Treacher Collins syndrome is a congenital craniofacial malformation with autosomal dominant inheritance as the main genetic pattern. In this condition, the biosynthesis of ribosomes in neural crest cells and neuroepithelial cells is blocked and the number of neural crest cells that migrate to the craniofacial region decreases, causing first and second branchial arch dysplasia. Definite causative genes include treacle ribosome biogenesis factor 1 (tcof1), RNA polymerase Ⅰ and Ⅲ subunit C (polr1c), and RNA polymerase Ⅰ and Ⅲ subunit D (polr1d). This paper provides a review of research of three major patho-genic genes, pathogenesis, phenotypic research, prevention, and treatment of the syndrome.
DNA-Directed RNA Polymerases ; genetics ; Humans ; Mandibulofacial Dysostosis ; genetics ; Neural Crest ; Nuclear Proteins ; Phosphoproteins

OBJECTIVETo synthesize highly pure HBV post-transcriptional regulatory element (HPRE) via transcription in vitro by T7 RNA polymerase.

METHODSHPRE gene was amplified by PCR from a template containing HBV complete genomic DNA and cloned into plasmid pGEM-11zf. The cloned DNA sequence was transcribed by T7 RNA polymerase.

RESULTSThe construction of HPRE gene recombinant plasmid and production of HPRE via transcription in vitro was successful.

CONCLUSIONIn vitro transcription by T7 RNA polymerase can be used to synthesize highly pure HPRE.

DNA-Directed DNA Polymerase ; DNA-Directed RNA Polymerases ; Hepatitis B virus ; genetics ; RNA Processing, Post-Transcriptional ; RNA Splicing ; RNA-Binding Proteins ; physiology ; Transcription, Genetic ; Viral Proteins

To enhance the efficiency of the expression of target gene in eukaryotic cells, one of the strongest prokaryotic expression systems, the T7 RNA polymerase and T7 promoter, was introduced into eukaryotic cells. A duel-plasmid gene expression system of T7 bacteriophage components was developed; one containing the T7 phage RNA polymerase gene under the control of eukaryotic promoter CMV (pCMV-T7pol) and the other (pT7IRES) containing the T7 promoter and T7 terminator as well as EMCV IRES. To test the feasibility of this plasmid system for eukaryotic expression, hepatitis B virus envelop HBV preS2/S was used to construct pT7IRES-HBs. The target genes were expressed efficiently by the eukaryonized prokaryotic expression system in a variety of the cells indicating C2C12, SP2/0, NIH3T3 and BALB/c 3T3, suggesting the potential applications of the expression system in gene therapy and gene immunization.
Animals ; Bacteriophage T7 ; genetics ; Cell Line ; DNA-Directed RNA Polymerases ; genetics ; Gene Targeting ; Promoter Regions, Genetic ; genetics ; Viral Proteins ; genetics

Treacher Collins syndrome (TCS, OMIM 154500), also known as Franceschetti-Klein syndrome, is a rare disorder that affects the first and second branchial arches. The estimated incidence is 1/50 000 live births. Mutations in TCOF1 (78%-93%) and POLR1C or POLR1D (8%) cause the disease. Most of TCS cases are inherited in a dominant pattern, while a small proportion are inherited in a recessive pattern. TCS has a variable phenotype with typical clinical characteristics including downward-slant of palpebral fissure, malar hypoplasia, mandibular hypoplasia and microtia. TCS management is a multidisciplinary affair, as interventions range from reconstructive to psychosocial. For hearing rehabilitation, TCS patients may have the choices of BAHA, ponto, vibrant soundbridge or bonebridge implantation. In this review, we summarize the TCS clinical malformations, diagnosis, genetics, management and auditory rehabilitation.
DNA-Directed RNA Polymerases ; genetics ; Facial Bones ; abnormalities ; Humans ; Mandibulofacial Dysostosis ; diagnosis ; genetics ; rehabilitation ; Mutation ; Nuclear Proteins ; genetics ; Phosphoproteins ; genetics

