Theodore Friedmann

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The restricted host-cell range and low titer of retroviral vectors limit their use for stable gene transfer in eukaryotic cells. To overcome these limitations, we have produced murine leukemia virus-derived vectors in which the retroviral envelope glycoprotein has been completely replaced by the G glycoprotein of vesicular stomatitis virus. Such vectors can(More)
Acetylcholinesterase, an essential enzyme of the nervous system, rapidly terminates the action of acetylcholine released into the synapse. Acetylcholinesterase is also found (in lower abundance) in extrajunctional areas of muscle and nerve and on erythrocyte membranes. Hydrodynamic analyses of the native enzyme and characterization of its dissociated(More)
Replication-defective mutants of herpes simplex virus type 1 (HSV-1) may prove useful as vectors for gene transfer, particularly to nondividing cells. Cgal delta 3 is an immediate-early gene 3 (IE 3) deletion mutant of HSV-1 that expresses the lacZ gene of Escherichia coli from the human cytomegalovirus immediate-early control region but does not express(More)
We have previously shown that the G protein of vesicular stomatitis virus (VSV-G) can be incorporated into the virions of retroviruses. Since expression of VSV-G is toxic to most mammalian cells, development of stable VSV-G packaging cell lines requires inducible VSV-G expression. We have modified the tetracycline-inducible system by fusing the ligand(More)
We have cloned a full-length 1.6-kilobase cDNA of a human mRNA coding for hypoxanthine phosphoribosyltransferase (HPRT; IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) into a simian virus 40-based expression vector and have determined its full nucleotide sequence. The inferred amino acid sequence agrees with a partial amino acid sequence determined(More)
The zebrafish is rapidly becoming a popular model system for the study of vertebrate development because it is ideal for both embryological studies and genetic analysis. To determine if a retroviral vector pseudotyped with the envelope glycoprotein of the vesicular stomatitis virus could infect zebrafish embryos, and in particular, the cells destined to(More)
Encapsidation of the VSV G protein into the virions of MoMLV-derived retroviral vectors in the absence of other VSV-encoded proteins is shown to be an efficient process, although the exact mechanism for this process is currently unclear. Unlike the conventional retroviral vectors bearing the amphotropic envelope protein, the pseudotyped virus has the(More)
To explore the role of DNA methylation in maintaining dosage compensation of X chromosome-linked genes and in regulating the transcriptional activity of "housekeeping" genes, we characterized DNA methylation of active, inactive, and derepressed alleles at the locus for hypoxanthine phosphoribosyltransferase (HPRT) on the human X chromosome. The methylation(More)