Fig. 4

Ca²⁺ transients occur more frequently in hec mutant embryos than in wild-type embryos. (a–f) Surface plot representations showing the number of Ca²⁺ transients in individual embryos during the cellular blastoderm stage. Wild-type (a) has less activity when compared to untreated hec embryos (b and e: hec mutant embryos from different females). Sibling embryos from clutches with similar activity to untreated embryo (b) were unilaterally injected with XeC on the left side (c) and L-690,330 on the right side (d). Sibling embryo from a clutch with similar activity to untreated embryo (e) was injected with A-protomer of pertussis toxin on the left side (f). White arrows in panels c, d, and f indicate side of injection and the inset in panel d demonstrates the location of Texas red lineage marker coinjected with the reagent. Embryos were oriented in a lateral view relative to the long axis. The image represents a composite of all the transient activity in a single embryo. The color and peak size represent the total number of Ca²⁺ transients that occurred in that location in the embryo. The color bar shows the frequency range with low numbers as cooler colors (purple = 0–1) and high numbers as hotter colors (orange–red = 25). Composites in panels a–f were accumulated from 200 data frames, 50 min. (g–h) Graphical output of the number of Ca²⁺ transients as a function of time (after image analysis was initiated) for wild-type (black) and hec (red) (g). Graphical plot of hec mutant embryo injected with A-protomer of pertussis toxin demonstrating recovery of Ca²⁺ transients after 45 min (h). Imaging was initiated at the 32- to 128-cell stage (1.75–2.25 hpf = time 0 in plots). (i–k) Surface plot representation showing the number of Ca²⁺ transients in individual embryos during the cellular blastoderm stage. Wild-type control (i). Wild-type embryo with unilateral injection of tcfBD (j). Wild-type embryo with unilateral injection of β-catenin MO (k). Composites in panels i–k were accumulated from 260 data frames, 65 min. Note that control embryo (i) was imaged for a longer time than the wild-type embryo in panel a; thus, it has more transients in total (and hence the peaks are taller) but a similar frequency of transients.