Prox1^tm4.1Gco

A targeting vector containing a 2.5 kb fragment upstream of the ATG of mouse Prox1, a 1.5 kb fragment containing a fusion of synthetic avitag-encoding sequence (avitag is a 17-amino-acid peptide (MSGLNDIFEAQKIEWHE) that can be biotinylated by the BirA biotin ligase, and therefore can be used for immunoprecipitation of tagged proteins using streptavidin), and Prox1 exon 1 carrying mutations in the sequence coding for the nuclear hormone-binding site (LRKLL->ARKAL, ISQLL->ASQAL), was generated. The targeting vector also contained a loxP-flanked neomycin selection cassette for positive selection and a DTA cassette for negative selection. Homologous recombination of the Prox1 locus was carried out in W9.5 ES cells. Correctly targeted embryonic stem cells were used for the generation of chimeric mice. The neomycin cassette in the F1 Prox1 mutants was removed by crossing with a Vav-iCre transgenic line. (J:158959)