MOLECULAR-CLONING AND EXPRESSION OF THE RAT HOMOLOG OF PRESENILIN-1

The rat homologue of the presenilin-1 (PS-I) gene, which is responsibl e for early-onset familial Alzheimer's disease linked to chromosome 14 , was cloned and sequenced. The predicted amino acid sequence showed q uite high homology among rat, mouse, and human PS-1. Especially, the a mino acid sequences of the putative transmembrane domains were highly conserved among the three species. The expression level of the PS-I ge ne increased during brain development and the number of transcripts of the PS-I gene changed during brain development. We found one transcri pt of the PS-1 gene in embryonic day 12 (E12)-E15 rat brain and two tr anscripts in E18-adult rat brain. Therefore, PS-1 may play a role in n eurogenesis.