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Bradysia hygida (Diptera, Sciaridae) presents two eukaryotic Elongation Factor 1A gene homologues: partial characterization of the eukaryotic Elongation Factor 1A-F1 gene

CANDIDO-SILVA, J.A.; MONESI, N.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.66%
Elongation factor 1A is a highly conserved protein that participates in translation. We report the occurrence of two genes homologous to the eukaryotic Elongation Factor 1A in Bradysia hygida and describe the partial cloning and characterization of the B. hygida eukaryotic Elongation Factor 1A-F1 (BheEF1A-F1) gene. The pattern of BheEF1A-F1 expression in the salivary gland at the end of the fourth larval instar was investigated using real-time PCR. The results showed that BheEF1A-F1 expression levels are relatively constant at the time when rapid changes in protein synthesis occur in this tissue. In situ hybridization experiments coupled to Southern blot analyses showed that the BheEF1A-F1 gene is located at position 3d of the A chromosome and a second gene homologous to eEF1A is located at position 6a of the X chromosome. Southern blot analyses showed that both the BheEF1A-F1 gene and the second gene homologous to eEF1A constitute non-amplified genes. The present results contribute to the molecular characterization of a sciarid eEF1A gene.

Caracterização do fator de elongação Tu (EF-Tu) de Leptospira: aspectos relacionados à colonização e evasão ao sistema complemento do hospedeiro; Characterization of elongation factor Tu (EF-Tu) Leptospira: aspects related to colonization and evasion of the host complement system

Wolff, Danielly Gonçalves
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/08/2013 PT
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36.42%
A leptospirose é uma zoonose causada por bactérias patogênicas do gênero Leptospira. A doença representa um grave problema de saúde pública nos países tropicais subdesenvolvidos. Mais de 500.000 casos graves de leptospirose são notificados a cada ano e a taxa de mortalidade excede 10% (World Health Organization, 1999). Os roedores são o principal reservatório urbano da doença, e eliminam leptospiras viáveis no meio ambiente ao longo de toda a vida. As bactérias entram no hospedeiro por abrasões na pele ou por membranas mucosas e rapidamente se espalham pelo organismo atingindo vários órgãos. A identificação de mecanismos de invasão e de evasão imune apresentados por leptospiras patogênicas é extremamente relevante e tem sido alvo de pesquisas recentes desenvolvidas por vários grupos. Nesse contexto, a caracterização funcional de proteínas de membrana externa de Leptospira, principais alvos de interação com moléculas do hospedeiro, é de grande importância. O Fator de Elongação Tu (EF-Tu), uma proteína bacteriana abundante envolvida na síntese protéica, pertence à categoria das proteínas conhecidas como "moonlighting". Tais moléculas possuem a capacidade de exercer mais de uma função e, normalmente...

eIF5A has a function in the elongation step of translation in yeast

Gregio, Ana P. B.; Cano, Veridiana P. S.; Avaca, Juliana S.; Valentini, Sandro R.; Zanelli, Cleslei F.
Fonte: Academic Press Inc. Elsevier B.V. Publicador: Academic Press Inc. Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 785-790
ENG
Relevância na Pesquisa
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); The putative translation factor eIF5A is essential for cell viability and is highly conserved throughout evolution. Here, we describe genetic interactions between an eIF5A Mutant and a translation initiation mutant (eIF4E) or a translation elongation mutant (eEF2). Polysome profile analysis of single and double mutants revealed that mutation in eIF5A reduces polysome run-off, contrarily to translation initiation mutants. Moreover, the polysome profile of an eIF5A mutant alone is very similar to that of a translation elongation mutant. Furthermore, depletion of eIF5A causes a significant decrease in total protein synthesis and an increase of the average ribosome transit time. Finally, we, demonstrate that the formation of P bodies is inhibited in an eIF5A mutant, similarly to the effect of the translation elongation inhibitor cycloheximide. taken together, these results not only reinforce a role for eIF5A in translation but also strongly support a function for eIF5A in the elongation step of protein synthesis. (C) 2009 Elsevier B.V. All rights reserved.

