A nurse cell specific regulon, consisting of two copies of the Hsp26 nurse cell enhancer fragment (-543 to -373bp, coordinates according to FBrf0055875) linked to the Sgs3 promoter (-127 to +27bp, coordinates according to FBrf0039858), drives expression of a lacZ coding region fragment (which lacks the first six amino acids). The 3' end of the fs(1)K10 gene (+3956 to +5345bp, coordinates according to FBrf0048127) is fused downstream of the lacZ coding region.
In germarium, β-gal signal higher in nurse cells than in oocyte until stage S11, at which time the nurse cells donate their entire cytoplasm to the oocyte.