Figure 4.

CySC depletion of Dp results in non-autonomous hub-to-CySC transdifferentiation

(A) Model indicating experimental design to deplete Dp from CySCs while concomitantly tracing hub cells using independent binary expression systems. To trace the lineage of hub cells, we used hh-QF, which is expressed only in hub cells, to induce QUAS-FLP. In turn, FLP recombines FRT sites in the act>STOP>LexA transgene. This leads to the production of LexA. Then LexA induces expression of lexAop-GFP, hereby exclusively labeling hub cells and their lineage with membrane GFP. In the same animal, C587-GAL4 drives expression of a Dp-RNAi transgene, which depletes Dp from CySCs but not from hub cells.

(B and C) There are GFP-positive cells expressing Zfh1 (C, arrowheads) outside the cluster of hub cells in a C587>Dp-RNAi; hh>lineage testis but not in a control C587>+; hh>lineage testis (B). Hub lineage is in green, Zfh1 (red) labels CySCs, Fas3 (blue) labels hub cell membranes, and Eya (blue) labels the nuclei of differentiating cyst cells.

(D) Graph showing the percentage of testes in which hub-lineage-positive CySCs were present in C587>+ (control) (gray bar, n = 53) or C587>Dp-RNAi (brown bar, n = 49).

(E) Graph of the number of hub cells in testes in which babo^QD was mis-expressed in hub cells (upd^TS>) with either escargot (esg-NLAP, gray bar, n = 41) or the control transgene (NLAP, blue bar, n = 38).

Error bars represent the data range. ^∗∗∗∗ p < 0.0001; ^∗∗∗ p < 0.001 as assessed by Fisher’s exact test (D) or Student’s t test (E).

See also Tables S1 and S2, Figure S5. Scale bar, 10 μM.