mRNA expression level of transgenic flies, elav-Gal4/+ as control fly. Target gene human APP and BACE-1 electrophoresis results (A) and semi-quantitative RT-PCR analysis of human APP and BACE-1 genes mRNA expression level (B). Gene RP49 was used as the reference gene to normalize mRNA amount. For RP49 mRNA expression amount, there was no significant difference between control flies and transgenic flies, however, mRNA of target genes human APP and BACE-1 were not expressed in control flies. ns: no significant difference. Each bar represents standard error.