Full text
| |
| Author(s): |
Alícia Greyce Turatti Pessolato
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2011-08-16 |
| Examining board members: |
Maria Angélica Miglino;
Dimas Tadeu Covas;
Daniele dos Santos Martins
|
| Advisor: | Maria Angélica Miglino |
| Abstract | |
The yolk sac is the single attachment embryo present in all species of vertebrate embryos, reptiles, birds and mammals. In domestic mammals the yolk sac is initially large, since these species it is transient. After implantation, appears in the lateral mesenchyme to the notochord cell clusters, called \"blood islands\" that represent the progenitors of vascular and hematopoietic systems: the hemangioblasts. The central islands hemangioblasts form the first blood hematopoietic stem cells, while peripheral hemangioblasts, the angioblastic differentiate into the precursors of blood vessels. The initial development of the yolk sac hematopoietic activity leads to the hypothesis that this tissue is the primary site of development and that hematopoietic stem cells derived from them sow other intraembryos sites. It was observed in the microscopic analysis that there is indeed a relationship between the two lineages. In the analysis of gene expression, some genes expressed by hemangioblasts showed high expression in D+0 and other specific genes also hemangioblasts, but in secondary stages of differentiation as found in the aortic region, the level of hemogenic endothelium showed high levels of expression after 3 days in culture. We therefore conclude that the yolk sac to be the primary site of formation of blood and endothelial cells in the early stages of embryogenesis, for its cells be primitive and therefore do not express markers of mature cells on the surface, these cells become an important source of cells relevant to stem cell therapy for hemophilia and many other human diseases. (AU) | |
| FAPESP's process: | 09/03343-0 - CHARACTERIZATION OF THE YOLK SAC STEM CELLS AND ULTRASTRUCTURAL ANALYSIS OF THE VITELINE MEMBRANE FROM OVINE EMBRYOS (Ovis aries) |
| Grantee: | Alicia Greyce Turatti Pessolato |
| Support Opportunities: | Scholarships in Brazil - Master |