Fertilized chicken eggs were bombarded with a biolistic device. Transient expression of the lacZ gene under the control of a human cytomegalovirus (CMV) promoter was assessed after in situ gene transfer using this approach. The influence of different pressures, vacuum levels and particles was tested. Survival rate improved as particle velocity decreased, but resulted in lower levels of expression. The best survival and expression were obtained with gold particles, a helium gas pressure of 600 psi and a vacuum of 600 mmHg. Under these conditions, all bombarded embryos showed <FONT FACE="Symbol">b</FONT>-galactosidase activity, indicating that this was an effective method for transformation of chicken embryos.
