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2.
J Prev Alzheimers Dis ; 8(2): 218-223, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33569570

RESUMO

BACKGROUND/OBJECTIVES: Elenbecestat, an oral BACE-1 inhibitor that has been shown to reduce Aß levels in cerebrospinal fluid, was investigated in two global phase 3 studies in early AD. Here we report on differences observed in characteristics of APOE ε4 and amyloid positive subjects in the large screening cohort. DESIGN: Screening was performed in 5 sequential tiers over a maximum of 80 days, as part of placebo controlled, double blind phase 3 studies. SETTING: Subjects were evaluated at sites in 7 regions (29 countries). PARTICIPANTS: Overall, 9758 subjects were screened. INTERVENTION: All screened subjects that were eligible received either placebo or 50 mg QID elenbecestat post randomisation. MEASUREMENTS: Gender, disease staging, APOE ε4 status, amyloid status, amyloid positron emission tomography (PET) standard uptake value ratio (SUVr) and amyloid PET Centiloid (CL) values were determined for screened subjects; by country and region. RESULTS: In this program, 44% of subjects were APOE ε4 positive. Frequency of females was similar in both APOE ε4 positive and negative groups. However, early mild AD subjects were slightly higher in the APOE ε4 positive group compared with the APOE ε4 negative group. 56% of subjects were amyloid positive. The mean age in the amyloid positive group was slightly higher than the amyloid negative group. The gender distribution was similar between amyloid groups. A lower number of mild cognitive impairment was observed in the amyloid positive group along with a higher number of early mild AD. APOE ε4 positive subjects were higher in amyloid positive group compared to the amyloid negative group. China had the lowest APOE ε4 and amyloid positivity rates with Western Europe and Oceania performing best. Subjects received florbetapir, florbetaben or flutemetamol amyloid PET tracer. Amyloid negative and positive subjects CL values were normally distributed around their respective means of 1.5 CL and 83 CL. However, there was an appreciable overlap in the 20-40 CL range. CONCLUSIONS: In this large cohort of cognitively impaired subjects, subject demographics characteristics were comparable regardless of APOE genotype or amyloid positivity. APOE ε4 positivity and amyloid positivity varied by country and by geographical region.


Assuntos
Amiloide/metabolismo , Compostos de Anilina/uso terapêutico , Apolipoproteína E4/líquido cefalorraquidiano , Disfunção Cognitiva/tratamento farmacológico , Etilenoglicóis/uso terapêutico , Amiloide/efeitos dos fármacos , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Apolipoproteína E4/genética , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/metabolismo , Feminino , Genótipo , Humanos , Masculino , Tomografia por Emissão de Pósitrons/métodos
3.
Theor Appl Genet ; 133(1): 365, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31637458

RESUMO

The above-mentioned article was published in 2015 with an error in the reverse primer sequence for the PPOA2d1074 marker, which made amplification difficult. The reverse primer was missing a thymine nucleotide at the thirteenth position (GCGGTGCTTCACTTGGT).

5.
Plant Genome ; 10(2)2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28724083

RESUMO

The wheat stem sawfly (WSS) is an economically important pest of wheat in the Northern Great Plains. The primary means of WSS control is resistance associated with the single quantitative trait locus (QTL) , which controls most stem solidness variation. The goal of this study was to identify stem solidness candidate genes via RNA-seq. This study made use of 28 single nucleotide polymorphism (SNP) makers derived from expressed sequence tags (ESTs) linked to contained within a 5.13 cM region. Allele specific expression of EST markers was examined in stem tissue for solid and hollow-stemmed pairs of two spring wheat near isogenic lines (NILs) differing for the QTL. Of the 28 ESTs, 13 were located within annotated genes and 10 had detectable stem expression. Annotated genes corresponding to four of the ESTs were differentially expressed between solid and hollow-stemmed NILs and represent possible stem solidness gene candidates. Further examination of the 5.13 cM region containing the 28 EST markers identified 260 annotated genes. Twenty of the 260 linked genes were up-regulated in hollow NIL stems, while only seven genes were up-regulated in solid NIL stems. An -methyltransferase within the region of interest was identified as a candidate based on differential expression between solid and hollow-stemmed NILs and putative function. Further study of these candidate genes may lead to the identification of the gene(s) controlling stem solidness and an increased ability to select for wheat stem solidness and manage WSS.


Assuntos
Perfilação da Expressão Gênica , Genes de Plantas , Caules de Planta/genética , Triticum/genética , Alelos , Etiquetas de Sequências Expressas , Polimorfismo de Nucleotídeo Único
6.
Osteoporos Int ; 27(12): 3439-3447, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27368699

RESUMO

We analysed the impact of a standardized order set empowering staff nurses to independently manage a Fracture Liaison Service over a 9-month period. Nurses identified between 30 and 70 % of non-hip fragility fractures to the unit in charge of management over time. The latter managed 58 % of referred patients. INTRODUCTION: The main goal of this study was to evaluate the impact of a standardized order set empowering nurses to independently manage a fracture liaison service (FLS). METHODS: Since November 2014, an order set allowed nurses of a Montreal hospital, Quebec, Canada to entirely manage an FLS on their own. Nurses followed an 6-h training program on-site. Emergency department (ED) and orthopaedic outpatient clinic (OC) nurses identified non-hip fragility fractures. Medical day treatment unit (MDTU) nurses were in charge of the management (investigation and treatment initiation). The list of patients, 50 years and older, with a fracture were retrieved for the period of November 2014 to July 2015. Performance was assessed with the rate of identification over time and the rate of management of non-hip fragility fractures. RESULTS: Over the 9-month period, 346 patients of ≥50 years old were seen for a fracture, of which 190 met fragility criteria (excluding hip fractures). A sinusoid pattern of rates of identification between 30-70 % was observed over time. An average proportion of 58.1 % of fracture patients were managed by MDTU nurses. CONCLUSIONS: A standardized order set legally allowing nurses to manage an FLS led to identification rates varying from 30-70 % and a management rate close to 60 % for referred patients over a 9-month period, which largely exceeds that of standard care. Identification was mostly compromised by difficulty integrating the order set into routine practice. Enforcement of the hospital policy on fragility fractures could help yield efficiency of identification of osteoporosis-related fractures by the staff.


Assuntos
Fraturas por Osteoporose/enfermagem , Fraturas por Osteoporose/terapia , Avaliação de Processos em Cuidados de Saúde , Humanos , Recursos Humanos de Enfermagem Hospitalar , Osteoporose , Quebeque
7.
Plant Dis ; 100(6): 1192-1201, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30682280

RESUMO

Fusarium head blight (FHB) is a fungal disease of wheat (Triticum aestivum L.) causing frequent economic losses to farmers under growing conditions of Eastern Canada. To assess risks associated with this disease and guide fungicide use decisions, many researchers from numerous countries have developed weather-based forecasting models. This work aims at evaluating which model produces the most accurate predictions of disease infection or deoxynivalenol (DON) content under climatic conditions occurring in Quebec. Spring wheat was grown during two seasons and winter wheat during one season at four experimental sites located in Quebec. Nine selected models for evaluation produced predictions of DON content (Canada and Italy), disease incidence (Argentina and Italy), and probability of epidemics (United States). Data from plots without fungicide (52 samples) were used to test the models listed above. Reliability of the selected forecasting models was evaluated with receiver operating characteristic (ROC) curve analysis. DON content (≥1 ppm) was the best crop damage indicator to differentiate epidemic (cases) and nonepidemic (controls) situations. Two American and the Argentinean forecasting models were more reliable than the others when the thresholds recommended in the literature were adjusted using the results for the ROC curve analyses. Those models are a good starting point for the implementation of an FHB forecasting system adapted to wheat production in Quebec.

9.
Theor Appl Genet ; 128(8): 1605-15, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25982131

RESUMO

KEY MESSAGE: Characterized novel mutations present at Ppo loci account for the substantial reduction of the total kernel PPO activity present in a putative null Ppo - A1 genetic background. Wheat (Triticum aestivum) polyphenol oxidase (PPO) contributes to the time-dependent discoloration of Asian noodles. Wheat contains multiple paralogous and orthologous Ppo genes, Ppo-A1, Ppo-D1, Ppo-A2, Ppo-D2, and Ppo-B2, expressed in wheat kernels. To date, wheat noodle color improvement efforts have focused on breeding cultivars containing Ppo-D1 and Ppo-A1 alleles conferring reduced PPO activity. A major impediment to wheat quality improvement is a lack of additional Ppo alleles conferring reduced kernel PPO. In this study, a previously reported very low PPO line, 07OR1074, was found to contain a novel allele at Ppo-A2 and null alleles at the Ppo-A1 and Ppo-D1 loci. To examine the impact of each mutation upon kernel PPO, populations were generated from crosses between 07OR1074 and the hard white spring wheat cultivars Choteau and Vida. Expression analysis using RNA-seq demonstrated no detectable Ppo-A1 transcripts in 07OR1074 while Ppo-D1 transcripts were present at less than 10% of that seen in Choteau and Vida. Novel markers specific for the Ppo-D1 and Ppo-A2 mutations discovered in 07OR1074, along with the Ppo-A1 STS marker, were used to screen segregating populations. Evaluation of lines indicated a substantial genotypic effect on PPO with Ppo-A1 and Ppo-D1 alleles contributing significantly to total PPO in both populations. These results show that the novel mutations in Ppo-A1 and Ppo-D1 present in 07OR1074 are both important to lowering overall wheat seed PPO activity and may be useful to produce more desirable and marketable wheat-based products.


