Avian Retroviruses: Tools for Generating Immortalized Neural Cells and Studying Neural Differentiation

Avian embryos, especially those of chick and quail, offer powerful systems for studying very early steps of both central and peripheral neurogenesis, but the lack of permanent neural avian cell lines constitutes an obstacle to analyzing differentiating events at the molecular level. In this paper, we present a strategy whereby new avian cell lines can be generated by infecting, in vitro, cells arising from different parts of the nervous system with natural occurring retroviruses. In particular, the cells from neural crest, neuroretina, peripheral ganglia, and neural tube were induced to proliferate highly by either MC29 or RSV infection. We also discuss some investigations performed with retroviral-infected cells aimed at testing factors or searching for genes that are implicated in the cellular cycle or in differentiating events. Finally, we include a discussion concerning the potential uses and limitations of such a system.