Proliferation of exogenously injected primordial germ cells (PGCs) into busulfan-treated chicken embryos

This study was designed to investigate the effect of busulfan treatment on the proliferation of chicken primordial germ cells (PGCs) in vivo, focusing on the preferential settlement of PGCs onto the germinal ridges of chicken embryos.

Busulfan (250 ng/egg) was injected into the egg white of freshly oviposited fertilized eggs, which were then incubated. Embryonic development and viability were examined, and exogenous PGCs collected from embryonic blood vessels were injected into the germinal crescent region of recipient embryos. The number of PGCs resided onto germinal ridges of the right and left sides were compared.

Busulfan had a slight harmful effect on the embryo viability and the PGCs proliferation. The number of PGCs resided onto the left side of germinal ridges was slightly higher as compared with the right side.

Busulfan suppressed the viability of embryos and the proliferation of endogenous PGCs in the recipient embryos. However, the number of exogenous PGCs proliferated was higher in embryos treated with busulfan than those without busulfan. Data also suggest the possibility of a preferential residence of PGCs toward the left side of the germinal crescent region as compared with the right, which may be due to a more advanced functional development of the left gonad than the right.