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1.
Braz. j. biol ; 77(4): 868-875, Nov. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-888816

RESUMO

Abstract Roots and leaves of Panicum maximum Tanzânia, Mombaça and Massai; Urochloa brizantha Piatã, Marandu and Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II and Cynodon nlemfuensis Estrela-roxa were analyzed, seeking to identify characters for better adaptation to the environment that may interfere with digestibility of tissue from the point of view of the rumen in cattle. Were planted ten cultivars in a completely randomized blocks with three repetitions. Was collected vegetative material, which histological slides were prepared from middle third of the sections of roots and leaves. Were observed differences (p>0.05) in the roots: higher volume of epidermal cells (28.62 µm) and overall diameter (1926.41 µm) of Llanero; thicker vascular cylinder (975.09 µm) and more protoxylem (42.25) in Estrela-roxa and occurrence of aerenchyma in cultivars Piatã, Mulato II, Xaraés, Massai, Llanero and Estrela-roxa; Were found higher proportions of bulliform cells in the leaves (121.07 µm) and thicker leaf mesophyll in U. humidicola Llanero (263.63 µm); higher proportion of sclerenchyma fibers in Xaraés and Marandu; lower results for amount of fibers in P. maximum Massai. We conclude that the cultivars Estrela-roxa, Llanero and Massai have greater adaptability to the environment and better nutritional quality.


Resumo Foram analisadas raízes e folhas de Panicum maximum Tanzânia, Mombaça e Massai; Urochloa brizantha Piatã, Marandu e Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II e Cynodon nlemfuensis Estrela-roxa, procurando identificar caracteres relacionados à melhor adaptação ao ambiente e à qualidade nutritiva das forrageiras. As dez cultivares foram semeadas em blocos inteiramente casualizados com três repetições. Após estabelecidas foi coletado material vegetativo, do qual lâminas histológicas foram confeccionadas a partir de secções do terço médio de raízes e folhas. Foram observadas diferenças significativas (p>0,05) nas raízes: maior volume de células epidérmicas (28,62 µm) e diâmetro total (1926,41 µm) de Llanero; em Estrela-roxa maior espessura do cilindro vascular (975,09 µm) e número maior de protoxilemas (42,25) e formação de aerênquimas nas cultivares Piatã, Mulato II, Xaraés, Massai, Llanero, e Estrela-roxa; Nas folhas, foram constatadas maiores proporções de células buliformes (121,07 µm) e mesofilo foliar mais espesso (263,63 µm) em Llanero; em Xaraés e Marandu maiores proporções de fibras esclerenquimáticas; em Massai menores resultados para quantidade de fibras. Conclui-se que as cultivares Estrela-roxa, Llanero e Massai apresentam maior adaptabilidade ao ambiente e melhor qualidade nutritiva.


Assuntos
Animais , Poaceae/anatomia & histologia , Criação de Animais Domésticos , Brasil , Bovinos , Raízes de Plantas/anatomia & histologia , Folhas de Planta/anatomia & histologia , Aclimatação
2.
Braz J Biol ; 77(4): 868-875, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28492803

RESUMO

Roots and leaves of Panicum maximum Tanzânia, Mombaça and Massai; Urochloa brizantha Piatã, Marandu and Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II and Cynodon nlemfuensis Estrela-roxa were analyzed, seeking to identify characters for better adaptation to the environment that may interfere with digestibility of tissue from the point of view of the rumen in cattle. Were planted ten cultivars in a completely randomized blocks with three repetitions. Was collected vegetative material, which histological slides were prepared from middle third of the sections of roots and leaves. Were observed differences (p>0.05) in the roots: higher volume of epidermal cells (28.62 µm) and overall diameter (1926.41 µm) of Llanero; thicker vascular cylinder (975.09 µm) and more protoxylem (42.25) in Estrela-roxa and occurrence of aerenchyma in cultivars Piatã, Mulato II, Xaraés, Massai, Llanero and Estrela-roxa; Were found higher proportions of bulliform cells in the leaves (121.07 µm) and thicker leaf mesophyll in U. humidicola Llanero (263.63 µm); higher proportion of sclerenchyma fibers in Xaraés and Marandu; lower results for amount of fibers in P. maximum Massai. We conclude that the cultivars Estrela-roxa, Llanero and Massai have greater adaptability to the environment and better nutritional quality.


