Compared with controls (Fig. 3a-b””), Pc knockdown in CySCs showed an apparent increase of Zfh1 positive cells (Fig. 3b,e and Supplementary Fig. 2g), a significant decrease of Eya positive cells and an interruption of germline cell differentiation, whereas Pc knockdown in either germline cells, late cyst cells or hub cells showed no obvious abnormality in testes (Supplementary Fig. 2). Here, PC is linked to cyst.