Expression of Hsap\SPAST^{Scer\UAS.T:Avic\GFP-YFP.Venus} under the control of Scer\GAL4^{elav.Switch.PO} partially rescues the eclosion defects seen in spas^5.75 homozygotes. A similar level of rescue is seen when two copies of the transgene are expressed, however increasing the concentration of RU486 leads to increased lethality. The increased bouton number phenotype is partially rescued, with the number of boutons restored to close to wild type levels. The boutons seen are arranged linearly rather than being small and clustered as in spas^5.75. Terminal bouton microtubule distribution is also rescued to close to wild type levels. Flies carrying either one or two copies of the transgene have lifespans of approximately 15 days.

Co-expression of Hsap\SPAST^{Scer\UAS.T:Avic\GFP-YFP.Venus} and Hsap\SPAST^{R388.Scer\UAS.T:Avic\GFP-YFP.Venus} under the control of Scer\GAL4^{elav.Switch.PO} partially rescues the eclosion defects seen in spas^5.75 homozygotes, although only 75% of flies eclose compared to when two copies of Hsap\SPAST^{Scer\UAS.T:Avic\GFP-YFP.Venus} are expressed. The movement defects seen in spas^5.75 homozygotes are also partially rescued, with rescue flies still exhibiting mild walking rate, jumping and flying defects. The bouton number phenotype is partially rescued although less efficiently than when two copies of Hsap\SPAST^{Scer\UAS.T:Avic\GFP-YFP.Venus} are expressed. Bouton number is reduced significantly compared to spas^5.75, but boutons seen are still small and clustered rather than linear. Terminal bouton microtubule distribution is not rescued. Flies of this genotype have a severely reduced lifespan of approximately 10 days.

Co-expression of Hsap\SPAST^{Scer\UAS.T:Avic\GFP-YFP.Venus} and Hsap\SPAST^{L44.Scer\UAS.T:Avic\GFP-CFP} under the control of Scer\GAL4^{elav.Switch.PO} restores the eclosion and movement defects seen in spas^5.75 homozygotes to a similar level as when two copies of Hsap\SPAST^{Scer\UAS.T:Avic\GFP-YFP.Venus} are expressed. The spas^5.75 increased bouton number phenotype is partially rescued, although bouton number is slightly higher than when Hsap\SPAST^{Scer\UAS.T:Avic\GFP-YFP.Venus} is expressed alone. Terminal bouton microtubule distribution is also partially rescued. Flies of this genotype have an average lifespan of approximately 16 days.