Biomedical subjects

Y Zan

Publications and source records attributed to Y Zan.

4 recordsLinked to original sources

PubMed2006

Characterizing a rat Brca2 knockout model.

Evidence exists that BRCA2 carriers may have an elevated risk of breast, ovarian, colon, prostate, and pancreatic cancer. In general, carriers are defined as individuals with protein truncating mutations within the BRCA2 gene. Many Brca2 knockout lines have been produced and characterized in the mouse. We previously produced a rat Brca2 knockout strain in which there is a nonsense mutation in exon 11 between BRC repeats 2 and 3, and a truncated protein is produced. Interestingly, while such a mutation in homozygous mice would lead to limited survival of approximately 3 months, the Brca2-/- rats are 100% viable and the vast majority live to over 1 year of age. Brca2-/- rats show a phenotype of growth inhibition and sterility in both sexes. Aspermatogenesis in the Brca2-/- rats is due to a failure of homologous chromosome synapsis. Long-term phenotypes include underdeveloped mammary glands, cataract formation and lifespan shortening due to the development of tumors and cancers in multiple organs. The establishment of the rat Brca2 knockout model provides a means to study the role of Brca2 in increasing cancer susceptibility and inducing a novel ocular phenotype not previously associated with this gene.

Animals↗

PubMed2001

Expression and glycosylation of rotavirus strain SA11 VP4 protein in a recombinant adenovirus.

OBJECTIVE: Using a recombinant human adenovirus to express modified VP4 gene of rotavirus SA11 strain. METHODS: A whole VP4 gene was obtained with PCR and induced the signal peptide at the gene N terminal. The chimera gene was cloned into pCMV plasmid that consists of human cytomegalovirus promoter, and then the gene was cloned to the transfer vector of human adenovirus type 5. Homologous recombination was performed by co-transfection to 293 cell lines with recombinant plasmid and viral genome using CaPO4 precipitation. RESULTS: No mutation was found in the whole VP4 gene sequence of 2362 base pair. The expressed product in recombinant adenovirus was confirmed to be specific and more antigenicity by indirect immunofluorescence assay. Both the Western blot and immunoprecipitation assay showed that the molecular mass of the expressed protein was higher than the wild type VP4 protein, and that the modified product was corresponding to a glycosylation of VP4 protein. CONCLUSION: To modify the target gene might be an effective method to enhance the stability, antigenicity and immunogenicity of expressed protein.

Adenoviruses, Human↗

PubMed1998

[Synthesis of hirudin variant 1 (HV1) gene and primary study of expression in yeast].

OBJECTIVE: Hirudin is an extremely efficient and specific thrombin inhibitor. It is clinically used to prevent the formation of thrombus. In this research the hirudin gene was put into yeast system for expression to evaluate the feasibility of artificially synthesized gene expressed in eukaryotic system and study the factor affecting expression level. METHODS: According to the amino acid sequence of hirudin variant 1 (HV1), the genetic code saccharomyces cerevisiae was used to design and synthesize the HV1 gene. Amplified by PCR, it was inserted into cloning vector pBS-SK(+) and sequenced. Ligation with the signal peptide gene of yeast alpha factor the correct HV1 gene was inserted into yeast expression vector pYC-DE. The recombinant plasmid was transformed into the cell of S. cerevisiae BJ1990 to carry out the primary expression experiment. RESULTS: In cultured supernatant of screened positive clone the hirudin activity was detected to be 30 ATU/ml. The expression level was higher than HV2 in yeast and HV1 in prokaryotic system. The N terminal amino acid sequence completely matches with natural hirudin. CONCLUSIONS: It was proved by this study that the synthesized hirudin gene had been expressed in yeast successfully. This result showed that it was a better way to carry out the expression in yeast using synthesized HV1 gene and a stronger promoter.

Base Sequence↗

PubMed1998

[The construction of poliovirus chimera and the analysis of its antigenic structure].

The construction of poliovirus chimera is an useful way to investigate the antigenic structure conformation of poliovirus. In this research, the poliovirus chimera containing a piece of antigenic fragment of hepatitis A virus was constructed for analysis of poliovirus antigenic structure conformation. Depending on the characterization of this chimera, the conformation of poliovirus neutralization antigenic site I in VP1 was analyzed, and that the possible influence of hepatitis A virus antigenic fragment inserted to the structure conformation of poliovirus antigen was also investigated.

Animals↗