Phenotypic analysis of the mouse placenta

Placental development is a dynamic and complex process and much of our current understanding of the underlying molecular processes comes from analysis of targeted gene mutations in mice. There are more than 50 strains of mutant mice that have placental defects, and it has become widely appreciated that placental defects should be suspected in cases where embryonic lethality is observed. The degree to which these phenotypes are investigated is highly variable, owing to a general lack of expertise in the field. However, there has been considerable progress in developing techniques and reagents for analyzing placental phenotypes that are relatively simple to apply and that should be accessible to all investigators. This chapter provides a basic outline of the strategies for the general identification and then the subsequent detailed investigation of placental phenotypes.