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1.
Thorax ; 70(6): 595-7, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25616486

RESUMEN

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.


Asunto(s)
Envejecimiento , Desarrollo Infantil , Enfermedad Crónica/prevención & control , Desarrollo Fetal , Adulto , Anciano , Enfermedad de Alzheimer/prevención & control , Asma/prevención & control , Depresión/prevención & control , Diabetes Mellitus/prevención & control , Conducta Alimentaria , Femenino , Humanos , Hipersensibilidad/prevención & control , Lactante , Recién Nacido , Auditoría Médica , Persona de Mediana Edad , Osteoporosis/prevención & control , Factores de Riesgo
2.
Gene Ther ; 19(1): 109-13, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21677690

RESUMEN

Coagulation factor X (FX)-binding ablated adenovirus type 5 (Ad5) vectors have been genetically engineered to ablate the interaction with FX, resulting in substantially reduced hepatocyte transduction following intravenous administration in rodents. Here, we quantify viral genomes and gene transfer mediated by Ad5 and FX-binding-ablated Ad5 vectors in non-human primates. Ad5 vectors accumulated in and mediated gene transfer predominantly to the liver, whereas FX-binding-ablated vectors primarily targeted the spleen but showed negligible liver gene transfer. In addition, we show that Ad5 binding to hepatocytes may be due to the presence of heparan sulfate proteoglycans (HSPGs) on the cell membrane. Therefore, the Ad5-FX-HSPG pathway mediating liver gene transfer in rodents is also the mechanism underlying Ad5 hepatocyte transduction in Microcebus murinus.


Asunto(s)
Adenoviridae/genética , Factor X/metabolismo , Técnicas de Transferencia de Gen , Genoma Viral , Adenoviridae/metabolismo , Animales , Membrana Celular/metabolismo , Cheirogaleidae , Factor X/genética , Marcación de Gen/métodos , Terapia Genética , Vectores Genéticos/administración & dosificación , Vectores Genéticos/genética , Vectores Genéticos/metabolismo , Proteoglicanos de Heparán Sulfato/metabolismo , Hepatocitos/citología , Hepatocitos/metabolismo , Inmunohistoquímica , Hígado/citología , Hígado/metabolismo , Unión Proteica , Bazo/citología , Bazo/metabolismo
3.
J Mol Biol ; 177(1): 33-51, 1984 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-6379196

RESUMEN

Forward mutations induced by the ultimate carcinogen N-acetoxy-N-2-acetylaminofluorene (N-Aco-AAF) in the tetracycline resistance gene carried on plasmid pBR322 are shown to be dependent upon the induction of the host SOS functions in wild-type and umuC Escherichia coli cells. The mutation frequency in the umuC strain is equal to about 40% of the mutation frequency observed in the umu+ background. In the excision-repair-deficient uvrA mutant strain the mutagenic response is the same as in SOS-induced wild-type cells whether or not the uvrA bacteria are SOS-induced. Equal mutation frequencies are obtained in both the wild-type and the uvrA strains for equal modification levels although the survival of AAF-modified plasmid DNA is greatly reduced in the uvrA strain as compared to the wild-type strain. Sequence analysis of the mutations reveals that more than 90% of the N-Aco-AAF-induced mutations are frameshift mutations. Two types of mutational hotspots are observed occurring either at repetitive sequences or at non-repetitive sequences. Both types of mutants appear at similar locations and frequencies in both the wild-type and the uvrA strains. On the other hand, only the non-repetitive sequence mutants are obtained in the umuC background. These non-repetitive sequence mutants preferentially occur within the sequence 5' G-G-C-G-C-C 3' (the NarI restriction enzyme recognition sequence). The analysis of the -AAF binding spectrum to the same DNA fragment shows that there is no direct correlation between the modification spectrum and the mutation spectrum. We suggest that certain sequences are "mutation-prone" in the sense that only these sequences can be efficiently mutated as the result of an active processing mediated by specific proteins. When a sequence is said to be mutation-prone it probably corresponds to a particular structure that is induced within this sequence as a result of the binding to the DNA of the mutagen. This sequence-specific conformational change is the substrate for the protein(s) that fixes the mutation. The mutagenic processing pathway(s) is part of the cellular response to DNA-damaging agents (the so-called SOS response). Two pathways for frameshift mutagenesis are suggested by the data: an umuC-dependent pathway, which is involved in the mutagenic processing of lesions within repetitive sequences; an umuC-independent pathway responsible for the fixation of mutations within specific non-repetitive sequences.


