During early stages in avian embryogenesis primordial germ cells (PGCs
) show a unique migration pathway toward the gonadal anlage through th
e circulation. In the present study, liposomes consisting of plasmid D
NA (pMiwZ; containing lacZ as a reporter) and Lipofectin were injected
into the marginal veins of quail embryos during the stages PGCs were
circulating in the blood vessels. The lacZ expression was then histoch
emically detected in the gonads at later embryonic stages, indicating
the expression of the injected DNA in PGCs.