Figure 3
From: The transcription factor Spores Absent A is a PKA dependent inducer of Dictyostelium sporulation
PkaC overexpression and 8Br-cAMP treatment of spaA-. (A) Mound arrest. Ax2 and spaA- cells, transformed with an A15::pkaC-YFP construct, were developed for 24 h (when wild-type has formed fruiting bodies, see Fig. 1E) and photographed. Bar: 300 µm. (B) Spore formation. The efficiency of sporulation of A15::pkaC-YFP transformed AX2 and spaA- cells was measured as described for Fig. 1G. (C) PkaC effects on gene expression. Cells were developed for 16 h at 12 °C and 1, 3 and 5 h at 22 °C. At 3 and 5 h spores have formed in Ax2/A15::pkaC-YFP. RNA was isolated and transcription of spiA, sigF, bzpF and Ig7 was determined by qRT-PCR. Values are expressed as fraction of the highest expression obtained with Ax2/A15::pkaC-YFP. Results of three individual experiments are shown. (D) 8Br-cAMP effects on gene expression. Ax2 and spaA- early culminants were dissociated, resuspended to 107 cells/ml and incubated with or without 15 mM 8Br-cAMP. RNAs were isolated at t0 and after 2 h of incubation, and levels of spiA, sigF, bzpF, srfA, and control Ig7 transcripts were determined by qRT-PCR. Data are expressed as fraction of the highest expression obtained with Ax2, and means and SD of 3 experiments are shown. Significant differences between some treatments as determined by a rank sum test are indicated (*P < 0.01; -: P ≥ 0.05).
