A cassette containing a polyadenylation sequence in the same orientation as Nespas and a self-excising neo cassette was inserted into exon 1. Cre-mediated recombination removed the neo cassette. The absence of Nespas transcript expression was confirmed by RT-qPCR on newborn brain extracts with paternal inheritance of the allele. De-repression of Gnas was confirmed by RT-qPCR. (J:171195)