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1.
Heliyon ; 10(8): e29368, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38655323

RESUMO

Kidney clear cell renal cell carcinoma (KIRC) is also the most lethal subtype among all kidney cancer subtypes, posing a severe threat to public health. Therefore, it is crucial to identify new, reliable biomarkers in KIRC. Therefore, it is crucial to identify novel, reliable biomarkers associated with KIRC. We analyzed RNA sequence results from TCGA and several GEO datasets. The commonly deregulated gene, ALDOB, was found in multiple data and confirmed its important prognostic value. Subsequently, we explored the specific mechanism by which ALDOB regulates anti-tumor immunity through in vivo and in vitro experiments. We found that ALDOB may play a role in regulating tumor growth by regulating CD8+ T cell infiltration. This is consistent with the results of our immune infiltration-related analysis. In addition, we have also discovered the effect of ALDOB in previous studies on other cancer types. Finally, we concluded that ALDOB may have potential reference value for immunotherapy and can also be used as an independent predictor of prognosis in KIRC.

2.
iScience ; 26(8): 107450, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37583552

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) poses a severe threat to the health of pigs globally. Host factors play a critical role in PRRSV replication. Using PRRSV as a model for genome-scale CRISPR knockout (KO) screening, we identified a host factor critical to PRRSV infection: sphingomyelin phosphodiesterase acid-like 3B (SMPDL3B). Our findings show that SMPDL3B restricted PRRSV attachment, entry, replication, and secretion and that its depletion significantly inhibited PRRSV proliferation, indicating that SMPDL3B plays a positive role in PRRSV replication. Our data also show that SMPDL3B deficiency resulted in an accumulation of intracellular lipid droplets (LDs). The expression level of key genes (ACC, SCD-1, and FASN) involved in lipogenesis was increased, whereas the fundamental lipolysis gene, ATGL, was inhibited when SMPDL3B was knocked down. Overall, our findings suggest that SMPDL3B deficiency can effectively inhibit viral infection through the modulation of lipid metabolism.

3.
Vaccine ; 41(14): 2387-2396, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-36872144

RESUMO

Pasteurella multocida (P. multocida) infection frequently results in porcine atrophic rhinitis and swine plague, leading to large economic losses for the swine industry worldwide. P. multocida toxin (PMT, 146 kDa) is a highly virulent key virulence factor that plays a vital role in causing lung and turbinate lesions. This study developed a multi-epitope recombinant antigen of PMT (rPMT) that showed excellent immunogenicity and protection in a mouse model. Using bioinformatics to analyse the dominant epitopes of PMT, we constructed and synthesized rPMT containing 10 B-cell epitopes, 8 peptides with multiple B-cell epitopes and 13 T-cell epitopes of PMT and a rpmt gene (1,974 bp) with multiple epitopes. The rPMT protein (97 kDa) was soluble and contained a GST tag protein. Immunization of mice with rPMT stimulated significantly elevated serum IgG titres and splenocyte proliferation, and serum IFN-γ and IL-12 were upregulated by 5-fold and 1.6-fold, respectively, but IL-4 was not. Furthermore, the rPMT immunization group exhibited alleviated lung tissue lesions and a significantly decreased degree of neutrophil infiltration compared with the control groups post-challenge. In the rPMT vaccination group, 57.1% (8/14) of the mice survived the challenge, similar to the bacterin HN06 group, while all the mice in the control groups succumbed to the challenge. Thus, rPMT could be a suitable candidate antigen for developing a subunit vaccine against toxigenic P. multocida infection.


Assuntos
Infecções por Pasteurella , Pasteurella multocida , Animais , Camundongos , Suínos , Pasteurella multocida/genética , Epitopos de Linfócito B/genética , Proteínas de Bactérias/genética , Infecções por Pasteurella/prevenção & controle , Vacinação , Imunização
4.
Front Microbiol ; 14: 1087484, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36819040