Assuntos
Catecol Oxidase/genética , Mutação , Sementes/enzimologia , Triticum/genética , Alelos , Cruzamento , Catecol Oxidase/metabolismo , Cruzamentos Genéticos , DNA de Plantas/genética , Marcadores Genéticos , Triticum/enzimologia
10.
Br J Pharmacol ; 172(7): 1769-82, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25521311

RESUMO

BACKGROUND AND PURPOSE: Selective agonists of the sigma-1 receptor (σ1 protein) are generally reported to protect against neuronal damage and modulate oligodendrocyte differentiation. Human and rodent lymphocytes possess saturable, high-affinity binding sites for compounds binding to the σ1 protein and potential immunomodulatory properties have been described for σ1 protein ligands. Experimental autoimmune encephalomyelitis (EAE) is recognized as a valuable model of the inflammatory aspects of multiple sclerosis (MS). Here, we have assessed the role of a σ1 protein agonist, containing the tetrahydroisoquinoline-hydantoin structure, in EAE. EXPERIMENTAL APPROACH: EAE was induced in SJL/J female mice by active immunization with myelin proteolipid protein (PLP)139-151 peptide. The σ1 protein agonist was injected i.p. at the time of immunization (day 0). Disease severity was assessed clinically and by histopathological evaluation of the CNS. Phenotyping of B-cell subsets and regulatory T-cells were performed by flow cytometry in spleen and cervical lymph nodes. KEY RESULTS: Prophylactic treatment of EAE mice with the σ1 protein agonist prevented mononuclear cell accumulation and demyelination in brain and spinal cord and increased T2 B-cells and regulatory T-cells, resulting in an overall reduction in the clinical progression of EAE. CONCLUSIONS AND IMPLICATIONS: This σ1 protein agonist, containing the tetrahydroisoquinoline-hydantoin structure, decreased the magnitude of inflammation in EAE. This effect was associated with increased proportions of B-cell subsets and regulatory T-cells with potential immunoregulatory functions. Targeting of the σ1 protein might thus provide new therapeutic opportunities in MS.


Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Esclerose Múltipla/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Receptores sigma/agonistas , Animais , Linfócitos B/imunologia , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Citocinas/sangue , Encefalomielite Autoimune Experimental/sangue , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Feminino , Imunoglobulina G/sangue , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Camundongos , Esclerose Múltipla/sangue , Esclerose Múltipla/imunologia , Esclerose Múltipla/patologia , Proteína Proteolipídica de Mielina/imunologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/imunologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Baço/efeitos dos fármacos , Baço/imunologia , Linfócitos T Reguladores/imunologia , Receptor Sigma-1
12.
Genes Immun ; 14(2): 115-26, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23328844

RESUMO

Transforming growth factor-ß (TGF-ß) maintains self-tolerance through a constitutive inhibitory effect on T-cell reactivity. In most physiological situations, the tolerogenic effects of TGF-ß depend on the canonical signaling molecule Smad3. To characterize how TGF-ß/Smad3 signaling contributes to maintenance of T-cell tolerance, we characterized the transcriptional landscape downstream of TGF-ß/Smad3 signaling in resting or activated CD4 T cells. We report that in the presence of TGF-ß, Smad3 modulates the expression of >400 transcripts. Notably, we identified 40 transcripts whose expression showed Smad3 dependence in both resting and activated cells. This 'signature' confirmed the non-redundant role of Smad3 in TGF-ß biology and identified both known and putative immunoregulatory genes. Moreover, we provide genomic and functional evidence that the TGF-ß/Smad3 pathway regulates T-cell activation and metabolism. In particular, we show that TGF-ß/Smad3 signaling dampens the effect of CD28 stimulation on T-cell growth and proliferation. The impact of TGF-ß/Smad3 signals on T-cell activation was similar to that of the mTOR inhibitor Rapamycin. Considering the importance of co-stimulation on the outcome of T-cell activation, we propose that TGF-ß-Smad3 signaling may maintain T-cell tolerance by suppressing co-stimulation-dependent mobilization of anabolic pathways.


