Cell lineage in mammalian craniofacial mesenchyme

Abstract

We have analysed the contributions of neural crest and mesoderm to mammalian craniofacial mesenchyme and its derivatives by cell lineage tracing experiments in mouse embryos, using the permanent genetic markers Wnt1-cre for neural crest and Mesp1-cre for mesoderm, combined with the Rosa26 reporter. At the end of neural crest cell migration (E9.5) the two patterns are reciprocal, with a mutual boundary just posterior to the eye. Mesodermal cells expressing endothelial markers (angioblasts) are found not to respect this boundary; they are associated with the migrating neural crest from the 5-somite stage, and by E9.5 they form a pre-endothelial meshwork throughout the cranial mesenchyme. Mesodermal cells of the myogenic lineage also migrate with neural crest cells, as the branchial arches form. By E17.5 the neural crest-mesoderm boundary in the subectodermal mesenchyme becomes out of register with that of the underlying skeletogenic layer, which is between the frontal and parietal bones. At E13.5 the primordia of these bones lie basolateral to the brain, extending towards the vertex of the skull during the following 4-5 days. We used DiI labelling of the bone primordia in ex-utero E13.5 embryos to distinguish between two possibilities for the origin of the frontal and parietal bones: (1) recruitment from adjacent connective tissue or (2) proliferation of the original primordia. The results clearly demonstrated that the bone primordia extend vertically by intrinsic growth, without detectable recruitment of adjacent mesenchymal cells.

Defining the earliest step of cardiovascular progenitor specification during embryonic stem cell differentiation

“…In addition to differentiating into cardio vascular cells, Mesp1 GFP cells could also differentiate into skeletal muscle and bone cells (Myogenin, Runx2, and Col1a1; Fig. S1 B), which is consistent with the in vivo Mesp1 lineage tracing experiments that showed that Mesp1 expressing cells give rise to some muscles and bones of the face (McBratney Owen et al, 2008;Yoshida et al, 2008;Harel et al, 2009). However, not all mesoderm derivatives were increased in Mesp1 GFP cells; e.g., no increase in hematopoietic markers, such as Gata1 and HoxB1, was observed.…”

Identification of a progenitor cell of origin capable of generating diverse meningioma histological subtypes

“…Using quail-chick chimeras, all layers of the forebrain meninges as well as bone and overlying dermis originate from the cephalic neural crest (Le Lievre and Le Douarin, 1975;Couly and Le Douarin, 1987), whereas the meninges covering the brainstem and spinal cord arise from a different embryological lineage, likely the mesoderm (Catala, 1998). Recent studies using transgenic mice with neural crest (Wnt1Cre)-and mesoderm (Mesp1Cre)-specific promoters have shown that the meninges covering the telencephalon are of neural crest origin, whereas the midbrain meninges derive from the cephalic mesoderm (McBratney-Owen et al, 2008;Yoshida et al, 2008). In this report, we conclusively establish that the inner part of the dura mater (DBC) and the outer part of the arachnoid (ABC) derive from a common PGDS ( þ ) precursor cell.…”

Retinoic acid receptors exhibit cell‐autonomous functions in cranial neural crest cells

“…2c,d), similar to that described in Rara/g-null mutants although exencephaly was not observed . Skeletal analysis of E18.5 Rara/b/g NCCÀ/À fetuses revealed agenesis or malformations of NCC-derived craniofacial bones and cartilages (Noden, 1988;Le Douarin et al, 1993;Chai and Maxson, 2006;Gross and Hanken, 2008;McBratney-Owen et al, 2008;Yoshida et al, 2008). Large portions of frontal bones were missing; the premaxilla, palatal process of premaxilla, and nasal cartilage were rudimentary; the upper incisors were absent, the presphenoid bone hardly distinguishable, and the basisphenoid bone was deformed in its anterior part.…”