Differential, regional, and cellular expression of the stathmin family transcripts in the adult rat brain

Stathmin is a ubiquitous cytosolic phosphoprotein, preferentially expressed in the nervous system, and previously described as a relay integrating div erse intracellular signaling pathways. Stathmin is the generic element of a mammalian protein family including SCG10, SCLIP, and RB3 with its splice v ariants RB3' and RB3 ", In contrast with stathmin, SCG10, SCLIP, and RB3/RB 3'/RB3 " are exclusively expressed in the nervous system, stathmin and SCG1 0 being mostly expressed during cell proliferation and differentiation, and SCLIP and RB3 rather in mature neural cells. To further understand their s pecific roles in the CNS, we compared the localization of the stathmin, SCG 10, SCLIP, and RB3 transcripts in adult rat brain. Northern blot analysis a s well as in situ hybridization experiments showed that all stathmin-relate d mRNAs are expressed in a wide range of adult rat brain areas. At a region al level, SCG10 and SCLIP appear generally distributed similarly except in a few areas, The pattern of expression of the RB3 transcript is very differ ent from that of the three other members of the stathmin family. Furthermor e, unlike SCG10 and SCLIP, which were detected only in neurons, but like st athmin, RB3 was detected in neurons and also in glial cells of the white ma tter, Altogether, our results suggest distinct roles for each member of the stathmin-related phosphoprotein family, in regard to their specific region al and cellular localization in the rat brain. (C) 1999 Wiley-Liss, Inc.