Development and tissue origins of the mammalian cranial base

Abstract

The vertebrate cranial base is a complex structure composed of bone, cartilage and other connective tissues underlying the brain; it is intimately connected with development of the face and cranial vault. Despite its central importance in craniofacial development, morphogenesis and tissue origins of the cranial base have not been studied in detail in the mouse, an important model organism. We describe here the location and time of appearance of the cartilages of the chondrocranium. We also examine the tissue origins of the mouse cranial base using a neural crest cell lineage cell marker, Wnt1-Cre/R26R, and a mesoderm lineage cell marker, Mesp1-Cre/R26R. The chondrocranium develops between E11 and E16 in the mouse, beginning with development of the caudal (occipital) chondrocranium, followed by chondrogenesis rostrally to form the nasal capsule, and finally fusion of these two parts via the midline central stem and the lateral struts of the vault cartilages. X-Gal staining of transgenic mice from E8.0 to 10 days post-natal showed that neural crest cells contribute to all of the cartilages that form the ethmoid, presphenoid, and basisphenoid bones with the exception of the hypochiasmatic cartilages. The basioccipital bone and non-squamous parts of the temporal bones are mesoderm derived. Therefore the prechordal head is mostly composed of neural crest-derived tissues, as predicted by the New Head Hypothesis. However, the anterior location of the mesoderm-derived hypochiasmatic cartilages, which are closely linked with the extra-ocular muscles, suggests that some tissues associated with the visual apparatus may have evolved independently of the rest of the “New Head”.

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.…”

Molecular anatomy and functions of the choroidal blood-cerebrospinal fluid barrier in health and disease

“…It should be noted, however, that the endothelial cells of the stromal vessels from the forebrain choroid plexuses originate from the cephalic mesoderm and not from the neural crest as the rest of the connective tissue of the stroma [27]. In mice, such a dichotomy in the origin of the sus-and sub-tentorial meninges (and choroidal stroma) was also demonstrated [92].…”