Characterization of BAF155 and BAF170 in Early Porcine Embryogenesis

Hayly Goebel, Purdue University

Abstract

The production of developmentally competent in vitro derived embryos is necessary to decreasing both economic and emotional losses. Epigenetic abnormalities/insults have been shown to occur at a higher incidence in in vitroembryos. An increased prevalence of epigenetic derived disorders such as Parkinson’s disease, Prader-Willi syndrome, and α-thalassemia as well as elevated preimplantation embryo arrest and reduced developmental rates are theorized to be caused by errors in the mediation of chromatin remodeling. Chromatin remodeling refers to the restructuring of packaged DNA so that transcription factors are either given more or less access to specific sequences. This can be done by covalent modification through histone methylation, acetylation, and phosphorylation as well as noncovalent modifications which employ ATP dependent chromatin remodeling complexes. The purpose of this thesis was to characterize two structurally integral core subunits, BAF155 and BAF170, of the SWI/SNF chromatin remodeling complex in porcine oocytes and preimplantation embryos. The first study concentrated on the transcript abundance of BAF155 and BAF170 in porcine oocytes and embryos. First, BAF155 and BAF170 transcript sequences were identified in porcine muscle and heart tissues. Those sequences were used to create quantitative polymerase chain reaction (qPCR) primers. mRNA from pools of GV oocytes (100-800) was converted to cDNA for transcript abundance measurements. However, transcript abundance remained too low for either BAF155 or BAF170to be accurately quantified. The second study focused on developmental competency of embryos post interfering RNA (RNAi) knockdown of BAF155, BAF170, or both BAF155/BAF170 combined. After 7 days of culture, an analysis of variance (ANOVA) was performed to determine differences in mean nuclei numbers and morphological blastocyst percentages across the three groups. No significant difference was seen between means of treatment groups vs. both control groups. Significant differences were seen between siRNA and Non-Injected groups as well as Non-Injected and Scramble RNA groups. However this indicates that loss of BAF155, BAF170, or a combination of the two transcripts is not the driving force of the significant differences, rather the microinjection itself caused the differences.

Degree

M.Sc.

Advisors

Cabot, Purdue University.

Subject Area

Biochemistry|Cellular biology|Genetics|Neurosciences

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