The viteline enigma

Abstract

The successive different phases of gestation are characterized by two clearly distinct parts. The first one is related to the beginning of the gestation and means the first three months of pregnancy in human important events just as embryogenesis, placentation and organogenesis occur during this period. Some evidence found in animal models suggests problems could reflect early or late interruption of gestation and other deleterious effects during this phase of the development. The second phase is the fetal development. The relation and regulation of functional mechanisms evolved in the beginning of the gestation are still unknown. The yolk sac is the only embryonic annex present in all species. Therefore, the histotrophic nutrition, celomic obliteration, yolk sac degeneration, intense yolk sac vascularization, yolk sac placentation, yolk sac absorption, cellular yolk sac differentiation, yolk sac inversion and specific yolk sac functions including synthesis, storage and transport in the yolk sac, yolk sac plasticity and specialization and the genes evolved in the yolk sac connections need further information. For this reason, with the experience of who has devoted more than 20 years to study placenta and placentation in many animal models, this research group presents this proposal. These researchers want now study and correlate data and ideas around the yolk sac enigma. Initially, the group focus will be on the morphofunctional analysis related to the yolk sac activity in animal models with compared to without yolk sac placentation. Furthermore, a proteomic analysis of the yolk sac, the inversion mechanisrn, absorption, introspection, specialization and transport in the yolk sac will also be studied. Culture of cells from yolk sac or from progenitor cells from the yolk sac will be performed aiming to establish yolk sac cell lines and to study the plasticity of the in vitro yolk sac cells in vitro, including pre clinical tests for cellular therapy in genetic or other animal diseases. Moreover, this proposal includes the study of the VEGF function in the formation of the yolk sac, the differentiation and migration of the different cell types, and the study of the genes evolved on the yolk sac connections. (AU)