Notchless (Nle) has been identified in Drosophila as a direct regulator of Notch activity. In the mouse, we have previously demonstrated that mNle is instrumental for the maintenance of pluripotent cells at the blastocyst stage. To characterize the function of mNle in post-implantation embryos, we used mosaic epiblast-specific inactivation of a conditional mNle allele (mNle) taking advantage of...

Mechanisms implied in tissues response to the oxygen partial pressure remain poorly understood as well as the role of hypoxia in developmental processes. However, the activation of transcription factors such as FoxO and HIF and the recruitment of signalling pathways including Calcineurin, PI3K, p38-MAPK and mTOR are known to be involved in hypoxia responses. Currently, little information is kno...

Notchless (Nle) has been identified in Drosophila as a direct regulator of Notch activity. In the mouse, we have previously demonstrated that mNle is instrumental for the maintenance of pluripotent cells at the blastocyst stage. To characterize the function of mNle in post-implantation embryos, we used mosaic epiblast-specific inactivation of a conditional mNle allele (mNle) taking advantage of...

Neural crest cells (NCCs) arising from trunk neural tube (NT) during primary and secondary neurulation give rise to melanocytes, glia and neurons, except for those in the caudal-most region during secondary neurulation (somites 47 to 53 in the chick embryo), from which no neurons are formed, either in vivo or in vitro. To elucidate this discrepancy, we have specifically analyzed caudal-most NCC...

Notchless (Nle) has been identified in Drosophila as a direct regulator of Notch activity. In the mouse, we have previously demonstrated that mNle is instrumental for the maintenance of pluripotent cells at the blastocyst stage. To characterize the function of mNle in post-implantation embryos, we used mosaic epiblast-specific inactivation of a conditional mNle allele (mNle) taking advantage of...

The Crim1 gene encodes a transmembrane protein containing six cysteine-rich repeats similar to those found in the BMP antagonist, chordin (chd). To investigate its physiological role, zebrafish crim1 was cloned and shown to be both maternally and zygotically expressed during zebrafish development in sites including the vasculature, intermediate cell mass, notochord, and otic vesicle. Bent or ho...

Notchless (Nle) has been identified in Drosophila as a direct regulator of Notch activity. In the mouse, we have previously demonstrated that mNle is instrumental for the maintenance of pluripotent cells at the blastocyst stage. To characterize the function of mNle in post-implantation embryos, we used mosaic epiblast-specific inactivation of a conditional mNle allele (mNle) taking advantage of...

In order to research the influences of the somites or their derivatives on the migration and differentiation of neural crest cells, unilateral extirpation of somites was performed in the larvae of the salamander (Hynobius lichenatus Boulenger). Two types of neural crest cells appeared in the somite-free environment. They could already be distinguished from each other shortly after beginning of ...

The aim of this study performed in the embryonic chick wing is to test the ability of the tendons to form and develop in the absence of the muscle bellies. The experiments were performed on 2-day chick embryos by destroying a portion of the somitic mesoderm by local X-irradiation. The irradiated part included the wing somite level 15-20 and extended three somites (or presumptive somites) in fro...

The purpose of this study was to determine whether the neurula stage mouse embryo can regulate tumor formation of C-1300-3 neuroblastoma cells. Five neuroblastoma cells were injected into the second somite of neurula stage embryos, and their ability to form tumors was tested, 24 hr later, by transplanting the portion of the embryo containing the cancer cells into the testes of adult mice. Only ...