Fig. 6. Drosokinin-induced cytosolic calcium signals in itpr mutants. (A) Typical traces of changes in intracellular Ca²⁺ concentration ([Ca²⁺]_i) in tubule stellate cells stimulated by 10^-7 mol l^-1 Drosokinin (arrows) in the following lines: (i) aeq;hsGAL4;+ (control), (ii) aeq;hsGAL4; itpr^XR12/+, (iii) aeq;hsGAL4;itpr^90B.0/+, (iv) aeq;hsGAL4;itpr¹⁶⁶⁴/+, (v) aeq;hsGAL4;itpr¹⁶⁶⁴/itpr¹⁶⁶⁴ and (vi) aeq;hsGAL4;itpr^WC361/itpr^UG3. Each sample contains 20 intact tubules. While no changes in the resting [Ca²⁺]_i is seen in any of the mutants, changes in amplitude of the calcium peak can be observed in aeq;hsGAL4;itpr¹⁶⁶⁴/itpr¹⁶⁶⁴ and aeq;hsGAL4;itpr^WC361/itpr^UG3 (also in B). (B) Pooled results of changes in tubule [Ca²⁺]_i in itpr mutants in response to 10^-7 moll^-1 Drosokinin. Results are expressed as means ± S.E.M. (N=8) for background (open bars) and Drosokinin-stimulated peaks (filled bars) for the lines described in A. Drosokinin-stimulated primary peaks that are significantly different from aeq;hsGAL4;+ tubules are denoted by ^* (P<0.05, Student's t-test, unpaired samples).