Abstract: The present invention concerns a pseudotyped viral vector particle for transferring biological material into cells, wherein said vector particle comprises at least:—a chimeric envelope glycoprotein which comprises or consists in a fusion of the transmembrane and extracellular domain of a baboon endogenous retrovirus (BaEV) envelope glycoprotein and the cytoplasmic tail domain of a murine leukemia virus (MLV) envelope glycoprotein; or—a modified BaEV envelope glycoprotein wherein the cytoplasmic tail domain is devoid of the fusion inhibitory R peptide.

Abstract: A culture medium for avian embryonic cells and an avian cell culture medium is disclosed. The culture medium is characterized in that it has elements complementary to avian embryonic cells. The complementary elements include insulin-like growth factors and stem cell growth factors. The medium is substantially free of active retinoic acid. A method of culturing avian embryonic cells and the resulting products are disclosed.