Expression of Green Fluorescent Protein Gene in Somatic Chimeric Chickens Produced by Transplantation of Transfected Chicken Embryonic Fibroblasts

To investigate whether the genetically modified somatic cells can survive and express foreign gene for a long time after being transplanted into avian embryo, chicken embryonic fibroblasts (CEFs) as a cell vehicle for delivering foreign protein were transfected with the green fluorescent protein (GFP) gene, and were introduced into early chicken embryos via blood vessel microinjection at 65-70 h of incubation at 38.5°C. The manipulated eggs were continued to incubate at same condition. The chimerisms of the transplanted CEFs were preliminarily observed under fluorescence microscopy at the different stages in the embryos and the hatchlings. Meanwhile, the chimeric positions of the donor CEFs and the expression of GFP were further examined by polymerase chain reaction (PCR) and immunohistochemistry. The results showed that fluorescent-labeled CEFs embed in the different organs of the recipients including brain, heart, liver, intestine, muscle, etc. and can survive in post-hatch chickens for at least 134 days and the GFP gene can be expressed normally. Long-term survival of the donor CEFs in recipient and normal expression of the GFP gene imply that this approach can be explored for continuous production of target protein in the host chicken.