Cooperative RNA Polymerase Molecules Behavior on a Stochastic Sequence-Dependent Model for Transcription Elongation

Costa, Pedro Rafael; Acencio, Marcio Luis; Lemke, Ney
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.53%
The transcription process is crucial to life and the enzyme RNA polymerase (RNAP) is the major component of the transcription machinery. The development of single-molecule techniques, such as magnetic and optical tweezers, atomic-force microscopy and single-molecule fluorescence, increased our understanding of the transcription process and complements traditional biochemical studies. Based on these studies, theoretical models have been proposed to explain and predict the kinetics of the RNAP during the polymerization, highlighting the results achieved by models based on the thermodynamic stability of the transcription elongation complex. However, experiments showed that if more than one RNAP initiates from the same promoter, the transcription behavior slightly changes and new phenomenona are observed. We proposed and implemented a theoretical model that considers collisions between RNAPs and predicts their cooperative behavior during multi-round transcription generalizing the Bai et al. stochastic sequence-dependent model. In our approach, collisions between elongating enzymes modify their transcription rate values. We performed the simulations in Mathematica® and compared the results of the single and the multiple-molecule transcription with experimental results and other theoretical models. Our multi-round approach can recover several expected behaviors...

It’s all about sex: what urban zimbabwean men know of labia minora elongation

Pérez, Guillermo Martínez; Aznar, Concepción Tomás; Namulondo, Harriet
Fonte: Centro de Estudos Internacionais do Instituto Universitário de Lisboa (ISCTE-IUL) Publicador: Centro de Estudos Internacionais do Instituto Universitário de Lisboa (ISCTE-IUL)
Tipo: Artigo de Revista Científica
Publicado em /06/2014 ENG
Relevância na Pesquisa
36.66%
Labia minora elongation is one of the vaginal practices that some Zimbabwean women engage in during the pre-menarche age. This practice has not been thoroughly investigated in Zimbabwe. The objective of this study is to learn about the knowledge, attitudes and perceptions of urban Zimbabwean men towards labia minora elongation. A qualitative study was conducted in Chitungwiza, Harare, in 2012. Thirty-one adult men were interviewed. Data was collected on men’s understanding of the procedure, motivations, its relevance for marriage and sexual life, and its implications on health. The findings demonstrate that labia minora elongation is recognized in Zimbabwe as a practice that enhances the sexual pleasure for both male and female partners, and that there are no perceived harms to women’s health. More research is necessary to better understand the role of labia minora elongation in sexuality and acceptance of HIV/STI barrier methods.; O alongamento dos pequenos lábios vaginais (labia minora) é praticado por algumas mulheres zimbabueanas antes de atingirem a fase menstrual. Esta prática não tem sido investigada em profundidade no Zimbábue. O objetivo deste estudo é analisar os conhecimentos, as atitudes e as perceções de homens zimbabueanos residentes em meios urbanos relativamente ao alongamento dos pequenos lábios. Esta análise tem por base um estudo qualitativo realizado em Chitungwiza...

IgG and IgG2 antibodies from cattle naturally infected with Anaplasma marginale recognize the recombinant vaccine candidate antigens VirB9, VirB10, and elongation factor-Tu

Araújo,Flábio R; Costa,Cátia M; Ramos,Carlos AN; Farias,Thais A; Souza,Ingrid Ieda F de; Melo,Elaine SP; Elisei,Carina; Rosinha,Gracia MS; Soares,Cleber O; Fragoso,Stênio P; Fonseca,Adivaldo H
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2008 EN
Relevância na Pesquisa
36.42%
Anaplasma marginale is an important vector-borne rickettsia of ruminants in tropical and subtropical regions of the world. Immunization with purified outer membranes of this organism induces protection against acute anaplasmosis. Previous studies, with proteomic and genomic approach identified 21 proteins within the outer membrane immunogen in addition to previously characterized major surface protein1a-5 (MSP1a-5). Among the newly described proteins were VirB9, VirB10, and elongation factor-Tu (EF-Tu). VirB9, VirB10 are considered part of the type IV secretion system (TFSS), which mediates secretion or cell-to-cell transfer of macromolecules, proteins, or DNA-protein complexes in Gram-negative bacteria. EF-Tu can be located in the bacterial surface, mediating bacterial attachment to host cells, or in the bacterial cytoplasm for protein synthesis. However, the roles of VirB9, VirB10, and TFSS in A. marginale have not been defined. VirB9, VirB10, and EF-Tu have not been explored as vaccine antigens. In this study, we demonstrate that sera of cattle infected with A. marginale, with homologous or heterologous isolates recognize recombinant VirB9, VirB10, and EF-Tu. IgG2 from naturally infected cattle also reacts with these proteins. Recognition of epitopes by total IgG and by IgG2 from infected cattle with A. marginale support the inclusion of these proteins in recombinant vaccines against this rickettsia.