Asunto(s)
2-Acetilaminofluoreno/análogos & derivados , Acetoxiacetilaminofluoreno/farmacología , Escherichia coli/efectos de los fármacos , Mutación , Secuencia de Bases , Reparación del ADN , ADN Bacteriano/genética , Escherichia coli/genética , Escherichia coli/efectos de la radiación , Plásmidos/efectos de los fármacos , Plásmidos/efectos de la radiación , Secuencias Repetitivas de Ácidos Nucleicos , Especificidad de la Especie , Rayos Ultravioleta
4.
Neurobiol Aging ; 22(1): 79-88, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11164279

RESUMEN

According to one of the theories formulated to explain the etiology of Alzheimer's disease (AD), amylosis may reflect a specific inflammatory response. Two inflammatory proteins, lithostathine and PAP, were evidenced by immunohistochemistry in senile plaques and neurofibrillary tangles of patients with AD. In addition, lithostathine and PAP were significantly increased in the cerebrospinal fluid of patients with AD when compared to patients with multiple sclerosis, another inflammatory disease, and to normal control subjects. However, no correlation was observed with age of occurrence. Furthermore, lithostathine and PAP were increased even at the very early stages of AD, and their level remained elevated during the course of the AD unlike TNFalpha whose level, very high at very early stages, regularly decreased. Finally, if part of lithostathine and PAP are synthesized in the brain, a large part comes from serum by passage over the blood-brain barrier. These results indicate (i) the existence of an acute phase response followed by a chronic inflammation in AD, and (ii) that lithostathine and PAP are involved even at the first pre-clinical biochemical events of AD. In addition, because lithostathine undergoes an autolytic cleavage leading to its precipitation and the formation of fibrils, we believe that it may be involved in amyloidosis and tangles by allowing heterogeneous precipitation of other proteins.


Asunto(s)
Proteínas de Fase Aguda/líquido cefalorraquídeo , Enfermedad de Alzheimer/líquido cefalorraquídeo , Antígenos de Neoplasias , Biomarcadores de Tumor , Proteínas de Unión al Calcio/líquido cefalorraquídeo , Lectinas Tipo C , Proteínas del Tejido Nervioso , Ovillos Neurofibrilares/metabolismo , Placa Amiloide/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/sangre , Proteínas de Unión al Calcio/sangre , Distribución de Chi-Cuadrado , Citocinas/líquido cefalorraquídeo , Humanos , Litostatina , Persona de Mediana Edad , Esclerosis Múltiple/sangre , Esclerosis Múltiple/líquido cefalorraquídeo , Proteínas Asociadas a Pancreatitis , Lóbulo Parietal/metabolismo , Lóbulo Parietal/patología , Estadísticas no Paramétricas
5.
Neuroreport ; 11(16): 3599-601, 2000 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-11095526

RESUMEN

The APOE4 allele is widely accepted as a major risk factor for late-onset Alzheimer's disease (AD). Recently, it has been reported that polymorphisms in the APOE promoter and in the alpha2-macroglobulin gene (A2M) are associated with AD. We have analyzed the distribution of APOE alleles, -219T/G APOE promoter polymorphism, and A2M/A2Mdel polymorphism in a large case-control study. Our results showed that APOE genotype was the only informative marker of AD risk contrary to -219T/G and A2M/A2Mdel polymorphism. In AD patients however, a strong linkage disequilibrium was observed between the T allele of -219T/G polymorphism and APOE4 allele. This result indicates that -219T/G APOE promoter polymorphism is a risk factor for AD by increasing the APOE4-associated risk.


Asunto(s)
Enfermedad de Alzheimer/genética , Apolipoproteínas E/genética , Polimorfismo Genético , Regiones Promotoras Genéticas , alfa-Macroglobulinas/genética , Anciano , Alelos , Apolipoproteína E4 , Francia , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Desequilibrio de Ligamiento , Valores de Referencia , Factores de Riesgo , Población Blanca
6.
Rev Neurol (Paris) ; 157(11 Pt 1): 1365-75, 2001 Nov.
Artículo en Francés | MEDLINE | ID: mdl-11924005

