ISNfT a MOUSE MORE LIKE a MAN?

l acques Monod was saying fond o f "that 'an elephant is like an E. coli, only more so'. Mouse geneticists have long felt, and partially justified their research in the belief, that 'a human is like a mouse, only more so'. Many excellent mouse models of genetic disease support this belief 1. However, as more genetic models are identified in mice, more differences are being found between some of the mouse mutants and human diseases. Given the greatly increased ability to create desired mouse mutations 2, it is timely to review some of these mouse models and consider possible reasons why they do not always replicate the human disease associated with the same mutations. Three general mechanisms for the differences will be considered: (1) different biochemical pathways, (2) different developmental pathways, and (3) the possibility that some pathological processes occur at the same absolute rate in man and mice instead of being related to life span.