CONSERVATION OF A PUTATIVE APL BINDING-SITE AND COMPLETE HOMOLOGY TO A FETAL BRAIN EST IN A REGION UPSTREAM OF THE CORE MUSCLE PROMOTER IN THE HUMAN DYSTROPHIN GENE

A region of 744 basepairs (bp) upstream of the muscular dystrophin pro moter (UMDP) was amplified by inverse-polymerase chain reaction (PCR), cloned and sequenced. Analysis of this sequence for the presence of p utative transcriptional control elements identified several similariti es with known cis-acting sequence motifs including two MyoD and two Ap 1 motifs. One of these Ap1 motifs was found to be completely conserved within an otherwise highly variable region among five primate species . Complete homology to a human fetal brain expressed sequence tag (EST ) was also observed over 201 bp at the 5' end of the UMDP region. Nort hern blot analysis using a radiolabelled EST probe identified a 1 kb m RNA expressed in human placenta and at lower levels in the heart. Thes e results raise the possibility that additional transcriptional regula tory elements are located upstream of the core muscle promoter, and pr ovide the first evidence for the existence of a gene that overlaps the human dystrophin gene. (C) 1997 Elsevier Science B.V.