Martin J Cohn,

Fun Fact: Following news coverage of a Cohn lab paper on the role of testosterone in sexually dimorphic digit development, the Red Hot Chili Peppers appeared on late-night television wearing giant prosthetic fingers. The Cohn lab studies the molecular mechanisms of external genitalia and limb development. Our overarching goal is to understand how changes during embryonic development lead to anatomical variation in two contexts, structural birth defects and morphological evolution. Our studies of genitalia development use mouse models to investigate genetic and environmental causes of genitourinary malformations, which are among the most common birth defects in humans. We use a variety of techniques, including molecular genetics, experimental embryology, multi-omics, 3-D imaging, and in vitro models. Our studies of sexual differentiation of genitalia have led to new lines of investigation into the causes of sex differences in other organs. Our evolutionary developmental (evo-devo) research aims to understand how mechanisms of embryonic development have evolved over deep time to produce the rich diversity of animal form. These studies use comparative biology to investigate development in a phylogenetic context, which has led us to study embryos from a range of species, including birds (chickens, ducks, emus, ostriches) reptiles (pythons, lizards, turtles, alligators), cartilaginous fishes (sharks, skates), jawless fishes (lampreys, hagfishes), and even invertebrates (cuttlefish, horseshoe crabs).