Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Hum Gene Ther ; 11(1): 91-100, 2000 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-10646642

RESUMO

We have investigated the minimal time required for efficient transduction of human hematopoietic repopulating cells using a surrogate nonobese diabetic (NOD)/severe combined immunodeficient (SCID) xenoengraftment assay. Cord blood CD34+ cells were transduced to high levels over 24-48 hr in the presence of Flt-3 ligand, stem cell factor, interleukin 3, and interleukin 6. Under these conditions, high levels of NOD/SCID repopulating activity were preserved, but the levels of gene marking in engrafting cell populations measured by expression of a reporter transgene were low. Extension of the transduction period by 24 hr (total culture period, 72 hr) under the same cytokine conditions resulted in high levels of gene marking, but on closer analysis expression was limited predominantly to the myeloid population. Efficient transduction of both lymphoid and myeloid lineages could be achieved only if the transduction protocol was extended by a further 24 hr (total culture period, 96 hr), suggesting that myeloid lineage-committed precursors are capable of repopulation, and that over shorter time periods transduction is largely restricted to this population. This adds to the emerging evidence of heterogeneity within the SRC compartment, and has important implications for the interpretation of this assay in stem cell transplantation and gene transfer studies.


Assuntos
Marcadores Genéticos , Vetores Genéticos , Vírus da Leucemia do Macaco Gibão/genética , Imunodeficiência Combinada Severa/imunologia , Animais , Antígenos CD34/genética , Citocinas/uso terapêutico , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/terapia
3.
Blood ; 92(9): 3163-71, 1998 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9787152

RESUMO

Stable gene transfer to human pluripotent hematopoietic stem cells (PHSCs) is an attractive strategy for the curative treatment of many genetic hematologic disorders. In clinical trials, the levels of gene transfer to this cell population have generally been low, reflecting deficiencies in both the vector systems and transduction conditions. In this study, we have used a pseudotyped murine retroviral vector to transduce human CD34(+) cells purified from bone marrow (BM) and umbilical cord blood (CB) under optimized conditions. After transduction, 71% to 97% of the hematopoietic cells were found to express a low-affinity nerve growth factor receptor (LNGFR) marker gene. Six weeks after transplantation into immunodeficient NOD/LtSz-scid/scid (NOD/SCID) mice, LNGFR expression was detected in 6% to 57% of CD45(+) cells in eight of nine engrafted animals. Moreover, proviral DNA was detected in 8.3% to 45% of secondary colonies derived from BM cells of engrafted NOD/SCID mice. Our data show consistent transduction of SCID-repopulating cells (SRCs) and suggest that the efficiency of gene transfer to human hematopoietic repopulating cells can be improved using existing retroviral vector systems and carefully optimized transduction conditions.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Transfecção , Animais , Transplante de Medula Óssea , Células Cultivadas/transplante , Ensaio de Unidades Formadoras de Colônias , Meios de Cultura Livres de Soro , Sangue Fetal/citologia , Genes Reporter , Vetores Genéticos/genética , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptor de Fator de Crescimento Neural , Receptores de Fator de Crescimento Neural/biossíntese , Receptores de Fator de Crescimento Neural/genética , Proteínas Recombinantes de Fusão/biossíntese , Retroviridae/genética
4.
Immunogenetics ; 48(5): 305-11, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9745007

RESUMO

B-cell commitment is characterized by the expression of specific membrane proteins and the rearrangement and expression of immunoglobulin (Ig) heavy (H) and light (L) chain genes. At early stages of B-cell development, unrearranged Ig loci are transcribed, which correlates with these regions becoming accessible for Ig gene rearrangement. Some germline transcripts can be translated into protein and potentially play a role in cell signaling during B-cell development. In this report an early stage in human B-cell development is characterized using Epstein-Barr virus (EBV)-transformed cell lines from patients with a severe combined immunodeficiency (SCID). These lines were shown to produce germline constant (C) gene transcripts from the IGH and IGK loci. We demonstrate here that these cells are committed to the B-cell lineage as substantiated by expression of CD79a and CD79b. No surrogate light chain (SLC) gene transcription was detected, indicative of a very early differentiation stage. From these cell lines two types of germline IgV gene transcripts were isolated: a transcript containing the IGKV4-1 gene and a germline IGHV-1 transcript nearly identical to IGHV1/OR15-1 (HC15-1, DP-1), an orphon VH gene on chromosome 15. Germline VH transcripts originating from the VH locus on chromosome 14 could not be detected. It is of interest that, apart from Ig V and C genes (non-functional), V genes that reside outside the Ig locus are a target for the transcription factors that are postulated to initiate Ig gene rearrangement early in B-cell development.


