espectroscopia de Ressonância de Spin Eletrônica , Cobaias , Hemeproteínas/química , Íleo/efeitos dos fármacos , Íleo/fisiologia , Imidazóis/metabolismo , Técnicas In Vitro , Cinética , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Óxido Nítrico/metabolismo , Ligação Proteica , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/químicaRESUMO
Pilocarpine-induced saliva of the tick, Ixodes dammini, inhibited platelet aggregation triggered by ADP and collagen, as well as platelet-aggregation factor. In addition, we found apyrase activity (which degrades ATP and ADP to AMP and orthophosphate) and an anticoagulant. We showed the presence of prostaglandin E2 (PGE2) by bioassay and radioimmunoassay. This saliva inhibited interleukin 2 production by T cell hybridomas, an activity consistent with that of PGE2. A kininase was demonstrated, and this may counteract the algesia- and edema-promoting properties of PGE2. Together, these salivary components produce antihemostatic, antiinflammatory, and immunosuppressive effects that may facilitate feeding, as well as transmission of tick-borne pathogens.
Assuntos
Anti-Inflamatórios/fisiologia , Hemostasia , Imunossupressores/fisiologia , Saliva/fisiologia , Carrapatos/fisiologia , Animais , Anticoagulantes/fisiologia , Apirase/metabolismo , Dinoprostona , Ativação Linfocitária , Peptidil Dipeptidase A/metabolismo , Agregação Plaquetária , Prostaglandinas E/análise , Coelhos , Saliva/enzimologia , Saliva/imunologia , Linfócitos T/imunologia , Carrapatos/enzimologia , Carrapatos/metabolismoRESUMO
Leishmania parasites are transmitted to their vertebrate hosts by infected phlebotomine sand fly bites. Sand fly saliva is known to enhance Leishmania infection, while immunity to the saliva protects against infection as determined by coinoculation of parasites with vector salivary gland homogenates (SGHs) or by infected sand fly bites (Kamhawi, S., Y. Belkaid, G. Modi, E. Rowton, and D. Sacks. 2000. Science. 290:1351-1354). We have now characterized nine salivary proteins of Phlebotomus papatasi, the vector of Leishmania major. One of these salivary proteins, extracted from SDS gels and having an apparent mol wt of 15 kD, was able to protect vaccinated mice challenged with parasites plus SGH. A DNA vaccine containing the cDNA for the predominant 15-kD protein (named SP15) provided this same protection. Protection lasted at least 3 mo after immunization. The vaccine produced both intense humoral and delayed-type hypersensitivity (DTH) reactions. B cell-deficient mice immunized with the SP15 plasmid vaccine successfully controlled Leishmania infection when injected with Leishmania plus SGH. These results indicate that DTH response against saliva provides most or all of the protective effects of this vaccine and that salivary gland proteins or their cDNAs are viable vaccine targets against leishmaniasis.
Assuntos
Insetos Vetores/genética , Insetos Vetores/imunologia , Leishmania major/imunologia , Leishmaniose/imunologia , Leishmaniose/prevenção & controle , Phlebotomus/genética , Phlebotomus/imunologia , Sequência de Aminoácidos , Animais , Antígenos/genética , Antígenos/isolamento & purificação , Sequência de Bases , Primers do DNA/genética , Proteínas de Insetos/genética , Proteínas de Insetos/imunologia , Proteínas de Insetos/isolamento & purificação , Insetos Vetores/parasitologia , Leishmania major/patogenicidade , Leishmaniose/transmissão , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Dados de Sequência Molecular , Phlebotomus/parasitologia , Vacinas Protozoárias/genética , Vacinas Protozoárias/imunologia , Vacinas Protozoárias/isolamento & purificação , Proteínas e Peptídeos Salivares/genética , Proteínas e Peptídeos Salivares/imunologia , Proteínas e Peptídeos Salivares/isolamento & purificação , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Vacinas de DNA/isolamento & purificaçãoRESUMO
The present study investigated the occurrence of passalids in dead trunks with structural variations. Trunks were found in areas of white sand forests, locally known as Campinarana, in the state of Amazonas, Brazil. The collections were extended from May to December 2009. The mean diameter of the trunks and their stage of decomposition were classified, and the species of Passalidae were classified according to the location of their galleries. We used multiple generalized models to investigate the relationship between abundance and permutational multivariate analysis of variance (PERMANOVA) to investigate the relationships between predictors and passalid composition. A total of 361 passalids belonging to 13 species were collected from 11 tree species, of which Aldina heterophylla represented the highest proportion of logs (55%). Only the diameter of the trunk was related to the abundance of species, with trunks of larger diameters presented more individuals. The passalid composition was correlated with the diameter and decomposition of the trunks of all species of trees and only with the diameter of the trunks of A. heterophylla. Most of the species collected in Campinaranas construct their galleries in two or more regions of the trunk. The region that supported a greater number of colonies was the sapwood, followed by the inner bark and the soil-stem interface. The general habit of passalids found may be advantageous, probably to compensate for the low dispersion and isolation in areas with low availability of resources, such as Campinaranas forests in the Amazon.
