Chicken Embryonic Stem cells (cESC) were isolated from the in vitro establishment of cultured blastodermal cells (cBC) derived from pregastrulating stage IX-XII chicken embryo (EG & K) (Pain et al., 1996, Petitte et al., 2004). These cESC present typical features of embryonic stem cells (ESC) such self renewing and differentiation properties both in vitro and in vivo. The cells cESC have a strong potential of in vitro differentiation and can be induced in the three germ layer, the ectoderm, mesoderm and endoderm derivatives. In vivo, these cells can contribute to embryo morphogenesis all along early development. While the cBC were shown to contribute to the germ line once reinjected into recipient embryos (Carscience et al, 1993; Thoraval et al, 1994), the ability of cESC to enter and differentiate into functional germ cells is still elusive and it appears that the establishment of in vitro culture of the cESC induces a loss of this competence germinal (Petitte et al, 2004; Van de Lavoir et al, 2005) which is maintained for the PGCs cells under conditions of particular cultures (Van de Lavoir et al, 2006).
We performed the first studies of the molecular characterization of the cells cESC, cBC and of the germinal cells. Our results indicate the maintenance and the relative losses of expression of certain genes characteristic of these various cellular types. In particular, the cells cESC express very strongly a set f key genes which control pluripotency like cPouV, Nanog, Tra1, Gcnf, etc... We were the first to identify, clone and charaterise the role of such pluripotency associated genes in non mammalian species and in birds in particular (Lavial et al, 2007). Relationship between pluripotency and germ line competency will be also presented and discussed.