Assuntos
Linfócitos B/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Cadeias Leves de Imunoglobulina/genética , Imunoglobulinas/genética , Transcrição Gênica/genética , Antígenos CD/genética , Sequência de Bases , Biomarcadores , Antígenos CD79 , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Região Variável de Imunoglobulina/genética , Dados de Sequência Molecular , Receptores de Antígenos de Linfócitos B/genética , Alinhamento de Sequência
5.
Clin Exp Immunol ; 107(2): 235-40, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9030858

RESUMO

X-linked agammaglobulinaemia (XLA) is an immunodeficiency caused by mutations in Bruton's tyrosine kinase (Btk) and is characterized by an almost complete arrest of B cell development. We analysed expression of Btk in B lymphoblastoid cell lines (BLCL) derived from four unrelated XLA patients. In one patient, with a 3 x 5 kb genomic deletion encompassing the first (untranslated) exon, mRNA levels and in vitro kinase activities were very low. The patient manifested a mild phenotype with a delayed onset of the disease. Another mutation, in which the intron 3 donor splice site is lost, was also associated with very low mRNA levels and an absence of detectable Btk protein. Patients with this mutation showed extensive heterogeneity of the immunological phenotype. In the BLCL of a third patient, with an Arg288 substitution in the SH2 domain, the mutation did not appear to affect the expression level, nor to abrogate in vitro phosphorylation activity. In the BLCL of the fourth patient, with an Arg28 mutation in the PH domain, tyrosine kinase activity in BTK precipitates appeared to be decreased compared with control BLCL.


Assuntos
Agamaglobulinemia/genética , Linfócitos B , Proteínas Tirosina Quinases/genética , Cromossomo X , Adolescente , Adulto , Tirosina Quinase da Agamaglobulinemia , Linhagem Celular , Transformação Celular Viral/genética , Criança , Pré-Escolar , Expressão Gênica , Ligação Genética , Herpesvirus Humano 4/fisiologia , Humanos , Lactente , Fosforilação , Proteínas Tirosina Quinases/metabolismo , RNA Mensageiro/análise
6.
J Biol Chem ; 271(32): 19272-8, 1996 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-8702609

RESUMO

The pre-B cell receptor (BCR) complex, consisting of micro heavy chain, a pseudo-light chain, and the Mb-1/B29 heterodimer, directs the transition to the mature B cell stage. Plasma membrane expression of the pre-BCR is extremely low, despite its presumed signaling function. We have compared assembly and intracellular transport of the pre-BCR complex with that of the BCR complex in mature B cells. Synthesis and assembly rate of pre-BCR and BCR components are comparable. However, the pre-BCR is subject to a highly efficient retention mechanism, which only allows exit of a few percent of the complexes from the endoplasmic reticulum (ER). This small transported pool of pre-BCR complexes is significantly enriched for protein-tyrosine kinase activity, as compared with the ER-localized receptor pool. Accordingly, the Src-related tyrosine kinase Lyn was found in the transported glycoprotein fraction but not in association with ER-localized glycoproteins. Upon introduction of a conventional light chain into pre-B cells, plasma membrane receptor levels increased, but the efficiency of intracellular transport of the receptor complex was not restored to that in mature B cells. This indicates that the ER retention mechanism is not selective for the pseudo-light chain and may be inherent to pre-B cells. We propose that this retention mechanism contributes to the regulation of pre-BCR-mediated signal transduction.


Assuntos
Retículo Endoplasmático/metabolismo , Cadeias Leves de Imunoglobulina/metabolismo , Precursores de Proteínas/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Transporte Biológico , Humanos , Cinética , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas
7.
Curr Opin Immunol ; 8(2): 181-90, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8725941

RESUMO

The precursor T-cell receptors (TCRs) and B-cell receptors (BCRs) direct lymphocyte development to the mature T-cell and B-cell stage, respectively. Recent genetic and biochemical experiments reveal the striking parallel in structure and function of these receptors. They consist of TCR beta and BCR mu chains paired with surrogate TCR alpha and BCR light chains. Both receptors employ a two-component signal transduction unit: CD3 gamma epsilon for the pre-TCR, and CD79ab for the pre-BCR. Plasma membrane levels of pre-TCR/BCR complexes are kept extremely low, most probably by a mechanism involving specific retention in the endoplasmic reticulum. This mechanism may control the signalling activity of pre-TCR/BCR and therewith the lymphocyte differentiation process.


Assuntos
Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/metabolismo , Receptores de Antígenos de Linfócitos B/química , Receptores de Antígenos de Linfócitos B/fisiologia , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/fisiologia , Animais , Humanos , Relação Estrutura-Atividade
8.
Int Immunol ; 7(3): 359-68, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7794818

RESUMO

The B cell antigen receptor (BCR) complex consists of transmembrane (m) Ig, in non-covalent association with a disulphide-linked heterodimer of mb-1 and B29 gene products. The MB-1-B29 heterodimer is required for deposition of the BCR at the plasma membrane, as well as for coupling of the antigen receptor to intracellular signal transduction cascades. We have performed biosynthetic labelling studies using the mature B cell line Ramos to investigate the process of assembly of the BCR components. We conclude that association of the four components, Ig-heavy chain (HC) and -light chain (LC), MB-1 and B29, is required and sufficient to permit exit of the BCR complex out of the endoplasmic reticulum (ER). With the short pulse labelling procedures used, no evidence was found for transient participation of other molecules in complex formation. A 32 kDa glycoprotein was identified, which is serologically related to MB-1, but has a more acidic isoelectric point (pl) and a protein backbone of 21 kDa, as compared with 25 kDa for MB-1. This protein did not appear to participate in BCR complex formation and is most likely degraded prior to reaching the cis-Golgi. The MB-1 component was found to be the rate-limiting step in BCR complex formation, while Ig-HC, -LC and B29 are synthesized in excess. Ig-HC and -LC form disulphide-linked tetrameric complexes within 3 min after biosynthesis, with which B29 and MB-1 components associate independently, followed by disulphide bond formation between these heterodimeric partners. While partial BCR complexes containing B29 and mlg-H2L2 tetramers are rapidly formed and have a half-life of a few hours in the ER, entry of MB-1 into these complexes controls exit out of this compartment.


Assuntos
Antígenos CD/metabolismo , Linfócitos B/metabolismo , Cadeias lambda de Imunoglobulina/metabolismo , Cadeias mu de Imunoglobulina/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Linfócitos B/imunologia , Transporte Biológico , Linfoma de Burkitt/patologia , Antígenos CD79 , Cistina/metabolismo , Retículo Endoplasmático/metabolismo , Glicosilação , Humanos , Substâncias Macromoleculares , Proteínas de Neoplasias/metabolismo , Conformação Proteica , Dobramento de Proteína , Processamento de Proteína Pós-Traducional , Transdução de Sinais , Células Tumorais Cultivadas
9.
J Biol Chem ; 269(39): 23857-60, 1994 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-7929028

RESUMO

X-linked agammaglobulinemia (XLA) is an inherited human immunodeficiency disease, characterized by an arrest in B-cell development, which results in a dramatic decrease in immunoglobulin production. The gene product defective in XLA has been identified as a cytoplasmic protein tyrosine kinase, named Bruton's tyrosine kinase (Btk). The dramatic XLA phenotype indicates a critical role for Btk in the regulation of B-cell development. However, neither external stimuli leading to Btk activation nor any of its in vivo substrates have thus far been identified, and the mechanism of disease induction remains unexplained. We report here that stimulation of the B-cell antigen receptor (membrane immunoglobulin) on mature B-cells induces tyrosine phosphorylation of Btk in vivo, accompanied by an increase in its kinase activity in vitro. These results place Btk in the B-cell receptor signal transduction pathway, which is known to be essential in driving B-cell differentiation.


Assuntos
Agamaglobulinemia/enzimologia , Ligação Genética , Proteínas Tirosina Quinases/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Cromossomo X , Tirosina Quinase da Agamaglobulinemia , Agamaglobulinemia/genética , Citosol/enzimologia , Ativação Enzimática , Humanos , Fosforilação , Proteínas Tirosina Quinases/deficiência , Células Tumorais Cultivadas , Tirosina/metabolismo
10.
Verpleegkunde ; 9(2): 91-102, 1994 Aug.
Artigo em Holandês | MEDLINE | ID: mdl-8087322

RESUMO

In this article account is given of a validation study, according to the nursing diagnosis 'social isolation'. The label, definition and cluster of defining characteristics according to cluster of defining characteristics according to Townsend (1990) are the starting point, the related factors are left out of consideration. The validation mentioned above was carried out in accordance with the Delphi-method, that consisted of three Delphi rounds. A panel of experts was asked particularly to compile defining characteristics that are relevant for 'social isolation' and to indicate the critical defining characteristics. This procedure generated a cluster of seven defining characteristics for 'social isolation' of which the content validity turned out to be considerably increased with regard to the cluster formulated by Townsend. The distinction between critical defining characteristics and supporting defining characteristics was not clarified by this study.


Assuntos
Pacientes Internados/psicologia , Transtornos Mentais/psicologia , Diagnóstico de Enfermagem/normas , Isolamento Social , Técnica Delphi , Humanos , Transtornos Mentais/enfermagem , Pesquisa em Avaliação de Enfermagem
11.
Leukemia ; 7(12): 1939-47, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8255092

RESUMO

The transmembrane forms of all immunoglobulin (Ig) classes are associated with two glycoproteins, mb-1 and B29, that are crucial for signal transduction following antigen binding to the Ig molecule. We have investigated the transcription and protein expression of mb-1 and B29 genes during B-cell development. Sixty human continuous cell lines (35 B-lineage, 11 T-lineage, 11 myeloid-lineage and three non-hematopoietic) and 75 hematopoietic malignancies (55 B-lineage, 12 T-lineage and eight myeloid-lineage), were tested for RNA expression by Northern blotting experiments with the mb-1 pRA3 cDNA probe, and a newly isolated B29 cDNA probe. Protein expression was analyzed by immunofluorescence microscopy of cytocentrifuge preparations, which were labeled with the anti-mb-1 HM57 monoclonal antibody (mAb) and an anti-B29 polyclonal antiserum, directed against intracellular epitopes of these polypeptides. Except for two early precursor B-cell lines, mb-1 and B29 transcripts and proteins were detected in all B-cell lines and B-cell malignancies, i.e. from immature to more mature B cells, irrespective of their Ig class expression. Transcription of mb-1 genes seems to be down-regulated at the plasma cell stage, because no mb-1 transcripts and mb-1 proteins could be detected in the four plasma cell lines and two plasma cell leukemias tested. B29 transcripts were detectable in these cell samples, but low levels of B29 proteins were only detected in one plasma cell line. The HM57 mAb gave strong labeling on fresh cytocentrifuge preparations of all B-cell samples, and this mb-1 protein expression appeared to be B-cell specific. We therefore conclude that the HM57 mAb is well suited for the detection of the mb-1 molecule as a pan-B-cell marker for the diagnosis of immature and mature B-cell malignancies. The expression pattern of the mb-1 protein is comparable to that of the CD19 and CD22 antigens, but has the advantage of being B-lineage specific. Although B29 protein expression was restricted to B-lineage cells, the anti-B29 antiserum is less suitable for diagnosis of B-cell malignancies, because of the variable and generally weak signals on cytocentrifuge preparations.


Assuntos
Antígenos CD , Expressão Gênica , Genes de Imunoglobulinas/genética , Células-Tronco Hematopoéticas/metabolismo , Leucemia/genética , Linfoma/genética , Glicoproteínas de Membrana/genética , Fosfoproteínas/genética , Receptores de Antígenos de Linfócitos B/genética , Transcrição Gênica , Linfócitos B/metabolismo , Linfócitos B/patologia , Biomarcadores Tumorais/análise , Northern Blotting , Antígenos CD79 , Linhagem Celular , Células-Tronco Hematopoéticas/patologia , Humanos , Leucemia/metabolismo , Leucemia/patologia , Leucemia de Células B/diagnóstico , Linfoma/metabolismo , Linfoma/patologia , Linfoma de Células B/diagnóstico , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/metabolismo , Fosfoproteínas/análise , Fosfoproteínas/metabolismo , Receptores de Antígenos de Linfócitos B/análise , Receptores de Antígenos de Linfócitos B/metabolismo , Células Tumorais Cultivadas/metabolismo
13.
Int J Nurs Stud ; 30(4): 331-42, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8375976

RESUMO

The purpose of this study was translation and construct validity testing of the appraisal of the self-care agency ASA-scale. This scale measures operability of self-care agency. The original English version of the scale was translated into Dutch. Subsequently the Dutch version was retranslated into English and compared with the original for semantic and cross-cultural differences. Construct validity of the translated scale was tested on 140 elderly in the Netherlands. The scale was administered to 40 randomly selected patients of a nursing home, 30 residents of a personalized care facility, 30 residents of a service flat and 40 randomly selected elderly who lived independently in the adjacent community. As hypothesize, mean ASA scores of the four groups of elderly differed significantly. The less dependent on institutionalized nursing care the higher the operability of the self-care agency scores of the elderly.


Assuntos
Autocuidado/estatística & dados numéricos , Tradução , Atividades Cotidianas , Idoso , Análise de Variância , Estudos de Avaliação como Assunto , Assistência Domiciliar , Instituição de Longa Permanência para Idosos , Humanos , Teoria de Enfermagem , Assistência Individualizada de Saúde , Distribuição Aleatória , Reprodutibilidade dos Testes , Inquéritos e Questionários
14.
Eur J Immunol ; 23(5): 1088-97, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8477803

RESUMO

Prior to immunoglobulin (Ig) light (L) chain rearrangement, pre-B cells can express mu heavy (H) chains at the cell surface in association with pseudo (psi) L chains. This complex may be essential for B cell development. We have investigated the composition of the mu/psi L chain complex of a human pre-B cell line, in view of its potential role in transmembrane signal transduction. The mu/lambda receptor of a mature B cell line was analyzed in comparison. The mu/psi L chain complex is associated with disulfide-linked molecules that are homologous or identical to the mb-1 and B29 proteins, known to be integral components of membrane Ig receptors on mature B cells. Both receptors contain tyrosine (Tyr) kinase activity. In the mu/lambda receptor, the lyn and lck Tyr kinases could clearly be identified. The mb-1 and B29 proteins in both mu/lambda and mu/psi L chain receptors are substrates for in vitro phosphorylation on Tyr, but also on serine (Ser) and threonine (Thr) residues. The undefined mu-associated Ser/Thr kinase also phosphorylates the src-related kinases in the mu/lambda receptor and a 43-kDa mu-associated protein that is present in both complexes. The 43-kDa protein may be an integral part of both receptor types, or a transiently associated molecule instrumental in the signaling process. We conclude that the mu/psi L receptor on human pre-B cells fulfills the presently known criteria to function as a signal transduction unit.


