Extended Data Fig. 9: Effects of ectopic and tissue-wide Fgf3 pulses on scale regeneration.

This figure indicates that Fgf3-induced tissue-wide and synchronous Erk oscillations lead to impaired tissue growth. a, b, Quantification of spatial (a) and temporal (b) patterns of Erk activity in regenerating scales in fish expressing fgf3 downstream of the heat-shock promoter hsp70l (hsp70l:fgf3) and control siblings not carrying the transgene. n = 5 scales from 5 fish per condition from a single trial. Transgenic fgf3 expression was induced by heat-shock every day; fish were imaged before and after heat-shock (shaded regions in b). In a, Erk activity is averaged along a 240 μm-wide stripe passing through the scale centre and the wave origin. In b, the fraction of active Erk cells with respect to total is calculated in the entire scale (cytoplasmic Erk KTR >1.1 nuclear Erk KTR). c, Average cell area increase (with s.e.m.) as function of time in regenerating scales in hsp70l:fgf3 fish and control siblings not carrying the transgene. Error bars, mean with s.e.m.; n = 5 scales from 5 fish per condition in a single trial; chi-squared test P is indicated. Transgenic fgf3 expression was induced by heat-shock every day starting from 3.5 dpp. Fish were imaged before and after heat-shock (shaded regions in b). d, e, Example of scale morphology as a function of time in fish expressing hsp70l:fgf3 and control siblings not carrying the transgene. n = 5 scales from 5 fish per condition in a single trial (d). Average deviation of scale morphology (e) (error bars, mean with s.e.m., n = 5 scales from 5 fish per condition in a single trial) is measured with respect to before heat-shock by calculating the total discrepancy of the rescaled scale borders in polar coordinates (Methods). Chi-squared test P is indicated. Transgenic fgf3 expression was induced by heat-shock every day; fish were imaged before and after heat-shock (shaded regions in b). Scale bar, 250 μm.

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