Use this URL to cite or link to this record in EThOS:
Title: Studies of early morphogenesis of the vertebrate nervous system
Author: Britto, J.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2000
Availability of Full Text:
Full text unavailable from EThOS.
Please contact the current institution’s library for further details.
To understand how the notochord controls morphogenesis in the mesencephalon, I have undertaken a study to fully characterize the microsurgical manipulation that perturbs development. I have discovered that the same phenotype can be achieved by merely separating, rather than removing, the notochord from the overlying neural tube and that this effect is stage- and regional-specific. It is known that the development of the mesencephalon is regulated by an organizing centre situated at the metencephalic boundary, referred to here as the MHB. I have addressed the contribution of the MHB, neutral tube and notochord towards the phenotype by analyzing the expression patterns of a variety of developmental control genes after the manipulation. In the MHB, Wnt1, En1 expression are initially reduced after the manipulation, and Wnt1 recovers to control levels by 48 hours; no change is seen in Fgf8 expression. The presence of notochord and floor plate was also assessed by the expression of Sonic hedgehog (SHH). Interestingly, while Stage 11 embryos maintained expression of Shh in both structures, Stage 12 embryos lost notochord expression after 24 hours and showed a reduced floor plate expression after 48 hours. This correlates with the stage specificity seen for the manipulation. These results provide an in vivo model to study the consequences of a conditional loss of notochord signalling after axial patterning. To examine the response of later embryos, a histological analysis was performed and revealed a reduction in neutral tissue and ventricular space.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available