The Kimble lab investigates fundamental controls of animal development. We take advantage of the genetic power and cellular simplicity of the nematode Caenorhabditis elegans, which can be viewed as the “E. coli of animal development”. Our goal is to understand the molecular logic of stem cells and differentiation within a single tissue. Our focus is the germ line, which is composed of totipotent cells that generate sperm or oocytes to launch the next generation. Our discoveries have implications for germ cells throughout phylogeny and reveal molecular mechanisms used in virtually all animal cells.