Assuntos
Besouros/classificação , Árvores/anatomia & histologia , Animais , Florestas , Casca de Planta , Solo , MadeiraRESUMO
Leishmaniasis is a parasitic disease transmitted by phlebotomine sand flies. The role of sand fly saliva in transmission of the disease was investigated by injecting mice with Leishmania major parasites in the presence of homogenized salivary glands from Lutzomyia longipalpis. This procedure resulted in cutaneous lesions of Leishmania major that were routinely five to ten times as large and contained as much as 5000 times as many parasites as controls. With inocula consisting of low numbers of Leishmania major, parasites were detected at the site of injection only when the inoculum also contained salivary gland material. This enhancing effect of sand fly salivary glands on cutaneous leishmaniasis occurred with as little as 10 percent of the contents of one salivary gland of one fly. Material obtained from other bloodsucking arthropods could not mediate the phenomenon.
Assuntos
Dípteros , Leishmania tropica/patogenicidade , Leishmaniose/fisiopatologia , Extratos de Tecidos/farmacologia , Animais , Artrópodes , Camundongos , Camundongos Endogâmicos CBA , Glândulas Salivares , Especificidade da EspécieRESUMO
Lectins of different activities were found in the crop, midgut, and hemolymph of the insect Rhodnius prolixus. These were not specific for N-acetyl-D-mannosamine, alpha-N-acetyl-D-galactosamine, and alpha- and beta-galactose, respectively. Lectin receptors were detectable in epimastigote but not in trypomastigote forms of Trypanosoma cruzi, a protozoan parasite of the insect and of humans.
Assuntos
Insetos Vetores/parasitologia , Lectinas , Rhodnius/parasitologia , Triatominae/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Hemaglutininas , Hemolinfa/parasitologia , Rhodnius/anatomia & histologia , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
Salivary gland lysates of the sand fly Lutzomyia longipalpis contain a potent vasodilator that aids the fly to feed on the blood of its vertebrate hosts. Chromatographic analysis, antibody reactivity, and data obtained from bioassays of the salivary erythema-inducing factor indicate striking similarity with human calcitonin gene-related peptide. The erythema-inducing factor is, however, at least one order of magnitude more potent than calcitonin gene-related peptide.
Assuntos
Músculo Liso Vascular/fisiologia , Proteínas e Peptídeos Salivares/isolamento & purificação , Vasodilatadores , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Calcitonina/farmacologia , Peptídeo Relacionado com Gene de Calcitonina , Cromatografia Líquida de Alta Pressão , Dípteros , Eritema , Humanos , Técnicas In Vitro , Músculo Liso Vascular/efeitos dos fármacos , Neuropeptídeos/farmacologia , Coelhos , Proteínas e Peptídeos Salivares/farmacologia , VasodilataçãoRESUMO
The bloodsucking bug Rhodnius prolixus has a salivary vasodilator, previously characterized as a nitrovasodilator, with salivary smooth muscle-relaxing and antiplatelet activity. Rhodnius salivary glands are bright red owing to the abundance of heme proteins. Electron paramagnetic resonance and optical spectroscopic experiments indicated that the salivary vasodilator is a nitrosylheme protein with an Fe(III) heme that binds nitric oxide (NO) reversibly. Dilution of the protein in neutral pH promoted NO release. This protein thus appears to be the NO carrier that helps R. prolixus to feed on blood.