The low expression rate of exogenous genes in cyanobacteria is one of the bottlenecks of cyanobacteria genetic engineering. The T7 RNA polymerase expression system has achieved the efficient expression of exogenous genes in Escherichia coli. Cyanobacteria and E. coli are both Gram-negative bacteria with high genetic homology. The construction of T7 RNA polymerase expression system in cyanobacteria may improve the expression of foreign genes. In order to construct the T7 RNA polymerase expression system in Anabaena sp. PCC 7120, methods such as overlapping extension PCR and digestion-ligation technique were used to construct a site-specific integration vector pEASY-T1-F1-TacT7RNAPCmR-F2 and a shuttle expression vector pRL-T7-hG-CSF. The site-specific integration vector is capable of expressing T7 RNA polymerase, and the shuttle expression vector expresses hG-CSF driven by the T7 promoter. Then we introduced the site-specific integration vector into the wild type cyanobacteria by electroporation and transferred the shuttle expression vector into the site-integrated transgenic cyanobacteria by triparental conjugative transfer. In the end, we identified the presence of foreign genes in cyanobacteria by PCR, tested the transcription level of foreign genes in cyanobacteria by RT-PCR, and detected the protein expression of foreign genes in cyanobacteria by Western blotting. The two vectors were successfully constructed, the T7 RNA polymerase gene and hG-CSF gene were transferred into cyanobacteria well, and both genes were also expressed in cyanobacteria. In summary, the T7 RNA polymerase expression system was successfully constructed in cyanobacteria, and the expression rate of hG-CSF gene was doubled than the traditional cyanobacteria expression systems. This expression system will provide a better tool for the application of cyanobacteria genetic engineering and will promote the development of cyanobacteria as a chassis cell in the fields of synthetic biology in the future.
Anabaena/genetics* ; Cloning, Molecular ; DNA-Directed RNA Polymerases ; Escherichia coli/genetics* ; Gene Expression ; Mercury ; Plasmids ; Viral Proteins

DNA-Directed RNA Polymerases ; genetics ; Genetic Vectors ; Hep G2 Cells ; Hepatic Stellate Cells ; metabolism ; Humans ; Promoter Regions, Genetic

In this study, we constructed the plasmid of Sendai virus (SeV) BB1 strain minigenome with Gaussia luciferase (Gluc) as reporter and compared the rescue efficiency of SeV minigenome mediated by T7 promoter with that by CMV promoter. Firstly, the sequence was designed and synthesized which contained hammerhead ribozyme, sequence composed of the trailer, untranslated region of L gene, untranslated region of N gene, and the leader from SeV, and mutant hepatitis delta virus ribozyme sequence. Then, the synthesized sequence was inserted into pVAX1 containing CMV and T7 promoters and the general vector for SeV minigenome pVAX-miniSeV was obtained. Furthermore, pVAX-miniSeV-Gluc (+) and pVAX-miniSeV-Gluc(-) were obtained by inserting Gluc gene into pVAX-miniSeV. From the supernatant of BHK-21 cell transfected with pVAX-miniSeV-Gluc(+), high level of Gluc expression was detection indicating the normal transcription function of CMV promoter. pVAX-SeV-miniGluc(-) and plasmids expressing N,P and L protein of SeV were co-transfected into BST T7/5 cell which derived from BHK-21 and expressed T7 RNA polymerase stably. And high expression of Gluc was found, which indicated that SeV minigenome was efficiently rescued. However, we failed to repeat the result on BHK-21 cell, implying that T7 promoter and CMV promoter may have different effects on the rescue efficiency of SeV minigenome. Therefore, we further constructed SeV minigenome vectors pT7-miniSeV-Gluc (-) and pCMV-miniSeV-Gluc(-) with single promoter of T7 or CMV. Then, these vectors were transfected into BSR T7/ 5 cells respectively accompanied with the N, P, and L protein expression vectors. The result demonstrated that high expression of Gluc was found in the group of pT7-miniSeV-Gluc(-), which failed in the group of pCMV-miniSeV-Gluc(-). It indicated that T7 promoter significantly increased the rescue efficiency of SeV minigenome. We successfully constructed a SeV minigenome vector with secreted luciferase gene as report er and proved T7 promoter can enhance the rescue efficiency of SeV minigenome, which provides basis for construction of infectious clone containing SeV full-length genome.
Animals ; Cell Line ; Cricetinae ; Cytomegalovirus ; genetics ; DNA-Directed RNA Polymerases ; genetics ; Genome, Viral ; Humans ; Promoter Regions, Genetic ; Respirovirus Infections ; virology ; Sendai virus ; genetics ; physiology ; Viral Proteins ; genetics ; metabolism

The purpose of this study is to provide a simple and reliable genetic typing approach for molecular drug susceptibility test of Mycobacterium tuberculosis, through the developing of fluorescence molecular marker of rifampicin resistance gene rpoB. Eleven fluorescent molecular markers of the rpoB gene were established by using the sequence difference between the amino acid positions 531, 526, 516, 511 and 513 of rpoB gene of rifampicin-resistant strains and the alleles of rifampicin-sensitive strains, combined with the PARMS technique (Penta-primer amplification refractory mutation system). We used 104 clinical isolates of Mycobacterium tuberculosis to validate this marker and it was verified by sequencing as 100% correct. These samples were also tested with proportional drug sensitivity test. The coincidence rate was 94.23%. The molecular markers had high reliability for genotyping of rpoB gene. It can also detect low-concentration drug-resistant samples (511/533 unit point mutations) whose phenotypic susceptibility cannot be detected. The eleven sets of fluorescent molecular markers could cover 92%-96% of rpoB gene mutation types of rifampicin-resistant strains, and provide new idea for rapid detection of rifampin-resistant Mycobacterium tuberculosis.
Bacterial Proteins/genetics* ; DNA-Directed RNA Polymerases/genetics* ; Drug Resistance, Bacterial/genetics* ; Microbial Sensitivity Tests ; Mutation ; Mycobacterium tuberculosis/genetics* ; Reproducibility of Results ; Rifampin/pharmacology* ; Technology

In vitro transcription systems with T7 RNA polymerase (T7 RNAP) were widely used in preparation of RNA because of their simplicity and high efficiency. The transcripts would have additional 5' sequence since T7 promoter spans the transcription start site, while deletion of the transcription start site would severely reduce the T7 RNAP transcriptional activity. We successfully developed an in vitro transcription by combining of T7 RNAP high efficient transcription system and highly specific self-splicing technology of ribozymes, in this system, ribozyme self-splices at the designed specific site and releases the aim RNA without affecting transcription efficiency of T7 RNAP, the aminoacylation activity of human mitochondrial tRNA(Trp) (HmtRNA(Trp) (UCA)) is 113.6 pmol/microg. This method with its high efficiency on transcription and good repeatability is very suitable for preparation of accurate RNA in large scale.
Base Sequence ; DNA-Directed RNA Polymerases ; genetics ; Humans ; Molecular Sequence Data ; RNA ; genetics ; RNA Splicing ; RNA, Catalytic ; genetics ; RNA, Transfer, Trp ; genetics ; Transcription, Genetic ; Transfer RNA Aminoacylation ; genetics ; Viral Proteins ; genetics

OBJECTIVETo detect the mutations of rpoB gene in Mycobacterium tuberculosis by pyrosequencing and to evaluate the values on detection of rifampin resistance in clinical isolates.

METHODSUsing the new technology of pyrosequencing, the mutations in the rifampin resistance determining region (RRDR) of rpoB gene were analyzed. The results were compared with those obtained from methods of the absolute concentration and the minimum inhibitory concentration (MIC).

RESULTSAmong the 150 Mycobacterium tuberculosis clinical isolates, 84 were susceptible and 66 resistant to RIF. 54 of the 66 resistant isolates were multidrug-resistant (MDR) strains. Ser531Leu and His526Asp or Tyr, including twelve different genotypes and six codons, were the most common mutations. In the drug susceptibility testing, the accordance rates of the pyrosequencing and the absolute concentration method as well as MIC were 92.7% and 97.8% respectively.

CONCLUSIONNot only is the pyrosequencing technology a fast, sensitive and high throughput method in detecting rifampin resistance in Mycobacterium tuberculosis, but also a useful tool in the research of rifampin resistance mechanism.

Bacterial Proteins ; genetics ; DNA-Directed RNA Polymerases ; Drug Resistance, Bacterial ; genetics ; Humans ; Microbial Sensitivity Tests ; Mutation ; Mycobacterium tuberculosis ; drug effects ; genetics ; Phosphoric Acids ; Polymerase Chain Reaction ; Rifampin ; pharmacology