Genes and the Genesis of the CNS: Hints from the Homeobox

Abstract

At least a third of the human genome is estimated to be devoted to the development and maintenance of the central nervous system (CNS). Recent advances in our understanding of the genetic programming of CNS development are based on the identification of master control genes that are essential for the earliest stages of neurogenesis and the subsequent specification of cell lineages. One class of control genes thought to be involved in CNS development are called "homeobox genes." First discovered in Drosophila (fruit flies), and now recognized in many species including humans, these highly conserved genes code for DNA binding proteins that regulate the expression of other subordinate genes. Although the relevance of homeobox genes to developmental psychopathology and pediatric psychopharmacology may appear remote, interactions between these basic genetic mechanisms and their increasingly complex environments (both macro- and micro-) undoubtedly play a critical role in the initial organization of the CNS and may contribute to the etiology of various developmental disorders.