Bradysia hygida (Diptera, Sciaridae) presents two eukaryotic Elongation Factor 1A gene homologues: partial characterization of the eukaryotic Elongation Factor 1A-F1 gene

Candido-Silva,J.A.; Monesi,N.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2010 EN
Relevância na Pesquisa
36.66%
Elongation factor 1A is a highly conserved protein that participates in translation. We report the occurrence of two genes homologous to the eukaryotic Elongation Factor 1A in Bradysia hygida and describe the partial cloning and characterization of the B. hygida eukaryotic Elongation Factor 1A-F1 (BheEF1A-F1) gene. The pattern of BheEF1A-F1 expression in the salivary gland at the end of the fourth larval instar was investigated using real-time PCR. The results showed that BheEF1A-F1 expression levels are relatively constant at the time when rapid changes in protein synthesis occur in this tissue. In situ hybridization experiments coupled to Southern blot analyses showed that the BheEF1A-F1 gene is located at position 3d of the A chromosome and a second gene homologous to eEF1A is located at position 6a of the X chromosome. Southern blot analyses showed that both the BheEF1A-F1 gene and the second gene homologous to eEF1A constitute non-amplified genes. The present results contribute to the molecular characterization of a sciarid eEF1A gene.

TiF1-Gamma Plays an Essential Role in Murine Hematopoiesis and Regulates Transcriptional Elongation of Erythroid Genes

Bai, Xiaoying; Trowbridge, Jennifer J.; Riley, Elizabeth Leman; Lee, Joseph A.; DiBiase, Anthony; Kaartinen, Vesa M.; Orkin, Stuart Holland; Zon, Leonard Ira
Fonte: Elsevier BV Publicador: Elsevier BV
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.61%
Transcriptional regulators play critical roles in the regulation of cell fate during hematopoiesis. Previous studies in zebrafish have identified an essential role for the transcriptional intermediary factor TIF1γ in erythropoiesis by regulating the transcription elongation of erythroid genes. To study if TIF1γ plays a similar role in murine erythropoiesis and to assess its function in other blood lineages, we generated mouse models with hematopoietic deletion of TIF1γ. Our results showed a block in erythroid maturation in the bone marrow following tif1γ deletion that was compensated with enhanced spleen erythropoiesis. Further analyses revealed a defect in transcription elongation of erythroid genes in the bone marrow. In addition, loss of TIF1γ resulted in defects in other blood compartments, including a profound loss of B cells, a dramatic expansion of granulocytes and decreased HSC function. TIF1γ exerts its functions in a cell-autonomous manner as revealed by competitive transplantation experiments. Our study therefore demonstrates that TIF1γ plays essential roles in multiple murine blood lineages and that its function in transcription elongation is evolutionally conserved.; Stem Cell and Regenerative Biology

Hox genes control vertebrate body elongation by collinear Wnt repression

Denans, Nicolas; Iimura, Tadahiro; Pourquié, Olivier
Fonte: eLife Sciences Publications, Ltd Publicador: eLife Sciences Publications, Ltd
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.61%
In vertebrates, the total number of vertebrae is precisely defined. Vertebrae derive from embryonic somites that are continuously produced posteriorly from the presomitic mesoderm (PSM) during body formation. We show that in the chicken embryo, activation of posterior Hox genes (paralogs 9–13) in the tail-bud correlates with the slowing down of axis elongation. Our data indicate that a subset of progressively more posterior Hox genes, which are collinearly activated in vertebral precursors, repress Wnt activity with increasing strength. This leads to a graded repression of the Brachyury/T transcription factor, reducing mesoderm ingression and slowing down the elongation process. Due to the continuation of somite formation, this mechanism leads to the progressive reduction of PSM size. This ultimately brings the retinoic acid (RA)-producing segmented region in close vicinity to the tail bud, potentially accounting for the termination of segmentation and axis elongation. DOI: http://dx.doi.org/10.7554/eLife.04379.001

TRIM28 as a novel transcriptional elongation factor

Bunch, Heeyoun; Calderwood, Stuart K
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.61%
TRIM28 is a multidomain protein with versatile functions in transcription and DNA repair. Recently it was shown that this factor plays unanticipated roles in transcriptional elongation. TRIM28 was shown to stabilize the pausing of RNA polymerase II (Pol II) close to the transcriptional start site in many unactivated genes, permitting Pol II accumulation and readying genes for induction. In addition, the factor was shown to respond rapidly to signals accompanying transcriptional activation permitting the productive elongation of RNA by previously paused Pol II. We discuss here critical regulatory mechanisms of TRIM28 in transcriptional control and DNA repair that may illuminate the novel roles of this factor in pausing and elongation of Pol II.

