How Does developmental regulation of cell number require YAP?
Mouse embryos in which the Yap gene has been disrupted die before birth (Figure 1) with several distinct developmental problems including defective yolk sac blood vessel development (see below), failure to initiate development of the placenta (see below), and a profound disruption in the growth and elongation of the embryo-proper. Possibly the defects observed in the mutant embryo can be explained in part by a failure of the embryo to produce the proper number of cells. We know that careful regulation of cell number is critical to proper embryogenesis in many ways. This control of cell number can include both removal of cells by programmed cell death (apoptosis) and increases or decreases in the rate at which cells are dividing (proliferation). We use molecular biology, cell culture, biochemical and embryological techniques to learn if YAP may be important to developmentally-regulated apoptosis and proliferation. These studies will help us better understand how YAP functions in cells a