Assuntos
Criação de Animais Domésticos , Poaceae/anatomia & histologia , Aclimatação , Animais , Brasil , Bovinos , Folhas de Planta/anatomia & histologia , Raízes de Plantas/anatomia & histologia
3.
Genet Mol Res ; 15(3)2016 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-27706696

RESUMO

Brazil is considered one of the domestication centers of cassava (Manihot esculenta), containing a large part of the biological diversity and traditional knowledge of the species. The aim of the present study was to evaluate the genetic diversity of cassava landraces grown by farmers in the north of Mato Grosso State, Brazil, using inter simple sequence repeat (ISSR) molecular markers. The study was carried out in the municipality of Alta Floresta, MT, on farms located in two rural areas. Seventeen cassava landraces were selected. The DNA was extracted and polymerase chain reaction amplifications were performed using 15 ISSR primers. Genetic similarity estimates were calculated using Jaccard's index and the generated matrix was used for clustering the genotypes by using UPGMA and Tocher's methods. The 15 ISSR primers amplified 120 fragments, revealing 61.67% polymorphism. The polymorphism information content ranged from 0.04 to 0.61, averaging 0.39. The most similar genotypes were AF5 and AF8, whereas the least similar were AF1 and AF16. The UPGMA clustering method formed five groups. Group I included twelve landraces, Group II contained two, and the other groups contained one landrace each. Tocher's method resulted in six groups: 12 landraces clustered in one group, and the other groups each contained one landrace. The ISSR markers proved efficient in revealing genetic diversity among the cassava landraces. The landraces grown by farmers in the two rural areas of Alta Floresta have a great variability and, thus, can be exploited in programs for breeding and preservation of the species.


Assuntos
DNA de Plantas/genética , Manihot/genética , Filogenia , Polimorfismo Genético , Brasil , Primers do DNA/química , DNA Intergênico , Domesticação , Fazendas , Genótipo , Manihot/classificação , Melhoramento Vegetal , Reação em Cadeia da Polimerase
4.
Phlebology ; 31(2): 133-40, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25736280

RESUMO

OBJECTIVES: To study the differences in impact on venous hemodynamics between larger size strong graduated elastic compression stockings (GECS) and appropriate size strong/moderate GECS. METHOD: In healthy legs fitted for a small (Group S; n = 8) and large (Group L; n = 8) GECS, air plethysmography was performed without GECS, with an appropriate size strong GECS (GECS1), with a three-size too large strong GECS (GECS2), and with an appropriate size moderate GECS (GECS3) in this order. RESULTS: In Group S, interface pressure with GECS2 was equal to or higher than that with GECS3. Decreased venous volume, unchanged ejection volume, and decreased residual volume were achieved by GECS, but differences in these parameters among GECS were not observed. Although insignificant, a similar tendency was found in Group L. CONCLUSIONS: A larger size strong GECS seemed to have equivalent interface pressure and impact on venous hemodynamics compared to an appropriate size moderate or strong GECS.


Assuntos
Hemodinâmica , Pressão , Meias de Compressão , Veias/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
5.
Phlebology ; 30(2): 92-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24307242

RESUMO

OBJECTIVES: The objective of this study was to investigate the relationship between interface pressure and stiffness of compression achieved by various combinations of bandages and application techniques. METHOD: There were eight healthy volunteers. One roll (4.5 m) of four types of bandages with different extensibilities (0, 90, 108 and 218%) was applied to the leg in single-layer bandage fashion with eight random tensions. Then, the leg was wrapped with one to eight rolls in multi-layer bandage fashion. RESULTS: Each combination of bandage and application technique displayed an indigenous linear interface pressure-static stiffness index relationship. With single-layer bandage, lower extensibility was associated with higher static stiffness index at a given interface pressure. With multi-layer bandage, the static stiffness index at a given interface pressure was independent of the bandage type. CONCLUSION: The stiffness at a given interface pressure was affected by the extensibility with single-layer bandage but not with multi-layer bandage.


