Expression of exogenous genes in blastodermal cells of chicken in vitro.

Chicken blastodermal cells (BCs) from stage X embryos produce both somatic and germline chimeras when injected into the subgerminal cavity of recipient embryos. Transfection of the donor cells in vitro could lead to the production of chimeras capable of transmitting the transgene to their offspring. The aim of this study was to transfer and express foreign genes under control of the ovalbumin promoter in the BCs. The results showed that luciferase activity in the BCs reached a plateau value with a 2.0:1.0 or 5.0:1.0 liposome-DNA ratio and using 1 microg of DNA. Under this same condition, no difference was found in relative activity between the pGL-control and pOVALUC plasmid. The expression of other exogenous genes (green fluorescent protein and interferon alpha2a) driven by the chicken ovalbumin promoter in cultured chicken blastodermal cells in vitro is possible by this assay. Hatchability of recipient embryos after injection of 1,500 or 800 transfected BCs was compared. The advantage of using a smaller number (800) of injected transfected BCs was that early embryonic mortality was reduced and resulted in higher (P<0.01) hatchability (24.5%) than in the case of 1,500 BCs injected.