Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
HIV Med ; 22(3): 212-217, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33012065

RESUMO

OBJECTIVES: We aimed to characterize neurocognitive impairment (NI) in an HIV-2 population using an observational cross-sectional study in four Portuguese hospitals. METHODS: Adult HIV-2-infected patients were included. Montreal Cognitive Assessment Test (MoCA) and International HIV Dementia Scale (IHDS) scales were applied for screening of NI. Patient Health Questionnaire-9 (PHQ-9) and Instrumental Activities of Daily Living (IADL) scales were used for assessment of depression and functionality. A multivariate analysis was performed to assess for risk factors for NI. RESULTS: Eighty-one patients were included, 50.6% of African origin (n = 41) and 49.4% of Portuguese origin (n = 40). The MoCA scale showed alterations in 81.5% of patients (100% of migrants vs. 62.5% of non-migrants, P < 0.001) and the IHDS scale showed alterations in 42%. Both scales were altered simultaneously in 35.8%. Variables independently associated with NI were age [odds ratio (OR) = 0.885] and migrant status (OR = 9.150). CONCLUSIONS: Neurocognitive impairment (both scales altered) was present in 35.8%, which is comparable to what is described for HIV-1. The MoCA performed worse in the migrant population and might not be applicable in this setting.


Assuntos
Complexo AIDS Demência , Disfunção Cognitiva , Infecções por HIV , Atividades Cotidianas , Adulto , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/etiologia , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/psicologia , HIV-2 , Humanos , Testes de Estado Mental e Demência , Testes Neuropsicológicos
2.
Br J Nutr ; 126(11): 1611-1625, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33583435

RESUMO

The intestinal tract is the entry gate for nutrients and symbiotic organisms, being in constant contact with external environment. DNA methylation is one of the keys to how environmental conditions, diet and nutritional status included, shape functionality in the gut and systemically. This review aims to summarise findings on the importance of methylation to gut development, differentiation and function. Evidence to date on how external factors such as diet, dietary supplements, nutritional status and microbiota modifications modulate intestinal function through DNA methylation is also presented.


Assuntos
Metilação de DNA , Microbioma Gastrointestinal , Dieta , Expressão Gênica , Intestinos , Nutrientes
3.
Bull Entomol Res ; : 1-14, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34130764

RESUMO

Plants not only respond to herbivorous damage but adjust their defense system after egg deposition by pest insects. Thereby, parasitoids use oviposition-induced plant volatiles to locate their hosts. We investigated the olfactory behavioral responses of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) to volatile blends emitted by maize (Zea mays L.) with singular and stacked events after oviposition by Spodoptera frugiperda Smith, 1797 (Hymenoptera: Trichogrammatidae) moths. Additionally, we examined possible variations in gene expression and on oviposition-induced volatiles. We used a Y-tube olfactometer to test for the wasp responses to volatiles released by maize plants oviposited by S. frugiperda and not-oviposited plants. Using the real-time PCR technique (qRT-PCR), we analyzed the expression of lipoxygenase and three terpene synthases genes, which are enzymes involved in the synthesis of volatile compounds that attract parasitoids of S. frugiperda. Olfactometer tests showed that T. pretiosum is strongly attracted by volatiles from transgenic maize emitted by S. frugiperda oviposition (VTPRO 3, more than 75% individuals were attracted). The relative expression of genes TPS10, LOX e STC was higher in transgenic hybrids than in the conventional (isogenic line) hybrids. The GC-MS analysis revealed that some volatile compounds are released exclusively by transgenic maize. This study provides evidence that transgenic hybrids enhanced chemical cues under oviposition-induction and helped to increase T. pretiosum efficiency in S. frugiperda control. This finding shows that among the evaluated hybrids, genetically modified hybrids can improve the biological control programs, since they potentialize the egg parasitoid foraging, integrating pest management.

4.
Scand J Gastroenterol ; 55(3): 371-375, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32150486

RESUMO

Background: A new computer algorithm called Express-View has recently been introduced by Mirocam, but data concerning its application and efficacy are scarce.Objective: To evaluate the lesion detection rate, per-patient sensitivity and the diagnostic accuracy using Express-View.Methods: All patients who performed CE between January 2018 and June 2019, whose indication was obscure gastrointestinal bleeding (OGIB) and with findings on CE, were included. Lesions identified in conventional reading were selected and considered as reference.Results: Eighty-nine patients were included, 50.6% male, with a mean age of 68.4 years-old (±12.3). The Express-View mode detected 85.5% of lesions previously detected by conventional reading (524 out of 613). There were 89 missed lesions, mainly erosions or ulcers (44.9%) and angioectasias (38.2%). The lesion detection rate was found to be lower in the jejunum and ileum compared to extra-small bowel locations and duodenum (p = .04). Although Express-View had a per-patient sensitivity for all lesions of 56.2% and a per-patient sensitivity for all clinically significant lesions of 83.1%, it achieved a diagnostic accuracy of 91%.Conclusions: The per-patient sensitivity for all lesions was shown to be below expectations, although the lesion detection rate, the per-patient sensitivity for all clinically significant lesions, and the diagnostic accuracy were shown to be higher.


Assuntos
Endoscopia por Cápsula/métodos , Hemorragia Gastrointestinal/diagnóstico por imagem , Intestino Delgado/patologia , Software , Idoso , Idoso de 80 Anos ou mais , Feminino , Hemorragia Gastrointestinal/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos
5.
Curr Neurol Neurosci Rep ; 20(11): 49, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32880775

RESUMO

PURPOSE OF REVIEW: In 2016, the World Health Organization declared the Zika virus (ZIKV) outbreak a Public Health Emergency of International Concern following a cluster of associated neurological disorders and neonatal malformations. Our aim is to review the clinical and neuroimaging findings seen in congenital Zika syndrome. RECENT FINDINGS: ZIKV injures neural progenitor cells in the hippocampus, a brain region important for learning, memory, cognition, and emotion/stress response. Positron emission tomography has revealed global neuroinflammation in ZIKV infection in animal models. Congenital Zika syndrome is associated with a spectrum of brain abnormalities, including microcephaly, parenchymal calcifications, malformations of cortical development and defective neuronal migration, corpus callosum abnormalities, ventriculomegaly, and brainstem and cerebellar abnormalities.


Assuntos
Microcefalia , Complicações Infecciosas na Gravidez , Infecção por Zika virus , Zika virus , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Microcefalia/diagnóstico por imagem , Microcefalia/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Infecção por Zika virus/complicações , Infecção por Zika virus/diagnóstico por imagem , Infecção por Zika virus/epidemiologia
6.
J Appl Microbiol ; 129(4): 1071-1078, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32248631

RESUMO

AIM: To investigate factors influencing Campylobacter spp. colonization of broiler chickens. METHODS AND RESULTS: Campylobacters were isolated from caeca from 319 flocks of two different breeds (199 Cobb and 120 Hubbard), reared as standard (199), Freedom Food/corn fed (57), free-range (47) or organic (16). The standard category exclusively used Cobb birds slaughtered at 38-41 days. The Freedom Food/corn-fed and free-range Hubbard birds were slaughtered at 49-56 days and the organic flocks at 70 days. Campylobacters were picked at random from direct plates. Both breed of chicken (Hubbard) and age at slaughter were independently associated with increased likelihood of colonization by Campylobacter coli rather than Campylobacter jejuni, but breed could not be separated from other aspects of husbandry with the data available. CONCLUSIONS: Chickens are frequently colonized by C. jejuni and C. coli and most human infections originate from poultry. In most developed countries approximately 90% of human infections are caused by C. jejuni, but fewer than 10% by C. coli. This might be due to C. coli being less pathogenic than C. jejuni to humans, and/or to chicken meat carrying fewer C. coli than C. jejuni. More investigations are needed into these aspects before it can be concluded that slaughtering older birds from slower-growing breeds would reduce the risk of human Campylobacter disease. SIGNIFICANCE AND IMPACT OF THE STUDY: Meat from certain breeds of poultry are predominantly colonized by C. coli rather than C. jejuni. More research is needed to understand the impact this may have on the number and severity of human campylobacter infections.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter/isolamento & purificação , Aves Domésticas/microbiologia , Criação de Animais Domésticos/métodos , Animais , Cruzamento , Campylobacter/classificação , Infecções por Campylobacter/microbiologia , Ceco/microbiologia , Galinhas , Humanos , Fatores de Tempo
7.
Trop Anim Health Prod ; 52(5): 2461-2468, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32350820

RESUMO

The use of agricultural by-products might provide an important alternative to improve animal agriculture and to reduce feeding costs. The effects of inclusion in the diet of four levels of delinted cottonseed (0, 80, 160, and 240 g/kg) on intake, digestibility, nitrogen balance, blood parameters, and the ingestive behaviour of confined sheep were studied. Twenty-four mixed-breed rams with an average body weight of 27.6 ± 2.9 kg were used in a completely randomised design with four treatments. The addition of delinted cottonseed (DCS) did not alter (P > 0.05) the intake of dry matter, crude protein, organic matter, neutral detergent fibre, or ether extract in the two forms calculated (g/day and % body weight). The use of different levels of DCS in sheep feed did not influence (P > 0.05) the voluntary water intake. The dietary DCS levels linearly affected (P < 0.05) the digestibility coefficients of the dry matter (DM), organic matter, neutral detergent fibre, ether extract, and non-fibrous carbohydrates. The DCS inclusion levels did not affect the nitrogen balance (P = 0.22), plasma concentrations of urea (P = 0.51), and glucose (P = 0.17).The feeding efficiency and rumination in g DM/h reduced linearly (P < 0.05) with the addition of DCS in the diet. Therefore, the addition of delinted cottonseed affects the intake, digestibility, and ingestive behaviour of confined sheep, and the addition of up to 80 g/kg delinted cottonseed in the diet of confined sheep is recommended.


Assuntos
Ração Animal/análise , Dieta/veterinária , Gossypium/química , Sementes/química , Ovinos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal , Fibras na Dieta/metabolismo , Digestão , Comportamento Alimentar , Masculino , Doenças dos Ovinos
8.
Reprod Domest Anim ; 53(2): 393-400, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29194804

RESUMO

The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty-six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination.


Assuntos
Análise do Sêmen/veterinária , Sus scrofa/fisiologia , Testículo/diagnóstico por imagem , Ultrassonografia/veterinária , Animais , Cruzamento , Processamento de Imagem Assistida por Computador , Masculino , Sêmen/fisiologia , Motilidade dos Espermatozoides , Espermatozoides , Testículo/patologia , Ultrassonografia/métodos
9.
Genet Mol Res ; 16(3)2017 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-28692118

RESUMO

In recent years, there has been a large incidence of fungi causing "ear rot" in maize in Brazil, the main fungus being Fusarium verticillioides. The most efficient and competitive alternative for control of this disease consists of using maize hybrids resistant to this pathogen. Thus, the aims of this study were to analyze the genetic variability of maize inbred lines in regard to resistance to ear rot to observe if there is a maternal effect to resistance to ear rot, to study genetic control of the traits evaluated in hybrids originating from inbred lines of the maize breeding program at the Agriculture Department of Universidade Federal de Lavras (Lavras, MG, Brazil), and characterize the gene expression pattern related to the plant defense mechanism against F. verticillioides. High genetic availability was observed for resistance to this disease among the inbred lines evaluated. Considering combined diallel analysis, it was observed that the mean square of general combining ability (GCA) was not significant for the characteristic under study. However, specific combining ability (SCA) was significant, which indicates the predominance of non-additive effects involved in control of the characteristic for the population evaluated. A maternal effect was not observed for the characteristic of ear rot resistance in this study. Inbred lines 22, 58, and 91 showed potential for use in breeding programs aiming at resistance to F. verticillioides. Only two genes, LOX8 and Hsp82, had a satisfactory result that was able to be related to a plant defense mechanism when there is ear rot infection, though expression of these genes was observed in only one susceptible genotype. Thus, the genes LOX8 and Hsp82 are potential molecular markers for selection of maize inbred lines resistant to F. verticillioides.


Assuntos
Melhoramento Vegetal , Imunidade Vegetal/genética , Seleção Genética , Zea mays/genética , Fusarium/patogenicidade , Regulação da Expressão Gênica de Plantas , Marcadores Genéticos , Variação Genética , Proteínas de Choque Térmico/genética , Endogamia , Lipoxigenase/genética , Herança Materna , Proteínas de Plantas/genética , Zea mays/imunologia , Zea mays/microbiologia
10.
Genet Mol Res ; 16(2)2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28671255

RESUMO

In several crops, the water deficit is perhaps the main limiting factor in the search for high yields. The objective of this study was to evaluate the phenotypic stability of maize hybrids in environments with and without water restriction using the analytical factor (AF) approach. We evaluated 171 maize hybrids in 14 environments, divided into environments with (A1, A2, A3, A4, A5, A6, and A7) and without (A8, A9, A10, A11, A12, A13, and A14) water restriction, over a period of 7 years. Each year, 36 hybrids were evaluated. A square lattice design (6 x 6) was used, with common treatments between years. The characteristics of grain yield (GY), male flowering (MF) and female flowering (FF), plant height (PH), and ear height (EH) were evaluated. Phenotypic adaptability and stability of the hybrids were also verified. Hybrids G66, G99, G86, and G26 were the most stable and showed potential for use in environments with and without water restriction. The AF models showed to be useful for evaluating hybrids over many years, allowing selection of better hybrids with adaptability, specific and general stability, and correlation of hybrids with their production components, in addition to allowing identification of mega-environments that permit stability in the response of the adapted hybrids.


Assuntos
Instabilidade Genômica , Hibridização Genética , Melhoramento Vegetal/métodos , Estresse Fisiológico , Zea mays/genética , Secas , Meio Ambiente , Modelos Genéticos , Característica Quantitativa Herdável , Zea mays/crescimento & desenvolvimento
11.
Reprod Domest Anim ; 52(2): 335-343, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28111814

RESUMO

This study was conducted to characterize the daily profile of testosterone secretion and its mean concentrations in the four seasons as well as to evaluate the semen characteristics and testicular biometry of Mangalarga Marchador stallions throughout the year in a tropical region. Three stallions were submitted to semen collections and evaluation of testicular biometry every 14 days along a year. Blood samples were collected once at the middle of each season, in a 20-min interval during 24 hr in order to evaluate the testosterone secretion profiles among seasons. Testosterone concentrations along the day were higher at the beginning of the afternoon (from 12:00 to 15:00 hr), but a circadian secretion was not clearly observed. Mean testosterone concentrations did not differ among seasons (p > .05), but a pattern of secretion along the day showed variations with higher concentrations in the afternoon during the winter. Ejaculate volume was higher during summer; however, sperm motility decreased in summer and spring. Total sperm in ejaculate, sperm morphology and testicular biometry kept constant along the year showing no differences among the seasons. The results demonstrated that in a tropical region, reproductive aspects of stallions did not show a clearly defined seasonal variation, and months of autumn and winter were not unsuitable for reproduction of the males.


Assuntos
Cavalos/fisiologia , Análise do Sêmen/veterinária , Sêmen/fisiologia , Testículo/anatomia & histologia , Testosterona/sangue , Animais , Brasil , Masculino , Razão de Chances , Periodicidade , Estações do Ano , Temperatura
12.
Cryobiology ; 73(1): 1-6, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27393245

RESUMO

The objective of this study was to investigate the effect of cyclodextrin-loaded cholesterol conjugates addition to freezing extenders on plasma membrane viability of frozen-thawed spermatozoa of the Piau swine breed. Twenty semen samples were used from five males. The freezing extender was based on lactose-egg yolk extender, added to 2% glycerol, 3% dimethylacetamide. The addition of cyclodextrin-loaded cholesterol conjugates was performed after centrifugation, when semen was diluted with the cooling extender. Four groups were subjected to the following treatment: without addition (group 1); 1.5 mg of cyclodextrin-loaded cholesterol/120 × 10(6) sperm (group 2); 1.5 mg of cyclodextrin-loaded cholestanol/120 × 10(6) sperm (group 3); 1.5 mg of cyclodextrin-loaded desmosterol/120 × 10(6) sperm (group 4). To check post-thawing sperm quality sperm motility and sperm morphology evaluation were used. Additionally, to check sperm viability the hypoosmotic swelling test, supravital staining, and fluorescent assay were used. The mean values recorded for total sperm motility of semen immediately after thawing were 54.5 ± 5.8, 55.5 ± 5.3, 53.7 ± 6.7, and 52.5 ± 6.6% respectively for groups one to four, without difference between themselves (p > 0.05). Regarding fluorescent assay the results were 28.3 ± 13.2, 26.9 ± 12.2, 22.2 ± 11.4, and 32.0 ± 15.3% respectively for groups one to four, also without difference between groups (p > 0,05). Similarly, complementary tests for evaluating the integrity and functionality of the plasma membrane showed no difference between treatments (p > 0.05). In conclusion, use of cyclodextrin-loaded cholesterol conjugates added to the plasma membrane of sperm did not demonstrate any additive effect on increasing and/or maintaining sperm motility.


Assuntos
Membrana Celular/efeitos dos fármacos , Criopreservação/métodos , Crioprotetores/farmacologia , Preservação do Sêmen/métodos , Motilidade dos Espermatozoides/efeitos dos fármacos , Animais , Membrana Celular/metabolismo , Colesterol/farmacologia , Ciclodextrinas/farmacologia , Masculino , Espermatozoides/efeitos dos fármacos , Suínos
13.
Genet Mol Res ; 15(1): 15017232, 2016 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-26985952

RESUMO

The main objective of a maize breeding program is to generate hybrid combinations that are more productive than those pre-existing in the market. However, the number of parents, and consequently the number of crosses, increases so rapidly that the phenotypic evaluation of all the possible combinations becomes economically and technically infeasible. In this context, predicting the performance of the most promising genotypes may increase the genetic gains with increased selection intensity and reduced breeding cycles. Thus, the present study aimed to use the total effects of associated markers method to predict genomic breeding values (GBVs) via cross-validation and by using different imbalance levels (10, 30, 50, and 70%). A set of 51 genotyped strains was used with 79 microsatellite markers and 273 hybrids that were generated by a partial diallel. A total of 186 and 272 hybrids were analyzed in the experiments within the southern and central regions of Brazil, respectively. The GBVs were, thus, predicted for each location in both the regions, and for training in one region and validation in another region. The correlation between the predicted and observed GBVs ranged from 0.48 to 0.91, depending on the imbalance level and the region analyzed. Overall, the results obtained in the present study were promising, particularly considering that a small number of markers were used and that the training and predictions occurred in the very distinct regions of southern and central Brazil.


Assuntos
Cruzamentos Genéticos , Repetições de Microssatélites , Melhoramento Vegetal/métodos , Zea mays/genética , Brasil , Meio Ambiente , Marcadores Genéticos/genética , Genoma de Planta , Modelos Genéticos , Fenótipo , Locos de Características Quantitativas
14.
Genet Mol Res ; 15(3)2016 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-27706782

RESUMO

The aim of this study was to identify inbred progenies of S0:1 maize (Zea mays L.) plants that were efficient at a low level of technology and responsive at a high level of technology through the use of topcrosses. Two contrasting environments were created using two levels of base fertilization and topdressing, so that the levels of nitrogen, phosphorus, and potassium were applied four times higher in one environment than in the other. We used S0:1 progenies derived from commercial hybrids in topcrosses with two testers (an elite line from the flint heterotic group and an elite line from the dent heterotic group). The progenies and three controls were evaluated in an augmented block design in Nossa Senhora das Dores, SE, Brazil in the 2010 crop season. The average grain yield in the high-technological level was 21.44% greater than that in the low-technological level. There were no changes in progeny behavior in the two technological levels for grain yield. The testers did not differ in the average grain yield of the progenies at the two technological levels. Therefore, it is possible to select progenies derived from commercial hybrids that have an efficient response to fertilization.


Assuntos
Cruzamentos Genéticos , Meio Ambiente , Endogamia , Seleção Genética , Zea mays/genética , Alelos , Zea mays/anatomia & histologia
15.
Genet Mol Res ; 15(3)2016 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-27525950

RESUMO

Low water availability is one of the factors that limit agricultural crop development, and hence the development of genotypes with increased water stress tolerance is a challenge in plant breeding programs. Heat-resistant proteins have been widely studied, and are reported to participate in various developmental processes and to accumulate in response to stress. This study aimed to evaluate heat-resistant protein expression under water stress conditions during the germination of maize seed inbreed lines differing in their water stress tolerance. Maize seed lines 91 and 64 were soaked in 0, -0.3, -0.6, and -0.9 MPa water potential for 0, 6, 12, 18, and 24 h. Line 91 is considered more water stress-tolerant than line 64. The analysis of heat-resistant protein expression was made by gel electrophoresis and spectrophotometry. In general, higher expression of heat-resistant proteins was observed in seeds from line 64 subjected to shorter soaking periods and lower water potentials. However, in the water stress-tolerant line 91, a higher expression was observed in seeds that were subjected to -0.3 and -0.6 MPa water potentials. In the absence of water stress, heat-resistant protein expression was reduced with increasing soaking period. Thus, there was a difference in heat-resistant protein expression among the seed lines differing in water stress tolerance. Increased heat-resistant protein expression was observed in seeds from line 91 when subjected to water stress conditions for longer soaking periods.


Assuntos
Germinação , Proteínas de Choque Térmico/genética , Proteínas de Plantas/genética , Sementes/metabolismo , Zea mays/metabolismo , Desidratação/genética , Desidratação/metabolismo , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Temperatura Alta , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Zea mays/genética , Zea mays/crescimento & desenvolvimento
16.
Genet Mol Res ; 14(3): 11052-62, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26400335

RESUMO

Leaf disease and ear rot have caused reductions in maize yield in Brazil and other producer countries. Therefore, the aims of this study were to analyze the association between husked ear yield and the severity of maize white spot, gray leaf spot, helminthosporium, and ear rot caused by Fusarium verticillioides and Diplodia maydis using biplots in a mixed-model approach. The responses of 238 lines introduced to Brazil and four controls were evaluated using an incomplete block design with three replicates in two locations: Lavras and Uberlândia, Minas Gerais, Brazil. Two experiments were conducted in each location, one with F. verticillioides and the other with D. maydis. The mixed models elucidated the relationship between yield, leaf disease, and ear disease. Significant genotype x environment and genotype x pathogen interactions were observed. In conclusion, husked ear yield is more associated with ear rot than with the leaf diseases evaluated, justifying the indirect selection for resistance to kernel rot in maize-F. verticillioides and maize-D. maydis pathosystems by yield evaluation.


Assuntos
Doenças das Plantas/microbiologia , Zea mays/microbiologia , Ascomicetos/fisiologia , Resistência à Doença , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/microbiologia , Fusarium/fisiologia , Genes de Plantas , Predisposição Genética para Doença , Doenças das Plantas/genética , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Seleção Genética , Zea mays/genética , Zea mays/crescimento & desenvolvimento
17.
Reprod Domest Anim ; 50(4): 545-53, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25865710

RESUMO

This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post-thaw viability of Piau-breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800 g for 10 min and 2400 g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour - freezing 1 and automated cooling using a programmed freezing machine - freezing 2) were tested. Therefore, the treatments were divided into M3 - centrifugation at 2400 g for 3 min and freezing 2; M10 - centrifugation at 800 g for 10 min and freezing 2; R3 - centrifugation at 2400 g for 3 min and freezing 1; and R10 - centrifugation at 800 g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post-thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo-osmotic test (HO), sperm-egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post-thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury.


Assuntos
Centrifugação/métodos , Criopreservação/veterinária , Preservação do Sêmen/veterinária , Sus scrofa , Acrossomo/ultraestrutura , Animais , Membrana Celular/ultraestrutura , Sobrevivência Celular , Criopreservação/métodos , Congelamento , Temperatura Alta , Masculino , Nitrogênio , Preservação do Sêmen/métodos , Motilidade dos Espermatozoides , Interações Espermatozoide-Óvulo , Espermatozoides/anormalidades , Espermatozoides/fisiologia , Espermatozoides/ultraestrutura , Fatores de Tempo
18.
Genet Mol Res ; 14(1): 2674-90, 2015 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-25867416

