cyp6a17 Is Required for TPB in Drosophila Figure 5. cyp6a17 is required in the mushroom bodies for temperature preference behavior. (A–C) Effects of mushroom bodies-specific knockdown of cyp6a17 on TPB. cyp6a17 was knockdowned by RNAi in the cyp6a17-specific cells by cyp6a17MB-Gal4 (A) or in the mushroom bodies by MB247-Gal4 (B). (C) Rescue of cyp6a17 mutant phenotype. Expression of cyp6a17 transgene in the mushroom bodies by MB247-Gal4 restored the cyp6a17D173 phenotype. Black bars, AIHigh; gray bars, AILow. One asterisks, P,0.005 and two asterisks, P,0.001. doi:10.1371/journal.pone.0029800.g005 Third, tissue-specific RNAi knockdown of cyp6a17 expression in the mushroom bodies resulted in TPB defects. TPB assays are measured by two indices, AILow and AIHigh, for avoiding low and high temperatures, respectively. It is interesting to note that loss of cyp6a17 results in a preferential reduction of the AILow value compared with the AIHigh score. This asymmetric effect of cyp6a17 mutations suggests that cyp6a17 might be selectively required for avoidance of low temperatures. We noted that the transgenic expression by MB247.cyp6a17 from the cyp6a17 mutant significantly lowers the AIHigh index. However, one of the control strains for this test, cyp6a17D173; UAS-cyp6a17/+, shows a very low AI-High value in the absence of any Gal4 driver. Thus, the reduction of AIHigh in this strain is unlikely to be due to cyp6a17 overexpression. cyp6a17 mutant and this transgene were PLoS ONE | www.plosone.org 7 December 2011 | Volume 6 | Issue 12 | e29800