BioWorld International Correspondent

PARIS - Cellectis SA entered an agreement with Lexicon Genetics Inc. that grants the French firm a worldwide, nonexclusive commercial sublicense for the use of Lexicon's isogenic DNA technology for homologous recombination in eukaryotic cells by double-stranded break methodology.

At the same time, Paris-based Cellectis granted Lexicon Genetics, of The Woodlands, Texas, an exclusive worldwide license to its technology for the specific replacement or insertion of a gene in a eukaryotic genome. The license applies to the use of Cellectis' technology in combination with internal ribosome entry site (IRES) or isogenic DNA technology in the generation of genetically modified mice.

Lexicon already held a nonexclusive license to Cellectis' technology for the insertion of markers of gene expression and the generation of knockout mice to complement its own gene-targeting technologies. The new license grants Lexicon exclusive rights to make, use, sell and import genetically engineered mice generated from the use of the technology in combination with IRES or isogenic DNA technology. It also has the right to grant sublicenses.

Lexicon was granted an exclusive license to IRES technology for genetically modified mice by Stem Cell Sciences plc, of Edinburgh, Scotland, in November 2005. IRES technology is used to enhance the accuracy and versatility of gene expression in genetically altered mice and cultured stem cells.

The isogenic DNA technology developed by Lexicon Genetics improves the success rate of homologous recombination, an approach to gene targeting widely used to perform gene knock-in or knockout in organisms or cell lines. Isogenic DNA also can be used in conjunction with engineered meganucleases, sequence-specific enzymes developed by Cellectis to induce targeted recombination at high efficiency in chosen locations in genomes.