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1.
Zhonghua Bing Li Xue Za Zhi ; 48(2): 120-126, 2019 Feb 08.
Artigo em Zh | MEDLINE | ID: mdl-30695864

RESUMO

Objective: To investigate the clinicopathologic characteristics, molecular and genetic features, differential diagnoses and prognosis of fumarate hydratase-deficient renal cell carcinoma (FH-RCC). Methods: The immunohistochemical (IHC) expression of FH in 391 renal neoplasms in tissue chips collected from the Affiliated Hospital of Qingdao University and 971 Hospital of PLA Navy from January 2011 to December 2017 was evaluated. The clinicopathologic data of eight FH negative cases were collected.Polymerase chain reaction (PCR) and sequencing were used to detect the changes in FH gene in three cases. Interphase FISH with a dual color and break-apart probe was applied to detect the TFE3 gene alteration in the cases showing TFE3 protein expression. Results: Among the eight patients, seven were male and one was female, and age ranged from 28 to 50 years (mean 39 years). Tumor size ranged from 3.5 cm to 12.0 cm (mean 7.9 cm). Renal pelvis invasion was identified in six cases, and the tumor emboli in renal vein and inferior vena cava were found in four patients. The cut surface of most tumors was solid, colorful, grayish white or yellow with no clear border showing invasive growth pattern. Microscopically, the tumors showed different proportions of papillary, tubular cystic, cribriform and solid structures. The tumor cells were rounded or polygonal with eosinophilic or amphotropic cytoplasm, round or oval nuclei, and focal large and prominent nucleoli (WHO/ISUP grade 3-4). Two cases had sarcomatoid or rhabdoid components. Intravascular tumor emboli were found in five cases. IHC staining showed most tumors expressed PAX8(7/8), CK19(7/8), vimentin (6/8) and P504s(8/8). However, other immunomarkers including CK7, CD10, CD117, RCC, 34ßE12, HMB45 and Melan A were all negative. Sequencing showed all three cases had FH gene mutations in exon 1. FISH revealed no TFE3 gene translocation or amplification in the two cases with TFE3 IHC expression. Follow-up data were available in seven patients with the follow-up period from 11 to 66 months. Among them, five patients died between 11 to 31 months after the surgery because of extensive distant metastases of the tumor to the lung, liver and lymph nodes. The other two patients were alive at the 36th and 66th month after the surgery. Conclusions: Morphologically, FH-RCC overlaps with papillary RCC, collecting duct carcinoma and tubular-cystic RCC, showing a mixture of papillary, tubular cystic, cribriform or tubular papillary structures with at least focal large and prominent nucleoli. The negative expression of FH and the detection of FH gene mutation could facilitate the diagnosis of the tumor. FH-RCC is a high aggressive tumor, prone to metastasize, and is associated with poor prognosis. The timely diagnosis of FH-RCC could benefit the patients and their relatives as well.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/enzimologia , Fumarato Hidratase/genética , Neoplasias Renais/enzimologia , Adulto , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Neoplasias Renais/genética , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Carga Tumoral
2.
Bull Entomol Res ; 108(3): 388-399, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28920565

RESUMO

RNA interference (RNAi) is a very effective technique for studying gene function and may be an efficient method for controlling pests. Trehalose-6-phosphate synthase (TPS), which plays a key role in the synthesis of trehalose and insect development, was cloned in Tribolium castaneum (Herbst) (TcTPS) and the putative functions were studied using RNAi via the injection of double-stranded RNA (dsRNA) corresponding to conserved TPS and trehalose-6-phosphate phosphatase domains. Expression analyses show that TcTPS is expressed higher in the fat body, while quantitative real-time polymerase chain reaction results show that the expression of four trehalase isoforms was significantly suppressed by dsTPS injection. Additionally, the expression of six chitin synthesis-related genes, such as hexokinase 2 and glutamine-fructose-6-phosphate aminotransferase, was suppressed at 48 and 72 h post-dsTPS-1 and dsTPS-2 RNA injection, which were two dsTPS fragments that had been designed for two different locations in TcTPS open reading frame, and that trehalose content and trehalase 1 activity decreased significantly at 72 h post-dsRNA injection. Furthermore, T. castaneum injected with dsTPS-1 and dsTPS-2 RNA displayed significantly lower levels of chitin and could not complete the molting process from larvae to pupae, revealing abnormal molting phenotypes. These results demonstrate that silencing TPS gene leads to molting deformities and high mortality rates via regulation of gene expression in the chitin biosynthetic pathway, and may be a promising approach for pest control in the future.