Transcript elongation by RNA polymerase II

Selth, L.; Sigurdsson, S.; Svejstrup, J.
Fonte: Annual Reviews Publicador: Annual Reviews
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
36.53%
Until recently, it was generally assumed that essentially all regulation of transcription takes place via regions adjacent to the coding region of a gene—namely promoters and enhancers—and that, after recruitment to the promoter, the polymerase simply behaves like a machine, quickly “reading the gene.” However, over the past decade a revolution in this thinking has occurred, culminating in the idea that transcript elongation is extremely complex and highly regulated and, moreover, that this process significantly affects both the organization and integrity of the genome. This review addresses basic aspects of transcript elongation by RNA polymerase II (RNAPII) and how it relates to other DNA-related processes.; Luke A. Selth, Stefan Sigurdsson, and Jesper Q. Svejstrup

Insights into the regulation of eukaryotic elongation factor 2 kinase and the interplay between its domains

Pigott, C.; Mikolajek, H.; Moore, C.; Finn, S.; Phippen, C.; Werner, J.; Proud, C.
Fonte: Portland Press Publicador: Portland Press
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
36.53%
eEF2K (eukaryotic elongation factor 2 kinase) is a Ca2+/CaM (calmodulin)-dependent protein kinase which regulates the translation elongation machinery. eEF2K belongs to the small group of so-called ‘α-kinases’ which are distinct from the main eukaryotic protein kinase superfamily. In addition to the α-kinase catalytic domain, other domains have been identified in eEF2K: a CaM-binding region, N-terminal to the kinase domain; a C-terminal region containing several predicted α-helices (resembling SEL1 domains); and a probably rather unstructured ‘linker’ region connecting them. In the present paper, we demonstrate: (i) that several highly conserved residues, implicated in binding ATP or metal ions, are critical for eEF2K activity; (ii) that Ca2+/CaM enhance the ability of eEF2K to bind to ATP, providing the first insight into the allosteric control of eEF2K; (iii) that the CaM-binding/α-kinase domain of eEF2K itself possesses autokinase activity, but is unable to phosphorylate substrates in trans; (iv) that phosphorylation of these substrates requires the SEL1-like domains of eEF2K; and (v) that highly conserved residues in the C-terminal tip of eEF2K are essential for the phosphorylation of eEF2, but not a peptide substrate. On the basis of these findings...

Identification of autophosphorylation sites in eukaryotic elongation factor-2 kinase

Pyr Dit Ruys, S.; Wang, X.; Smith, E.; Herinckx, G.; Hussain, N.; Rider, M.; Vertommen, D.; Proud, C.
Fonte: Portland Press Publicador: Portland Press
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
36.61%
eEF2K [eEF2 (eukaryotic elongation factor 2) kinase] phosphorylates and inactivates the translation elongation factor eEF2. eEF2K is not a member of the main eukaryotic protein kinase superfamily, but instead belongs to a small group of so-called α-kinases. The activity of eEF2K is normally dependent upon Ca2+ and calmodulin. eEF2K has previously been shown to undergo autophosphorylation, the stoichiometry of which suggested the existence of multiple sites. In the present study we have identified several autophosphorylation sites, including Thr348, Thr353, Ser366 and Ser445, all of which are highly conserved among vertebrate eEF2Ks. We also identified a number of other sites, including Ser78, a known site of phosphorylation, and others, some of which are less well conserved. None of the sites lies in the catalytic domain, but three affect eEF2K activity. Mutation of Ser78, Thr348 and Ser366 to a non-phosphorylatable alanine residue decreased eEF2K activity. Phosphorylation of Thr348 was detected by immunoblotting after transfecting wild-type eEF2K into HEK (human embryonic kidney)-293 cells, but not after transfection with a kinase-inactive construct, confirming that this is indeed a site of autophosphorylation. Thr348 appears to be constitutively autophosphorylated in vitro. Interestingly...

