Learn More
We have used the quail-chick chimera technique to study the origin of the bones of the skull in the avian embryo. Although the contribution of the neural crest to the facial and visceral skeleton had been established previously, the origin of the vault of the skull (i.e. frontal and parietal bones) remained uncertain. Moreover formation of the occipito-otic(More)
The developmental fate of the cephalic paraxial and prechordal mesoderm at the late neurula stage (3-somite) in the avian embryo has been investigated by using the isotopic, isochronic substitution technique between quail and chick embryos. The territories involved in the operation were especially tiny and the size of the transplants was of about 150 by 50(More)
The mesencephalic and rhombencephalic levels of origin of the hypobranchial skeleton (lower jaw and hyoid bone) within the neural fold have been determined at the 5-somite stage with a resolution corresponding to each single rhombomere, by means of the quail-chick chimera technique. Expression of certain Hox genes (Hoxa-2, Hoxa-3 and Hoxb-4) was recorded in(More)
In addition to pigment cells, and neural and endocrine derivatives, the neural crest is characterized by its ability to yield mesenchymal cells. In amniotes, this property is restricted to the cephalic region from the mid-diencephalon to the end of rhombomere 8 (level of somites 4/5). The cephalic neural crest is divided into two domains: an anterior region(More)
It is well established that hemopoietic cells arising from the yolk sac invade the avian embryo. To study the fate and role of these cells during the first 2.5-4.5 days of incubation, we constructed yolk sac chimeras (a chick embryo grafted on a quail yolk sac and vice versa) and immunostained them with antibodies specific to cells of quail hemangioblastic(More)
We have used two molecular markers to label blood vessel endothelial cells and their precursors in the early avian embryo. One marker, called Quek1, is the avian homologue of the mammalian VEGF receptor flk-1 and the other is the MB1/QH1 monoclonal antibody. Quek1 is expressed in a subset of mesodermal cells from the gastrulation stage. Quek1 positive cells(More)
A phagocytic cell system of hemopoietic origin exists in the early avian embryo (Cuadros, Coltey, Nieto, and Martin: Development 115:157-168, '92). In this study we investigated the presence of cells belonging to this system in the central nervous system (CNS) of chick and quail embryos by using both histochemical staining for acid phosphatase and(More)
Previous work by our group has demonstrated that mesencephalic neural crest cells at an early stage of migration are able to synthesize acetylcholine (ACh). Acetylcholinesterase (AChE), the enzyme responsible for ACh degradation, was examined in neural crest cells of the chick embryo, using cytochemical and biochemical methods. Observations at the light(More)
Vascularization and endothelial phenotype were investigated in embryonic tissues grafted onto chorioallantoic membrane (CAM) by means of immunocytochemistry and electron microscopy. Single grafts of adrenal gland or cerebellum and double grafts of adrenal gland plus cerebellum were performed, using tissues from chick or quail embryos as donors and CAMs of(More)
Macrophage-like cells have been previously shown within the suboptic necrotic centres of chick embryos during the period just previous to, and coinciding with, growth of the earliest optic axons through suboptic necrotic centres. In this paper, light and electron microscopy observations of chick embryos suggest that these macrophage-like cells originate(More)