The open reading frame was replaced LacZ gene with a nuclear localization signal and a floxed neo cassette. The expression of the reporter gene from the Vwa1 locus in heterozygous mice recapitulated gene expression in wild type mice. Northern blot analysis of total RNA extracted from spinal cord and brain demonstrated that the gene transcript is undetectable in homozygous mutant mice. The encoded protein was undetectable in nerve lysates by immunoblotting and in sections of sciatic nerve by immunofluorescence staining.