Ken R. Harewood

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An enhancer within intron 1 of the amyloid precursor protein gene (APPb) of zebrafish is identified functionally using a novel approach. Bacterial artificial chromosomes (BACs) were retrofitted with enhancer traps, and expressed as transgenes in zebrafish. Expression from both transient assays and stable lines were used for analysis. Although the enhancer(More)
Contrary to several earlier reports, we find that cross-recombination between wild-type and the mutant loxP511 sites is <0.5% of that between two wild-type sites if Cre protein is expressed by phage P1 during an infection. The finding enabled us to develop a procedure to truncate DNA progressively from both ends of large genomic inserts flanked by these two(More)
Cells releasing the endogenous baboon virus (BV) can interact with human KC cells containing the Rous sarcoma virus (RSV) genome, resulting in cell fusion and syncytium formation. This interaction has been utilized in the development of a sensitive infectivity assay for BV. The titration pattern is of a one-hit type, demonstrating a linear relationship(More)
Production of infectious Mason-Pfizer monkey virus (M-PMV) was enhanced after treatment of the CMMT cell line with 2.5 x 10(-5) M dexamethasone phosphate (DXM). The reverse transcriptase (RT) activity and infectivity titers of treated culture fluids were enhanced by five- and tenfold, respectively. Along with stimulation of M-PMV synthesis, a simian type C(More)
Recombination of wild-type and mutant loxP sites mediated by wild-type Cre protein was analyzed in vivo using a sensitive phage P1 transduction assay. Contrary to some earlier reports, recombination between loxP sites was found to be highly specific: a loxP site recombined in vivo only with another of identical sequence, with no crossover recombination(More)
Chromatin adjoining the site of integration of a transgene affects expression and renders comparisons of closely related transgenes, such as those derived from a BAC deletion series retrofitted with enhancer-traps, unreliable. Gene targeting to a pre-determined site on the chromosome is likely to alleviate the problem. A general procedure to replace the(More)
Highly polymorphic di- and tetranucleotide repeats in and around Npr3, a potential candidate gene for hypertension, have been identified using a novel approach. Because this chromosomal site is rich in repetitive DNA and difficult to sequence, P1 artificial chromosomes were retrofitted with a loxP transposon to map the gene sequence within a clone using a(More)
Efficacious systems are described for the large-scale growth in tissue culture and concentration of infectious (P3HR-1) and transforming (B95-8) Epstein-Barr virus. Also recorded here are our updated procedures for growing stock cultures and protocols to harvest fluids containing biologically active virus which is infectious or transforming. Various methods(More)