This mutant allele retains the 5' region of the gene through the first 20 base pairs of exon 2, which encode the first zinc finger of the protein. A lacZ-PGK-neo cassette has replaced the remaining 3' portion of exon2 and all of intron 2 and exon3, including the second and third zinc finger coding sequences. Neither RT-qPCR analysis nor in situ hybridization to E10.5 embryos detected any transcripts. (J:155855)