Figure 3. Role for Chk1 in the regulation of tracheoblast proliferation post mitotic entry.

(A). Graph shows cell numbers in Tr2 DT at WL3 in tub-Gal80^ts/UAS-Chk1^RNAi; Btl-Gal4/+larvae grown at 18°C (uninduced (wild type), black) or grown at 29°C from the embryonic period (constitutively induced, grey) (mean ± standard deviation, n = 10 tracheae per condition). (B) Graph shows cell numbers in Tr2 DT at WL3 in tub-Gal80^ts/UAS-Chk1^RNAi; Btl-Gal4/+larvae grown at 18°C (uninduced (wild type), black, same as (A)) or grown at 29°C from the embryonic period till 24 h L3 then shifted to 18°C till WL3 (conditionally induced, grey) (mean ± standard deviation, n = 10 tracheae per condition). (C) Graph showing relative frequencies of BrdU⁺ or pH3⁺ cells in Tr2 DT in wild type (UAS-nuGFP; Btl-Gal4/TM3,Ser)and Btl-Chk1^RNAi at 48–56 h (mean ± standard deviation, n = 10 tracheae per timepoint). (D) Graph showing frequency of cleaved-Caspase 3⁺cells in Tr2 DT in wild type (UAS-nuGFP; Btl-Gal4/TM3,Ser) and Btl-Chk1^RNAi WL3 larvae (mean ± standard deviation, n = 13 tracheae each). Student's paired t-test: *p<0.05. n.s = not significant.