Figure 2. (A) The germarium located in the anterior tip of each ovariole contains the GSC niche, consisting of TF, CC, and ESC. The FSCs are positioned more posterior and attach to the surrounding basement membrane. (B) JAK-STAT signaling partly controls BMP signaling, which is required for GSC self-renewal and inhibition of differentiation. (C) Antagonistic Hh and Upd gradients determine the position of FSCs within the germarium. JAK-STAT activity within FSCs regulates Integrin-mediated adhesion to the basement membrane (BM). See text for details.