Assuntos
Antígenos CD28/metabolismo , Linfócitos T CD4-Positivos/fisiologia , Transdução de Sinais , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Linfócitos T CD4-Positivos/metabolismo , Proliferação de Células , Imunossupressores/farmacologia , Ativação Linfocitária , Camundongos , Camundongos Knockout , Sirolimo/farmacologia , Proteína Smad3/genética , Serina-Treonina Quinases TOR/antagonistas & inibidores
13.
Rev Neurol (Paris) ; 166(1): 96-9, 2010 Jan.
Artigo em Francês | MEDLINE | ID: mdl-19394988

RESUMO

INTRODUCTION: Near 10 to 20% of patients with myositis have another systemic, sometimes inaugural, disease. CASE REPORT: A 48-year-old woman was admitted with progressive hypoesthesia in V2 and V3 areas on both sides, difficulties to chew and swallow and then, proximal and axial muscular deficiency, with weight loss. Brain MRI showed gadolinium-enhanced trigeminal nerves and biological tests revealed anti-SSA and anti-Pm/Scl antibodies and a grade IV in Chisholm scoring system on the labial salivary gland biopsy. Neurophysiological studies revealed a myogenic pattern on tibialis anterior muscles and a muscle biopsy confirmed the diagnosis of polymyositis. CONCLUSION: The diagnosis of primitive Sjogren's syndrome was suspected because of the association of bilateral trigeminal neuropathy and anti-SSA and anti-Pm/Scl antibodies.


Assuntos
Polimiosite/complicações , Síndrome de Sjogren/complicações , Anticorpos/análise , Autoanticorpos/análise , Complexo CD3/análise , Complemento C5b/imunologia , Transtornos de Deglutição/complicações , Feminino , Lateralidade Funcional/fisiologia , Antígeno HLA-A1/análise , Humanos , Imageamento por Ressonância Magnética , Meninges/patologia , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Exame Neurológico , Doenças Neuromusculares/complicações , Polimiosite/patologia , Glândulas Salivares/patologia , Síndrome de Sjogren/patologia , Nervo Trigêmeo/patologia , Neuralgia do Trigêmeo/patologia
14.
Genetics ; 183(3): 853-60, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19752217

RESUMO

In planta analysis of protein function in a crop plant could lead to improvements in understanding protein structure/function relationships as well as selective agronomic or end product quality improvements. The requirements for successful in planta analysis are a high mutation rate, an efficient screening method, and a trait with high heritability. Two ideal targets for functional analysis are the Puroindoline a and Puroindoline b (Pina and Pinb, respectively) genes, which together compose the wheat (Triticum aestivum L.) Ha locus that controls grain texture and many wheat end-use properties. Puroindolines (PINs) together impart soft texture, and mutations in either PIN result in hard seed texture. Studies of the PINs' mode of action are limited by low allelic variation. To create new Pin alleles and identify critical function-determining regions, Pin point mutations were created in planta via EMS treatment of a soft wheat. Grain hardness of 46 unique PIN missense alleles was then measured using segregating F(2):F(3) populations. The impact of individual missense alleles upon PIN function, as measured by grain hardness, ranged from neutral (74%) to intermediate to function abolishing. The percentage of function-abolishing mutations among mutations occurring in both PINA and PINB was higher for PINB, indicating that PINB is more critical to overall Ha function. This is contrary to expectations in that PINB is not as well conserved as PINA. All function-abolishing mutations resulted from structure-disrupting mutations or from missense mutations occurring near the Tryptophan-rich region. This study demonstrates the feasibility of in planta functional analysis of wheat proteins and that the Tryptophan-rich region is the most important region of both PINA and PINB.


