Kpna6^{Gt(AJ0609)Wtsi}

A gene trap cassette was inserted into intron 1. Western blot analysis confirmed the absence of protein expression in the brain, heart, lung, spleen and kidney of homozygous mice. Although protein is missing in most tissues examined, use of an alternative promoter and exon 1 (exon 1A) located downstream of the gene trap cassette leads to exclusive expression of a full-length and fully functional protein in the testis of homozygous mutant males. Sequencing of mRNA variants in testis revealed that only the shorter transcript starting from exon 1A is present at wild-type expression levels. (J:171441, J:311959)