Assuntos
Hemeproteínas/metabolismo , Óxido Nítrico/metabolismo , Rhodnius/metabolismo , Animais , Espectroscopia de Ressonância de Spin Eletrônica , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Peso Molecular , Óxido Nítrico/química , Glândulas Salivares/metabolismo , Análise EspectralRESUMO
BACKGROUND: Multidrug-resistant bacteria such as extended-spectrum beta-lactamase (ESBL), Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus (MRSA) pose a challenge to the human health care system. MRSA is among the major causes of hospital-acquired and community infections. METHODS: Therefore, in the present study, we evaluated the antibacterial activity of silver nanoparticles synthesized by Fusarium oxysporum (AgNPbio) in combination with simvastatin against reference and multidrug-resistant bacterial strains. RESULTS: Simvastatin showed a minimal inhibitory concentration (MIC) ranging from 0.062 to 0.25 mg mL-1 against MRSA. AgNPbio with a size of 77.68± 33.95 nm and zeta potential -34.6 ± 12.7 mV showed an MIC of 0.212 mg mL-1 against S. aureus including MRSA strains. The checkerboard assay and time-kill curves exhibited a synergistic effect of the simvastatin-AgNPbio combination on antibacterial activity against MRSA strains. The combination of simvastatin and AgNPbio demonstrated antibacterial activity against Escherichia coli producing ESBL. Scanning electron microscopy showed the formation of cell surface protrusions after treatment with AgNPbio and the formation of a large amorphous mass after treatment with simvastatin, both in MRSA. CONCLUSION: Our results indicate that the combination of AgNPbio and simvastatin could be a great future alternative in the control of bacterial infections, where, when combined with simvastatin, smaller doses of AgNPbio are required, with the same antibacterial activity.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fusarium/metabolismo , Nanopartículas Metálicas/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Prata/farmacologia , Sinvastatina/farmacologia , Morte Celular/efeitos dos fármacos , Sinergismo Farmacológico , Eritrócitos/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Fusarium/ultraestrutura , Humanos , Nanopartículas Metálicas/ultraestrutura , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Testes de Sensibilidade MicrobianaRESUMO
All adult mosquitoes take sugar meals, and most adult females also take blood meals to develop eggs. Salivary glands (SG) of males are thus much smaller and do not contain many of the antihemostatic and antiinflammatory compounds found in females. In the past 5 years, transcriptome analyses have identified nearly 70 different genes expressed in adult female SG. For most of these, no function can be assigned in either blood or sugar feeding. Exceptionally, Toxorhynchites mosquitoes are unusual in that they never feed on blood, and the SG of adults are identical in both sexes. Transcriptome analysis of the adult SG of this mosquito was performed to increase knowledge of the evolution of blood feeding--and to identify polypeptide families associated with sugar feeding--in mosquitoes.
Assuntos
Culicidae/metabolismo , Evolução Molecular , Proteínas de Insetos/metabolismo , Animais , Culicidae/química , Culicidae/genética , DNA Complementar , Comportamento Alimentar/fisiologia , Feminino , Perfilação da Expressão Gênica , Proteínas de Insetos/genética , Masculino , Mucinas/genética , Mucinas/metabolismo , Família Multigênica , Peptídeos/metabolismo , Proteômica , Saliva/química , Glândulas Salivares/metabolismoRESUMO
Feed contamination can lead to nutrient losses and detrimental effects on animal health and production. The purposes of this study were to investigate the mycobiota in equine mixed feeds and to determine natural contamination with aflatoxin B1 (AFB1) and fumonisin B1 (FB1). Fungal enumeration of equine feed samples was done. A commercially available enzyme-linked immunosorbent assay kit was applied to quantify AFB1 and FB1. A comparison between ELISA and HPLC was carried out. Feed mould counts ranged from <1 x 10(2) to 1 x 10(5) cfu/g. The most frequent genus isolated was Aspergillus (40.54%), followed by Penicillium (18.38%) and Fusarium (16.22%). The most prevalent Aspergillus sp. was A. flavus (36%). AFB1 values ranged between 0.01 and 99.4 microg/kg. FB(1) levels ranged between 0.01 and 7.49 microg/kg. HPLC and ELISA methods showed positive correlation for AFB1 and FB1 determinations (r = 0.9851 and r = 0.9791, respectively). The ELISA analytical method was efficient for AFB1 and FB1 detection. The scarcity of studies on natural fungal contamination and on the presence of AFB1 and FB1 in materials used as equine feed ingredients highlights the value and contribution of this study.
Assuntos
Aflatoxina B1/análise , Ração Animal/microbiologia , Fumonisinas/análise , Doenças dos Cavalos/microbiologia , Aflatoxina B1/intoxicação , Animais , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Cromatografia Líquida de Alta Pressão/veterinária , Contagem de Colônia Microbiana/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Fumonisinas/intoxicação , Fusarium/isolamento & purificação , Fusarium/metabolismo , Doenças dos Cavalos/metabolismo , Cavalos , Penicillium/isolamento & purificação , Penicillium/metabolismoRESUMO
The biosynthesis of insect juvenile hormone (JH) and its neuroendocrine control are attractive targets for chemical control of insect pests and vectors of disease. To facilitate the molecular study of JH biosynthesis, we analyzed ESTs from the glands producing JH, the corpora allata (CA) in the cockroach Diploptera punctata, an insect long used as a physiological model species and compared them with ESTs from the CA of the mosquitoes Aedes aegypti and Anopheles albimanus. The predicted genes were analyzed according to their probable functions with the Gene Ontology classification, and compared to Drosophila and Anopheles gambiae genes. A large number of reciprocal matches in the cDNA libraries of cockroach and mosquito CA were found. These matches defined known and suspected enzymes of the JH biosynthetic pathway, but also several proteins associated with signal transduction that might play a role in the modulation of JH synthesis by neuropeptides. The identification in both cockroach and mosquito CA of homologs of the small ligand binding proteins from insects, Takeout/JH binding protein and retinol-binding protein highlights a hitherto unsuspected complexity of metabolite trafficking, perhaps JH precursor trafficking, in these endocrine glands. Furthermore, many reciprocal matches for genes of unknown function may provide a fertile ground for an in-depth study of allatal-specific cell physiology. ESTs are deposited in GenBank under the accession numbers DV 017592-DV 018447 (Diploptera punctata); DR 746432-DV 747949 (Aedes aegypti); and DR 747950-DR 748310 (Anopheles albimanus).
