Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.651459
Title: Nature and modulation of the higher-order chromatin fibre
Author: Gilbert, N.
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 2000
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Abstract:
In this project I have analysed and modulated the higher-order chromatin fibre to determine the role this fibre plays in the regulation of cellular processes. By analysing the chromatin fibre from cells with different differentiation potentials I have been unable to show that there are any inherent differences between the chromatin fibres and that the conformation of the chromatin fibre does not alter when these cells are differentiated. Interestingly, I have found that the chromatin fibres do have inherent differences in their nuclease sensitivities, suggesting that although the overall structures are similar there are some differences between cells with various differentiation potentials. To establish whether an alteration in the chromatin conformation will alter a cell's differentiation potential I have expressed histone H5, a replacement linker histone normally found in nucleated erythrocytes, in pluripotential embryonic stem (ES) cells. My results showed that constitutive expression of H5 in ES cells causes substantial cell death and although I have a regulated, tetracycline based, histone H5 expression construct I was unable to express H5 in a controlled manner to investigate the underlying chromatin structure. In addition, I expressed mutant H5 molecules in ES cells which also caused substantial cell death, so in conclusion I was unable to determine whether this cellular phenotype was directly due to an alteration in chromatin structure or a non-specific effect from expressing a positively charged molecule in ES cells. As a first step towards studying the expression of linker histones in living cells and during development, I constructed and analysed a green fluorescent protein (GFP)-histone H5 fusion. As for histone H5, the GFP-H5 fusion protein is correctly expressed in a variety of cell types, but is lethal to cells when expressed at high levels for longer periods of time.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.651459  DOI: Not available
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