Biomedical subjects
Publications and source records attributed to Jian-Bo Yang.
As the third generation of genetic markers SNPs (single nucleotide polymorphisms) has been used extensively in gene mapping,disease-correlativity analysis ,population genetics and drug research. Here methods for detection are reviewed. Most SNP genotyping are a combination of method for interrogating SNPs and analysis technique.It described both parts and give a outlook for detection.
Biochip technology which had emerged from the fusion of biotechnology and micro/nanofabrication technology at the end of 1980s has been widely used in life science, medicine, clinical diagnosis, drug development, agriculture, environmental protection and strategies. DNA microarray (also call gene chip, DNA chip), one kind of biochips, is small chip containing many oligonucleotide probes. It can hybridize with labelled sample, making it possible to detect large numbers of oligonucleotides at one time. So DNA microarray can overcome the disadvantage of traditional hybridization technology such as complexity, low automation, poor efficiency and quantity of molecules detected. This paper describes a new method to detect transgenic plant with gene chip. We have developed a novel arrayed-primer extension technique. It combines hybridization and PCR in one step, while ordinary DNA microarray needs two separate steps. Therefore our method provide a feasibility to detect long DNA fragment .
PURPOSE: To investigate the role of the NGX6 gene in carcinoma proliferation and profile the downstream genes regulated by NGX6 in a nasopharyngeal carcinoma (NPC) cell line. METHODS: We established a NPC cell line with NGX6 overexpression by gene transfection. Subsequently, a high-density cDNA array was used to identify differentially expressed genes in NGX6-overxepressed cells. Four differentially expressed genes or EST(expressed sequence tags) were examined using Northern blot. Furthermore, flow cytometry was employed to analyze the percentages of cells in the G(0)-G(1), S, and G(2)-M phase of the cell cycle in a NGX6 overexpression cell line. RESULTS: Fifty-five genes and ESTs were differentially expressed after NGX6 transfection in a cDNA array assay. Several genes related to cell cycle and transcription regulation were identified using this technique. Flow cytometry analysis showed NGX6 overexpression can increase the length of the G(1) phase of the cell cycle in NPC cells. CONCLUSION: We demonstrated the existence of a panel of genes that can be regulated by NGX6. Overexpression of NGX6 can influence the distribution of the cell cycle in NPC cells. Further studies are necessary to elucidate the exact function of these genes and their relationship to NGX6 expression.
Mitochorndrial DNA (mtDNA), nuclear DNA (nDNA), and genomic DNA (gDNA) were individually extracted from Zhenshan 97A, Xieqingzao A and A-23, which were cytoplasmic male sterile (wild abortive, dwarf abortive and BT), and from Zhenshan 97B, Xieqingzao B and BT, which were maintainers lines. Each of them was analyzed with 500 random primers by RAPD. Six fragments specific to male sterile lines were amplified. A fragment, PWH-17, associated with wild and dwarf abortive type cytoplasmic male sterility was analyzed by Southern blotting and sequencing, and also tested by SCAR. It was 1879 bp in length, which contained 6 open reading frames and 8 repeated sequences. BLAST search revealed that partial sequence in PWH-17 showed high similarity to the upstream sequence of tRNA-Asp gene in Elytrigia elongate (GenBank accession number U14335) and wheat (X13243). The similarity ratios were 97% and 100%. It was inferred that the possible position of PWH-17 in rice (wild abortive) could be located between tRNA-Asp and Cox II, which will be discussed further.
In this paper we introduce a new storage method of PCR ingredient. PCR mixture except DNA template has been frozen to dry powder by the DNA-Plus system. This kind of powder was stored at room temperature or 4 degrees. PCR has been run in different period of storage. It was discovered that the samples of lyophilization could keep activity for a long time.
In this paper we introduce a new method of PCR and RAPD reaction by using a small quantity of wheat leaf tissue with alkali treatment. It can be used either to detect target gene or to analyze polymorphism of wheat varieties. This method is simple and reliable, especially for a large-scale detection.
The 9p21-22 region shows loss of heterozygosity in up to 60% of human nasopharyngeal carcinomas (NPC), indicating the presence of a tumor suppressor gene in this region. We have identified a novel minimal common deletion region at 9p21-22. Twenty-two epithelial-derived expressed sequence tags (ESTs) in this critical region were systematically screened by differential RT-PCR to investigate the expression patterns in NPC cell line HNE1 and primary cultures of normal nasopharyngeal epithelial cells. One of these ESTs was found down-expressed in HNE1, whose differential expression was confirmed by Northern blot. Subsequently the corresponding gene sequence for this EST was established by cDNA cloning and RACE procedures (GenBank Accession No.AF222043). Furthermore, a mouse homologueof this gene was identified (GenBank Accession No.AF275549). This gene is 2.7 kb long and contains two UBA domains. It is a new member of UBA domain protein family, encoding a putative protein of 502 amino acids with a theoretical molecular mass of 55 kD, so we have named this gene UBAP1 for ubiquitin associated protein 1 (HUGO Gene Nomenclature Committee-approved symbol). Northern blot and RT-PCR analysis demonstrated a ubiquitous pattern of gene expression in human and mouse tissues. Direct sequencing analysis of the coding region of hUBAP1 following RT-PCR failed to reveal any mutations in a preliminary screening of NPC cell line HNE1 and primary nasopharyngeal carcinomas samples. However, more detailed analysis is to be performed to reveal if fine mutations of this gene are present in NPC.