Molecular mechanism for the control of eukaryotic elongation factor 2 kinase by pH: role in cancer cell survival

Xie, J.; Mikolajek, H.; Pigott, C.R.; Hooper, K.J.; Mellows, T.; Moore, C.E.; Mohammed, H.; Werner, J.M.; Thomas, G.J.; Proud, C.G.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
Relevância na Pesquisa
36.53%
Acidification of the extracellular and/or intracellular environment is involved in many aspects of cell physiology and pathology. Eukaryotic elongation factor 2 kinase (eEF2K) is a Ca(2+)/calmodulin-dependent kinase that regulates translation elongation by phosphorylating and inhibiting eEF2. Here we show that extracellular acidosis elicits activation of eEF2K in vivo, leading to enhanced phosphorylation of eEF2. We identify five histidine residues in eEF2K that are crucial for the activation of eEF2K during acidosis. Three of them (H80, H87, and H94) are in its calmodulin-binding site, and their protonation appears to enhance the ability of calmodulin to activate eEF2K. The other two histidines (H227 and H230) lie in the catalytic domain of eEF2K. We also identify His108 in calmodulin as essential for activation of eEF2K. Acidification of cancer cell microenvironments is a hallmark of malignant solid tumors. Knocking down eEF2K in cancer cells attenuated the decrease in global protein synthesis when cells were cultured at acidic pH. Importantly, activation of eEF2K is linked to cancer cell survival under acidic conditions. Inhibition of eEF2K promotes cancer cell death under acidosis.; Jianling Xie, Halina Mikolajek, Craig R. Pigott...

The primary σ factor in Escherichia coli can access the transcription elongation complex from solution in vivo

Goldman, Seth R; Nair, Nikhil U; Wells, Christopher D; Nickels, Bryce E; Hochschild, Ann
Fonte: eLife Sciences Publications, Ltd Publicador: eLife Sciences Publications, Ltd
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.66%
The σ subunit of bacterial RNA polymerase (RNAP) confers on the enzyme the ability to initiate promoter-specific transcription. Although σ factors are generally classified as initiation factors, σ can also remain associated with, and modulate the behavior of, RNAP during elongation. Here we establish that the primary σ factor in Escherichia coli, σ70, can function as an elongation factor in vivo by loading directly onto the transcription elongation complex (TEC) in trans. We demonstrate that σ70 can bind in trans to TECs that emanate from either a σ70-dependent promoter or a promoter that is controlled by an alternative σ factor. We further demonstrate that binding of σ70 to the TEC in trans can have a particularly large impact on the dynamics of transcription elongation during stationary phase. Our findings establish a mechanism whereby the primary σ factor can exert direct effects on the composition of the entire transcriptome, not just that portion that is produced under the control of σ70-dependent promoters. DOI: http://dx.doi.org/10.7554/eLife.10514.001

Influencia de la elongación transcripcional sobre el splicing alternativo; Influence of transcriptional elongation on alternative splicing

Nogués, Guadalupe
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2004 SPA
Relevância na Pesquisa
36.53%
El splicing alternativo de los pre-mRNAs es un mecanismo fundamental de las células eucariotas, que permite generar una gran diversidad proteica a partir de un número relativamente pequeño de genes. Desde hace unos años se sabe que las reacciones de procesamiento de los pre-mRNAs tales como la adición de una caperuza o cap en el extremo 5', el splicing de intrones, y el corte y poliadenilación en el extremo 3', no sólo ocurren cotranscripcionalmente, sino que todos estos procesos estin acoplados funcionalmente entre si. Esto llevó a proponer una posible influencia de la transcripción sobre todos ellos. En particular, nuestro grupo demostró en 1997 que si se cambian los promotores que dirigen la transcripción de un minigén de fibronectina humana, se modifica el patrón de splicing del exón alternativo EDI. En esta tesis continuamos con esta línea de investigación, y nos preguntamos si la modulación de la capacidad de la RNA polimerasa II (Pol II) de elongar a través de pausas del molde, también llamada procesividad, puede modificar el splicing alternativo de EDI. Para responder esto, estudiamos el efecto, sobre el splicing alternativo, de distintos activadores transcripcionales capaces de estimular la iniciación y/o la elongación transcriptional. Además...

