Inpp5k^tm1Brd

A vector isolated from a targeting vector library described in J:115976 was used to generate this null allele. The vector consisted of an upstream portion of the Hprt gene, a loxP site, and a neomycin resistance cassette followed by approximately 6.5 kb of the gene locus that contained exons 4 through 7. A 1,040-bp fragment of this genomic segment was removed by HpaI and BstBI restriction enzyme digestion. This vector was used in gap repair targeting where the genomic gap in the vector is repaired by the chromosomal DNA template, creating a duplication on the chromosome. In this allele exons 4-7 were duplicated with the partial Hprt gene, loxP site and the neo cassette in between the duplicated regions. This was predicted to cause a frameshift mutation and a null allele. Heterozygotes had half the expression of the gene in quadriceps muscle compared to wild-type mice, as determined by immunoblot assays. (J:115976, J:139745)