Peafowl-chicken Interspecific Chimera

The present experiment was designed to investigate a possibility of the in vitro cultured somatic cells to produce the germ line interspecific chimera in bird. The frozen-thawed fibroblast-like cells derived from a male 9-day embryo of Indian peafowl were cultured and treated with polyethylene glycol(PEG, mw8000). The treated cells were injected into the blastoderm of unincubated fertile White Leghorn eggs(at stage X). The manipulated eggs were incubated until hatching. A total of 108 White Leghorn eggs were manipulated with the injection of about 800-1600 peafowl cells for each egg. The chimerism was assesed by observation of the plumage and DNA analysis. To do DNA assay, peafowl mitochondrial cytochrome b (cyt b) gene carrying species-specific DNA loci with 418 bp fragments was adopted as a genetic marker. Of 108 manipulated eggs, only four hatched and two of them revealed partially pigmented feather mosaicism, denoting the existence of peafowl-specific cyt b gene in the feather pulp. In addition, the peafowl-contributed mosaic tissues were also found in the muscle, testis and ovary of dead embryos and one chick. The present results demonstrate that the cultured peafowl fibroblast-like cells, which were treated with PEG before the injection into the blastoderm of White Leghorn eggs, differentiated and integrated into the recipient tissues during embryonic development. This experiment also suggests that intersepcific chimera birds may be produced by using this method in the future.