Differential expression of dihydropyrimidinase-related protein genes in developing and adult enteric nervous system

Dihydropyrimidinase-related proteins (DRPs) are involved in axonal outgrowth and pathfinding. However, little is known about their significance in the enteric nervous system (ENS), the largest and most complex division of the peripheral nervous system. Using in situ hybridization (ISH) and northern blotting, we examined mRNA expression of DRP-1-4 transcripts in the developing and adult mouse digestive tract and in the adult human colon. ISH detected the mouse DRP-3 transcript in the developing ENS on embryonic day (E)12 and at the later stages as well as in the adult intestine. Mouse DRP-1 and -2 transcripts appeared at E14. DRP-2 transcript was also detected in the adult intestine although DRP-1 expression was lower in the adult. DRP-4 gene was not expressed in the ENS during development or adulthood whereas the signal was apparent in the developing and adult central nervous system (CNS). The DRP expression pattern in the human colon was similar to that of the mouse large intestine. Northern blot analysis showed that DRPs were differentially expressed in the mouse and human intestines, supporting the results of ISH. These data suggest that DRPs play a role not only in the CNS but also in the ENS.