Additional Author(s): Qiling Xu
Embryonic Patterning: Segmentation; Compartments/Boundaries
Gene Regulation: Transcriptional Control
Ectoderm-derived: Nervous System
Organism: Zebrafish, Chick
Stage of Development: Embryo
This diagram depicts specific aspects of neuronal organization (upper part) and segmental gene expression (lower part) to illustrate key features of hindbrain segmentation. The developing vertebrate hindbrain is divided into segments called rhombomeres (r). Neurons in the hindbrain are specified based on the rhombomeres from which they arise. In amniotes such as chick (top row), the branchiomotor neurons that make up nerves V, VII, and IX are organized in columns across the anteroposterior length of the segments and arise from specific sets of rhombomeres. In zebrafish (second row), specific cell types are organized stereotypically within each rhombomere: reticulospinal neurons at the center (blue circles), and fibers of radial glial cells (green squares) adjacent to the specialized boundary cells (orange circles) that form at each segment interface. The lower half of the diagram shows the expression domains of selected genes that have key roles in rhombomere anteroposterior identity (grey), segment formation (turquoise), and cell segregation (green and pink). Most of these expression domains are conserved between species, and for internal consistency, the patterns shown are for zebrafish (corresponding zebrafish genes are in brackets). WIREs Dev Biol 2013. DOI: 10.1002/wdev.106
Xu, Q., Wilkinson, D.G. Boundary formation in the development of the vertebrate hindbrain. WIREs Dev Biol, 2013, Published Online: Jan 25 2013.