An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes. In this study, firstly, a genetic transformation system based on intergeneric conjugation was developed in Streptomyces rimosus M527, a bacterial strain which exhibits strong antagonistic activity against a broad range of plant-pathogenic fungi. Some experimental parameters involved in this procedure were optimized, including the conjugative media, ratio of donor to recipient, heat shock temperature, and incubation time of mixed culture. Under the optimal conditions, a maximal conjugation frequency of 3.05×10^-5 per recipient was obtained. Subsequently, based on the above developed and optimized transformation system, the synthetic promoters SPL-21 and SPL-57, a native promoter potrB, and a constitutive promoter permE^* commonly used for gene expression in streptomycetes were selected and their activity was analyzed using gusA as a reporter gene in S. rimosus M527. Among the four tested promoters, SPL-21 exhibited the strongest expression activity and gave rise to a 2.2-fold increase in β-glucuronidase (GUS) activity compared with the control promoter permE^*. Promoter SPL-57 showed activity comparable to that of permE^*. Promoter potrB, which showed the lowest activity, showed a 50% decrease in GUS activity compared with the control permE^*. The transformation system developed in this study and the tested promotors provide a basis for the further modification of S. rimosus M527.
Conjugation, Genetic ; Glucuronidase/genetics* ; Promoter Regions, Genetic ; Streptomyces rimosus/genetics*

BACKGROUNDNumerous studies have evaluated the association between interleukin-18 (IL-18) promoter gene -607C/ A (rs1946518) polymorphism and tuberculosis (TB) risk. However, the results remain apparently conflicting. The aim of this study was to investigate whether IL-18-607C/A polymorphism is associated with susceptibility to TB.

METHODSPublications addressing the association between the IL-18-607C/A polymorphism and TB risk were selected from the Pubmed, Cochrane Library, Embase, CNKI and Wanfang databases. Data were extracted from the studies by two independent reviewers. Statistical analysis was performed using RevMan 5.0.25 and STATA 11.0 software.

RESULTSEight case-control studies with a total of 1166 TB patients and 1734 controls were retrieved. Meta-analysis results showed significant association between IL-18-607C/A polymorphism and TB risk in all comparisons of the A allele versus C allele (OR=1.17, 95% CI 1.05-1.30, P=0.004), AA versus CC (OR=1.43, 95% CI 1.14-1.81, P=0.002), CA+AA versus CC (OR=1.20, 95% CI 1.01-1.42, P=0.04) and AA versus CA+CC (OR=1.30, 95% CI 1.07-1.58, P=0.007). In subgroup analysis by nationality, a significant association between IL-18-607C/A polymorphism and TB risk in the comparisons of A versus C, CA+AA versus CC and AA versus CA+CC (OR=1.22, 95% CI 1.07-1.38, P=0.002; OR=1.31, 95% CI 1.06-1.61, P=0.01; OR=1.32, 95% CI 1.07-1.63, P=0.01, respectively) were found in Chinese population but not in Indian and Iranian populations.

CONCLUSIONThis study suggests that the -607C/A polymorphism of IL-18 gene would be a risk factor for TB, especially in Chinese population. To further evaluate gene-to-gene and gene-to-environment interactions on -607C/A polymorphism and tuberculosis risk, more studies with thousands of patients are required.

Genetic Predisposition to Disease ; genetics ; Humans ; Interleukin-18 ; genetics ; Promoter Regions, Genetic ; genetics ; Tuberculosis ; epidemiology ; genetics

BACKGROUNDOsteoarthritis (OA) is the most common form of human polyarthritis. Many genetic factors have been implicated in OA. It was reported that a polymorphism in the gene of interleukin-6 (IL-6) was associated with OA of knee. The aim of this study was to determine whether functional IL-6 promoter -174G/C (rs1800795) polymorphisms confer susceptibility to knee OA.

METHODSA meta-analysis was conducted on the association between the IL-6 polymorphism and knee OA. Electronic search at PubMed, EMBASE, Weipu database, and Wanfang database was conducted to select studies. Case-control studies containing available genotype frequencies of IL-6 -174G/C were chosen, and odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of this association.

RESULTSA total of seven studies involving 6 464 subjects (knee OA 3 331 and controls 3 133) were considered in this study. The results suggested that the variant genotypes were not associated with knee OA risk in all genetic models (additive model: OR = 1.144, 95% CI 0.934-1.402, P = 0.194; recessive model: OR = 1.113, 95% CI 0.799-1.550, P = 0.526; dominant model: OR = 1.186, 95% CI 0.918-1.531, P = 0.191). A symmetric funnel plot, the Begg's test (P > 0.05), suggested that the data lacked publication bias.

