Expression of Mef2^EP1751 under the control of Scer\GAL4^P0.5.Pdf causes long locomotor activity rhythms, with a period of 24.7 +/- 0.1 hours.

Flies expressing Mef2^EP1751 under the control of Scer\GAL4^tim.Scer\UAS show weak locomotor activity rhythms for the first 3 days in constant darkness, followed by superimposed short and long rhythms for days 4-12. 32.3% of the flies have "complex" rhythms (classified as more than one rhythmic period detectable above the 95% significance line using Lomb-Scargle analysis of periodograms). 6.5% of the flies are arrhythmic. The average period of the most significant peaks for rhythmic flies is 25.2 +/- 0.2 hours.

Adult LN[[v]] neurons are present and project normally when Mef2^EP1751 is expressed under the control of Scer\GAL4^tim.Scer\UAS.

Flies carrying Mef2^EP1751, Scer\GAL4^tim.Scer\UAS and Scer\GAL80^ts.αTub84B which have been raised at the permissive temperature of 25[o]C (at this temperature Scer\GAL80^ts.αTub84B represses Scer\GAL4^tim.Scer\UAS activity) show normal locomotor rhythms at 25[o]C. However, after shifting to the restrictive temperature of 31.5[o]C (allowing Scer\GAL4^tim.Scer\UAS activity) the period of locomotor activity lengthens, reaching an average of 26.0 +/- 0.8 hours. After returning to 25[o]C, the flies remain rhythmic and their periods shorten again (although there is a residual long period of 24.6 +/- 0.6 hours).