Assuntos
Antígenos CD , Linfócitos B/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Cadeias Leves de Imunoglobulina/química , Cadeias mu de Imunoglobulina/química , Transdução de Sinais , Sequência de Aminoácidos , Antígenos CD79 , Linhagem Celular , Imunofluorescência , Humanos , Glicoproteínas de Membrana/análise , Dados de Sequência Molecular , Fosfoproteínas/análise , Proteínas Serina-Treonina Quinases/análise , Proteínas Tirosina Quinases/análise , Receptores de Antígenos de Linfócitos B/análise
15.
Verpleegkunde ; 8(1): 2, 1993 May.
Artigo em Holandês | MEDLINE | ID: mdl-8298756
17.
J Exp Med ; 175(6): 1511-9, 1992 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-1375264

RESUMO

We have recently reported that on human B lymphocytes, membrane IgM (mIgM) associates with a heterodimer of 47- and 37-kD polypeptides, the 47-kD subunit being encoded by the mb-1 gene. We show here that expression of mb-1, both at the mRNA and the protein level, is not restricted to IgM+ B cells but can also be found in IgM- pre-B cells and mIgM-IgG+ B cells. Membrane forms of IgD and IgG, isolated from freshly isolated human B cells and B cell lines, are expressed together with heterodimeric protein structures biochemically similar to the mIgM-associated polypeptides, and these were shown to comprise the products of the mb-1 and B29 genes, or homologous genes. Finally, all three classes of antigen receptors are linked to protein kinases, capable of phosphorylating the Ig-associated heterodimers. Our findings provide insight in the structural organization of the different antigen receptors on human B cells and have implications for their function.


Assuntos
Linfócitos B/imunologia , Genes de Imunoglobulinas , Imunoglobulina D/metabolismo , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Anticorpos Monoclonais , Northern Blotting , Linhagem Celular , Membrana Celular/imunologia , Imunofluorescência , Humanos , Imunoglobulina D/análise , Imunoglobulina D/genética , Imunoglobulina G/análise , Imunoglobulina G/genética , Imunoglobulina M/análise , Imunoglobulina M/genética , Cadeias lambda de Imunoglobulina/análise , Cadeias mu de Imunoglobulina/análise , Substâncias Macromoleculares , Peso Molecular , Tonsila Palatina/imunologia , Fosforilação , RNA/genética , RNA/isolamento & purificação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Antígenos de Linfócitos B/análise
18.
Plant Cell ; 2(5): 393-401, 1990 May.
Artigo em Inglês | MEDLINE | ID: mdl-2152165

RESUMO

We have analyzed the spatial and temporal activities of chalcone flavanone isomerase (chi) A and B gene promoters from petunia. To study the tandem promoter regulation of chiA, various chiA promoter fragments were fused with the beta-glucuronidase (GUS) reporter gene. Analysis of transgenic plants containing these chimeric genes provided definitive proof that the chiA coding region is regulated by two distinct promoters (designated PA1 and PA2). We also showed that both promoters can function independently and that the chiA PA1 promoter is expressed in limb (epidermal and parenchyma cells), tube (inner epidermal and parenchyma cells), seed (seed coat, endosperm, and embryo), sepal, leaf, and stem. The use of chiA and chiB promoters in the regulation of anther- and pollen-specific gene expression has been studied. By analyzing transgenic plants containing chimeric genes consisting of chiA and B promoter fragments and the GUS reporter gene, we were able to identify a 0.44-kilobase chiA PA2 promoter fragment that drives pollen-specific gene expression and a 1.75-kilobase chiB PB promoter fragment that confers anther-specific (pollen and tapetum cells) expression to the GUS gene.


Assuntos
Regulação da Expressão Gênica , Genes de Plantas/genética , Liases Intramoleculares , Isomerases/genética , Plantas/genética , Regiões Promotoras Genéticas/genética , Sequência de Bases , DNA Recombinante , Glucuronidase/biossíntese , Glucuronidase/genética , Glucuronidase/isolamento & purificação , Histocitoquímica , Dados de Sequência Molecular , Especificidade de Órgãos , Fatores de Tempo , Transformação Genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA