Flies lacking Cdk5 function (Df(2R)Exel9026 homozygotes with all deleted gene functions except Cdk5 restored using P{Flo-1^wt.Cdk5^Δ.CG30466^wt.CG8204^wt}) are viable and fertile and have no evident morphological defects. Circadian rhythm of these animals is normal, but they show reduced flight ability compared to wild type. The adults have locomotor defects, including a higher rate of falling from the culture vial wall than wild type and an inability to right themselves after falling on their back. Mutant larvae show synaptic overgrowth at the neuromuscular junction. The number of boutons per muscle area is increased compared to wild type and the boutons are smaller than normal. The miniature (mEJC) and evoked (eEJC) postsynaptic currents have normal amplitude and frequency in these larvae.

Flies lacking Cdk5 function (Df(2R)Exel9026/Df(2R)ED2426 animals with all deleted gene functions except Cdk5 restored using P{Flo-1^wt.Cdk5^Δ.CG30466^wt.CG8204^wt}) are viable and fertile and have no evident morphological defects. Circadian rhythm of these animals is normal, but they show reduced flight ability compared to wild type.