CONCLUSIONSThis meta-analysis does not support the idea that rs1800795 genotype is associated with increased risk of knee OA. However, to draw comprehensive and more reliable conclusions, further prospective studies with larger numbers of participants worldwide are needed to examine the association between rs1800795 polymorphism and knee OA.

Humans ; Interleukin-6 ; genetics ; Osteoarthritis, Knee ; epidemiology ; genetics ; Polymorphism, Genetic ; genetics ; Promoter Regions, Genetic ; genetics

4-Hydroxybutyric acid (4HB) is a psychotropic drug used for polymer synthesis such as poly (4-hydroxybutyric acid) (P4HB) and poly (3-hydroxybutyric acid-co-4-hydroxybutyric acid) (P3HB-co-4HB). 1,4-butanediol (BD) can be converted to 4-hydroxybutyric acid by alcohol dehydrogenase (DhaT) and aldehyde dehydrogenase (AldD). In this study, high efficiency promoters including T7 promoter and P(Re) promoter were cloned to increase expression of dhaT and aldD, and thus accelerate the conversion from BD to 4HB. A. hydrophila 4AK4 (pZQ01), the recombinant strain under the control of T7 promoter, produced 6.00 g/L 4HB from 10 g/L BD with the productivity increased by 43.20%. While A. hydrophila 4AK4 (pZQ04), the strain under the control of T7 promoter, produced 4.87 g/L 4HB from 10 g/L BD, and the productivity was increased by 16.23%. Thus, the gene expression was increased by T7 and P(Re) promoters, leading to an accelerated biosynthesis of 4HB.
Aeromonas hydrophila ; genetics ; metabolism ; Genetic Engineering ; Hydroxybutyrates ; metabolism ; Promoter Regions, Genetic ; genetics ; Recombination, Genetic

OBJECTIVETo study the transcriptional regulation of human delta globin gene with C-->T point mutation at -64 in its promoter.

METHODSHuman delta globin genes including wild CAAT box and mutant CAAT box (-64C-->T) were separately cloned into eukaryotic expression vector pcDNA3.1 (-)/Myc-His A which was cut out the strong promoter CMV, transfected MEL cells, and induced by DMSO to express. The transcriptional regulation of human delta globin gene was analysed using semi-quantitative RT-PCR.

RESULTSThe expression level of human delta globin gene with mutant CAAT box was 2.2-fold as high as that with wild CAAT box.

CONCLUSIONThe defective CAAT box of human delta globin gene promoter region may be one of the major reasons for its low expression level.

CCAAT-Enhancer-Binding Proteins ; genetics ; Globins ; genetics ; Humans ; Point Mutation ; Promoter Regions, Genetic ; genetics ; Transcription, Genetic

Manipulation of genes, including knock-out or knock-in, replacement of gene elements (such as promoters), fusion with a fluorescent protein gene, and construction of in situ gene reporter, is required in most of the biotechnological laboratories. The widely used gene manipulating methods based on two-step allelic exchange are cumbersome in terms of constructing plasmids, transforming and screening. In addition, the efficiency of using this method for long fragment knockout is low. To simplify the process of gene manipulation, we constructed a minimized integrative vector pln2. When a gene needs to be inactivated, an internal fragment of the target gene (non-frameshift) is cloned into the pln2 plasmid. Once the single-crossover recombination between genome and the constructed plasmid occurs, the endogenous gene is segmented by the plasmid backbone and thus inactivated. We developed a toolbox based on pln2 that can be used for different genomic operation mentioned above. With the help of this toolbox, we successfully knocked out large fragments of 20-270 kb.
Genetic Vectors/genetics* ; Pseudomonas aeruginosa/genetics* ; Plasmids/genetics* ; Promoter Regions, Genetic ; Genome

The choice of specific promoters used within a transgene construct is a vital strategy to achieve the transgene regulation in the temporal, spatial and measurable manner. The strategy has been widely used in diverse aspects of plant gene engineering, such as quality improvement, resistance breeding and bioreactor. In this paper, we describe the structure feature, classification and research method of the specific promoter and its application progresses in plant gene engineering.
Animals ; Bioreactors ; Breeding ; Genetic Engineering ; methods ; Humans ; Immunity, Innate ; Plants ; genetics ; immunology ; Promoter Regions, Genetic ; genetics

BACKGROUNDThe highly polymorphic interleukin 10.G (IL10.G) microsatellite located in the promoter region of the interleukin-10 (IL-10) gene exerts a positive transcriptional regulatory effect on IL-10 gene expression and correlates with the in vitro IL-10 secretion. This study was conducted to investigate whether IL10.G microsatellite is associated with the incidence and/or the outcome of severe sepsis.

METHODSOne hundred and fifteen patients with severe sepsis who had been treated at the intensive care unit of the university hospital were studied. One hundred and forty-one healthy individuals served as controls. IL10.G microsatellite genotyping was performed with the following two methods: fluorescent based polymerase chain reaction (PCR) techniques and silver staining of the amplified DNA fragment in polyacrylamide gel. Alleles were defined according to the size of the amplified DNA product.

RESULTSTen alleles and 36 genotypes were detected both in the patients with severe sepsis and in the healthy controls. Allele IL10.G9 and allele IL10.G13 were the commonest alleles with the frequencies of 32.6% and 21.3% respectively in the patients with severe sepsis, and 34% and 27% respectively in the healthy controls. The allele frequencies of IL10.G microsatellite were neither different between the patients with severe sepsis and the healthy controls (P > 0.05), nor between survivors and non-survivors (P > 0.05). However, the frequency of one common allele IL10.G13 was slightly lower in the patients with severe sepsis than in the healthy controls (21.3% vs 27%, P > 0.05), and the frequency of allele IL10.G9 was slightly higher in the non-survivors than in the survivors (37.1% vs 28.1%, P > 0.05).

CONCLUSIONIL10.G microsatellite may neither contribute to the susceptibility to severe sepsis nor to the fatal outcome of severe sepsis.

Female ; Genetic Predisposition to Disease ; Humans ; Interleukin-10 ; genetics ; Male ; Microsatellite Repeats ; Promoter Regions, Genetic ; Sepsis ; genetics

OBJECTIVETo study the potential transcriptional depression activities of HPV2 E2 proteins with mutations in different functional domains.

METHODSThe primers for constructing various E2 mutants were synthesized based on a HPV2 isolate containing several point mutations within E2 open reading frame. Different E2 mutations were generated by the method of extending PCR and inserted into plasmid pcDNA3. 1. Various recombinant mammalian expression plasmids pcDNA3. 1-E2 were co-transfected into HeLa cells together with a CAT-reporter plasmid pBLCAT-LCR containing HPV-2 prototype LCR, respectively. The transcriptional repression activities of the E2 mutants were evaluated by detection of CAT expression values.

RESULTSCompared with the full-length prototype E2, removals of both N- and C-terminal domains abolished E2 transcriptional repressive activities. The point mutations in the transactivation domain (nt 3037), the internal hinge region (nt 3387) and DNA binding domain (nt 3697) showed remarkable inhibition on its transcriptional depression function.

CONCLUSIONThe transcriptional regulation activity of HPV2 E2 is related with its DNA binding and transactivation domains. The exchanges of the single amino acid within E2, derived from a HPV2 isolate, abolish significantly the repressive effect on viral promoter in the context of full-length E2.

HeLa Cells ; Humans ; Oncogene Proteins, Viral ; genetics ; Papillomaviridae ; genetics ; Promoter Regions, Genetic ; genetics ; Transcriptional Activation ; genetics

ObjectiveThe objective of the study was to summarize the role of DNA methylation in the development and metastasis of uveal melanoma (UM).

Data SourcesThe relevant studies in MEDLINE were searched.

Study SelectionIn this review, we performed a comprehensive literature search in MEDLINE using "uveal melanoma" AND ("DNA methylation" OR "epigenetics") for original research/review articles published before February 2018 on the relationship between DNA methylation and UM. References of the retrieved studies were also examined to search for potentially relevant papers.

ResultsPrevious studies on the relationship between DNA methylation and UM covered many genes including tumor suppressor genes (TSGs), cyclin-dependent kinase genes, and other genes. Among them, the TSG genes such as RASSF1A and p16INK4a, which encodes a cyclin-dependent kinase inhibitor, are relatively well-studied genes. Specifically, a high percentage of promoter methylation of RASSF1A was observed in UM cell lines and/or patients with UM. Promoter methylation of RASSF1A was also associated with the development of metastasis. Similarly, a high percentage of promoter hypermethylation of p16INK4a was found in UM cell lines. DNA promoter methylation can control the expression of p16INK4a, which affect cell growth, migration, and invasion in UM. Many other genes might also be involved in the pathogenesis of UM such as the Ras and EF-hand domain containing (RASEF) gene, RAB31, hTERT, embryonal fyn-associated substrate, and deleted in split-hand/split-foot 1.

ConclusionsOur review reveals the complex mechanisms underlying the tumorigenesis of UM and highlights the great needs of future studies to discover more genes/5'-C-phosphate-G-3' sites contributing to the development/metastasis of UM and explore the mechanisms through which epigenetic changes exert their function in UM.

Cell Transformation, Neoplastic ; genetics ; DNA Methylation ; genetics ; Epigenesis, Genetic ; genetics ; Humans ; Melanoma ; genetics ; Promoter Regions, Genetic ; genetics ; Uveal Neoplasms ; genetics