Fig. 3

Cluster 1A relies on the germline piRNA pathway. A Schematic representation of the experimental cross: Oregon flies containing cluster 1A carrying T3 and the nos-Gal4 germline driver were crossed with w¹¹¹⁸ flies devoid of cluster 1A (Δ-1A) but expressing the pRFP-T3 sensor. B Strong ovarian germline RFP expression of progenies from control nos-Gal4 females crossed with males encoding the pRFP-T3 sensor in the absence of cluster 1A. Maternally (C) or paternally (D) inherited T3 strongly represses ovarian germline expression of the pRFP-T3 piRNA sensor. E Ovarian pRFP-T3 repression of maternally inherited T3 is strongly affected by germline knockdown of piwi, nxf2, boot, and moon (piwi-KD, nxf2-KD, boot-KD, moon-KD). Knockdown for white served as control. Repression was assayed by counting the percentage of RFP-silenced egg chambers at stages 8–10. The total numbers of counted egg chambers are indicated in parenthesis. RFP expression is in red, and DAPI staining, indicating nuclei, is in white. Parental crosses are indicated above micrographs