Assuntos
Quitina/biossíntese , Glucosiltransferases/metabolismo , Controle de Pragas/métodos , Interferência de RNA , Tribolium/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Glucose/metabolismo , Glucosiltransferases/genética , Trealose/metabolismo , Tribolium/genética
4.
Zhonghua Liu Xing Bing Xue Za Zhi ; 44(6): 942-948, 2023 Jun 10.
Artigo em Zh | MEDLINE | ID: mdl-37380417

RESUMO

Objective: To grasp the epidemiological characteristics of influenza outbreaks in Guangdong Province by analyzing the outbreaks of influenza-like cases reported in Guangdong Province from January 2015 to the end of August 2022. Methods: In response to the outbreak of epidemics in Guangdong Province from 2015 to 2022, information on on-site epidemic control was collected, and epidemiological analysis was conducted to describe the characteristics of the epidemics. The factors that influence the intensity and duration of the outbreak were determined through a logistic regression model. Results: A total of 1 901 influenza outbreaks were reported in Guangdong Province, with an overall incidence of 2.05%. Most outbreak reports occurred from November to January of the following year (50.24%, 955/1 901) and from April to June (29.88%, 568/1 901). A total of 59.23% (1 126/1 901) of the outbreaks were reported in the Pearl River Delta region, and primary and secondary schools were the main places where outbreaks occurred (88.01%, 1 673/1 901). Outbreaks with 10-29 cases were the most common (66.18%, 1 258/1 901), and most outbreaks lasted less than seven days (50.93%,906/1 779). The size of the outbreak was related to the nursery school (aOR=0.38, 95%CI:0.15-0.93), the Pearl River Delta region (aOR=0.60, 95%CI:0.44-0.83), the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=3.01, 95%CI:1.84-4.90), the influenza A(H1N1) (aOR=2.02, 95%CI:1.15-3.55) and the influenza B (Yamagata) (aOR=2.94, 95%CI: 1.50-5.76). The duration of outbreaks was related to school closures (aOR=0.65, 95%CI: 0.47-0.89), the Pearl River Delta region (aOR=0.65, 95%CI: 0.50-0.83) and the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=13.33, 95%CI: 8.80-20.19; 4-7 days compared with ≤3 days: aOR=2.56, 95%CI: 1.81-3.61). Conclusions: An influenza outbreak in Guangdong Province exhibits two peaks, one in the winter and spring seasons and the other in the summer. Primary and secondary schools are high-risk areas, and early reporting of outbreaks is critical for controlling influenza outbreaks in schools. Furthermore, comprehensive measures should be taken to prevent the spread of the epidemic.


Assuntos
Epidemias , Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Humanos , Influenza Humana/epidemiologia , Surtos de Doenças , China/epidemiologia
5.
Science ; 257(5066): 85-8, 1992 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-1621099

RESUMO

A proteinaceous elicitor of the plant defense reaction known as the hypersensitive response was isolated from Erwinia amylovora, the bacterium that causes fire blight of pear, apple, and other rosaceous plants. The elicitor, named harpin, is an acidic, heat-stable, cell-envelope-associated protein with an apparent molecular weight of 44 kilodaltons. Harpin caused tobacco leaf lamina to collapse and caused an increase in the pH of bathing solutions of suspension-cultured tobacco cells. The gene encoding harpin (hrpN) was located in the 40-kilobase hrp gene cluster of E. amylovora, sequenced, and mutated with Tn5tac1. The hrpN mutants were not pathogenic to pear, did not elicit the hypersensitive response, and did not produce harpin.


