Characterisation of expression of mDMAHP, a homeodomain-encoding gene at the murine DM locus

We examined the expression of the murine homologue of myotonic dystrophy associated homeodomain protein (mDMAHP) using two different strategies. The first approach, RT-PCR, detected spliced transcripts in a wide range of embryonic and adult tissues, in a pattern overlapping substantially with the expression of mDMPK. A second approach, the generation 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 conclude that murine DMAHP has a similar pattern of expression to human DMAHP 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.