Per1^tm1Brd

A 5.3kb region, encompassing exons 4 through 18, was replaced by an Hprt minigene. The vector was designed such that the excision of the inserted cassette and potential subsequent splicing of exon 3 to exon 19 would introduce a frameshift mutation. Such a transcript was not found, however, a fusion transcript consisting of the first three exons of the endogenous gene aberrantly spliced to exons 3 through 9 of the Hprt transgene was identified by RT-PCR and sequence analysis. Because exons 1 through 3 encode a putatively non-functional region of the protein, the mutation was believed to be null. (J:69769)