Figure 4. A schematic illustration of the localization of eel PGCs during embryonic development.

Localization of PGCs in embryos at each stage is shown by means of dots, and is summarized in this illustration. The regions where PGCs were well observed are colored red. At the 50%-epiboly stage, PGCs were found widely around the embryonic shield. During the somitogenesis period, they were localized bilaterally and spread loosely by the somites. During this period, some of the PGCs were observed to first coalesce and then disperse once more. The PGCs finally localized around the upper part of the gut; these cells did not form clusters.