Scientists at the University of Michigan Medical School have discovered a molecular switch that controls the formation of fat cells in mice. If the switch is on, fat cells will not develop. Switch it off, and even would-be muscle cells turn to fat. Wnts regulate the complex genetic and biochemical changes that take place during embryological development. Development begins with a ball of generic stem cells capable of becoming any type of cell.
Stem cells become precursor cells, which can change into a limited number of cell types.
By the end of the developmental stage, cells are committed to just one cellular future. Scientists knew that Wnt proteins were involved in early cell development, but the U-M study is the first to identify the importance of Wnts in fat cell formation. Tissue samples from experimental and control mice in the U-M study show how expression of Wnt blocks formation of adipocytes. Fat cells develop in tissue grown from preadipocyte cells. Understanding this developmental pathway could help scientists learn how and why obesity develops.