Assuntos
Bandagens Compressivas , Perna (Membro) , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
J Integr Neurosci ; 9(4): 381-406, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21213411

RESUMO

For the purpose of statistical characterization of the spatio-temporal correlation structure of brain functioning from high-dimensional fMRI time series, we introduce an innovation approach. This is based on whitening the data by the Nearest-Neighbors AutoRegressive model with external inputs (NN-ARx). Correlations between the resulting innovations are an extension of the usual correlations, in which mean-correction is carried out by the dynamic NN-ARx model instead of the static, standard linear model for fMRI time series. Measures of dependencies between regions are defined by summarizing correlations among innovations at several time lags over pairs of voxels. Such summarization does not involve averaging the data over each region, which prevents loss of information in case of non-homogeneous regions. Statistical tests based on these measures are elaborated, which allow for assessing the correlation structure in search of connectivity. Results of application of the NN-ARx approach to fMRI data recorded in visual stimuli experiments are shown. Finally, a number of issues related with its potential and limitations are commented.


Assuntos
Córtex Cerebral/anatomia & histologia , Córtex Cerebral/fisiologia , Simulação por Computador/normas , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Mapeamento Encefálico/métodos , Humanos , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Análise de Regressão , Fatores de Tempo , Percepção do Tato/fisiologia , Percepção Visual/fisiologia
7.
Rev. bras. plantas med ; 11(2): 202-208, 2009. graf, tab
Artigo em Português | LILACS | ID: lil-614847

RESUMO

Ruta graveolens L., também conhecida com arruda, é planta originária do sul da Europa, cultivada no Brasil e em outros países como planta medicinal, muito utilizada em rituais religiosos. Tendo em vista que a germinação constitui um fator primordial para que a semente possa gerar uma planta vigorosa e com alto potencial produtivo, o presente trabalho teve como objetivo avaliar a resposta germinativa de sementes para arruda sob condições de temperatura, luminosidade, estresse hídrico e salino e emergência de plântulas em diferentes profundidades de semeadura. Sementes de Ruta graveolens são indiferentes à luz, germinando melhor em temperatura constante de 25ºC ou alterna (20-30ºC). Os potenciais osmóticos induzidos por manitol a partir de -0,4MPa e por NaCl a partir de -0,8MPa influenciam negativamente o processo germinativo. Maiores percentuais de plântulas são obtidas quando a espécie é semeada na superfície do substrato.


Ruta graveolens L., also known as rue, is from the south of Europe, cultivated in Brazil and other countries as a medicinal plant greatly used in religious rituals. Since germination is essential for the seed to generate a vigorous plant of high productive potential, this work aimed to evaluate the germinative response of rue seeds under different temperatures, luminosity conditions, and water and salt stress, besides seedling emergence at different sowing depths. Ruta graveolens L. seeds are indifferent to light, better germinating at constant temperature of 25ºC or alternated temperature (20-30ºC). The osmotic potentials induced by mannitol from -0.4MPa and by NaCl from -0.8MPa negatively influenced the germination process. Higher seedling percentages are obtained when the species is sown on the substratum surface.


Assuntos
Sementes/classificação , Germinação , Ruta/classificação , Plântula/metabolismo , Temperatura , Luz
8.
Insect Mol Biol ; 17(2): 185-95, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18353107

RESUMO

In order to better understand the relationship between dopamine and the release of diapause hormone into the blood, we cloned and characterized cDNAs encoding Bombyx mori dopamine receptor-1 and -2 (BmDopR1 and 2) from the pupal brain-suboesophageal ganglion. BmDopR1 and 2 had high similarities to group 1 (Drosophila melanogaster DOP1 and Apis mellifera DOP1) and group 2 (D. melanogaster DopR99B, A. mellifera DOP2 and Papilio xuthus DOP1), respectively. When BmDopR1 and 2 were expressed in human embryonic kidney (HEK) cells, they responded to dopamine by increasing intracellular cAMP levels, thus indicating the presence of D1-like receptors. There were no clear differences in BmDopR1 and 2 mRNA levels between brain-suboesophageal ganglion complexes of diapause and nondiapause egg producers during pupal-adult development. BmDopR1 and 2 mRNAs were concentrated in the mushroom body calyx rather than in the suboesophageal ganglion. Taking into account the results of earlier experiments on excised regions corresponding to mushroom bodies, BmDopR1 and 2 in the mushroom body apparently play a role in the release of diapause hormone.


Assuntos
Bombyx/genética , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/metabolismo , Linhagem Celular , Clonagem Molecular , DNA Complementar/genética , Feminino , Gânglios dos Invertebrados/química , Gânglios dos Invertebrados/metabolismo , Humanos , Hibridização In Situ , Dados de Sequência Molecular , Neuropeptídeos/fisiologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Transfecção
9.
Insect Mol Biol ; 15(4): 507-12, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16907837

RESUMO

To elucidate the molecular mechanisms underlying the tremendous diversity of insect wing colour patterns, it is imperative to identify and functionally characterize the genes involved in this developmental process. Here we report the first successful germ-line transformation using the transposable element vector piggyBac in the ladybird beetle Harmonia axyridis, which demonstrates typical genetic polymorphism in its wing colour patterns. The transformation efficiency by piggyBac was 3.7% per fertile G(0). We investigated the effectiveness of RNAi in Harmonia by injecting EGFP (enhanced green fluorescent protein) dsRNA into early transgenic EGFP-expressing embryos and observed substantial reduction of EGFP fluorescence in 87.2% of hatched larvae. Application of these new genetic tools to non-model insects such as Harmonia will facilitate the broad understanding of developmental mechanisms and evolutionary processes that are inaccessible using established model systems.


Assuntos
Besouros/genética , Variação Genética , Células Germinativas/fisiologia , Pigmentação/genética , Transformação Genética/fisiologia , Asas de Animais/fisiologia , Animais , Sequência de Bases , Western Blotting , Besouros/fisiologia , Primers do DNA , Elementos de DNA Transponíveis/genética , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Pigmentação/fisiologia , Interferência de RNA
10.
Insect Mol Biol ; 14(5): 501-8, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16164606

RESUMO

The main blood sugar in insects, trehalose, differs from glucose in mammals. To incorporate trehalose into cells and utilize it, tissue cells possess the enzyme trehalase (EC3.2.1.28), which catalyses trehalose into glucose, in the organellar membrane or in the cytoplasm. Soluble and membrane-bound trehalase proteins have been isolated from insects. To date, however, only genes encoding the soluble trehalase have been reported in insects. Soluble trehalase is therefore believed to become localized on the cell surface via modification. In contrast, cDNAs encoding trehalase localized on the apical cell surface via the glycosylphosphatidylinositol-anchor have been isolated from mammalian small intestines. The amino acid sequence contains a specific hydrophobic region and an upstream omega site, which is cleaved for glycosylphosphatidylinositol-attachment, at the C-terminus. Here, we describe a cDNA from the silkworm Bombyx mori that encodes a novel trehalase (type-2) with one transmembrane domain and lacking the omega site. Immunoblotting and immunohistochemical analyses demonstrated that in the midgut tissue of Bombyx larvae, soluble trehalase-1 is present mainly in goblet cell cavities, but membrane-bound trehalase-2 is predominantly seen on the visceral muscle surrounding the midgut. To our knowledge, this is the first report of a cDNA encoding trehalase that penetrates the cell membrane in insects and its cellular localization.


Assuntos
Bombyx/enzimologia , Proteínas de Insetos/biossíntese , Trealase/química , Trealase/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Trato Gastrointestinal/metabolismo , Larva/metabolismo , Dados de Sequência Molecular , Pupa/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
11.
Neuroimage ; 23(2): 680-97, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15488418

RESUMO

The most significant progresses in the understanding of human brain functions have been possible due to the use of functional magnetic resonance imaging (fMRI), which when used in combination with other standard neuroimaging techniques (i.e., EEG) provides researchers with a potential tool to elucidate many biophysical principles, established previously by animal comparative studies. However, to date, most of the methods proposed in the literature seeking fMRI signs have been limited to the use of a top-down data analysis approach, thus ignoring a pool of physiological facts. In spite of the important contributions achieved by applying these methods to actual data, there is a disproportionate gap between theoretical models and data-analysis strategies while trying to focus on several new prospects, like for example fMRI/EEG data fusion, causality/connectivity patterns, and nonlinear BOLD signal dynamics. In this paper, we propose a new approach which will allow many of the abovementioned hot topics to be addressed in the near future with an underlying interpretability based on bottom-up modeling. In particular, the theta-MAP presented in the paper to test brain activation corresponds very well with the standardized t test of the SPM99 toolbox. Additionally, a new Impulse Response Function (IRF) has been formulated, directly related to the well-established concept of the hemodynamics response function (HRF). The model uses not only the information contained in the signal but also that in the structure of the background noise to simultaneously estimate the IRF and the autocorrelation function (ACF) by using an autoregressive (AR) model with a filtered Poisson process driving the dynamics. The short-range contributions of voxels within the near-neighborhood are also included, and the potential drift was characterized by a polynomial series. Since our model originated from an immediate extension of the hemodynamics approach [Friston, K.J., Mechelli, A., Turner, R., Price C.J. (2000a). Nonlinear responses in fMRI: the balloon model, volterra kernels, and other hemodynamics. NeuroImage 12, 466-477.], a natural interpretability of the results is feasible.


Assuntos
Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Algoritmos , Circulação Cerebrovascular/fisiologia , Análise por Conglomerados , Simulação por Computador , Eletroencefalografia , Humanos , Modelos Lineares , Modelos Neurológicos , Movimento/fisiologia , Oxigênio/sangue , Estimulação Luminosa , Reprodutibilidade dos Testes
12.
Biosci Biotechnol Biochem ; 65(5): 1033-7, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11440114

RESUMO

Very fast tryptic degradation of the silkworm diapause hormone was found and the degradation pathway was analyzed by moderating the reaction conditions. It proceeded via cleavage at Arg23 and finally at Arg15 of DH. As the C-terminal structure of DH was essential for exhibiting bioactivity, the first cleavage caused rapid inactivation of the hormone. This tryptic digestion was strongly suppressed by adding VAP-map, a synthetic analog of the cuticular peptide of silkmoths, Bm ACP-6.7 (VAP-peptide), which is a natural synergist of DH. VAP-map suppressed the enzymic reaction by interacting with the substrate, but not with the enzyme.


Assuntos
Bombyx/metabolismo , Hormônios de Inseto/metabolismo , Neuropeptídeos/metabolismo , Peptídeos/farmacologia , Tripsina/metabolismo , Sequência de Aminoácidos , Animais , Cromatografia Líquida de Alta Pressão , Hidrólise , Hormônios de Inseto/antagonistas & inibidores , Cinética , Dados de Sequência Molecular , Neuropeptídeos/antagonistas & inibidores , Mapeamento de Peptídeos , Peptídeos/química , Homologia de Sequência de Aminoácidos
13.
Eur J Biochem ; 268(12): 3432-42, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11422373

RESUMO

Cellular responses to cold-acclimation have not yet been studied in depth. To explore this field, we focussed on insect diapause development. Although embryonic diapause of Bombyx mori is sustained at 25 degrees C, chilling at 5 degrees C for 2 months causes diapause termination, a transition that is marked when the sorbitol dehydrogenase gene (SDH) is activated. To clarify the relationship between this activation and incubation at 5 degrees C, we isolated a novel cold-inducible gene, Samui. Expression of Samui mRNA and protein was activated after incubation at 5 degrees C for 5-6 days, lasted for another 30 days and then weakened. Exposure to 25 degrees C suppressed both mRNA and protein expression. In nondiapause eggs incubated at 5 degrees C, Samui was also up-regulated, although the expression was weaker. Samui contained nuclear localization-signals, a ssDNA-binding motif and a BAG domain similar to that of SODD/BAG-4. Because Samui could bind to HSP70, it is a member of BAG protein family. It is proposed that Samui serves to transmit the '5 degrees C signal' for SDH expression in diapause eggs, while also protecting against cold-injures in nondiapause eggs, through binding to respective partners. This is the first report that a member of BAG protein family is up-regulated by cold.


Assuntos
Temperatura Baixa , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Insetos , Óvulo/química , Sequência de Aminoácidos , Animais , Sequência de Bases , Bombyx , DNA Complementar , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/metabolismo , Dados de Sequência Molecular , Óvulo/crescimento & desenvolvimento , Ligação Proteica , Biossíntese de Proteínas , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
14.
Insect Biochem Mol Biol ; 31(4-5): 407-13, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11222950

RESUMO

We have cloned and sequenced the cDNA encoding the major component (43-kDa peptide) of 30kP protease A which selectively hydrolyzes 30-kDa yolk proteins of the silkworm, Bombix mori. The deduced amino acid sequence consisted of 318 amino acids and shared sequences conserved in many serine proteases. Northern blot analysis using the cDNA as probe revealed that 43-kDa peptide mRNA began to rise at the last phase of embryogenesis and reached a maximum level at larval hatching. This level was maintained with some fluctuations throughout post-embryonic development. The concentration of 43-kDa peptide increased greatly toward larval hatching coinciding with the changing pattern of mRNA. When larvae were fed, the peptide concentration abruptly decreased and remained near zero throughout post-embryonic development. The decrease in peptide concentration did not occur, however, when the hatched larvae were starved. Thus, the nutritional shift from endogenous yolk to exogenous food plays a key role in 30kP protease A elimination from neonate larvae.


Assuntos
Bombyx/metabolismo , Proteínas do Ovo/metabolismo , Proteínas de Insetos/metabolismo , Serina Endopeptidases/metabolismo , Sequência de Aminoácidos , Animais , Bombyx/genética , Clonagem Molecular , DNA Complementar/genética , Ingestão de Alimentos/fisiologia , Proteínas do Ovo/genética , Privação de Alimentos/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Hidrólise , Proteínas de Insetos/genética , Larva/genética , Larva/metabolismo , Dados de Sequência Molecular , Pupa/genética , Pupa/metabolismo , Homologia de Sequência de Aminoácidos , Serina Endopeptidases/genética
15.
Insect Biochem Mol Biol ; 30(2): 119-25, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10696587

RESUMO

The VAP-peptide (BmACP-6.7) is a hydrophobic peptide localized in adult cuticle of the silkworm, Bombyx mori. We isolated and characterized the VAP-peptide gene as a useful marker gene to analyze molecular mechanisms of terminal differentiation processes in the adult. The gene is composed of two exons interrupted by one intron. The 5' upstream promoter region is shown to bear a nucleotide sequence similar to the cis-element that is recognized and bound by the Bombyx mori FTZ-F1 protein (BmFTZ-F1). Expression of the BmFTZ-F1 gene preceded expression of the VAP-peptide gene and injection of 20-hydroxyecdysone suppressed the expression of both genes. An in vitro binding assay indicated direct interaction of BmFTZ-F1 with the VAP-peptide gene promoter sequence. Therefore, BmFTZ-F1 is proposed to be a possible factor regulating the stage-specific expression of the VAP-peptide gene towards adult life.


Assuntos
Bombyx/genética , Proteínas de Ligação a DNA/genética , Genes de Insetos , Hormônios de Inseto/genética , Proteínas de Insetos/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bombyx/efeitos dos fármacos , Bombyx/crescimento & desenvolvimento , DNA/genética , Ecdisterona/farmacologia , Fatores de Transcrição Fushi Tarazu , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Proteínas de Homeodomínio , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Receptores Citoplasmáticos e Nucleares , Fator Esteroidogênico 1
16.
J Insect Physiol ; 45(7): 621-627, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12770347

RESUMO

Rates of oxygen consumption were followed throughout the entire period of diapause in eggs of Bombyx mori. In non-diapause eggs at 25 degrees C, O(2) uptake was divisible into three phases, corresponding to morphogenetic processes. In diapause eggs at 25 degrees C, O(2) uptake showed a peak (100 &mgr;l/g eggs/h) at 1 day and then suddenly dropped to reach a level of 8-10 &mgr;l/g eggs/h at 10 days and thereafter. To break diapause, eggs were exposed to 5 degrees C for varying periods. When O(2) uptake was measured at 5 degrees C, it remained at 6 &mgr;l/g eggs/h. When eggs were chilled for increasing periods and O(2) uptake was measured immediately after warming to 25 degrees C, the rates increased after a lag phase. In HCl-treated eggs, O(2) uptake increased immediately after acid-treatment. In all cases, highly increasing O(2) uptake at 25 degrees C coincided with termination of diapause. These results were discussed in relation to sorbitol utilization at the termination of diapause.

17.
Biosci Biotechnol Biochem ; 62(10): 1875-9, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9836422

RESUMO

Diapause hormone is a 24-amino acid peptide amide, and its C-terminal penta-peptide amide structure of FGPRL-NH2 is believed to be essential for biological activity. The penta-peptide amide, the shorter peptide amides, and their derivatives and analogs were prepared to determine the minimal structure for biological activity. The C-terminal amide group of penta-peptide amide was not replaced with the other functional groups, but Gly, the 4th amino acid from the C terminal, could be substituted with an other amino acid while maintaining the biological activity. The shorter peptide amide, PRL-NH2, possessed low but significant activity, indicating the minimum structure of diapause hormone. By modifying its N-terminal, the aromatic ring of Phe is shown to enhance the activity of PRL-NH2.