RESUMEN

We describe the follow-up of a cohort of 255 Alzheimer's disease (AD) patients (81 males, 174 females) treated by tacrine during 4 years. We performed the survey of hepatic, cholinergic and general tolérance. Drug efficacy was measured by MMS examination on weeks 0, 18, 30, 52, 104, 156 and 208. A total of 190 patients (74.5 percent) were dropped out of this study, 75 (29 percent) for adverse events. We found 85 hepatic (33 percent), 79 cholinergic (31 percent), 31 (12 percent) neuropsychiatric and 72 general (28 percent) side effects. In term of drug efficacy we observed a global decline of 2.5 MMS points during the first year and 2 MMS points between W52 and W156. Tacrine's symptomatic efficacy, defined as the number of patients improved or stabilized at W30, was present in 50 patients (46 percent) among the 109 patients reaching W30. The intensity of symptomatic efficacy was expressed by a 2.7 MMS points increase in 37 patients improved on W30. The long term effects of Tacrine, measured by the MMS score at one year, showed a positive impact as the MMS was 2.5 points above the expected score in non treated AD patients. This study raises the practical problem of optimal cholinesterase inhibitors use in AD and the theoretical question of long term action of cholinesterase inhibitors on cerebral lesions of AD.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Inhibidores de la Colinesterasa/uso terapéutico , Tacrina/uso terapéutico , Anciano , Inhibidores de la Colinesterasa/efectos adversos , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Pacientes Desistentes del Tratamiento/estadística & datos numéricos , Tacrina/efectos adversos , Factores de Tiempo
7.
Rev Med Interne ; 23(3): 312-6, 2002 Mar.
Artículo en Francés | MEDLINE | ID: mdl-11928379

RESUMEN

INTRODUCTION: Monoclonal TNF alpha antibodies are a new treatment of severe rheumatoid arthritis. One of the possible side effects is the appearance of opportunistic infections. We report here on three cases of disseminated tuberculosis observed in patients undergoing treatment with infliximab. EXEGESIS: A 45-year-old woman, treated with infliximab, was hospitalised after five infusions for fever and dyspnoea. The exams showed pulmonary and peritoneal tuberculosis. The second case is a 75-year-old woman whose symptoms were fever, cough and cervical adenopathy after three infliximab infusions. Diagnosis was disseminated tuberculosis. The third case is a 59-year-old man who was hospitalised for an infectious syndrome with dyspnoea, after two infliximab infusions. We discovered pulmonary tuberculosis. CONCLUSION: These three cases added to the 68 cases of tuberculosis registered with the treatment of infliximab. This confirms the risk of severe opportunist infectious side effects. TNF alpha is a cytokine which has anti-infectious properties. These tuberculoses are severe and generalized. It is recommended to search for an active or latent tuberculosis before beginning treatment with infliximab, and to check these patients frequently.


Asunto(s)
Anticuerpos Monoclonales/efectos adversos , Antirreumáticos/efectos adversos , Tuberculosis/etiología , Anciano , Anticuerpos Monoclonales/administración & dosificación , Antirreumáticos/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Femenino , Humanos , Infliximab , Masculino , Persona de Mediana Edad , Enfermedades Peritoneales/etiología , Factores de Tiempo , Tuberculosis Gastrointestinal/etiología , Tuberculosis Miliar/etiología , Tuberculosis Pulmonar/etiología
8.
Acta Biomater ; 8(9): 3302-12, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22617741

RESUMEN

Designing synthetic microenvironments for cellular investigations is a very active area of research at the crossroads of cell biology and materials science. The present work describes the design and functionalization of a three-dimensional (3D) culture support dedicated to the study of neurite outgrowth from neural cells. It is based on a dense self-assembled collagen matrix stabilized by 100-nm-wide interconnected native fibrils without chemical crosslinking. The matrices were made suitable for cell manipulation and direct observation in confocal microscopy by anchoring them to traditional glass supports with a calibrated thickness of ∼50µm. The matrix composition can be readily adapted to specific neural cell types, notably by incorporating appropriate neurotrophic growth factors. Both PC-12 and SH-SY5Y lines respond to growth factors (nerve growth factor and brain-derived neurotrophic factor, respectively) impregnated and slowly released from the support. Significant neurite outgrowth is reported for a large proportion of cells, up to 66% for PC12 and 49% for SH-SY5Y. It is also shown that both growth factors can be chemically conjugated (EDC/NHS) throughout the matrix and yield similar proportions of cells with longer neurites (61% and 52%, respectively). Finally, neurite outgrowth was observed over several tens of microns within the 3D matrix, with both diffusing and immobilized growth factors.