Assuntos
Genômica , Insetos/genética , Hormônios Juvenis/biossíntese , Aedes/genética , Sequência de Aminoácidos , Animais , Anopheles/genética , Baratas/genética , Corpora Allata/metabolismo , Drosophila/genética , Etiquetas de Sequências Expressas , Proteínas de Insetos/química , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Insetos/metabolismo , Hormônios Juvenis/química , Hormônios Juvenis/genética , Dados de Sequência Molecular , Alinhamento de Sequência , Transdução de SinaisRESUMO
In Brazil, commercial feedstuffs are an important component in modern animal husbandry, but there is no information available about fungal contamination and ochratoxin A (OTA) production. The aims of this study were to determine the mycoflora incidence in poultry feeds and evaluate OTA production. In addition, the ability to produce OTA by several Aspergillus and Penicillium species was investigated. A total of 96 samples of poultry feeds were collected from four factories in Rio de Janeiro. Samples were examined for total moulds, for Aspergillus and Penicillium spp. occurrence and for their relative densities on dichloran rose bengal chloramphenicol and dichloran 18% glycerol media. The capacity to produce ochratoxin A by selected Aspergillus and Penicillium species was determined by HPLC. Total mould counts were generally higher than 1 x 10(5 )CFU ml(-1). Aspergillus and Penicillium species were isolated in the highest numbers. Aspergillus flovus and Penicillium citrinum were the most prevalent species. There was a high percentage of potential OTA producers (46%). The amount of OTA produced on this substrate was enough to cause adverse effects in animals. Several strains isolated from poultry feeds were able to produce high levels of OTA on chloramphenicol yeast medium. OTA in raw materials needs to be surveyed and storage practices must be investigated to determine occurrence and establish the livestock toxicological risk in poultry feed.
Assuntos
Ração Animal/microbiologia , Aspergillus/metabolismo , Fungos/isolamento & purificação , Ocratoxinas/biossíntese , Penicillium/metabolismo , Animais , Aspergillus/classificação , Aspergillus/crescimento & desenvolvimento , Aspergillus/isolamento & purificação , Contagem de Colônia Microbiana/veterinária , Fungos/classificação , Fungos/crescimento & desenvolvimento , Ocratoxinas/análise , Penicillium/classificação , Penicillium/crescimento & desenvolvimento , Penicillium/isolamento & purificação , Aves DomésticasRESUMO
Transposable elements (TEs) are widespread in insect's genomes. However, there are wide differences in the proportion of the total DNA content occupied by these repetitive sequences in different species. We have analyzed the TEs present in R. prolixus (vector of the Chagas disease) and showed that 3.0% of this genome is occupied by Class II TEs, belonging mainly to the Tc1-mariner superfamily (1.65%) and MITEs (1.84%). Interestingly, most of this genomic content is due to the expansion of two subfamilies belonging to: irritans himar, a well characterized subfamily of mariners, and prolixus1, one of the two novel subfamilies here described. The high amount of sequences in these subfamilies suggests that bursts of transposition occurred during the life cycle of this family. In an attempt to characterize these elements, we performed an in silico analysis of the sequences corresponding to the DDD/E domain of the transposase gene. We performed an evolutionary analysis including network and Bayesian coalescent-based methods in order to infer the dynamics of the amplification, as well as to estimate the time of the bursts identified in these subfamilies. Given our data, we hypothesized that the TE expansions occurred around the time of speciation of R. prolixus around 1.4 mya. This suggestion lays on the "Transposon Model" of TE evolution, in which the members of a TE population that are replicative active are present at multiple loci in the genome, but their replicative potential varies, and of the "Life Cycle Model" that states that when present-day TEs have been involved in amplification bursts, they share an ancestral copy that dates back to this initial amplification.