Assuntos
Mutação de Sentido Incorreto , Proteínas de Plantas/genética , Sementes/genética , Triticum/genética , Sequência de Aminoácidos , Sequência Conservada/genética , Grão Comestível/genética , Grão Comestível/normas , Metanossulfonato de Etila/toxicidade , Evolução Molecular , Genótipo , Dados de Sequência Molecular , Mutagênese/efeitos dos fármacos , Fenótipo , Homologia de Sequência de Aminoácidos , Triptofano/genética
15.
Genes Immun ; 10(2): 192-6, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19129849

RESUMO

As a key component of the transforming growth factor-beta (TGF-beta) pathway, SMAD3 plays an essential role in development and maintenance of self-tolerance. Furthermore, a recent study based on gene-expression profiling in donors of allogeneic hematopoietic cell grafts revealed that the level of expression of several components of the TGF-beta pathway can predict the occurrence of graft-versus-host disease (GVHD) in recipients. The gene with the best GVHD predictive accuracy was SMAD3: no recipients suffered from GVHD when their donor cells expressed high levels of SMAD3 transcripts. The present study had two specific aims: to validate differential expression of SMAD3 transcripts in an independent and larger cohort of subjects and to determine whether interindividual differences were dictated by cis-acting genetic elements. In a cohort of 397 subjects, we found that SMAD3 transcript levels varied over a sixfold range. Analyses of SMAD3 single nucleotide polymorphisms and of SMAD3 promoter methylation patterns provide compelling evidence that interindividual differences in SMAD3 transcript levels do not result from in-cis genetic variations. Of note, part of the variance in SMAD3 expression was gender related as women expressed lower levels of SMAD3 transcripts than men.


Assuntos
Regulação da Expressão Gênica/fisiologia , Doadores Vivos , Caracteres Sexuais , Proteína Smad3/biossíntese , Estudos de Coortes , Metilação de DNA/genética , Feminino , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Proteína Smad3/genética , Fator de Crescimento Transformador beta/metabolismo , Transplante Homólogo
16.
Theor Appl Genet ; 118(2): 247-57, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18846362

RESUMO

The Hardness (Ha) locus controls grain texture and affects many end-use properties of wheat (Triticum aestivum L.). The Ha locus is functionally comprised of the Puroindoline a and b genes, Pina and Pinb, respectively. The lack of Pin allelic diversity is a major factor limiting Ha functional analyses and wheat quality improvement. In order to create new Ha alleles, a 630 member M(2) population was produced in the soft white spring cultivar Alpowa using ethylmethane sulfonate mutagenesis. The M(2) population was screened to identify new alleles of Pina and Pinb. Eighteen new Pin alleles, including eight missense alleles, were identified. F(2) populations for four of the new Pin alleles were developed after crossing each back to non-mutant Alpowa. Grain hardness was then measured on F(2:3) seeds and the impact of each allele on grain hardness was quantified. The tested mutations were responsible for between 28 and 94% of the grain hardness variation and seed weight and vigor of all mutation lines was restored among the F(2) populations. Selection of new Pin alleles following direct phenotyping or direct sequencing is a successful approach to identify new Ha alleles useful in improving wheat product quality and understanding Ha locus function.


Assuntos
Alelos , Proteínas de Plantas/genética , Triticum/genética , Metanossulfonato de Etila , Genótipo , Mutagênese , Mutação , Fenótipo , Proteínas de Plantas/química , Proteínas de Plantas/fisiologia
17.
Neurology ; 67(12): 2206-10, 2006 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-17190945

RESUMO

BACKGROUND: Polymorphisms in the glutathione S-transferase pi gene (GSTP1), encoding GSTP1-1, a detoxification enzyme, may increase the risk of Parkinson disease (PD) with exposure to pesticides. Using the GenePD Study sample of familial PD cases, we explored whether GSTP1 polymorphisms were associated with the age at onset of PD symptoms and whether that relation was modified by exposure to herbicides. METHODS: Seven single-nucleotide polymorphisms (SNPs) were genotyped and tested for association with PD onset age in men in three strata: no exposure to herbicides, residential exposure to herbicides, and occupational exposure to herbicides. Haplotypes were similarly evaluated in stratified analyses. RESULTS: Three SNPs were associated with PD onset age in the group of men occupationally exposed to herbicides. Three additional SNPs had significant trends for the association of PD onset age across the herbicide exposure groups. Haplotype results also provided evidence that the relation between GSTP1 and onset age is modified by herbicide exposure. One haplotype was associated with an approximately 8-years-earlier onset in the occupationally exposed group and a 2.8-years-later onset in the nonexposed group. CONCLUSIONS: Herbicide exposure may be an effect modifier of the relation between glutathione S-transferase pi gene polymorphisms and onset age in familial PD.


