Tg(Il7-cre)CRche

A BAC clone (RPCI-295A3) containing the murine Il7 locus and flanking sequences (96 kb 5'and 17 kb 3' of the Il7 locus) was modified by homologous recombination in E. coli to introduce the cre recombinase cDNA and an FRT site-flanked Zeocin resistance gene at nucleotide position 1 of exon 1 in the Il7 mRNA, replacing the open reading frame of exon 1 entirely as well as the first nucleotide of Iintron 1. The recombinant BACs were transformed to the FLP-expressing E. coli strain FLP-294 to remove the Zeocin resistance gene. The linearized BAC was microinjected into pronuclei of fertilized FVB oocytes. 2 lines were established and line C (with 3 copies of the transgene) was characterized further. (J:149246)