INTRAGENIC SEQUENCES ARE REQUIRED FOR CELL-TYPE-SPECIFIC AND INJURY-INDUCED EXPRESSION OF THE RAT PERIPHERIN GENE

Peripherin is a 57 kDa type III intermediate-filament protein that is thought to play a role in axonogenesis both during development and fol lowing nerve injury (Oblinger et al., 1989; Escurat et al., 1 990; Gor ham et al., 1 990; Troy et al., 1990b). We have used transgenic mouse technology to define peripherin gene sequences that are necessary for cell type-specific expression and for the increase in peripherin that occurs in response to axonal injury. Correct temporal and nervous syst em-specific expression resulted when 5.8 kilobases of peripherin 5' fl anking sequence were linked to a reporter gene, but precise cell type- specific expression was achieved only when intragenic sequences were i ncluded. When intragenic sequences were present, peripherin transgenes were expressed in dorsal root ganglion neurons and spinal cord motor neurons and were upregulated in these cells following nerve injury.