Fig. 2. Temperature sensitivity of development in strains tsaca2 and acaⁿ and their parent DH1. (A and B) A tsaca2 aggregate after 8 and 24 h of development at 22°C. (C) tsaca2 mounds were shifted to 28°C after 8 h of development at 22°C and photographed at 24 h. Development is arrested at the mound stage. (D) After 8 h of development at 22°C, tsaca2 cells were shifted to 28°C for 12 h and then returned to 22°C and left to develop for another 16 h. (E and F) Fruiting bodies formed by acaⁿ and DH1 cells, respectively, after development for 8 h at 22°C followed by 16 h at 28°C.