Knocking in and out genes and trans genes: the use of the engineered mouse to study normal and aberrant hemopoiesis.

Mouse genetics and engineered mice have become invaluable tools for the study of normal and aberrant hemopoiesis, in modeling hemopoietic disorders, and developing new therapeutic approaches using these models. However, the technological exploitation of these powerful genetic tools, as well as the scientific exploitation of the mutants which are generated is still in a primordial phase. For instance, the possibility to introduce specific point mutation, in vivo, in any desired locus, will allow the production of a second generation of mutants, which will be much more informative in the dissection of the function of any molecule. Furthermore, the possibility to interbreed mutants thus generating organisms harboring concomitantly "n" mutations in "n" loci will allow the possibility to test and validate, in vivo, the role of individual biochemical and cellular pathways.