The harvesting of immature mammalian oocytes (eggs) and their maturation in a laboratory environment, known as in-vitro maturation (IVM), provides an alternative to the harvesting of mature oocytes for in-vitro fertilisation (IVF) programs. The nutrient environment of an oocyte matured in vitro is known to have a significant effect on its potential to successfully mature, and it is desirable for the in-vitro nutrient environment to mimic the natural environment in vivo. This thesis describes an interaction between mathematical modelling and experimental investigation designed to build upon understanding of the nutrient environment of the oocyte in vivo, which is difficult to determine via experiment alone. A general mathematical model of nutrient transport to the oocyte, through its surrounding cumulus cells is developed. This model is applicable in-vivo and in-vitro across several species and to a number of important nutrients. Nutrient transport in this system - the cumulus-oocyte complex (COC) - is of particular importance, as it is this system that is normally removed for IVM treatments, and its solution under in-vivo conditions allows the nutrient concentration reaching the oocyte to be determined, given a known concentration immediately surrounding the COC. To successfully apply this model, parameters representing the rate of nutrient transport into cells within the COC must be accurately determined. These parameters are determined by a combination of experimental procedures and mathematical modelling in the case of an important nutrient to oocyte development, glucose. This work gives insight into the concentration dependence of glucose uptake into cell types that are important in regulating oocyte development, and to the behaviour of the oocyte itself with regard to glucose uptake. Finally models to describe the transport of two key nutrients, oxygen and glucose, from the vascular system in the ovary, through the ovarian follicle to the oocyte are developed. These make use of experimental results found in the study of glucose transport in the COC, and show that the geometry of the follicle has a significant impact on the nutrient environment of the COC, and hence by inference the nutrient environment of the oocyte. Work discussed in this thesis has been published [31, 156] and submitted for publication [30]. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1374636 / Thesis (Ph.D.) -- University of Adelaide, School of Mathematical Science, 2009
| Identifer | oai:union.ndltd.org:ADTP/269205 |
| Date | January 2009 |
| Creators | Clark, Alys Rachel |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
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