A FAMILY OF RAT CRMP GENES IS DIFFERENTIALLY EXPRESSED IN THE NERVOUS-SYSTEM

Members of the collapsin/semaphorin family play an important role in c reating the complex pattern of neuronal connectivity, Inhibition of gr owth cone motility by chick collapsin is mediated by the intraneuronal protein CRMP-62. We have now isolated four rat sequences that are hig hly related to chick CRM P-62. All four genes are expressed exclusivel y in the nervous system and primarily during development. Rat CRMP-2/T OAD-64 is most closely related to chick CRMP-62 and is the most widely expressed CRMP within the nervous system, Rat CRMP-1 and CRMP-4/rUlip are expressed during discrete periods of neuronal development and are not found in the adult nervous system, Rat CRMP-3 has a distinct dist ribution, being expressed transiently in developing spinal cord and se lectively in the postnatal cerebellum, The differential expression of these genes suggests that CRMPs may transduce signals from different s emaphorins and that semaphorins may regulate the plasticity of the adu lt nervous system.