Assuntos
Glutationa S-Transferase pi/genética , Herbicidas/efeitos adversos , Doenças Profissionais/induzido quimicamente , Doenças Profissionais/genética , Exposição Ocupacional/efeitos adversos , Doença de Parkinson Secundária/genética , Medição de Risco/métodos , Suscetibilidade a Doenças/induzido quimicamente , Feminino , Predisposição Genética para Doença/genética , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson Secundária/induzido quimicamente , Fatores de Risco
18.
Theor Appl Genet ; 113(8): 1563-70, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16988815

RESUMO

The tightly linked puroindoline genes, Pina and Pinb, control grain texture in wheat, with wild type forms of both giving soft, and a sequence alteration affecting protein expression or function in either giving rise to hard wheat. Previous experiments have shown that addition of wild type Pina in the presence of mutated Pinb gave intermediate grain texture but addition of wild type Pinb gave soft grain. This raises questions as to whether Pina may be less functional than Pinb. Our goal here was to develop and characterize wheat lines expressing the wild type Pina-D1a sequence in hard wheat with the null mutation (Pina-D1b) for Pina. Three transgenic lines plus Bobwhite were evaluated in two environments. Grain texture, grain protein, and kernel weight were determined for the transgenic lines and Bobwhite. The three transgenic lines had soft phenotype, and none of the transgenic lines differed from Bobwhite for grain protein or kernel weight. The soft phenotype was accompanied by increases in Pina transcript accumulation. Total Triton X-114 extractable PINA and PINB increased from 2.5 to 5.5 times those from a soft wheat reference sample, and friabilin, PINA and PINB bound to starch, increased from 3.8 to 7.8 times those of the soft wheat reference. Bobwhite showed no starch bound PINA, but transgenic lines had levels from 5.3 to 13.7 times those of the soft wheat reference sample. Starch bound PINB in transgenic lines also increased from 0.9 to 2.5 times that for the soft wheat reference sample. The transgenic expression of wild type Pina sequence in the Pina null genotype gave soft grain with the characteristics of soft wheat including increased starch bound friabilin. The results support the hypothesis that both wild type Pin genes need to be present for friabilin formation and soft grain.


Assuntos
Genes de Plantas/fisiologia , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas/anatomia & histologia , Triticum/anatomia & histologia , Triticum/genética , Alelos , Teste de Complementação Genética , Octoxinol , Fenótipo , Proteínas de Plantas/análise , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Polietilenoglicóis/química , Transcrição Gênica , Transformação Genética , Triticum/química
19.
J Anim Sci ; 84(3): 641-50, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16478956

RESUMO

Starch is the primary nutrient in ruminant diets used to promote high levels of performance. The site of starch digestion alters the nature of digestive end products (VFA in the rumen vs. glucose in the small intestine) and the efficiency of use. Cereal grain endosperm texture plays a major role in the rate and extent of starch degradation in ruminants. Wheat grain texture is regulated by the starch surface protein complex friabilin that consists primarily of puroindoline (PIN) A and B. Soft kernel texture in wheat is a result of both PIN genes being in the wild type active form and bound to starch. The objective of this study was to investigate the effect of varying PIN content in wheat on the rate of starch digestion in the rumen of beef cattle. In Exp. 1, 6 transgenic soft pin a/b isolines created in a hard wheat background, and 2 hard wheat controls were milled to yield a wide range of mean particle sizes across all lines. Milled samples were incubated in situ for 3 h. Increased expression of both PINA and PINB decreased DM digestibility (DMD) by 29.2% (P < 0.05) and decreased starch digestibility by 30.8% (P < 0.05). Experiment 2 separated the effects of particle size and total PIN content on digestion by milling the hardest and softest lines such that the mean particle size was nearly identical. Increased PIN decreased DMD by 21.7% (P < 0.05) and starch digestibility by 19.9% (P < 0.05) across particle sizes smaller than whole kernel. Experiment 3 addressed the time course of PIN effects in the rumen by observing ground samples of the hardest and softest lines over a 12-h in situ period. Increased PIN decreased DMD by 10.4% (P < 0.05) and starch digestibility by 11.0% (P < 0.05) across all time points. Dry matter and starch digestibility results demonstrated that increased expression of PIN was associated with a decreased rate of ruminal digestion independent of particle size. Puroindolines seem to aid in the protection of starch molecules from microbial digestion in the rumen, potentially increasing the amount of starch entering the small intestine.


Assuntos
Bovinos/metabolismo , Proteínas de Plantas/metabolismo , Rúmen/metabolismo , Amido/metabolismo , Triticum/metabolismo , Animais , Manipulação de Alimentos/métodos , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Amido/ultraestrutura , Fatores de Tempo , Triticum/química , Triticum/classificação , Triticum/genética
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