RESUMO

The aim of this study was to characterize maize lines tolerant to cold temperatures during the germination process. Seeds from lines with different levels of tolerance to low temperatures were used; 3 lines were classified as tolerant and 3 as susceptible to low germination temperatures. A field was set up to multiply seeds from selected lines. After the seeds were harvested and classified, we conducted physiological tests and analyzed fatty acid content of palmitic, stearic, oleic, linoleic, linolenic, and eicosenoic acids. In proteomic analysis, the expression of heat-resistant proteins, including catalase, peroxidase, esterase, superoxide dismutase, and α-amylase, were evaluated. Transcript analysis was used to measure the expression of the genes AOX1, AOX2, ZmMPK-17, and ZmAN-13. The material showing the highest susceptibility to low germination temperatures contained high saturated fatty acid content. Expression of α-amylase in seeds soaked for 72 h at a temperature of 10°C was lower than expression of α-amylase when soaked at 25°C for the same amount of time. We observed variation in the expression of heat-resistant proteins in seeds of the lines evaluated. The genes AOX and Zm-AN13 were promising for use in identifying maize materials that are tolerant to low germination temperatures.


Assuntos
Adaptação Fisiológica/genética , Temperatura Baixa , Germinação/genética , Proteínas de Plantas/genética , Sementes/genética , Zea mays/genética , Catalase/metabolismo , Cromatografia Gasosa , Eletroforese em Gel de Poliacrilamida , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas Mitocondriais/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Oxirredutases/genética , Ácido Palmítico/metabolismo , Peroxidase/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Ácidos Esteáricos/metabolismo , Superóxido Dismutase/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
19.
Genet Mol Res ; 14(4): 18047-58, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26782452

RESUMO

The identification of genes related to heat tolerance is fundamental for the development of high-quality seeds that are tolerant to heat stress condition. The objective of this study was to evaluate maize lineages and the gene expression involved in high temperature tolerance during germination using physiological tests, proteomics, and transcriptome analysis. Seeds from six maize lineages (30, 44, 54, 63, 64, and 91) with different levels of tolerance to high temperatures were used. Lineages 54 and 91 were observed to be more tolerant to high temperature conditions. The highest expression of α-amylase was observed in maize seeds from lineages 30 and 91 that were subjected to controlled deterioration. The highest expression of α-amylase was observed in maize seeds from lineages 30 and 91 that were subjected to controlled deterioration; with the controlled deterioration, the highest level of gene expression did not occur in the most tolerant materials; the association of lower expression of genes involved in heat-resistant protein systems was observed in seeds from lineage 44, which were more susceptible to high temperatures, and the highest gene expression of LEA D-34, ZmAN13, and AOX-1 was observed in seeds from lineage 64 when submitted to controlled deterioration.


Assuntos
Germinação/genética , Sementes/genética , Estresse Fisiológico/genética , Zea mays/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Sementes/fisiologia , Temperatura , Zea mays/fisiologia , alfa-Amilases/biossíntese
20.
Genet Mol Res ; 14(4): 18471-84, 2015 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-26782495

RESUMO

The prediction of single-cross hybrids in maize is a promising technique for optimizing the use of financial resources in a breeding program. This study aimed to evaluate Genomic Best Linear Unbiased Predictors models for hybrid prediction and compare them with the Bayesian Ridge Regression, Bayes A, Bayesian LASSO, Bayes C, Bayes B, and Reproducing Kernel Hilbert Spaces Regression models, with inclusion or absence of non-additive effects under three heritability scenarios. Data from a maize germplasm bank belonging to USDA were used to determine the effects of molecular markers, which were considered to be parametric, to build 400 single-cross hybrids between two line groups via simulation. The following parameters were used to compare the models: predictive ability, estimation of variance components, heritability of genetic effects present in all situations, and the sum of squares of the predicted errors. The models responded positively when dominance effects were included in non-additive models, with all models tending to show an increase in the values of heritability parameters under all scenarios. Differences occur between models depending on the heritability range considered. Estimates of additive and dominant effects were better than estimates of epistatic effects. Estimates increased in accuracy for all models when non-additive effects for maize cob weight were considered.


Assuntos
Cruzamentos Genéticos , Genoma de Planta , Estudo de Associação Genômica Ampla , Algoritmos , Teorema de Bayes , Cruzamento , Quimera , Bases de Dados Genéticas , Epistasia Genética , Modelos Genéticos , Fenótipo , Zea mays/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA