Chronicles of a switch hunt: gcm genes in development

Go-conservation of sequence and function is an important principle during e volution. As a consequence, sequence-related genes often have similar funct ions in evolutionarily distant species. Enter the 'glial cells missing' (gc m) genes. They code for a small family of novel transcription factors that share DNA-binding properties and domain structure, However, no evolutionari ly conserved function is apparent as yet. The prototypical gem from Drosoph ila dominates nervous system development as a fate switch and master regula tor of gliogenesis, whereas mammalian gem genes have roles in placental mor phogenesis and development of the parathyroid gland, Apparently, structure and function sometimes can go separate ways.