In this experiment, we used shhact/ctembryos prepared from incrosses of shhact/+fish and genotyped the embryos individually via PCR. We presented examples of the PCR genotyping results of embryos from incrosses of shhact/+fish and crosses of shhact/+fish with tcf21:CreER; shhact/+fish in Figure 3—figure supplement 1. Furthermore, we clarified that the screening was performed using individual embryos in the manuscript text as follows: