Electronic Thesis and Dissertation Repository


Master of Science


Physiology and Pharmacology


Watson, Andrew J.

2nd Supervisor

Betts, Dean H.



Palmitic acid (PA) and oleic acid (OA) are the most abundant saturated and monounsaturated non-esterified fatty acids, respectively, in serum. The consequences of PA and OA treatment on preimplantation mouse embryo development were investigated. It was hypothesized that OA treatment from the two-cell stage onwards would attenuate PA-induced reductions in mouse blastocyst development. PA significantly reduced development to the blastocyst stage. Transcript analysis revealed that PA increased ER stress pathway markers activating transcription factor 3 and C/EBP homologous protein transcripts, and XBP1 splicing. Co-culture of PA-treated embryos with OA prevented this PA-induced ER stress and rescued blastocyst development. Cytoplasmic lipid droplet accumulation was significantly increased by OA co-treatment. The results indicate that PA treatment induces ER stress, which limits lipid droplet accumulation and impairs blastocyst development. Co-treatment with OA is protective in reducing PA-induced ER stress and developmental impairments. These findings have applications in improving our understanding of embryo physiology and fertility outcomes for obese patients.