ABSTRACT
It is widely recognized that genetically defined mice provide (1) reproducible, experimental systems for understanding normal development and function, (2) model systems for analyzing the defects in comparable human disorders, and (3) model systems for preclinical testing of therapeutic agents. Model systems permit studies that are inappropriate or impossible in human beings. The mouse, in particular, provides a good model system because of the metabolic and internal anatomical similarities between mice and human beings, the availability of controlled genetic backgrounds, short life span, large litters, and short generation time. Because of their ease of maintenance and small size, mice are relatively economical to maintain. Their cells and tissues are readily accessible for studies of gene dosage effects on embryogenesis and organogenesis. Mouse embryogenesis is well studied and
described. More is known about the genetics of the mouse than any other experimental mammal, and specific regions of the mouse and human genomes are highly conserved.