RESUMO

Introduction: Pseudorabies virus (PRV) is the pathogenic virus of porcine pseudorabies (PR), belonging to the Herpesviridae family. PRV has a wide range of hosts and in recent years has also been reported to infect humans. N6-methyladenosine (m6A) modification is the major pathway of RNA post-transcriptional modification. Whether m6A modification participates in the regulation of PRV replication is unknown. Methods: Here, we investigated that the m6A modification was abundant in the PRV transcripts and PRV infection affected the epitranscriptome of host cells. Knockdown of cellular m6A methyltransferases METTL3 and METTL14 and the specific binding proteins YTHDF2 and YTHDF3 inhibited PRV replication, while silencing of demethylase ALKBH5 promoted PRV output. The overexpression of METTL14 induced more efficient virus proliferation in PRV-infected PK15 cells. Inhibition of m6A modification by 3-deazaadenosine (3-DAA), a m6A modification inhibitor, could significantly reduce viral replication. Results and Discussion: Taken together, m6A modification played a positive role in the regulation of PRV replication and gene expression. Our research revealed m6A modification sites in PRV transcripts and determined that m6A modification dynamically mediated the interaction between PRV and host.

5.
Front Cell Infect Microbiol ; 12: 866410, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35573790

RESUMO

Dental caries severely hinders efficient access to adequate energy in wildlife. Different food supplies will develop characteristic plaque, and the microorganisms of these plaque are closely related to dental health. Here, plaque samples from panda cubs with caries and caries-free were collected for 16S rRNA high-throughput sequencing. All sequences clustered into 337 operational taxonomic units (OTUs; 97% identity), representing 268 independent species belonging to 189 genera, 98 families, 51 orders, 24 classes, and 13 phyla. Two groups shared 218 OTUs, indicating the presence of a core plaque microbiome. α diversity analysis showed that the microbial diversity in plaques with caries exceeded that of caries-free. The dominant phyla of plaque microbiota included Proteobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Actinobacteria. The dominant genera included unclassified Neisseriaceae, Actinobacillus, Lautropia, Neisseria, Porhyromonas, unclassified Pasteurellaceae, Moraxella, Streptococcus, Bergeywlla and Capnocytophaga. ß diversity analysis showed that the plaque microbial community structure was different between two groups. Using LEfSe analysis, 19 differentially abundant taxa were identified as potential biomarkers. Finally, function predictions analysis showed All the energy related metabolic pathways on KEGG level 2 were enriched in caries-active group. Consistent with the mainstream caries-causing narrative, our results illuminate the lack of information regarding the oral microflora composition and function within giant panda cubs.


Assuntos
Cárie Dentária , Microbiota , Ursidae , Animais , Bactérias/genética , Humanos , Microbiota/genética , RNA Ribossômico 16S/genética , Ursidae/genética
6.
Exp Ther Med ; 22(2): 829, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34149875

RESUMO

Colorectal cancer (CRC) is one of the most common cancer types and a leading cause of cancer-associated mortality in China. Increased thioredoxin reductase 1 (TrxR1) levels have been previously identified as possible target for CRC. The present study revealed that the natural product hydroxytyrosol (HT), which exhibits a polyphenol scaffold, is a potent inhibitor of TrxR1. Inhibition of TrxR1 was indicated to result in accumulation of reactive oxygen species, inhibit proliferation and induce apoptosis and G1/S cell cycle arrest of CRC cells. Using a C-terminal mutant TrxR1 enzyme activity assay, TrxR1 RNA interference assay and HT binding model assay, the present study demonstrated the core character of the selenocysteine residue in the interaction between HT and TrxR1. HT can serve as polyphenol scaffold to develop novel TrxR1 inhibitors for CRC treatment in the future.

7.
Vet Microbiol ; 257: 109058, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33862332

RESUMO

Actinobacillus pleuropneumoniae (A.pleuropneumoniae) causes serious economic loss for the swine industry. A high-temperature requirements A (HtrA)-like protease and its homologs have been reported to be involved in protein quality control and expression of important immunoprotective antigens in many pathogens. In this study, we showed that HtrA of A.pleuropneumoniae exhibited both chaperone and proteolytic activities. Moreover, Outer membrane protein P5 (OmpP5) in A.pleuropneumoniae and Heat shock protein 90 (Hsp90) in porcine lung tissues were first discovered and identified as specific proteolytic substrates for rHtrA. The maximum cleavage activity occurs at 50 ℃ in a time-dependent manner. In addition, rHtrA mainly induced IgG 2a subtype of IgG and Th1 (IFN-γ, IL-2) response in a mice model, and promoted a significant proliferation of spleen lymphocytes compare with negative control (P < 0.05). The survival rates of 37.5 % were observed against A.pleuropneumoniae strain. Together, these data demonstrate that rHtrA plays a multi-functional role in A.pleuropneumoniae.


