Overexpression of SLOB alters behavioral rhythms. Elavc155, GMR and Kurs 45 GAL4 flies were crossed to UAS-slob, UAS-mtslob and Df(1)w flies. Progeny were entrained for three days in LD cycles and then transferred to a locomotor monitoring device for 14 days in DD. (A) Actograms representing control, UAS-slob and UAS-mtslob lines crossed to elavc155. There is an apparent breakdown of rhythmicity after 7 days in flies overexpressing wild type and mutant SLOBs (middle and right panels). (B) Summary of behavioral data for elavc155 flies crossed to control and UAS lines. The FFT value is a measure of rhythmic strength and is plotted in the bar graph for the first and second week periods per fly line. Using Student's t test, all overexpressing SLOB lines exhibit significant breakdown of rhythms during the second seven days (*p < 0.05 and **p < 0.001, respectively). Controls show no significant breakdown except for one line, UAS-slob1/+. However, as demonstrated by the inserted western blot, this line expresses transgenic SLOB in the absence of a GAL4 driver, whereas the UAS-mtslob1/+ line does not. The blot was probed with an anti-HA antibody that detects only transgenic SLOB. Levels of MAPK were used as loading controls (data not shown). (C) Summary of behavioral data for GMR and Kurs 45 GAL4 flies crossed to various lines. No change in rhythmicity is evident when SLOB is overexpressed only in the Drosophila eye or PI neurons.