MANIPULATIONS OF GERM-CELL POPULATIONS IN THE GONAD OF THE FOWL

1. Embryos of the domestic fowl have been partially sterilised by inje cting die drug busulphan into 24-h incubated eggs. 2. Some of these em bryos were injected with primordial germ cells (PGCs) after 55 h of in cubation to attempt to repopulate the gonads. 3. Primordial germ cells transfected with a defective retrovirus containing the reporter gene lac Z were shown to settle in these sterilised gonads. 4. Quantitative histology of 6-d embryos showed that busulphan produced 75% sterilisa tion but that PGCs could repopulate these gonads. 5. The technique of producing such germ line chimaeras is of value in studying cell kineti cs, gonad differentiation and the production of transgenics.