Dorsal dermis development depends on a signal from the dorsal neural tube, which can be substituted by Wnt-1

Abstract

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. By E10, grafts of the ventral neural tube plus notochord or of cells producing Shh led to differentiation of cartilage and muscles, and an impaired dermis derived from already segmented somites. In contrast, grafts of the dorsal neural tube, or of cells producing Wnt-1, triggered the formation of a feather-inducing dermis. These results show that the dermatome inducer is produced by the dorsal neural tube. The signal can be Wnt-1 itself, or can be mediated, or at least mimicked by Wnt-1.

Role of Pinin in neural crest, dorsal dermis, and axial skeleton development and its involvement in the regulation of Tcf/Lef activity in mice

“…3D,E). These data suggest defective development of derivatives from the dermomyotome, including dorsal dermis (Olivera-Martinez et al, 2001 and BAT (Atit et al, 2006). Consistently, hair follicles, whose development requires intimate interactions between epidermis and dermis (Schmidt-Ullrich and Paus, 2005), while normal in the flanks, exhibited significant reduction in number in the dorsum of Pnn 3f/3f embryos ( Fig.…”

“…Instead, Pnn hypomorphs exhibited a complex phenotype. Intriguingly, all of these phenotypes-vertebral patterning (Ikeya and Takada, 2001;Aulehla et al, 2003), dorsal dermis development (Olivera-Martinez et al, 2001, BAT formation (Atit et al, 2006), and palate and outflow tract development (Hamblet et al, 2002;Hutson and Kirby, 2003;Schmidt and Patel, 2005)-have been observed in mice having defects in Wnt/␤-catenin signaling. This finding raised an interesting possibility that PNN might be involved in the regulation of Wnt/␤-catenin signaling during mouse development.…”

“…The axial skeletal defects of Pnn 3f/3f mice may stem from the perturbation in the segmentation or differentiation of somites. Importantly, an increasing number of studies have demonstrated the major role of Wnt signaling in the formation, differentiation, and delamination of somites (Borello et al, 1999;Ikeya and Takada, 2001;Olivera-Martinez et al, 2001Aulehla et al, 2003;Atit et al, 2006 6C). Thus, the up-regulation of Tcf/Lef activity seems independent of ␤-catenin accumulation.…”

Molecular biology of feather morphogenesis: A testable model for evo‐devo research

“…To test the role of molecules in these processes, cells secreting exogenous proteins can be implanted into embryonic tissues. One recent attempt showed that cells secreting Wnt-1 can mimic the dorsal neural tube and induce a feathered skin (Olivera-Martinez et al, 2001). In this study a Wnt-1 producing cell line was grafted to the embryos after removal of the neural tube and notochord.…”

Un dermomyotome chez les poissons ?

“…Contrairement aux progéniteurs myogéniques, les cellules dermogéniques cessent rapidement d'exprimer les gènes Pax [8], migrent en direction de l'ectoderme et forment en dessous de ce dernier un mésenchyme qui exprimera le marqueur Dermo-1 [9]. Il a été montré que Wnt-1, qui est produit par la partie dorsale du tube neural, exerce une action inductrice du développement du derme dorsal [10]. Le dermomyotome produit également deux lignées endothéliales : les cellules endothéliales des vaisseaux sanguins (angioblastes) qui expriment VEGFR2 (vascular endothelial growth factor receptor-2), et les cellules endothéliales des vaisseaux lymphatiques (lymphangioblastes) [11].…”