Flies expressing Clk^{Δ.Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^P2.4.Pdf show a significant increase in sleep latency compared to controls.

Ectopic expression of dominant negative Clk^{Δ.Scer\UAS.T:Ivir\HA1} in LNvs under the control of Scer\GAL4^P2.4.Pdf leads to an increase in fat body triglycerides, in particular when two copies of Scer\GAL4^P2.4.Pdf are used to express Clk^{Δ.Scer\UAS.T:Ivir\HA1}. Expression of Clk^{Δ.Scer\UAS.T:Ivir\HA1} eliminates overt rhythms of rest:activity . These mutants do not consume more food over a 24hr period compared to controls.

Expression of Clk^{Δ.Scer\UAS.T:Ivir\HA1}, under the control of Scer\GAL4^P0.5.Pdf results in approximately 85% arrhymthmicity.

Flies expressing Clk^{Δ.Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^tim.PE or Scer\GAL4^P2.4.Pdf are arrhythmic with respect to locomotor activity when assayed for at least 5 days in constant darkness after being entrained to 12 hour light:12 hour dark cycles for 3 days, in contrast to controls which show robust locomotor activity rhythms under these conditions. The diurnal changes in the mean electroantennogram (EAG) response to ethyl acetate which are seen in wild-type flies maintained in 12 hour light:12 hour dark cycles are abolished in flies expressing Clk^{Δ.Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^tim.PE or Scer\GAL4^{Or83b.2.642.T:Hsim\VP22}. The diurnal changes in the mean electroantennogram (EAG) response to ethyl acetate which are seen in wild-type flies maintained in 12 hour light:12 hour dark cycles are abolished in flies expressing Clk^{Δ.Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Or22a.8197.