Assuntos
Proteínas da Membrana Bacteriana Externa , Proteínas de Bactérias/genética , Erwinia/fisiologia , Genes Bacterianos , Proteínas de Membrana/genética , Família Multigênica , Sequência de Aminoácidos , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Células Cultivadas , Erwinia/genética , Erwinia/patogenicidade , Escherichia coli/genética , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Plantas Tóxicas , Mapeamento por Restrição , Nicotiana/microbiologia
6.
Waste Manag ; 28(9): 1609-23, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17950590

RESUMO

A coupled fuzzy vertex and factorial-analysis approach was developed in this study for systematically characterizing effects of uncertainties in a municipal solid waste composting process. A comprehensive composting process model was also embedded into the system framework and used to address substrate decomposition and biomass growth, as well as the interactions between moisture contents, temperatures, and oxygen concentrations. The applicability of the proposed method was verified through a custom-made pilot-scale composting system. Results from fuzzy simulation indicated that the fuzzy vertex method could effectively communicate implicit knowledge into dynamic simulations and thus provide valuable information for enhancing composting process control under uncertainty. The factorial analysis was effective in quantifying the proportion to which the uncertainty of each single or interactive effect of model parameters contributes to the overall uncertainty of the system outcomes. Thus, sensitive parameters that may lead to errors or unreasonable predictions can be determined. The proposed study system could not only be used in characterizing combined effects of uncertainties for composting processes, but was also applicable to many other environmental modelling systems.


Assuntos
Lógica Fuzzy , Eliminação de Resíduos/métodos , Solo , Gerenciamento de Resíduos/métodos , Cidades , Modelos Teóricos , Projetos Piloto , Fatores de Tempo , Incerteza
7.
Mol Plant Microbe Interact ; 8(4): 484-91, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8589405

RESUMO

Mutants of the soft-rot pathogen Erwinia chrysanthemi EC16 that are deficient in the production of the pectate lyase isozymes PelABCE can elicit the hypersensitive response (HR) in tobacco leaves. The hrpNEch gene was identified in a collection of cosmids carrying E. chrysanthemi hrp genes by its hybridization with the Erwinia amylovora hrpNEa gene. hrpNEch appears to be in a monocistronic operon, and it encodes a predicted protein of 340 amino acids that is glycine-rich, lacking in cysteine, and highly similar to HrpNEa in its C-terminal half. Escherichia coli DH5 alpha cells expressing hrpNEch from the lac promoter of pBluescript II accumulated HrpNEch in inclusion bodies. The protein was readily purified from cell lysates carrying these inclusion bodies by solubilization in 4.5 M guanidine-HCl and reprecipitation upon dialysis against dilute buffer. HrpNEch suspensions elicited a typical HR in tobacco leaves, and elicitor activity was heat-stable. Tn5-gusA1 mutations were introduced into the cloned hrpNEch and then marker-exchanged into the genomes of E. chrysanthemi strains AC4150 (wild type), CUCPB5006 (delta pelABCE), and CUCPB5030 (delta pelABCE outD::TnphoA). hrpNEch::Tn5-gusA1 mutations in CUCPB5006 abolished the ability of the bacterium to elicit the HR in tobacco leaves unless complemented with an hrpNEch subclone. An hrpNEch::Tn5-gusA1 mutation also reduced the ability of AC4150 to incite infections in witloof chicory leaves, but it did not reduce the size of lesions that did develop. Purified HrpNEch and E. chrysanthemi strains CUCPB5006 and CUCPB5030 elicited HR-like necrosis in leaves of tomato, pepper, African violet, petunia, and pelargonium, whereas hrpNEch mutants did not.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Dickeya chrysanthemi/genética , Dickeya chrysanthemi/patogenicidade , Doenças das Plantas/microbiologia , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Bacteriano/genética , Escherichia coli/genética , Genes Bacterianos , Dados de Sequência Molecular , Mutação
8.
Cell Res ; 11(2): 156-60, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11453548

RESUMO

After pre-culture and treatment of osmosis, cotyledons of immature peanut (Arachis hypogaea L.) zygotic embryos were transformed via particle bombardment with a plasmid containing a chimeric hph gene conferring resistance to hygromycin and a chimeric intron-gus gene. Selection for hygromycin resistant calluses and somatic embryos was initiated at 10th d post-bombardment on medium containing 10-25 mg/L hygromycin. Under continuous selection, hygromycin resistant plantlets were regenerated from somatic embryos and were recovered from nearly 1.6% of the bombarded cotyledons. The presence and integration of foreign DNA in regenerated hygromycin resistant plants was confirmed by PCR (polymerase chain reaction) for the intron-gus gene and by Southern hybridization of the hph gene. GUS enzyme activity was detected in leaflets from transgenic plants but not from control, non-transformed plants. The production of transgenic plants are mainly based on a newly improved somatic embryogenesis regeneration system developed by us.


