Eight murine paired box-containing (Pax) genes have been isolated so far. The gene described here, Pax7, contains not only a paired box, but also an octapeptide and a paired-type homeobox. As shown by Northern and in situ analysis, Pax7 is expressed from day 8 to 17 p.c. during embryogenesis. At early stages Pax7 transcripts are present in a subset of cells throughout the entire brain, but later in development expression is limited to the mesencephalon. In the developing neural tube Pax7 is restricted to the dorsal ventricular zone along the entire antero-posterior axis, suggesting a role for Pax7 in the formation of certain parts of the CNS. Additionally Pax7 expression can be followed during myogenesis from the dermamyotome of the somites to the skeletal muscle tissues.