COMPARATIVE DISTRIBUTION OF NURR1 AND NUR77 NUCLEAR RECEPTORS IN THE MOUSE CENTRAL-NERVOUS-SYSTEM

NURR1 and NUR77 are members of the nuclear receptor superfamily of tra nscription factors. Both proteins can interact with common enhancer el ements to regulate target gene expression. In order to establish wheth er both transcription factors are likely to regulate overlapping genes , we have used an in situ hybridization approach to relate the constit utive expression pattern of these mRNAs with functionally defined regi ons of the adult mouse brain. By Western analysis, NURR1 mRNA expresse d by brain cells appeared to be translated. Here we show that both tra nscripts display a differential but partially overlapping pattern of e xpression within the central nervous system (CNS). The expression of N URR1 is more restricted than NUR77 and is localized predominantly in s ensory neuronal structures associated with the limbic system and in th e cerebellum. In contrast, the expression pattern of NUR77 is more wid espread. Positively staining cells for NUR77 appear to overlap with NU RR1-containing cells in the limbic system and cerebellum, suggesting o verlapping roles for these proteins in mediating behavioral and cognit ive function as well as equilibrium maintenance. However, the differen tial expression of NUR77 in motor areas of the cortex and basal gangli a suggest a selective role for this transcription factor in regulation of motor function at the constitutive level. Our data indicates that these nuclear receptors are likely to have both shared and independent gene regulatory roles in neuronal cells.