Assuntos
Arachis/genética , Cinamatos , Regulação da Expressão Gênica de Plantas/genética , Engenharia Genética/métodos , Higromicina B/análogos & derivados , Plantas Geneticamente Modificadas/genética , Regeneração/genética , Sementes/genética , Transformação Genética/fisiologia , Antibacterianos/metabolismo , Arachis/metabolismo , Técnicas de Cultura de Células/métodos , Quimera/genética , Cotilédone/genética , Resistência a Medicamentos/genética , Higromicina B/metabolismo , Osmose/fisiologia , Plasmídeos/genética
9.
Zhonghua Fu Chan Ke Za Zhi ; 28(4): 205-7, 252, 1993 Apr.
Artigo em Zh | MEDLINE | ID: mdl-8404301

RESUMO

Two hundred and sixteen cases of human papillomavirus infection of the vulva from 1984 to 1991 in the Affiliated Hospital of Qingdao Medical College were reviewed, and were immunohistochemically studied by ABC method to detect HPV-Ag. The results showed that the demonstration of diagnostic koilocytes is very important in diagnosis of HPV infection in routine tissue slides examination. But in cases of atypical morphological changes; when diagnostic koilocytes were not formed in early stage, the demonstration of brown color granules in the nuclei of prickle cells is very diagnostic for positive HPV infection. In occasional cases, the diagnostic koilocytes do not demonstrate brown color granules in their nuclei. The explanation is that HPV-Ag was exhausted during metabolism. Besides, the cell membrane of basal cells are stained with brown color granules, while the morphological changes of upper layers of squamous epithelium have not appeared yet, therefore, there were no HPV-Ag positive reactive cells. It is probably showed that the HPV-Ag is primarily formed and appeared in the cell membrane of basal cells.


Assuntos
Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/microbiologia , Infecções Tumorais por Vírus/microbiologia , Vulvite/microbiologia , Antígenos Virais/análise , Feminino , Humanos , Imuno-Histoquímica , Vulvite/patologia
10.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 23(2): 106-10, 2001 Apr.
Artigo em Zh | MEDLINE | ID: mdl-12905882

RESUMO

OBJECTIVE: To obtain recombinant human epidermal growth factor(hEGF) that can be used in animal experiments and clinical trial. METHOD: Chemically synthesized hEGF gene was expressed in Yeast Pichia pastoris and the secretory hEGF was purified by Phenysepharose 6 Fast Flow(high sub), Q-sepharose High Performance, and Superdex 30 chromatography, and its characters were studied by respective methods. RESULTS: The purified hEGF doesn't contain pyrogen, endotoxin, or yeast chromosome DNA and the purity reached 98%. The recombinant human EGF has correct molecular weight, pI, N-terminal amino acids sequences, peptide map, ultraviolet spectrum and well-biological activity. CONCLUSION: The purified hEGF is in accord with the requirements for animal experiments and clinical trial which provides the basis of preparing EGF agents for clinical test.


Assuntos
Fator de Crescimento Epidérmico/química , Fator de Crescimento Epidérmico/isolamento & purificação , Pichia/genética , Animais , Células 3T3 BALB , Fator de Crescimento Epidérmico/metabolismo , Humanos , Camundongos , Pichia/metabolismo , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
11.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 16(7): 402-4, 1996 Jul.
Artigo em Zh | MEDLINE | ID: mdl-9387732

RESUMO

The aim of the study is to investigate the effects of Injection Salviae Miltiorrhizae on the senile patients suffering from chronic asthmatic bronchitis. Fifty-three patients were divided randomly into group A(treated group, 33 cases) and group B(control group, 20 cases). The results showed that in group A, the treatment could ameliorate the symptoms, improve the pulmonary function, lower the PaCO2, elevate the PaO2 and enhance the immune function. They were markedly effective in 26 cases, effective in 6 cases and ineffective in 1 case. The cases in control group were 11, 8, 1 and 95% respectively. There was a significant difference between the effectiveness of the two groups.


