The embryonic neural crest is a unique vertebrate stem cell population that has the ability to retain its stem attributes while neighboring cells in the embryo undergo lineage restriction. These cells possess multi-germ layer developmental potential and can give rise to a diverse array of derivatives such as components of the craniofacial skeleton, connective tissue and parts of the peripheral nervous system that have contributed to the evolution of vertebrates. However, how neural crest cells came to possess this remarkable potency and the mechanisms utilized by them to retain their stem cell attributes has not yet been well characterized. Studies of the mechanisms of neural crest stem cell maintenance provide a unique opportunity to explore the regulation of stem cell potential during embryonic development and give us insights into molecular players that are necessary for the control of pluripotency. In this thesis, I explore the role of epigenetic regulation of pluripotency in blastula and neural crest stem cells and investigate the mechanisms through which neural crest cells retain their stem cell attributes during embryonic development. I found that HDAC activity and histone acetylation are critical for the maintenance of pluripotency of these two cell types. Loss of HDAC activity results in a failure to form the neural crest as well as loss of pluripotency in blastula cells. Further, depletion of HDAC activity in pluripotent blastula cells results in aberrant expression of markers of different lineages and failure to commit to a single lineage. Fascinatingly, I identified that low level of histone acetylation is a shared feature of both blastula and neural crest stem cells suggesting that HDACs are performing a similar role in these two cell types. Using genome scale approaches, I investigated the mechanisms through which HDACs and histone acetylation control the pluripotency of blastula cells. I found the low level of histone acetylation in blastula cells read by BET proteins is also critical for maintaining the stem cell state, and BET proteins regulate pluripotency through distinct mechanisms from HDACs. Further, using mass spectrometry, I elucidated the changes in histone modifications as cells progress from a pluripotent to a lineage restricted state. Finally, through a genome wide transcriptomics study, I characterized the gene expression changes that take place during neural crest formation and identify new factors that might play important roles in the maintenance of pluripotency of these cells. Taken together, the work presented in this thesis enhances our current understanding of the epigenetic mechanisms utilized by neural crest cells to retain their stem cell attributes and provides a framework to explore further the gene regulatory circuitry that controls the pluripotency of these cells.

Creator

• Rao, Anjali Narsing

DOI

• https://doi.org/10.21985/n2-x700-dn96

Subject

• Bioinformatics
• Developmental biology

Language

• en

Alternate Identifier

• etdadmin_upload_663294
• http://dissertations.umi.com/northwestern:14684

Keyword

• pluripotency
• HDAC
• Neural Crest
• TSA
• stem cell

Date created

• 2019-01-01

Resource type

• Dissertation

Rights statement

• In Copyright