Impairment of transcription elongation by R-loops in vitro

Tous, Cristina; Aguilera, Andrés
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
Relevância na Pesquisa
36.66%
PMID: 17603014.-- Final version of the paper available at: http://www.sciencedirect.com/science/journal/0006291X; Transcription elongation causes a local change in DNA superhelicity. An excess of negative supercoiling may lead to opening of DNA strands that could allow formation of R-loops. In yeast, mutants of the THO complex are impaired in transcription elongation and this defect has been linked to co-transcriptional formation of R-loops, which could constitute roadblocks for RNA polymerases. In this study, we found that stably formed 300-nt long DNA–RNA hybrids in a negatively supercoiled transcription template reduced the efficiency of transcription elongation by half, providing a first experimental evidence that transcription elongation is impaired by R-loops in vitro.; This work was supported by grants of the Spanish Ministry of Science and Education (GEN2001-4707-C08-02 and SAF2003-00204) and Junta de Andalucía (CVI102).; Peer reviewed

Wall architecture in the cellulose-deficient rsw 1 mutant of Arabidopsis thaliana: Microfibrils but not microtubules lose their transverse alignment before microfibrils become unrecognizable in the mitotic and elongation zones of roots

Sugimoto, K; Williamson, Richard; Wasteneys, Geoffrey
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.66%
The rsw1 mutant of Arabidopsis thaliana has a single amino acid substitution in a putative glycosyl transferase that causes a temperature-dependent reduction in cellulose production. We used recently described methods to examine root growth by surface marker particles, cell wall structure by field emission scanning electron microscopy and microtubule alignment by immunofluorescence after the mutant is transferred to its restrictive temperature. We find that raising the temperature quickly accelerates root elongation in both wild type and mutant, presumably as a result of general metabolic stimulation, but that in the mutant, the rate declines within 7-8 h and elongation almost ceases after 24 h. Radial swelling begins at about 6 h in the mutant and root diameter continues to increase until about 24 h. The normal transverse alignment of microfibrils is severely impaired in the mutant after 8 h, and chemical inhibition of cellulose synthesis by 2,6-dichlorobenzonitrile causes a similar loss of orientation. After 24 h, microfibrils are not clearly visible in the walls of cells that would have been in the mitotic and early-elongation zone of wild-type roots. Changes in older cells are less marked; loss of transverse microfibril orientation occurs without disruption to the transverse orientation of cortical microtubules. The wild type shows none of the changes except for acceleration of elongation...

Behaviour of enzymatic activities and root elongation in Argiudoll soils from the Argentine Humid Pampa treated with biosolids

Perotti,E.B.R.; Pidello,A.; Leyendeker,L.; Trasar-Cepeda,C.; Leirós,M.C.; Gil-Sotres,F.
Fonte: Revista argentina de microbiología Publicador: Revista argentina de microbiología
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
Relevância na Pesquisa
36.53%
The incorporation of biosolids to soil is a strategy aiming at the re-location of these materials in the environment with a useful end: soil fertilization. In this work, the response of two Argiudoll soils (one with more than 100 years of agriculture and the other, a virgin one) to biosolid incorporation was studied under laboratory conditions. To measure this response, soil enzymatic biodescriptors, such as dehydrogenase and urease activities, and tests related to plant physiology (the root elongation test) were employed. The addition of the biosolid to both soils had a stimulating effect though different on each soil according to the added dose. Adjustment of the regression line for dehydrogenase activity with root elongation was positive and statistically significant (p<0.001). Results suggest that biodescriptors employed were suitable for studying the impact of amended biosolids on different soils.

It’s All About Sex: What urban Zimbabwean men know of labia minora elongation

Pérez,Guillermo Martínez; Aznar,Concepción Tomás; Namulondo,Harriet
Fonte: Centro de Estudos Internacionais Publicador: Centro de Estudos Internacionais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
36.66%
Labia minora elongation is one of the vaginal practices that some Zimbabwean women engage in during the pre-menarche age. This practice has not been thoroughly investigated in Zimbabwe. The objective of this study is to learn about the knowledge, attitudes and perceptions of urban Zimbabwean men towards labia minora elongation. A qualitative study was conducted in Chitungwiza, Harare, in 2012. Thirty-one adult men were interviewed. Data was collected on men’s understanding of the procedure, motivations, its relevance for marriage and sexual life, and its implications on health. The findings demonstrate that labia minora elongation is recognized in Zimbabwe as a practice that enhances the sexual pleasure for both male and female partners, and that there are no perceived harms to women’s health. More research is necessary to better understand the role of labia minora elongation in sexuality and acceptance of HIV/STI barrier methods.