Fig. 6
Absence of sws1 Opsin Expression History in Zebrafish Rod Photoreceptors. (A) Lineage tracing strategy in zebrafish. Lineage tracing in zebrafish was accomplished using a feedforward system that has been previously designated as “Kaloop” (Distel et al., 2009) (see Figure S6). Two constructs, Tg[sws1:KalTA4] and Tg[UAS:nfsB-mCherry-V2A-KalTA4] (ua3139 and ua3137, respectively), were independently inserted to generate the transgenic zebrafish. In ua3137, a fluorescent reporter protein mCherry is fused in-frame to a bacterial nitroreductase gene (nfsB), and the fusion protein is connected via the labile linker peptide V2A to a second copy of the KalTA4 transcription factor.
(B) Lineage tracing of sws1-expressing cells using sws1:KalTA4; UAS:nfsB-mCherry-V2A-KalTA4 zebrafish line. The UV-sensitive cones (cyan, 10C9.1) and rods (green, 4C12) of 4-dpf zebrafish were labeled using immunohistochemistry. Representative images from 1 of 10 left eyes. D, dorsal; V, ventral; N, nasal; T, temporal. Scale bar, 50 µm in low-magnification images and 20 µm in high-magnification image (bottom right).