Assuntos
Actinobacillus pleuropneumoniae/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Actinobacillus pleuropneumoniae/química , Animais , Proteínas da Membrana Bacteriana Externa/imunologia , Modelos Animais de Doenças , Feminino , Proteínas de Choque Térmico HSP90/metabolismo , Imunoglobulina G/imunologia , Camundongos Endogâmicos BALB C , Proteólise , Serina Endopeptidases/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Células Th1/imunologia
8.
World J Clin Cases ; 8(24): 6473-6479, 2020 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-33392333

RESUMO

BACKGROUND: Acute arterial embolism of the extremities is a surgical emergency. Atrial fibrillation is the major etiology of acute arterial embolism of the extremities. Emergency femoral artery thrombectomy can successfully treat this issue. However, polycythemia vera (PV) may sometimes explain this medical emergency. Recurrent thrombosis in the lower extremities after thrombectomy can be found in patients with PV, and reoperation is needed for this condition. CASE SUMMARY: A 68-year-old man in China suffered from sudden pain in the left lower extremity for 14 h. The examination in the emergency department showed a diagnosis of acute arterial embolism of the extremities combined with PV. The patient's complaint disappeared after repeat emergency thrombectomy. CONCLUSION: Patients with acute arterial embolism of the extremities should be treated carefully, especially those who have recurrent thrombosis after emergency thrombectomy. Clinicians should be aware of PV, a rare cause of acute arterial embolism of the extremities. The combination of thrombectomy, phlebotomy, and antiplatelet and anticoagulant drugs may be a suitable therapeutic regimen for these patients.

9.
Medchemcomm ; 9(7): 1226-1231, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30109011

RESUMO

AIDS has evolved from a fatal infectious disease to a manageable chronic disease under the treatment of anti-AIDS medications. HIV fusion inhibitors with high activity, low side effects and strong selectivity are promising drugs against HIV. Only one fusion inhibitor is currently approved, thereby highly active long-acting fusion inhibitors need to be developed for long-term AIDS treatment. Here, we synthesised MT-SC22EK (a small HIV fusion inhibitor) derivatives containing 1-2 staples to improve its stability. Antiviral activity studies showed that MT-SC22EK-2 with two staples exhibited potent inhibitory activity against HIV-1 standard strains and Chinese epidemic strains, and at the same time, MT-SC22EK-2 presented strong anti-T20 resistance. Surprisingly, MT-SC22EK-2 possessed excellent protease stability with a half-life of 3665 min. MT-SC22EK-2 is a potential HIV fusion inhibitor considered as a long-acting anti-HIV drug candidate.

10.
J Huazhong Univ Sci Technolog Med Sci ; 36(6): 839-845, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27924500

RESUMO

Gefitinib is used as a first-line treatment for advanced non-small cell lung cancer (NSCLC). Unfortunately, most NSCLC patients inevitably develop gefitinib resistance during treatment. In addition to EGFR mutation status, the mechanisms involved are largely unknown. In this study, we showed that miR-124, a tumor suppressor, was significantly down-regulated in gefitinib-resistant NSCLC patients and cell lines compared with gefitinib-sensitive patients and cell lines. In addition, the miR-124 depletion induced gefitinib resistance, and miR-124 overexpression sensitized gefitinib-resistant cells to gefitinib. Mechanistic analysis revealed that miR-124 decreased SNAI2 and STAT3 expression by directly targeting their 3'UTRs and that knocking down SNAI2 or STAT3 partly reversed the gefitinib resistance induced by miR-124 depletion. Our data demonstrate that the miR-124 plays a new critical role in acquired resistance to gefitinib and that the manipulation of miR-124 might provide a therapeutic strategy for reversing acquired gefitinib resistance.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética , Quinazolinas/uso terapêutico , Regiões 3' não Traduzidas , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Gefitinibe , Células HEK293 , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Quinazolinas/farmacologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo
11.
World J Gastroenterol ; 22(12): 3506-10, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-27022233

