Morphogenesis and regionalization of the medaka embryonic brain

Kage, T., Takeda, H., Yasuda, T., Maruyama, K., Yamamoto, N., Yoshimoto, M., Araki, K., Inohaya, K., Okamoto, H., Yasumasu, S., Watanabe, K., Ito, H., and Ishikawa, Y.
The Journal of comparative neurology   476(3): 219-239 (Journal)
Registered Authors
Araki, Kazuo, Inohaya, Keiji, Takeda, Hiroyuki
development, central nervous system, forebrain, neural tube, fish, vertebrate
MeSH Terms
  • Animals
  • Body Patterning/genetics
  • Brain/embryology*
  • Brain Mapping*
  • Cell Lineage/genetics
  • Cell Lineage/physiology
  • Cell Movement/genetics
  • Cell Movement/physiology
  • Embryonic Development
  • Gene Expression Regulation, Developmental
  • Genetic Markers
  • In Situ Hybridization
  • Organogenesis/genetics
  • Organogenesis/physiology*
  • Oryzias/embryology*
  • Oryzias/genetics
15269967 Full text @ J. Comp. Neurol.
We examined the morphogenesis and regionalization of the embryonic brain of an acanthopterygian teleost, medaka (Oryzias latipes), by in situ hybridization using 14 gene probes. We compared our results with previous studies in other vertebrates, particularly zebrafish, an ostariophysan teleost. During the early development of the medaka neural rod, three initial brain vesicles arose: the anterior brain vesicle, which later developed into the telencephalon and rostral diencephalon; the intermediate brain vesicle, which later developed into the caudal diencephalon, mesencephalon, and metencephalon; and the posterior brain vesicle, which later developed into the myelencephalon. In the late neural rod, the rostral brain bent ventrally and the axis of the brain had a marked curvature at the diencephalon. In the final stage of the neural rod, ventricles began to develop, transforming the neural rod into the neural tube. In situ hybridization revealed that the brain can be divided into three longitudinal zones (dorsal, intermediate, and ventral) and many transverse subdivisions, on the basis of molecular expression patterns. The telencephalon was subdivided into two transverse domains. Our results support the basic concept of neuromeric models, including the prosomeric model, which suggests the existence of a conserved organization of all vertebrate neural tubes. Our results also show that brain development in medaka differs from that reported in other vertebrates, including zebrafish, in gene-expression patterns in the telencephalon, in brain vesicle formation, and in developmental speed. Developmental and genetic programs for brain development may be somewhat different even among teleosts. J. Comp. Neurol. 476:219-239, 2004. Copyright 2004 Wiley-Liss, Inc.
Genes / Markers
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes