Sequence encoding the Fab-4 domain (784bp, coordinates 3R:16857582..16856799 release 6 genome) has been inserted into the attP site present in TI{TI}Fab-7attP50. The inserted sequence also includes an FRT site and a ry+t* marker in an arrangement that allows for subsequent excision of the ry+t* marker, using the newly inserted FRT site plus the FRT site present in the original TI{TI}Fab-7attP50 insertion.