A Tag:StrepII-3xTag:FLAG-Tag:StrepII (SFS) multi-tag cassette has been inserted into the endogenous sgg locus, such that it tags the C-terminus end of the first exon of the PD protein isoform (this also tags isoforms PP and PQ).
The sgg-PD tag also tags sgg-PP and sgg-PQ. The sgg-PD isoform shows early expression that is largely restricted to mesoderm and becomes more prominent at stage 9 . At later stages the expression of sgg-PD is generally weak and ubiquitous with elevated levels found in the CNS, posterior spiracles, Malpighian tubules, proventriculus and salivary glands.