Rasgrf1^tm2Pds

The pBJR2 vector was used to insert a 1.5-kb neo cassette and a 500-nt Pgk enhancer and promoter fragment in reverse orientation such that it replaced the Rasgrf1 repeats located downstream of the differentially methylated domain. Removal of the paternal repeats caused a loss of paternal allele methylation as shown by Southern blot. The enhancer insertion enabled expression of the transcript whether it was transmitted maternally or paternally. Expression was due entirely to the presence of the Pgk-enhancer and promoter insertion and not due to a repeat deletion. (J:103751, J:185711)