Topography of lws1 and lws2 reporter patterning in adult lws:PAC(H) transgenic fish, in which GFP reports lws1 expression and RFP reports lws2 expression. (A–F) Projections of representative whole, imaged retinas from fish treated with 0.01% NaOH (control, A–C) or 386 nM T4 in 0.1% NaOH (treated, D–F) for 5 days. Insets show indicated regions enlarged by 1400%. (A,D) All imaging channels merged. (B,E) lws2:RFP. (C,F) lws1:GFP. Note expanded GFP expression domain in response to T4 (D–F). (G,H) Projections of representative sectioned retinas from fish treated with NaOH (control, G–G″′) or T4 (treated, H–H″′). (G,H) All imaging channels merged. (G′,H′) lws2:RFP. (G″,H″) lws1:GFP. (G″′,H″′) enlarged image of lws2:RFP-containing region. Arrows indicate cells coexpressing GFP and RFP (see also Supplementary Fig. S1). (I–K) Analysis of areas of expression domains, n = 3 for each group. (I) Percent of retina occupied by GFP+ cells (p = 0.0068, t-test). (J) Percent of retina occupied by RFP+ cells (p = 0.6910, t-test). (K) Percent of retina occupied by GFP+ and RFP+ cells interspersed or coexpressing (p = 0.0033, t-test). Fisher’s Exact Test was used to test for overall differences: p = 0.0034 with a 3 × 2 contingency table. D dorsal, T temporal.

Plasticity of cone transcripts in response to 5 days of T4 treatment. (A–F) Projections of representative whole, imaged retinas from fish treated with NaOH (control, A–C) or T4 (treated, D–F) followed by HCR in situ. Insets show indicated regions enlarged by 1400%. (A,D) All imaging channels merged. (B,E) lws2 (C,F) lws1. Note expanded lws1 domain and lack of lws2 mRNA in T4-treated retina. (G) qPCR of whole adult eyes. (lws1) n = 5, p = 0.0079 (Mann–Whitney). (lws2) n = 5, p = 1.2749E−05 (t-test). (gngt2b) n = 5, p = 0.0025 (t-test). (rh2-1) n = 4, p = 0.0168 (t-test). rh2-2) n = 5, p = 0.0355 (t-test). D dorsal, T temporal.

Plasticity of cone transcripts in response to 24-h T4 treatment. (A–F) Projections of representative whole, imaged retinas from fish treated with NaOH (control, A–C) or T4 (treated, D–F) followed by HCR in situ. Insets show indicated regions enlarged by 1400%. (A,D) All imaging channels merged. (B,E) lws2 (C,F) lws1. Note expanded lws1 domain and lack of lws2 mRNA in T4-treated retina. (G) qPCR of whole adult eyes, n = 6 for each group. (lws1) p = 1.3235E−07 (t-test). lws2) p = 0.0008 (t-test). (gngt2b) p = 0.0002 (t-test). (rh2-1) p = 0.0233 (t-test). (rh2-2) p = 0.0065 (t-test). D dorsal, T temporal.

Plasticity of cone transcripts in response to 12-h T4 treatment. (A–F) Projections of representative whole, imaged retinas from fish treated with NaOH (control, A–C) or T4 (treated, D–F) followed by HCR in situ. Insets show indicated regions enlarged by 1400%. (A,D) All imaging channels merged. (B,E) lws2 (C,F) lws1. Note expanded lws1 domain and colocalization of lws1 and lws2 mRNA in T4-treated retina. (G) qPCR of whole adult eyes. (lws1) n = 6 (control), 4 (treated); p = 0.0006 (t-test). (lws2) n = 6 (control), 4 (treated); p = 0.1424 (t-test). (gngt2b) n = 6 (control), 4 (treated); p = 0.7863 (t-test). (rh2-1) n = 6 (control), n = 5 (treated); p = 0.1860 (t-test). (rh2-2) n = 6 (control), n = 5 (treated); p = 0.3820 (t-test). D dorsal, T temporal.

Plasticity of cone transcripts in response to 7-h T4 treatment. (A–F) Projections of representative whole, imaged retinas from fish treated with NaOH (control, A–C) or T4 (treated, D–F) followed by HCR in situ. Insets show indicated regions enlarged by 1400%. (A,D) All imaging channels merged. (B,E) lws2 (C,F) lws1. Note expanded lws1 domain and colocalization of lws1 and lws2 mRNA in T4-treated retina. (G) qPCR of whole adult eyes. (lws1) n = 6 (control), 5 (treated); p = 0.0373 (t-test). (lws2) n = 6 (control), 5 (treated); p = 0.3173 (Mann–Whitney). (gngt2b) n = 5 (both treatments); p = 0.8277 (t-test). (rh2-1) n = 6 (control), n = 5 (treated); p = 0.8246 (t-test). (rh2-2) n = 6 (control), n = 5 (treated); p = 0.8941 (t-test). D dorsal, T temporal.

Five day T4 treatment of adult zebrafish alters skin pigmentation. (A) Brightfield photographs of representative fish. (B) Examples of representative stripe and interstripe colors of control and treated fish. Colors were sampled from regions denoted by rectangles in (A). (C) Color analysis of stripe and interstripe Red, Green, and Blue scale values, n = 3. Values denote “redness,” “greenness,” and “blueness” on a scale from 0 to 255. High red values indicate high redness. Low red values indicate green, low green values indicate red, low blue values indicate orange. Note trend of higher red and green values in stripes of T4-treated fish. (D) Percentages of fish in control and treated groups with altered pigmentation compared to untreated wildtype. All T4-treated fish showed altered skin pigmentation while all control fish showed normal pigmentation, p = 0.0143 (proportion test).