Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Animal, Dairy, and Veterinary Sciences

Committee Chair(s)

S. Clay Isom


S. Clay Isom


Lee Rickords


Irina Polejaeva


Embryos resulting from assisted reproductive technologies, such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), develop with lower efficiencies than embryos resulting from their in vivo counterparts. The reasons behind the developmental discrepancies remain largely unknown. Because the egg is the primary determinant of embryo developmental success, it is reasonable to consider inherent egg quality as a possible cause. The hypothesis for this project is that there are distinct mRNA transcript patterns, or molecular “fingerprints,” that distinguish high- versus low-quality eggs developing within the same environment. In this study, a small cytoplasmic biopsy was removed from 40 eggs and stored for later use. The eggs were chemically activated to stimulate development in the absence of sperm and cultured in vitro. Following an eight-day development period, embryos that reached the blastocyst stage (success) and embryos that failed to develop were identified. This was repeated five times, for a total of six experimental replicates. The relative transcript levels of 48 genes were evaluated in the egg biopsies corresponding to successful and failed embryos using quantitative PCR. Analysis of the qPCR data revealed no significant differences in levels of transcripts for any of the 48 genes between the successful and failed development groups. Therefore, the evidence does not support differential expression between the cytoplasmic biopsies from oocytes of divergent developmental success. However, this study provides technical innovation for future research of oocyte quality.



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