Excision of the progenitor insertion, resulting in a 1525bp deletion from the insertion site, which includes the entire Gbp1 gene and 594bp of the 5' end of the Gbp2 open reading frame.

Df(2R)Gbp-ex67/Df(2R)Gbp-ex67 significantly decreases male and female body size (body weight measured at pharate adult stage), significantly decreases larval growth rates and significantly increases the duration of the third instar larval stage (compared to wild type or Df(2R)Gbp-ex67/+.