caa a22 4500 445816570 CHVBK 20180317145230.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s10815-011-9554-4 doi (NATIONALLICENCE)springer-10.1007/s10815-011-9554-4 Sirard Marc-André Centre de Recherche en Biologie de la Reproduction, Département des Sciences Animales, Université Laval, G1K 7P4, Québec, Canada aut Follicle environment and quality of in vitro matured oocytes [Elektronische Daten] [Marc-André Sirard] In mammalian reproduction, the oocyte depends on the ovarian follicle for most of its growth. They form a bipolar partnership and the status of one will impact the functioning of the other. When oocytes are removed from their follicle by ovulation, they have normally completed all the steps required to begin their journey into the oviduct and drive the early embryonic development. When oocytes are removed from their follicle before natural ovulation, the process by which they acquire all the important components for their journey might not be completed and their ability to mature, fertilize or develop into embryos or to term might be compromised. Animal models have been useful to define the important steps required for the oocyte's growth phase, and in the mouse, when the oocyte has reached its full size, the program is ready. This is not the case in larger mammals where the completion of growth does not ensure that the oocyte is fully capable of undergoing all the steps to the embryo and to term. The final steps of oocyte preparation also involve a progressive condensation of the chromatin that may facilitate normal maturation but may also indirectly reduce the lifespan of the oocyte. In such a scenario, the oocyte would have an expiration date when fully competent. In humans, a number of indications may justify the aspiration of oocytes from unstimulated patients and the development of an in vitro maturation (IVM) process that would allow fertilization and subsequent development. This objective could be realized by a better understanding of the essential follicular contribution required before removing the oocyte. Therefore, this review will focus on the large animal models where IVM has been used and studied for more than 25years. The status of the follicle at the time of oocyte recovery and the status of the oocyte's chromatin will be described in detail as they have a significant impact on the outcome. Springer Science+Business Media, LLC, 2011 Oocyte nationallicence In vitro maturation nationallicence Chromatin nationallicence Competence nationallicence Follicle nationallicence Journal of Assisted Reproduction and Genetics Springer US; http://www.springer-ny.com 28/6(2011-06-01), 483-488 1058-0468 28:6<483 2011 28 10815 https://doi.org/10.1007/s10815-011-9554-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10815-011-9554-4 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Sirard Marc-André Centre de Recherche en Biologie de la Reproduction, Département des Sciences Animales, Université Laval, G1K 7P4, Québec, Canada aut NATIONALLICENCE 773 0- Journal of Assisted Reproduction and Genetics Springer US; http://www.springer-ny.com 28/6(2011-06-01), 483-488 1058-0468 28:6<483 2011 28 10815 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer