Fig. 3. Cardiac-specific mlp84B knockdown causes early mortality. (A,B) mlp84B expression level is significantly reduced in mlp84B RNAi-expressing Drosophila. A strong diminution in mlp84B expression level was observed using either a ubiquitous (Daughterless-Gal4, A) or a heart-specific (tinC4-Gal4, B) driver. mlp84B expression levels were determined by performing real-time quantitative PCR on reverse-transcribed mRNA from whole fly (A) or heart only (B) and normalized to actin79B expression. (C) Male flies expressing mlp84B RNAi in the heart have a dramatically shortened lifespan compared with controls (UAS-mlp84B-RNAi outcrossed to wild-type). No lifespan reduction was observed in females.