Expression of KIF3C kinesin during neural development and in vitro neuronal differentiation

KIF3A, KIF3B and KIF3C are kinesin-related motor subunits of the KIF3 famil y that associate to form the kinesin-ll motor complex in which KIF3C and KI F3B are alternative partners of KIF3A. We have analysed the expression of K if3 mRNAs during prenatal murine development. Kif3c transcripts are detecta ble from embryonic day 12.5 and persist throughout development both in the CNS and in some peripheral ganglia, Comparison of the expression patterns o f the Kif3 genes revealed that Kif3c and Kif3a mRNAs colocalize in the CNS, while only Kif3a is also present outside the CNS. In contrast, Kif3b is de tectable in several non-neural tissues. We have also performed immunocytoch emical analyses of the developing rat brain and have found the presence of the KIF3C protein in selected brain regions and in several fibre systems. U sing neuroblastoma cells as an in vitro model for neuronal differentiation, we found that retinoic acid stimulated the expression of the three Kif3 an d the kinesin-associated protein genes, although with different time course s. The selective expression of Kif3c in the nervous system during embryonic development and its up-regulation during neuroblastoma differentiation sug gest a role for this motor during maturation of neuronal cells.