Assuntos
Asma/tratamento farmacológico , Bronquite/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Antagonistas Muscarínicos/uso terapêutico , Idoso , Asma/fisiopatologia , Bronquite/fisiopatologia , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Extratos Vegetais , Testes de Função Respiratória , Salvia miltiorrhiza
12.
Theor Appl Genet ; 63(1): 71-3, 1982 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24270703

RESUMO

Pollen shed between 4-8 d from anthers of Triticum aestivum cultured in liquid medium gave rise to calluses. Tillers were harvested at the mid-to late-unicellular pollen stages and chilled for 8 d at 4-5 °C before the anthers were dissected out. Pollen cultures gave about 6 times as many calluses on a per anther basis as anthers cultured on solid medium. With the most productive of 5 cultivars tested, pollen culture results in roughly one callus for each anther used, though the calluses formed by pollen culture were less productive for the regeneration of shoots than calluses derived from anthers cultured on solid medium. The ratio of green to albino shoots is roughly 1∶ 1 for anther cultures but considerably less for pollen cultures.

13.
J Bacteriol ; 175(24): 7958-67, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8253684

RESUMO

HrpI, a 78-kDa protein, functions in the secretion of harpin, a proteinaceous elicitor of the hypersensitive response from Erwinia amylovora. The predicted amino acid sequence of HrpI is remarkably similar to that of LcrD of Yersinia species, the first member of a recently described protein family. Other proteins of the family are MixA from Shigella flexneri, InvA from Salmonella typhimurium, FlhA from Caulobacter crescentus, HrpI from Pseudomonas syringae pv. syringae, HrpO from Pseudomonas solanacearum, and HrpC2 from Xanthomonas campestris pv. vesicatoria. Cells of E. amylovora containing mutated hrpI genes or cells of Escherichia coli containing the cloned hrp gene cluster with mutated hrpI produce but do not export harpin. When similar cells with functional hrpI genes were grown at 25 degrees C, but not at 37 degrees C, harpin was exported to the culture supernatant. Direct evidence that HrpI is involved in the secretion of a virulence protein has been offered. Two other loci of the hrp gene cluster are involved in the regulation of harpin, and four other loci also are involved in the secretion of harpin. Since harpin and other proteins likely to be secreted by the LcrD family of proteins lack typical signal peptides, their secretion mechanism is distinct from the general protein export pathway.


Assuntos
Proteínas de Bactérias/metabolismo , Erwinia/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Sequência de Bases , Southern Blotting , Clonagem Molecular , DNA Bacteriano/análise , Erwinia/genética , Escherichia coli , Genes Bacterianos , Dados de Sequência Molecular , Família Multigênica , Plantas Tóxicas , Regiões Promotoras Genéticas , Mapeamento por Restrição , Homologia de Sequência de Aminoácidos , Nicotiana/metabolismo , Nicotiana/microbiologia
14.
Plant Cell Rep ; 7(5): 348-51, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24241881

RESUMO

Protoplasts were isolated from immature cotyledons of six cultivars of Glycine max L. and cultured in the KP8 liquid medium supplemented with 0.2 mg/L 2,4-D, 1 mg/L NAA and 0.5 mg/L ZT. The protoplasts started to divide after 3-5 days of culture. Sustained divisions resulted in mass production of cell colonies and small calli in 6 weeks. The calli further grew to 2-3 mm on the gelritesolidified K8 medium and were transferred onto the MSB medium with 1 mg/L 2,4-D and 0.25 mg/L BA, to obtain compact and nodular calli. Shoot formation was initiated on MSB medium with 0.15 mg/L NAA, and BA, KT and ZT, 0.5 mg/L of each, with or without 500 mg/L CH. It was followed by plant regeneration. So far, 87 plants have been regenerated from 4 cultivars, and normal seeds were obtained from them after transplanting into pots.

15.
Shi Yan Sheng Wu Xue Bao ; 32(4): 381-9, 1999 Dec.
Artigo em Zh | MEDLINE | ID: mdl-12548866

RESUMO

Several maize inbreds were transformed with Agrobacterium tumefaciens EHA101 (pGIH). Transgenic maize plants were obtained. Frequency of transformation of maize inbred Suyu No. 1 can reach 8.1%. Results of PCR and Southern blot analysis proved that T-DNA was stably integrated into the genome of maize. Staining with X-gluc confirmed the expression of GUS gene in maize cells. The band amplified by inverse PCR showed that the copy number of transgene in three transformants was single. After long term of subculture, some hygromycin resistant calli lost their regeneration ability. Although Southern blot probed the integration of gusA gene in their genome, GUS activity cannot be detected in those calli. Southern blot analysis of HpaII digest DNA showed that transgenic gusA gene was highly methylated.


Assuntos
Agrobacterium tumefaciens/genética , Transformação Genética , Zea mays/genética , Plantas Geneticamente Modificadas
16.
Shi Yan Sheng Wu Xue Bao ; 32(4): 409-13, 1999 Dec.
Artigo em Zh | MEDLINE | ID: mdl-12548869

RESUMO

The foreign Bt gene was transferred into protoplasts of soybean using PEG and PLO methods, respectively. The result indicated that the transformation frequency of PLO method was about 0.1% higher than PEG method. The PCR and Southern blotting analysis of the regeneration plants confirmed the integration of foreign gene into the genome of soybean.


Assuntos
Glycine max/genética , Peptídeos/farmacologia , Protoplastos/efeitos dos fármacos , Transformação Genética , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase , Glycine max/efeitos dos fármacos
17.
Plant Cell Rep ; 9(1): 51-3, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24226378

RESUMO

Protoplasts were isolated from immature inflorescence-derived embryogenic suspension cultures of two cultivars of Sorghum vulgare. The protoplasts were cultured in a modified K8P liquid medium. They started to divide after 4-5 days of culture, and achieved 16.8% division frequency by 10 days. Protocalli proliferated further upon transfer to C1 solid medium. After that, they were moved to C1 differentiation medium to induce shoot formation, followed by whole plant regeneration. So far, 60 plants have been obtained, with only two albinos. Some of these have been transplanted to soil in pots and grown to flowering and have set seeds.

18.
Plant Cell Rep ; 22(11): 793-800, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15022014

RESUMO

An efficient maize regeneration system was developed using mature embryos. Embryos were removed from surface-sterilized mature seeds and sliced into halves. They were used as explants to initiate callus on induction medium supplemented with 4.0 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). The induction frequency of primary calli was over 90% for all inbred lines tested. The primary calli were then transferred onto subculture medium supplemented with 2.0 mg l(-1) 2,4-D. Following two biweekly subcultures, embryogenic calli were formed. Inclusion of a low concentration (0.2 mg l(-1)) of 6-benzylaminopurine (BA) in the subculture medium significantly promoted the formation of embryogenic callus. The addition of silver nitrate (10 mg l(-1)) also supported an increased frequency of embryogenesis. The embryogenic callus readily formed plantlets on regeneration medium supplemented with 0.5 mg l(-1) BA. The regenerated plantlets were transferred to half-strength Murashige and Skoog medium supplemented with 0.6 mg l(-1) indole-3-butyric acid to develop healthy roots. The regenerated plantlets were successful on transfer to soil and set seed. Using this system, plantlets were regenerated from seven elite maize inbred lines. The frequency of forming green shoots ranged from 19.8% to 32.4%. This efficient regeneration system provides a solid basis for genetic transformation of maize.


Assuntos
Adenina/análogos & derivados , Zea mays/embriologia , Ácido 2,4-Diclorofenoxiacético/farmacologia , Adenina/farmacologia , Compostos de Benzil , Meios de Cultura/farmacologia , Técnicas de Cultura/métodos , Cinetina , Purinas , Regeneração , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Nitrato de Prata/farmacologia , Zea mays/efeitos dos fármacos
19.
J Bacteriol ; 177(21): 6201-10, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7592386

RESUMO

hrpL of Erwinia amylovora Ea321 encodes a 21.7-kDa regulatory protein, similar to members of the ECF (extra cytoplasmic functions) subfamily of eubacterial RNA polymerase sigma factors. hrpL is a single-gene operon in complementation group VI of the E. amylovora hrp gene cluster. Its product is required by Ea321 to elicit the hypersensitive response (HR) and to cause disease. HrpL controls the expression of five independent hrp loci, including hrpN, which encodes harpin, a proteinaceous elicitor of the HR. hrpL is environmentally regulated, and its expression is affected by hrpS, another regulatory gene of the hrp gene cluster of E. amylovora. pCPP1078, a multicopy plasmid carrying hrpL, is able to restore HR-eliciting ability to hrpS mutants. A conserved motif was identified upstream of the hrpI and hrpN operons, which are transcriptionally regulated by hrpL. This conserved motif shares a high degree of similarity with other biochemically defined or putative ECF-dependent promoter sequences, including sequences upstream of Streptomyces coelicolor dagA P2, Pseudomonas aeruginosa algD, Pseudomonas syringae pv. syringae 61 hrpZ, and P. syringae pv. tomato avrD. In spite of the similarity between the hrpL genes of E. amylovora and P. syringae 61, no functional cross-complementation was observed.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Ligação a DNA , Erwinia/genética , Regulação Bacteriana da Expressão Gênica , Fator sigma/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Proteínas da Membrana Bacteriana Externa/metabolismo , Sequência de Bases , Transporte Biológico , Mapeamento Cromossômico , RNA Polimerases Dirigidas por DNA/genética , Erwinia/patogenicidade , Genes Reguladores , Dados de Sequência Molecular , Óperon/genética , Plantas Tóxicas , Regiões Promotoras Genéticas/genética , Deleção de Sequência , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Nicotiana/microbiologia , Transcrição Gênica , Virulência/genética
20.
J Bacteriol ; 179(5): 1690-7, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9045830

RESUMO

A 6.2-kb region of DNA corresponding to complementation groups II and III of the Erwinia amylovora hrp gene cluster was analyzed. Transposon mutagenesis indicated that the two complementation groups are required for secretion of harpin, an elicitor of the hypersensitive reaction. The sequence of the region revealed 10 open reading frames in two putative transcription units: hrpA, hrpB, hrcJ, hrpD, and hrpE in the hrpA operon (group III) and hrpF, hrpG, hrcC, hrpT, and hrpV in the hrpC operon (group II). From promoter regions of the hrpA, hrpC, and hrpN operons, sequences similar to those of the HrpL-dependent promoters of Pseudomonas syringae pathovars were identified with a consensus sequence of 5'-GGAAC-N17-18-CACTNAA-3'. The protein products of seven genes, hrpA, hrcJ, hrpE, hrpF, hrpG, hrcC, and hrpV, were visualized with a T7 polymerase/promoter expression system. HrcC, HrcJ, and HrpT sequences contained potential signal peptides, and HrcC appeared to be envelope associated based on a TnphoA translational fusion. Comparison of deduced amino acid sequences indicated that many of the proteins are homologous to proteins that function in the type III protein secretion pathway. HrcC is a member of the YscC-containing subgroup in the PulD/pIV superfamily of outer membrane proteins. HrcJ is a member of a lipoprotein family that includes YscJ of Yersinia spp., MxiJ of Shigella flexneri, and NolT of Rhizobim fredii. Additional similarities were detected between HrpB and YscI and between HrpE and YscL. HrcJ and HrpE were similar to flagellar biogenesis proteins FliF and FliH, respectively. In addition, HrpA, HrpB, HrcJ, HrpD, HrpE, HrpF, and HrcC showed various degrees of similarity to corresponding proteins of P. syringae. Comparison of hrp clusters with respect to gene organization and similarity of individual proteins confirms that the hrp systems of E. amylovora and P. syringae are closely related to each other and distinct from those of Ralstonia (Pseudomonas) solanacearum and Xanthomonas campestris. Possible implications of extensive similarities between the E. amylovora and P. syringae hrp systems in pathogenesis mechanisms are discussed.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Erwinia/genética , Óperon , Sequência de Aminoácidos , Sequência de Bases , Sequência Consenso , Elementos de DNA Transponíveis , Erwinia/metabolismo , Escherichia coli/genética , Genes Bacterianos , Teste de Complementação Genética , Dados de Sequência Molecular , Mutagênese Insercional , Regiões Promotoras Genéticas , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
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