RESUMEN
Objective To construct the recombinant varicella zoster virus (VZV)carrying 3xflag gene,3xflag was added to the VZV open reading frame 7 (ORF7)using GalK-based homologous recombination.Methods GalK and 3xflag gene fragments with 50 bp VZV ORF7 homologous arms were amplified by PCR.The obtained fragments were purified and transferred to the competent cells of VZV bacterial artificial chromosome (SW102-VZVWTBAC). The clones of VZV ORF7 with 3xflag (SW102-VZV ORF7-3xflag-BAC)were obtained by homologous recombination and selection from medium containing GalK and replaced GalK. The recombinant plasmids were extracted and transfected into ARPE-19 cells.The effect of VZV ORF7-3xflag on ARPE-19 cells was observed.Results The clones of VZV ORF7 with 3xflag (SW102-VZV ORF7-3xflag-BAC)were obtained.The virus patches with green fluorescence were observed three days after SW102-VZVWTBAC and SW102-VZV ORF7-3xflag-BAC were transfected into ARPE-19 cells.Western blot showed that ORF7 expression was effectively enhanced with 3xflag.Conclusion The recombinant VZV carrying 3xflag gene was obtained,which suggests that GalK-based homologous recombination is convenient,efficient and accurate in manipulating the gene virus of interest.
RESUMEN
It is clear that the construction of large insert DNA libraries is important for map-based gene cloning, the assembly of physical maps, and simple screening for specific genomic sequences. The bacterial artificial chromosome (BAC) system is likely to be an important tool for map-based cloning of genes since BAC libraries can be constructed simply and analyzed more efficiently than yeast artificial chromosome (YAC) libraries. BACs have significantly expanded the size of fragments from eukaryotic genomes that can be cloned in Escherichia coli as plasmid molecules. To facilitate the isolation of molecular-biologically important genes in Ashbya gossypii, we constructed Ashbya chromosome-specific BAC libraries using pBeloBAC11 and pBACwich vectors with an average insert size of 100 kb, which is equivalent to 19.8X genomic coverage. pBACwich was developed to streamline map-based cloning by providing a tool to integrate large DNA fragments into specific sites in chromosomes. These chromosome-specific libraries have provided a useful tool for the further characterization of the Ashbya genome including positional cloning and genome sequencing.