To investigate the origin and nature of the signals responsible for specification of the dermatomal lineage, excised axial organs in 2-day-old chick embryos were replaced by grafts of the dorsal neural tube, or the ventral neural tube plus the notochord, or aggregates of cells engineered to produce Sonic hedgehog (Shh), Noggin, BMP-2, Wnt-1, or Wnt-3a.
Most cells with a premigratory neural crest signature localized to a heart shaped region bisected by the midline of the dorsal neural tube: the central-most portion expressed a combination of neural crest, pluripotency, and differentiation markers (NCstem, yellow), whereas the cells just lateral to that expressed neural crest "only" genes (NC, red).
When neural crest cells delaminate from the dorsal neural tube by EMT, these cells lose N-cadherin on their surfaces.
Early ventral patterning is governed by Shh secreted from the ventral neurons and floor plate cells, and development of the dorsal neural tube requires the absence of Shh signaling (Echelard et al., 1993; Ruiz i Altaba et al., 1995).
This has enabled characterization of a previously unknown pluripotent neural crest stem cell niche in the dorsal neural tube.
These snapshots of transcriptional profiles suggest that there is position dependent gene expression in the dorsal neural tube.
Pax3 is a transcription factor expressed in the dorsal neural tube and somite of the developing embryo.
This is particularly important when dealing with challenging tightly adhered epithelial tissues such as the dorsal neural tube, where the cells are highly intermingled.
Combining multiplex gene expression with spatial information provides intriguing biological insight about distinct stem cell niches in the dorsal neural tube.
In wild-type (D/-) embryos, melanophores and xanthophores begin to differentiate in the premigratory neural crest along the dorsal neural tube and migrate from this position to cover the flank.
