Incorporation of EdU in PGCs and MPGZ. Treatment with EdU for 3-8 hpf yields four labeled PGCs. Incubation during the emergence of the second pair of PGCs (7-9 hpf) lead to partial labeling of the PGCs, while none of the PGCs is labeled when incubation occurred after 8 hpf. Note: incorporation of EdU during S-phase precedes cell division by around 30 min. The MPGZ is labeled when larvae at 14 hpf or older are incubated with EdU. Arrows indicate formation of mesoblasts (blue), PGCs (green), and MPGZ (yellow), respectively. Red bars show time of EdU treatment with respect to developmental stage.