Figure 3
Loss of Tj in ECs results in expanded BMP signaling. (a–c,k & m) Germaria are stained for pMad (green), to indicate the BMP pathway activity, α-spectrin (red), to mark spectrosomes and fusomes. In germaria from newly eclosed flies (<1-day old), the control group (a) displays dense pMad staining in GSCs. The C587 > tj RNAi-1 (b) and C587 > tj RNAi-2 (c) groups display excess UGCs negative for pMad. (d–f, l & n) Germaria are stained for α-spectrin (red) to mark spectrosomes and fusomes. The bamP-GFP/+ (green) is introduced to indicate the transcriptional activity of bam. In germaria from newly eclosed flies (<1-day old), the control group (d) displays the absence of bamP-GFP in GSCs but upregulation in CBs. The C587 > tj RNAi-1 (e) and C587 > tj RNAi-2 (f) groups display bamP-GFP-positive UGCs. (g–i’) Germaria from newly eclosed flies (<1-day old) are stained for α-spectrin (red), to mark spectrosomes and fusomes. The dad-lacZ/+ is introduced to indicate BMP pathway activity (marked by β-gal, green). The control group (g,g’) presents high level of dad-lacZ activity in GSCs and intermediate CBs. The C587 > tj RNAi-1 (h,h’) and C587 > tj RNAi-2 (i,i’) groups present dad-lacZ-positive UGCs outside the GSC niche. (j) Graph shows the percentage of germaria that contain the indicated number of dad-lacZ-positive germ cells for each genotype. (k,l) C587ts > UAS-dpp flies are maintained at 18 °C up to eclosion and then shifted to 29 °C for 2–3 days before dissection. The germaria are full of pMad-positive UGCs (k) and bamP-GFP-negative UGCs (l). (m,n) Germaria from newly eclosed flies (<1-day old) of C587ts > UAS-dpp, which are maintained at 18 °C up to EP stage and then maintained at 25 °C till eclosion, exhibit excess pMad-negative UGCs (m) and bamP-GFP-positive UGCs (n). Scale bar is shown in panel (a). Anterior is always to the left.