RESUMO

Primary splenic angiosarcoma (PSA) is an unusual and highly malignant vascular tumour with a high rate of metastatic. Moreover, the research on prognosis of the disease is poor. The epidemiology, etiology, clinical diagnosis and treatment of the disease remain challenging, because case reports of the disease are few in number. In accordance with other malignant tumors, PSA is very aggressive, and the majority of patients in which this disease is found are at an advanced stage. Almost all patients die within 12 mo of diagnosis irrespective of treatment. We report here a woman who had complained of upper bellyache and anorexia for 10 d. Magnetic resonance imaging showed enlargement of the spleen with multiple heterogeneous masses in the lower pole of the spleen. A hand-assisted laparoscopic splenectomy was performed which allowed histopathologic diagnosis. The patient was diagnosed with PSA and liver metastasis, and succumbed to the disease 35 d after surgery. The literature was finished combined with the clinical features, diagnosis and management of PSA.


Assuntos
Hemangiossarcoma/secundário , Neoplasias Hepáticas/secundário , Neoplasias Esplênicas/patologia , Biomarcadores Tumorais/análise , Biópsia , Evolução Fatal , Feminino , Laparoscopia Assistida com a Mão , Hemangiossarcoma/química , Hemangiossarcoma/diagnóstico por imagem , Hemangiossarcoma/cirurgia , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/química , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Esplenectomia/métodos , Neoplasias Esplênicas/química , Neoplasias Esplênicas/diagnóstico por imagem , Neoplasias Esplênicas/cirurgia , Fatores de Tempo , Resultado do Tratamento
12.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 31(1): 57-60, 2013 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-23484304

RESUMO

OBJECTIVE: To evaluate the influence of different surface treatments on porcelain surface topography. METHODS: Metal ceramic prostheses in 6 groups were treated according to the different surface treatment methods, and the surface topography was observed through scanning electron microscope (SEM). Group A was the control one (untreated), group B was etched by 9.6% hydrofluoric acid(HF), group C was deglazed by grinding and then etched by 9.6% HF, group D was treated with Nd: YAG laser irradiation(0.75 W) and HF etching, group E was treated with Nd: YAG laser irradiation (1.05 W) and HF etching, and group F was treated with laser irradiation (1.45 W) and HF etching. RESULTS: Surface topography was different in different groups. A lot of inerratic cracks with the shapes of rhombuses and grid, and crater with a shape of circle were observed on the ceramic surface after treatment with energy parameters of 1.05 W Nd: YAG laser irradiation and 9.6% HF etching (group E). Surface topography showed a lot of concaves on the inner wall of the cracks, and the concaves with diameter of 1-5 microm could be observed on the inner wall of the holes, which had a diameter of 20 microm under SEM. CONCLUSION: The use of Nd: YAG laser irradiation with the energy parameters of 1.05 W and the HF with a concentration of 9.6% can evenly coarsen the porcelain surface, that is an effective surface treatment method.


Assuntos
Colagem Dentária , Porcelana Dentária , Cerâmica , Ácido Fluorídrico , Lasers de Estado Sólido , Resistência ao Cisalhamento , Propriedades de Superfície
13.
Yi Chuan ; 28(2): 195-9, 2006 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-16520316

RESUMO

A cross between bacterial wilt resistant tomato variety "T51A"and susceptible variety 'T9230' was made for mapping bacterial wilt resistance gene(s). Through inoculation test of its F1 and F2 progeny, it was proved that the resistance of 'T51A' to bacterial wilt was controlled by one heterozygous gene and cytoplasm. With 64 EcoR I/Muse I primer combinations, AFLP analysis was performed on two parents and their F2 resistant and susceptible bulks. A total of about 4200 distinguishable bands were amplified, of which two were stable. Genetic linkage analysis of the two polymorphic DNA fragments with the resistance gene(s) was tested in the F2 segregating population derived from the cross between 'T51A' and 'T9230'. The DNA fragment AAG/CAT was found closely linked to one of the bacterial wilt resistant genes, with a genetic distance of 6.7 cM, that was tentatively named RRS-342. The cloned fragment AAG/CAT was sequenced and then successfully converted to a SCAR marker, which can be used more conveniently in marker-assisted selection for tomato resistance to bacterial wilt gene.


Assuntos
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados/métodos , Proteínas de Plantas/genética , Solanum lycopersicum/genética , Solanum lycopersicum/microbiologia , Ligação Genética/genética , Imunidade Inata/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/fisiologia
14.
Zhonghua Yi Xue Za Zhi ; 85(5): 328-31, 2005 Feb 02.
Artigo em Chinês | MEDLINE | ID: mdl-15854510

RESUMO

OBJECTIVE: To investigate the molecular mechanism of transforming growth factor-beta1 (TGF-beta1) in regulating the production of matrix metalloproteinase-9 (MMP-9) protein. METHODS: Mouse immortal podocyte cells were cultured. Different concentrations (1, 2, and 5 ng/l) of TGF-beta1 were added into the culture medium. Cell culture without TGF-beta1 stimulation was used as control group. The activity of MMP-9 in the supernatant of the culture medion was assayed by gelatin zymography, expression of MMP-9 mRNA was assessed by RT-PCR; the activation of ERK pathway and the level of a transcriptional factor Ets-1 protein was analyzed by Western blotting. PD98059, a specific inhibitor of ERK1/2 activation, was added into the culture fluid of the podocytes for 30 minutes, than 2 ng/ml TGF-beta1 was added. The above mentioned tested were conducted to observe the influence of the inhibitor of ERK1/2 activation. RESULTS: The MMP-9 activity was very week in the supernatant of culture fluid of the control group and was increased in the TGF-beta1 groups dose-dependently. After the podocytes were co-incubated with 1 ng/ml TGF-beta1 for 24 hours, the MMP-9 activity was 26.86 times that of the control group (P < 0.01). Since the 12th hour after co-incubation with 2 ng/ml TGF-beta1 the MMP-9 activity in the supernatant of culture fluid began to be significantly increased and remained at high level till the 48 th hour. RT-PCR showed that low-level MMP-9 mRNA expression in the control group. After stimulation of 2 ng/ml TGF-beta1 for 6 hours the MMP-9 mRNA expression was 2.71 times that of the control group (P < 0.01) and the high-level expression lasted 24 hours. Western blotting showed low-level Ets-1 protein in the control group. At the time point of 12 th hour after stimulation of TGF-beta1 the Ets-1 protein expression was increased in all the three TGF-beta1 groups. After stimulation with 2 ng/ml TGF-beta1 for 4 hours the Ets-1 protein expression was 2.71 times that of the control group (P <0.01). After pretreatment of the podocyte with PD98059 for 30 minutes, the added 2 ng/ml TGF-beta1 failed to increase the MMP-9 activity and up-regulate the MMP-9 mRNA expression. CONCLUSION: TGF-beta1 stimulates the production of MMP-9 by activation of cytoplasmic ERK signaling pathway and upregulation of Ets-1 expression.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/biossíntese , Glomérulos Renais/citologia , Metaloproteinase 9 da Matriz/biossíntese , Proteína Proto-Oncogênica c-ets-1/biossíntese , Fator de Crescimento Transformador beta/farmacologia , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Metaloproteinase 9 da Matriz/genética , Camundongos , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Transdução de Sinais , Fator de Crescimento Transformador beta1
15.
Sheng Li Ke Xue Jin Zhan ; 36(4): 314-8, 2005 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-16408769

RESUMO

Tissue transglutaminase (tTG), an enzyme which can catalyze the posttranslational modification of proteins, is widely distributed and plays an important role in both physiological and pathological processes. More recently, tissue transglutaminase has been believed to participate in tissue fibrosis. Cross-linked extracellular matrix proteins by tissue transglutaminase are stable and highly resistant to proteolytic degradation, thus lead to accumulation of the ECM proteins in tissue fibrosis. This review summarizes the important features of this multifunctional enzyme and particularly introduces the correlation between tTG and renal fibrosis.


