The NK-2 homeobox gene scarecrow (scro) is expressed in pharynx, ventral nerve cord and brain of Drosophila embryos

Members of the NK homeobox family have been widely conserved during evoluti on. Here we describe the sequence and expression of a novel Drosophila NK-2 homeobox gene, named scarecrow (scro), which shows considerable homology t o vertebrate Nkx-2.1. During embryogenesis, sere expression is initially ob served in the pharyngeal primordia and later maintained in the pharynx. Dur ing band germ retraction, sere expression appears in two bilateral clusters of procephalic neuroblasts that give rise to distinct neuronal clusters in the brain. In addition, sere expression is observed in segmental clusters of neuronal precursors in the ventral nerve cord. In larval stages, sere ex pression occurs in portions of the optic lobe regions. These observations i ndicate that sere and vertebrate Nkx2.1 share similarities both in terms of their sequence and their expression patterns. (C) 2000 Elsevier Science Ir eland Ltd. All rights reserved.