Asunto(s)
Colágeno/farmacología , Péptidos y Proteínas de Señalización Intercelular/farmacología , Neuritas , Animales , Línea Celular , Humanos , Microscopía Confocal , Microscopía Electrónica de Rastreo , Ratas
9.
Ageing Res Rev ; 11(1): 150-62, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21802530

RESUMEN

The use of non-human primate models is required to understand the ageing process and evaluate new therapies against age-associated pathologies. The present article summarizes all the contributions of the grey mouse lemur Microcebus murinus, a small nocturnal prosimian primate, to the understanding of the mechanisms of ageing. Results from studies of both healthy and pathological ageing research on the grey mouse lemur demonstrated that this animal is a unique model to study age-dependent changes in endocrine systems, biological rhythms, thermoregulation, sensorial, cerebral and cognitive functions.


Asunto(s)
Envejecimiento/patología , Envejecimiento/fisiología , Cheirogaleidae/fisiología , Modelos Animales , Animales , Humanos , Especificidad de la Especie , Investigación Biomédica Traslacional/métodos , Investigación Biomédica Traslacional/tendencias
12.
Nephrologie ; 14(6): 251-5, 1993.
Artículo en Francés | MEDLINE | ID: mdl-8145881

RESUMEN

The current knowledges concerning macromolecular inhibitors of crystallization in saliva and in bile are reviewed. In saliva, four families of inhibiting proteins have been evidenced: the statherins, the acidic proline-rich proteins, the cystatins and the histatins. These proteins inhibit the nucleation and the growth of calcium phosphate salts. In the bile, two families of proteins that inhibit the nucleation of calcium carbonate and cholesterol are present: the apolipoproteins and the calcium binding protein also called anionic polypeptide fraction. The structure-function relationships of these molecules are particularly stressed.


Asunto(s)
Bilis/química , Calcio/química , Saliva/química , Apolipoproteínas , Proteínas de Unión al Calcio , Colesterol/química , Cristalización , Humanos , Proteínas y Péptidos Salivales
13.
Ann Parasitol Hum Comp ; 53(2): 131-46, 1978.
Artículo en Francés | MEDLINE | ID: mdl-677715

RESUMEN

Electron microscopy of the tegument of H. stylosa cysticercoid as compared with that of H. diminuta reveals great variations in the fine structure of the larval tegument of these two species. On the scolex and the inner cyst wall, the tegument of H. stylosa cysticercoid bears typical microtriches; at the level of the anterior pore, the microtriches are flexuous. The tegument of the outer cyst wall appears as a syncytial band with dense material which accumulates in the region below the unit membrane, and the tegument of the cercomer is increased by branchied microvillies. While, the scolex of H. diminuta cysticercoid is unarmed and the tegument of the outer cyst wall bears branched microvillies. The data permit the conclusion that the differentiation of tegumental structures is graduated from the scolex to the cercomer. This differenciation is more or less important according to the parasite and results of successive inductions which affect parts of the cysticercoid. The significance of these findings is discussed in terms of the possible function of these structures and the penetration of substances.


Asunto(s)
Cestodos/ultraestructura , Hymenolepis/ultraestructura , Animales , Larva/ultraestructura , Membranas/ultraestructura , Microvellosidades/ultraestructura
14.
Ann Parasitol Hum Comp ; 54(6): 621-35, 1979.
Artículo en Francés | MEDLINE | ID: mdl-550714

RESUMEN

The life cycle of Maupasina weissi Seurat, 1913, the parasite of the elephant shrew, has been experimentally obtained from the intermediate host Locusta migratoria. The biology of this Nematoda is considered as being more primitive than the Subuluridae: -- egg maturation in external environment is in fact necessary to the Maupasina larvae to penetrate into the insect, -- The different localizations of the infective larvae, such as mesenteron regeneration crypta, fat body, demonstrate that the parasite is not completely adaptated to its intermediate host, -- the ontogenesis of cephalic structures is characterized by an hypertrophy of the archaic structures mainly from cuticular origin.


