Chritian Vincent

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Most connective tissues in the head develop from neural crest cells (NCCs), an embryonic cell population present only in vertebrates. We show that NCC-derived pericytes and smooth muscle cells are distributed in a sharply circumscribed sector of the vasculature of the avian embryo. As NCCs detach from the neural folds that correspond to the future posterior(More)
Exposure of freshly ovulated mouse oocytes to a fertilising spermatozoon, thimerosal, Sr2+ or acetylcholine induced similar Ca2+ spiking responses. We propose that each of the four agents reduces the threshold for Ca2+ release from internal stores, but by different mechanisms. All agents except thimerosal stimulated oocyte activation, but thimerosal caused(More)
This study first shows a striking parallel between the expression patterns of the Bmp4, Msx1 and Msx2 genes in the lateral ridges of the neural plate before neural tube closure and later on, in the dorsal neural tube and superficial midline ectoderm. We have previously shown that the spinous process of the vertebra is formed from Msx1- and 2-expressing(More)
The effect of dimethylsulphoxide (DMSO) on microfilament organisation has been studied in the mouse oocyte after staining with (NBD)-phallacidin. The cortical actin meshwork was disrupted by exposure of oocytes to 1.5 M DMSO at 37 degrees C, and this disruption was associated with changes in the cell surface, especially microvilli length and distribution,(More)
It has previously been shown that the notochord grafted laterally to the neural tube enhances the differentiation of the vertebral cartilage at the expense of the derivatives of the dermomyotome. In contrast, the dorsomedial graft of a notochord inhibits cartilage differentiation of the dorsal part of the vertebra carrying the spinous process. Cartilage(More)
Nuclear maturation of the mouse oocyte becomes arrested in metaphase of the second meiotic division (MII). Fertilization or parthenogenetic activation induces meiotic completion, chromosomal decondensation and formation of a pronucleus. This completion of meiosis is probably triggered by a transient increase in cytosolic calcium ions. When activated just(More)
The prosencephalon, or embryonic forebrain, grows within a mesenchymal matrix of local paraxial mesoderm and of neural crest cells (NCC) derived from the posterior diencephalon and mesencephalon. Part of this NCC population forms the outer wall of capillaries within the prosencephalic leptomeninges and neuroepithelium itself. The surgical removal of NCC(More)
When mouse ovulated oocytes were exposed to 1.5 M-dimethylsulphoxide (DMSO) the resultant hardening of the zona pellucida was not a direct effect but required the presence of an oocyte. The hardening of the zona pellucida when zonae used were aged in vitro was also dependent upon the presence of the oocyte. Protocols of DMSO exposure that induce(More)
Fresh and aged (24 hours after ovulation) human oocytes and recently ovulated mouse oocytes may be activated by exposure to acidified Tyrode's solution. No activation of either type of human oocyte was observed after exposure to hyaluronidase or pronase, but significant numbers of fresh mouse oocytes were activated after exposure to pronase but not to(More)