Graduation Date
Fall 2018
Document Type
Thesis
Program
Master of Science degree with a major in Biology
Committee Chair Name
Dr. Amy Sprowles
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
Dr. John W. Steele
Second Committee Member Affiliation
HSU Faculty or Staff
Third Committee Member Name
Dr. Jacob P. Varkey Punnamkuzhyil
Third Committee Member Affiliation
HSU Faculty or Staff
Fourth Committee Member Name
Dr. Bruce A. O’Gara
Fourth Committee Member Affiliation
HSU Faculty or Staff
Subject Categories
Biology
Abstract
cJun is a transcription factor associated with proliferation and growth. Recent evidence has shown it plays a role in cell fate decision making of embryonic stem cells and correlates with changes in Oct4 expression, an important marker for pluripotency. There are multiple Oct4 isoforms that arise from alternative splicing and alternative translation. Oct4A is the variant most frequently associated with pluripotency, while evidence suggests that Oct4B variants have roles in potency as well as stress responses.
We aimed to study the effect of cJun over expression in murine embryonic stem cells on Oct4 gene expression through two methods: transient transfection of a pLVX cJun plasmid and treatment with nocodazole. We hypothesized that cJun expression would be increased with both of these methods and that these increases would affect Oct4 gene expression, which would affect the expression of the potency markers Nanog and Sox2 and possibly the expression of germ layer markers Brachyury, Sox1, Gata6, and Gata4. The unphosphorylatable cJun mutant L40/42A was also transfected to assess the role of cJun transcriptional activity on these processes. Our results revealed a trend where increased cJun correlated with changes in Oct4 variant expression that correlate with cJun transcriptional activity. Nanog expression appeared unaffected by transfection, but decreased with nocodazole treatment. Sox2 expression appeared to increase slightly with transfection, but remained relatively unaffected by nocodazole treatment. cJun overexpression through transfection increased endoderm markers Gata6 and Gata4, which correlates from other data in our laboratory that shows overexpression of cJun increases cardiomyocyte differentiation of mES cells (Brewer 2017). Further studies will better elucidate the relationship between cJun, the Oct4 variants, and their effect on potency and cell fate.
Citation Style
Council of Science Editors (CSE)
Recommended Citation
Teague, Kristine, "Characterizing the effect of cJun on the expression of Oct4 variants and how they correlate with the expression of genes associated with potency and cell fate of murine embryonic stem cells" (2018). Cal Poly Humboldt theses and projects. 235.
https://digitalcommons.humboldt.edu/etd/235