In wild-type ovaries, follicle cells (red) form a single layered epithelium around germline cysts (blue).  In Src64 loss-of-function mutants (Src64^LOF), follicle cell migration is impaired, resulting in the packaging of more than one germline cyst into a single follicle.  Expression of an activated version of Src64 (Src64^GOF) leads to the opposite phenotype:  actively migrating follicle cells split individual germline cysts.  Importantly, Src64 activity is required in the germline, not the migrating follicle cells for normal development to occur.  (O’Reilly, et al.  Development 2006)