An approximately 7.0kb genomic fragment (coordinates 2L:19509164..19502181 ) that encompasses the cyst gene (derived from the BACR27M12 BACPAC clone). Silent mutations have been introduced at two distinct sites to confer resistance to RNAi mediated by the P{TRiP.HMS01750} transgene. A S(GGGGS)[[2]] linker followed by a sfGFP tag has been inserted at the C-terminal end of the cyst coding sequence.