Abstract
The aim of present study was to analyze the frequency of M-phase and DNA content of primordial germ cells (PGCs) just after translocation to the germinal ridge (embryos at Stages 17-20) using interactive laser cytometry. The frequency of M-phase significantly increased from 8.0 to 21.6% with advancing embryonic stage. The data of the nuclear DNA content of PGCs were presented graphically, and two peaks (first and second) were recognized in all stages. The fluorescence value of the first peak was approximately one -half that of the second one. The PGCs of the M-phase had fluorescence values similar to or greater than the second peak in all stages. These results suggest that PGCs, just after translocation to the germinal ridge, undergo a periodic change in their nuclear DNA, and that intense proliferation occurs as the embryonic stage advances.
