Epidermal ectoderm is required for full elevation and for convergence during bending of the avian neural plate

Deborah A. Hackett, Jodi Smith, Gary C. Schoenwolf

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Previous studies suggest that bending of the neural plate requires the juxtaposition of neural plate and non-neuroepithelial tissues. The current study examines the role of one of these tissues, the epidermal ectoderm, in bending. Chick blastoderms were harvested from fertile eggs incubated for 24 hr and cultured dorsal-side-up on agar-albumen substrates. In one experiment, a rectangular flap of epidermal ectoderm on one side of each blastoderm was separated from underlying layers and gently reflected onto the area opaca; a fragment of tungsten wire was placed on top of the flap to hold it down and to prevent healing. Embryos were then allowed to develop in a humidified incubator for 2-18 hr. Asymmetric neurulation was observed between the operated and control sides as early as 2 hr after surgery. The amount of asymmetry was quantified in serial transverse sections from embryos collected 8 hr after surgery. Elevation of the lateral edge of the neural plate on the operated side averaged one half to two thirds of that on the control side, and convergence of the operated side around the dorsolateral hinge point toward the dorsal midline did not occur. These results demonstrate that epidermal ectoderm is required for full elevation and for convergence during bending. In another experiment, lateral epidermal ectoderm was removed, leaving only a medial strip consisting of both the epidermal component of the future neural fold and flanking future epidermis. This experiment revealed that although epidermal ectoderm is necessary for full elevation and for convergence of the neural folds, a medial strip of epidermal ectoderm is sufficient to drive bending. Collectively, these results further support the idea that neurulation is a multifactorial process driven by both intrinsic and extrinsic factors acting in concert.

Original languageEnglish (US)
Pages (from-to)397-406
Number of pages10
JournalDevelopmental Dynamics
Volume210
Issue number4
DOIs
StatePublished - Dec 1997
Externally publishedYes

Fingerprint

Neural Plate
Ectoderm
Neurulation
Blastoderm
Neural Crest
Embryonic Structures
Incubators
Intrinsic Factor
Tungsten
Epidermis
Eggs
Agar

Keywords

  • Chick embryo
  • Ectoderm
  • Neural plate
  • Neuroepithelium

ASJC Scopus subject areas

  • Developmental Biology
  • Cell Biology

Cite this

Epidermal ectoderm is required for full elevation and for convergence during bending of the avian neural plate. / Hackett, Deborah A.; Smith, Jodi; Schoenwolf, Gary C.

In: Developmental Dynamics, Vol. 210, No. 4, 12.1997, p. 397-406.

Research output: Contribution to journalArticle

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