Assuntos
Proteínas da Matriz Extracelular/metabolismo , Fibrose/enzimologia , Rim/patologia , Transglutaminases/fisiologia , Animais , Humanos , Rim/metabolismo , Glomérulos Renais/patologia , Túbulos Renais/patologia , Transglutaminases/metabolismo
16.
Sheng Wu Gong Cheng Xue Bao ; 19(2): 227-30, 2003 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-15966327

RESUMO

Fruit ripening is associated with a number of physiological and biochemical changes. They include degradation of chlorophyll, synthesis of flavor compounds, carotenoid biosynthesis, conversion of starch to sugars, cell wall solublisation and fruit softening. These changes are brought about by the expression of specific genes. People are interested in the molecular mechanism involved in the regulation of gene transcription during fruit ripening. Many fruit-specific promoters such as PG, E4, E8, and 2A11 have been characterized and shown to direct ripening-specific expression of reporter genes. AGPase plays the key role in catalyzing the biosynthesis of starch in plants. It is a heterotetrameric enzyme with two small subunits and two large subunits, which are encoded by different genes. In higher plants, small subunits are highly conserved among plant species and expressed in all tissues. And the large subunits are present at multiple isoforms and expressed in a tissue-specific pattern. In fruits, the expression pattern of the large subunits varies with plant species. That made it important to study the transcriptional regulation of the large subunits of AGPase in different plant species. Northern-blot analysis indicates in watermelon, an isoform of the large subunits Wml1 expressed specifically in fruits, not in leaves. The 5' flanking region of Wml1, which covers 1573bp, has been isolated through the method of uneven PCR. And transient expression assay has shown that the 1573bp (named WSP) can direct fruit-specific expression of GUS gene. Our goal in this study was to scan the promoter region for main regulatory regions involved in fruit-specific expression. A chimaeric gene was constructed containing the WSP promoter, the beta-glucuronidase (GUS) structural sequence as a reporter gene and the nopaline synthase polyadenylation site (NOS-ter). The plasmid pSPA was digested with Hind III + Hinc II and promoter fragment of 1573bp (from 180bp to 1752bp) was cut out and cloned into Sma I sites of pBluescript SK(-), to produce pBSPA-16. The same insert was then cut out with Hind III + BamH I, and ligated with transient expression vector pBI426 digested by HindIII + Bgl II to produce pISPA-16. Three 5'-end deletions of the promoter were obtained and fused to GUS gene in plant transient expression vector pBI426: the 1201bp fragment (from 551bp to 1752bp) was generated by digestion of pBSPA-16 with BamH I + SnaB I, the 898bp fragment (from 854bp to 1752bp) by BamH I + EcoRV. Both fragments were ligated with pBluescript SK(-) digested by BamH I + Sma I, to produce pBSPA-12 and pBS-PA-9. The inserts were cut out with HindmIII + BamH I and ligated with pBI426 digested by Hind III + Bgl II, to produce pISPA-12 and pISPA-9. The 795bp fragment (from 957bp to 1752bp) was generated by digestion of pSPA with Hinc II + EcoR I, promoter fragment was cut out and cloned into Sma I sites of pBluescript SK(-), to produce pBSPA-8. The same insert were cut out with Hind III + BamH I, and ligated with transient expression vector pBI426 digested by Hind III + Bgl II. The 1573bp fragment and three 5'-end deletions were delivered into watermelon leaf, stem, flower and fruit of different development stages (5, 10, 20 days after pollination) via particle bombardment using a biolistic PDS-1000/He particle gun. Bombardment parameters were as follows: a helium pressure of 1200 psi, vacuum of 91432.23Pa, 7 cm between the stopping screen and the plate. Histochemical assay were done on all the tissues bombarded after incubation for 2 days. The 1573bp fragment had the strongest promoter activity, and can induce GUS expression in fruits of 5 and 20 days after anthesis and flowers, but not in fruits of 10 days after anthesis, leaves and stems. Fragments of 1201bp and 898bp can induce GUS expression only in fruits of 20 days after anthesis, and with lower expression levels than 1573bp. Fragment of 795bp was not able to direct GUS expression in any of the tissues bombarded (data not shown). It can be concluded that of the 1573bp, 1201 bp, 898bp Wml1 5'flanking regions include the necessary information directing fruit-specific expression. Deletion from 180bp to 551bp doesn't affect the fruit-specificity of the promoter, but lowered the expression level. There may be some cis-acting elements located in this region, which can enhance external gene expression in later stages of fruit development. Deletion from 854bp and 958bp led to loss of GUS expression. This region includes the necessary information needed for gene expression as well as the regulatory elements for fruit-specific transcription.


Assuntos
Citrullus/genética , Frutas/genética , Regiões Promotoras Genéticas/genética , Sequências Reguladoras de Ácido Nucleico/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Sequências Reguladoras de Ácido Nucleico/genética
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