Homologous Recombination of Mouse ZAKI-4 Gene to Disrupt its Expression

Z4KI-4 inhibits the activity of calcineurin, a Ca 2 + -dependent protein phosphatase. From ZAKI-4 gene, two isoforms, a and β are generated by an alternative splicing. In adult mice ZAKI-4 a mRNA was mainly expressed in brain whereas ZAKI-4β mRNA was ubiquitously. To elucidate the specific function of ZAKI-4 isoforms, we plan to establish ZAKI-4 β knock out mice by homologous recombination. For this purpose, mouse embryonic stem cells were electroporated with a targeting vector in which ZAKI-4 β sequence was disrupted by cDNA coding neomycin resistance. Six independent clones out of 466 antibiotics-resistant colonies underwent homologous recombination at the ZAK1-4β locus. These clones will be used to establish the knock out mice.