Migrating border cells expressing spas^{Scer\UAS.T:Avic\GFP-EGFP} under the control of Scer\GAL4^slbo.2.6 show a reduction in microtubules compared to controls, but this does not result in a significant perturbation of net border cluster migration or single cell speed during migration. The mutant migrating border cells show an abnormal distribution of cell extensions: the normal strong bias for front extensions is reduced, with extensions from back cells being more abundant and larger than in wild type.

Expression of spas^{Scer\UAS.T:Avic\GFP-EGFP} under the control of Scer\GAL4^slbo.2.6 in the outer border follicle cells does not cause any mutant phenotype.

Expression of spas^{Scer\UAS.T:Avic\GFP-EGFP} under the control of Scer\GAL4^upd in the polar follicle cells results in a decrease in outer border follicle cell recruitment as well as migration defects, with approximately 30% of the border cell clusters failing to reach their final destination at stage 10 of oogenesis.

Expression of spas^{Scer\UAS.T:Avic\GFP-EGFP} does not change the distribution of Rab30^{Scer\UAS.T:Disc\RFP-mRFP}-positive vesicles, but their movement is severely curtailed.