A neomycin resistance cassette replaced 2.1kb of the gene, including the 3' portion of exon 1 that encodes amino acids 1 - 233 of the protein. Northern blots of total RNA from cerebella of homozygous mutant mice showed no detectable transcripts of the targeted gene. Western blots of extracts of the cerebella of homozygous mutant mice showed no detectable protein. (J:21086)