Asunto(s)
Saltamontes/parasitología , Nematodos/crecimiento & desarrollo , Musarañas/parasitología , Tejido Adiposo/parasitología , Animales , Sistema Digestivo/parasitología , Femenino , Larva/crecimiento & desarrollo , Masculino , Nematodos/anatomía & histología , Ovario/parasitología , Oviductos/parasitología
15.
Yeast ; 5(2): 79-90, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2540596

RESUMEN

The CDC33 gene of Saccharomyces cerevisiae belongs to the class II 'START' genes. Its product is required for the initiation of a new cell division cycle (Hartwell, 1974). Many results suggest that the cAMP signalling pathway is one of the major controlling elements of 'START'. Components of this pathway are encoded by class II 'START' genes. The aim of the present study is to determine whether or not the CDC33 gene interferes with the cAMP signalling pathway. We report here the molecular cloning of the CDC33 gene by complementation of the cdc33-1 thermosensitive mutant. The identity of the cloned gene is confirmed by site-specific reintegration and segregation analysis. This gene is transcribed into a 900-nucleotides mRNA and appears to be relatively abundant in the cell. We also show that the CDC33 gene product is essential for sporulation. cdc33-1 mutant cells are able to enter into the resting state. The cAMP intracellular pool is not modified when the cdc33-1 mutant is shifted to the restrictive temperature. The cdc33-1 mutation is not suppressed by other known elements of the cAMP cascade. All these results suggest that the CDC33 'START' gene does not interfere with the cAMP signalling pathway which controls cell division.


Asunto(s)
AMP Cíclico/biosíntesis , Proteínas Fúngicas/genética , Saccharomyces cerevisiae/genética , Southern Blotting , División Celular , Clonación Molecular , Sondas de ADN , ADN de Hongos/análisis , Genes Fúngicos , Prueba de Complementación Genética , Mutación , Hibridación de Ácido Nucleico , Fenotipo , ARN de Hongos/análisis , ARN Mensajero/análisis , Mapeo Restrictivo , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiología , Esporas Fúngicas
16.
Nucleic Acids Res ; 18(16): 4817-23, 1990 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-2204028

RESUMEN

We report the identification and purification of a yeast factor functionally homologous to the human upstream element factor (UEFh). Although the yeast protein (UEFy) has a higher molecular weight than the HeLa UEF (60 kD versus 45 kD) both have identical DNA-binding properties: the purified UEFy recognizes the Adenovirus 2 (Ad2) major late promoter upstream element (MLP-UE; from nucleotide -49 to -67) as well as the IVa2 upstream element (IVa2-UE; from nucleotide -98 to -122) with a higher affinity for the MLP-UE than for the IVa2-UE. Based on its DNA binding specificity, size and thermostability, the UEFy protein appears also similar or equivalent to the centromere binding protein CP1. In a competition assay with oligonucleotides containing the MLP-UE binding site, a drastic reduction of Ad2 MLP transcription was observed both in a HeLa and in a yeast cell free system, which was restored by addition of either the purified UEFh or UEFy proteins. We conclude that both UEFh and UEFy activate transcription from the Ad2 MLP upon binding to the upstream element, whatever is the in vitro cell-free system (yeast or HeLa). This indicate that some regulatory function represented by the upstream element and its cognate factor, is well conserved between human and yeast.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Regiones Promotoras Genéticas , Saccharomyces cerevisiae/genética , Factores de Transcripción/metabolismo , Transcripción Genética , Adenovirus Humanos/genética , Secuencia de Bases , Unión Competitiva , Sistema Libre de Células , ADN/genética , ADN/metabolismo , Proteínas de Unión al ADN/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Células HeLa , Humanos , Datos de Secuencia Molecular , Homología de Secuencia de Ácido Nucleico , Factores de Transcripción/aislamiento & purificación , Factores Estimuladores hacia 5'
17.
Nouv Presse Med ; 9(15): 1073-5, 1980 Mar 29.
Artículo en Francés | MEDLINE | ID: mdl-6162149

RESUMEN

The object of this study was to determine whether levels of beta-2-microglobulin and of rheumatoid factor measured by an enzyme-immunoassay allowed good discrimination between inflammatory and degenerative arthropathies. A multiparametric study of synovial fluid was performed on 85 specimens from patients with rheumatoid arthritis, chondrocalcinosis, mechanical arthritis and traumatic arthopathies. A beta-2-microglobulin level of less than 4 mg/l is a result very mich in favor of a non-inflammatory arthropathy (48/49 cases). The quantification of intra-articular rheumatoid factor allows for reclassification in the context of sero-negative rheumatoid arthritis.


