Genpharm International, Inc.

Pharming B.v.

Anton J Berns

Robert M Kay

Frank R Pieper

Rein Strijker

Paul J Krimpenfort

Hein Te Riele

Els Robanus Maandag

The present invention provides novel methods for modifying the genome of an animal cell which typically comprise the steps of: constructing a DNA molecule in which desired sequence modifications are contained in a segment of DNA (a &ldquo;targeting DNA&rdquo;) that is substantially isogenic with a DNA in the cell genome (a &ldquo;target DNA&rdquo;); introducing the targeting DNA construct into the cell (e.g., by microinjection, electroporation, transfection, or calcium phosphate precipitation); and selecting cells in which the desired sequence modifications have been introduced into the genome via homologous recombination.

High efficiency gene targeting in mouse embryonic stem cells

The present invention provides novel methods for modifying the genome of an animal cell which typically comprise the steps of: constructing a DNA molecule in which desired sequence modifications are contained in a segment of DNA (a 'targeting DNA') that is substantially isogenic with a DNA in the cell genome (a.'target DNA'); introducing the targeting DNA construct into the cell (e.g., by microinjection, electroporation, transfection, or calcium phosphate precipitation); and selecting cells in which the desired sequence modifications have been introduced into the genome via homologous recombination.

Gene targeting in animal cells using isogenic DNA constructs

The invention relates to methods for intracellularly producing DNA segments by homologous recombination of smaller overlapping DNA fragments and transgenic mammalian cells and transgenic non-human mammals produced by such methods.

Homologous recombination in mammalian cells

Methods are provided for determining the oncogenic potential of chemical compounds which utilizes a transgenic mouse predisposed to T-cell lymphomas. The transgenic mouse expresses a pim-1 oncogene and as a consequence is predisposed to the spontaneous onset of T-cell lymphomas. The oncogenic potential of a chemical compound is determined by administering a known dose of the chemical compound of interest to a pim-1 transgenic mouse. Thereafter, the transgenic mouse is monitored to detect the onset of a T-cell lymphoma. The time of onset of the T-cell lymphoma and the dosage of the chemical compound are compared to either the onset of spontaneous T-cell lymphomas in the pim-1 transgenic mouse or to the onset of a T-cell lymphoma in a pim-1 transgenic mouse which has been exposed to a known quantity of a carcinogenic agent. This provides an indication of the oncogenic potential of the chemical compound.

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Spaarndam, Netherlands

Anton J Berns