Dorsoventral patterning in the Drosophila central nervous system: the vnd homeobox gene specifies ventral column identity
- Jocelyn A. McDonald1,2,
- Scott Holbrook2,
- Takako Isshiki1,2,
- Joseph Weiss3,
- Chris Q. Doe1,2,5, and
- Dervla M. Mellerick4,5
- 1Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403 USA; 2Department of Cell and Structural Biology, University of Illinois/Howard Hughes Medical Institute (HHMI), Urbana, Illinois 61801; 3Department of Developmental Biology, HHMI, Stanford University School of Medicine, Stanford, California 94305 USA; 4Pediatric Neurology Research Laboratories, University of Michigan Medical Center, Ann Arbor, Michigan 48109 USA
Abstract
The Drosophila CNS develops from three columns of neuroectodermal cells along the dorsoventral (DV) axis: ventral, intermediate, and dorsal. In this and the accompanying paper, we investigate the role of two homeobox genes, vnd andind, in establishing ventral and intermediate cell fates within the Drosophila CNS. During early neurogenesis, Vnd protein is restricted to ventral column neuroectoderm and neuroblasts; later it is detected in a complex pattern of neurons. We use molecular markers that distinguish ventral, intermediate, and dorsal column neuroectoderm and neuroblasts, and a cell lineage marker for selected neuroblasts, to show that loss of vnd transforms ventral into intermediate column identity and that specific ventral neuroblasts fail to form. Conversely, ectopic vnd produces an intermediate to ventral column transformation. Thus, vnd is necessary and sufficient to induce ventral fates and repress intermediate fates within theDrosophila CNS. Vertebrate homologs of vnd(Nkx2.1 and 2.2) are similarly expressed in the ventral CNS, raising the possibility that DV patterning within the CNS is evolutionarily conserved.
Keywords
Footnotes
-
↵5 Corresponding authors.
-
E-MAIL cdoe{at}uoneuro.uoregon.edu; FAX (541) 346-4736; E-MAIL dervla_mellerick.pediatrics{at}mailgw.surg.med.umich.edu; FAX (734) 7644279.
-
- Received August 10, 1998.
- Accepted September 23, 1998.
- Cold Spring Harbor Laboratory Press
