CHARACTERIZATION OF EXPRESSION OF MDMAHP A HOMEODOMAIN-ENCODING GENE AT THE MURINE DM LOCUS

We examined the expression of the murine homologue of myotonic dystrop hy associated homeodomain protein (mDMAHP) using two different strateg ies. The first approach, RT-PCR, detected spliced transcripts in a wid e range of embryonic and adult tissues, in a pattern overlapping subst antially with the expression of mDMPK. A second approach, the generati on of transgenic mice expressing the lacZ reporter gene from a 4.3 kb promoter fragment, also demonstrated expression in a range of tissues with potential links to the phenotype in myotonic dystrophy. We conclu de that murine DMAHP has a similar pattern of expression to human DMAH P and will serve as a useful model for functional studies of this gene , although species differences, such as the reduced CpG island (1.8 kb compared with 3.5 kb) must be carefully considered.