Assuntos
Bombyx/metabolismo , Neuropeptídeos/química , Animais , Bombyx/efeitos dos fármacos , Relação Dose-Resposta a Droga , Neuropeptídeos/farmacologia , Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Relação Estrutura-Atividade
18.
Insect Biochem Mol Biol ; 28(9): 671-6, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9755477

RESUMO

A unique hydrophobic peptide (VAP-peptide) isolated from male adult heads of the silkworm, Bombyx mori, has been shown to act as a synergist to the diapause hormone when administered exogenously. Here, we investigated the true role of the endogenous VAP-peptide on differentiation and development of adult organs in the silkworm. By northern blot analyses, the VAP-peptide gene was shown to be exclusively expressed at the terminal phase of adult development in epithelial tissues, especially in the wing and the thoracic integument. In situ hybridization analysis revealed that the gene was highly expressed in the epidermal cells of the wing vein and the thoracic integument. The stage- and tissue-dependent gene expression were clearly correlated to the accumulation profile of VAP-peptide. In the adult thoracic integument, VAP-peptide was predominantly deposited in the cuticle layer. Affinity chromatography indicated the ability of VAP-peptide to bind to chitin. Based on its expression patterns, localization, and chemical properties, VAP-peptide is conceived to be a structural protein that participates in mechanical strengthening of specific cuticle structures, supporting their physical requirements in the adult life of the silkworm.


Assuntos
Bombyx/crescimento & desenvolvimento , Bombyx/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Hormônios de Inseto/genética , Metamorfose Biológica/genética , Animais , Cabeça , Hibridização In Situ , Hormônios de Inseto/biossíntese , Hormônios de Inseto/química , Masculino , Fases de Leitura Aberta , Reação em Cadeia da Polimerase , Tórax , Transcrição Gênica
19.
Insect Biochem Mol Biol ; 28(2): 75-82, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9639873

RESUMO

We have recently identified a unique lipophilic peptide (VAP-peptide) with diapause egg inducing activity in the silkworm, Bombyx mori (Imai et al., 1996). The cloning and sequencing of cDNA encoding VAP-peptide have demonstrated that the deduced amino acid sequence consisted of 84 amino acid residues, from which the mature VAP-peptide of 68 amino acid residues was released by cleaving a signal sequence. Searches of the GenBank data base revealed no significant sequence similarity to other proteins including diapause hormone (DH). VAP-peptide gene was selectively expressed just before and at adult eclosion in the head and the thorax not in the abdomen. By a Western blot analysis, VAP-peptide was also localized in the head and the thorax of adults. The purified recombinant VAP-peptide could not induce diapause eggs even when injected at a high dose of 10 nmol/pupa. Whereas, injection of a mixture of VAP-peptide and DH clearly decreased a half-maximum dose (ED50 value) and a threshold dose (TD value) of DH, and these values decreased according to increasing molar ratios of VAP-peptide to DH. Thus, the VAP-peptide is concluded to be an endogenous protein acting as a potent enhancer of DH activity through interaction with DH.


Assuntos
Bombyx/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Hormônios de Inseto/genética , Fragmentos de Peptídeos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bombyx/química , Bombyx/genética , DNA Complementar/química , Desenvolvimento Embrionário , Masculino , Dados de Sequência Molecular , Fragmentos de Peptídeos/isolamento & purificação
20.
J Insect Physiol ; 44(3-4): 333-342, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12769967

RESUMO

Members of the neuropeptide family having Phe-X-Pro-Arg-Leu-NH(2) (FXPRLamide; X=Ser, Thr, Val, or Gly) at the C-terminus serve as regulators of oviduct and visceral muscle contraction, sex pheromone production, and diapause induction. Antibody raised against Bombyx mori diapause hormone recognized a variety of FXPRLamide peptides. Using this antibody, the antigen was immunocytochemically localized in the central nervous system (CNS) of the silkworm, Bombyx mori. Immunoreactive somata were observed in all ganglia of the CNS including the brain. Twelve somata localized at the midline of the suboesophageal ganglion (SG) were most intensely stained, and their neurite projections reached the retrocerebral complex. Thus, these cells in the SG exhibited typical features of neuroendocrine neurons. Marked reduction in immunoreactivity was observed in a pair of neurosecretory cells in the labial neuromere in SG of diapause type pupae, which indicates an active release of FXPRLamide peptides from these cells. No clear connection to neurohemal sites were observed in immunoreactive cells in the brain, thoracic or abdominal ganglia, suggesting that the immunoreactive peptides in these organs are likely to serve as neurotransmitters or neuromodulators.

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