Fig. S2

Effect of thapsigargin, 2-APB, xestospongin C, dantrolene or ryanodine (at a high concentration) on the spontaneous Ca²⁺ activity of CaPs in SAIGFF213A;UAS:GCaMP7a double-transgenic embryos. SAIGFF213A;UAS:GCaMP7a embryos were treated with: (Aa) 1 µM thapsigargin; (Ab) 10 µM 2-APB; (Ac) 1 µM xestospongin C; (Ad) 50 µM dantrolene, or (Ae) 50 µM ryanodine at 17 hpf via tail-bud excision. (Aai-Aeiv) Time-lapse fluorescence images showing the changes of GCaMP7a fluorescence signals in the CaPs at different time intervals in the various treatment groups. The embryos are in a dorsal orientation and ROIs on two selected CaP cell bodies on the left (L) and right (R) sides of the spinal cord are shown. The arrowheads indicate the increase in GCaMP7a signals in the CaPs. Ant. and Pos. are anterior and posterior, respectively. Scale bar is 50 µm. (Aav-Aev) Line graphs to show the ΔF/F₀ against time (over a period of ~300 sec) in the ROIs of the representative embryos shown in (Aai-Aeiv), respectively. The time period that corresponds to the Ca²⁺ signaling events shown in the time-lapse fluorescence images (Aai-Aeiv) is denoted by a grey vertical bar in (Aav-Aevi). (B) Bar graphs to show the mean ± SEM cross correlation at zerolag of the (Ba) ipsilateral, and (Bb) contralateral CaP Ca²⁺ activity. (C-E) Bar graphs to show the mean ± SEM (C) frequency, (D) amplitude and (E) duration of the Ca²⁺ spikes in the CaPs of the double-transgenic embryos in the various treatment groups. Data were obtained from n=18-81 cells from 3-9 embryos, except for the duration data, which were n=6 cells from 3 embryos. p<0.01 (**) and p<0.001 (***), and NS indicates no significant difference between the data.