Asunto(s)
beta-Globulinas/análisis , Factor Reumatoide/análisis , Líquido Sinovial/análisis , Microglobulina beta-2/análisis , Artritis Reumatoide/metabolismo , Humanos , Técnicas para Inmunoenzimas , Radioinmunoensayo/métodos
18.
Clin Chem ; 38(6): 860-3, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1597011

RESUMEN

Analysis of urinary protein composition is an important tool in studies on renal physiology and physiopathology. Urine is, however, a complex mixture containing, besides protein, a variety of compounds such as salts, peptides, oligosaccharides, and glycosaminoglycans. Some of these compounds interfere with the electrophoretic migration of protein in sodium dodecyl sulfate-polyacrylamide gels and prevent correct analysis of the protein pattern. We describe a simple method for extracting urinary proteins that considerably improves their electrophoretic migration and subsequent immunodetection. This treatment involves ammonium sulfate fractionations (for precipitating proteins), EDTA (for inhibiting protein aggregation), and HCl hydrolysis (for removing glycosylaminoglycans). Recovery during extraction was found to be almost quantitative for total protein and three representative proteins: albumin, alpha 1-glycoprotein acid, and beta 2-microglobulin.


Asunto(s)
Western Blotting/normas , Electroforesis en Gel de Poliacrilamida/normas , Proteinuria/orina , Albuminuria/orina , Sulfato de Amonio , Ácido Edético/farmacología , Precipitación Fraccionada , Humanos , Ácido Clorhídrico , Orosomucoide/orina , Microglobulina beta-2/orina
19.
Ann Parasitol Hum Comp ; 52(3): 325-37, 1977.
Artículo en Francés | MEDLINE | ID: mdl-921192

RESUMEN

The study of allozymic variations at four enzymatic loci (Est-2, alpha-Gpd, Got-1 and Got-2) in populations of Aedes detritus (Hal.) from 27 localities in Southern France has shown that this species is composed of two kinds of sympatric populations which do not interbreed in nature. Single specimens of Aedes detritus can be attributed to one or other type of population (sibling species) by the genotype at the alpha-Gpd or Got-2 loci (type A populations are homozygous for Got-2R allele and the frequency of the alpha-GpdC allele is higher than 98%; type B populations are homozygous for Got-2L allele and the frequency of the alpha-GpdB allele is higher than 98%). Moreover, allelic frequencies at the Est-2 and Got-1 loci are different in both types of populations. The fact that both kinds of populations coexist in the same pond shows that the isolating mechanism is not an adaptation to the larval environment, but rather involves mechanisms pecular to adults (precopulatory mechanism or interpopulation sterility).


Asunto(s)
Aedes/genética , Aspartato Aminotransferasas/genética , Esterasas/genética , Variación Genética , Glicerolfosfato Deshidrogenasa/genética , Aedes/enzimología , Alelos , Animales , Aspartato Aminotransferasas/metabolismo , Esterasas/metabolismo , Francia , Genotipo , Glicerolfosfato Deshidrogenasa/metabolismo , Isoenzimas/metabolismo , Polimorfismo Genético
20.
Nucleic Acids Res ; 18(23): 7033-9, 1990 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-2263463

RESUMEN

We present a reproducible method for the preparation of nuclear extracts from the yeast Saccharomyces cerevisiae that support efficient RNA polymerase B (II)-dependent transcription. Extracts from both a crude nuclear fraction and Percoll-purified nuclei are highly active for site-specific initiation and transcription of a G-free cassette under the Adenovirus major late promoter. At optimal extract concentrations transcription is at least 5 times more efficient with the yeast extracts than with HeLa whole cell extracts. We show that the transcriptional activity is sensitive to alpha-amanitin and to depletion of factor(s) recognizing the TATA-box of the promoter. The in vitro reaction showed maximal activity after 45 min, was very sensitive to Cl-, but was not affected by high concentrations of potassium. We find that the efficiency of in vitro transcription in nuclear extracts is reproducibly high when spheroplasting is performed with a partially purified beta 1,3-glucanase (lyticase). Therefore a simplified method to isolate the lyticase from the supernatant of Oerskovia xanthineolytica is also presented.


Asunto(s)
Técnicas Genéticas , ARN Polimerasa II/metabolismo , Saccharomyces cerevisiae/genética , Transcripción Genética , Amanitinas/farmacología , Núcleo Celular/metabolismo , Glucano Endo-1,3-beta-D-Glucosidasa/aislamiento & purificación , Glucano Endo-1,3-beta-D-Glucosidasa/metabolismo , Complejos Multienzimáticos/aislamiento & purificación , Complejos Multienzimáticos/metabolismo , Péptido Hidrolasas/aislamiento & purificación , Péptido Hidrolasas/metabolismo , Saccharomyces cerevisiae/enzimología , Esferoplastos , TATA Box , Temperatura , Factores de Tiempo
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