Inflammation and Oxidative Stress Mechanisms that Regulate RNAs during Oocyte Maturation and Early Embryonic Development
Dr. Jennifer R. Wood
Dr. Andrea Cupp
Dr. Brett White
Date of this Version
Kelsey Timme (2019) Inflammation and Oxidative Stress Mechanisms that Regulate RNAs during Oocyte Maturation and Early Embryonic Development.
Maternal obesity is a major cause of infertility that is linked with increases in inflammation and oxidative stress within the female reproductive tract and alterations in maternal mRNAs in ovulated oocytes. One such mRNA is developmental pluripotency associated 3 (Dppa3). DPPA3 shuttles between the cytoplasm and nucleus. When in the nucleus it regulates histone methylation. Two studies described in this thesis were designed to study the effects of oxidative stress on maternal RNA abundance during murine oocyte maturation and pre-implantation embryonic development. In the first study, we optimized a fluorescent in situ hybridization technique for use with mouse oocytes and embryos. This technology allows for accurate quantitation of RNAs within a single cell. Images were obtained with a fluorescent confocal microscope which provides visualization of RNA localization patterns throughout the 3 dimensional structure of a cell. The second project utilizes this technique to investigate alterations of Dppa3 abundance during in vitro maturation of oocytes and in vitro culture of pre-implantation embryos in response to H2O2 exposure. C57BL/6J mice fed a high fat diet (HFD) expressed increased inflammatory and oxidative stress markers within the ovary compared to normal diet (ND) counterparts. ND CD1 MII oocytes exposed to H2O2 had a significant reduction in Dppa3 (p=0.004). Furthermore, there were distinct differences in the localization of Dppa3 in H2O2 compared to control MII oocytes. Specifically, it was sequestered along the outer region of the H2O2 oocytes (p2O2 was significantly increased (p2O2 (p=0.0489). In summary these data indicate that 1) obesity is linked with increased inflammation and oxidative stress markers within the ovary and 2) the simulation of oxidative stress by H2O2 in vitro alters Dppa3 mRNA and protein abundance within the MII oocyte and pre-implantation embryo suggesting that maternal obesity may impact transcription and/or translation mechanisms in early embryogenesis.
Advisor: Jennifer Wood
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Animal Science, Under the Supervision of Professor Jennifer R. Wood. Lincoln, Nebraska: May, 2019
Copyright 2019 Kelsey R. Timme