Retroviruses as tools for mammalian development.

Retroviruses have been used as probes for the study of mammalian development. Successful applications of this tool include (1) genetic labeling of cells for lineage studies in preimplantation and postimplantation development, (2) tagging important chromosomal regions of the mouse genome, (3) identifying genes that are expressed during early development, and (4) generating mutant mouse strains by insertional mutations that allow for molecular and functional analyses of developmental genes.