The diagnostic value of extracellular occurring DNA (eoDNA) is limited by our lack of
understanding its biological function. eoDNA exists in a number of forms, namely vesicle
bound DNA, histone/DNA complexes or nucleosomes and virtosomes. These forms of DNA
can also be categorized under the terms circulating DNA, cell free DNA, free DNA and
extracellular DNA. The DNA can be released by means of form–specific mechanisms and
seem to be governed by cell cycle phases and apoptosis. Active release is supported by
evidence of energy dependant release mechanisms and various immunological– and
messenger functions. Sequencing has shown that eoDNA sequences present in the nucleome
reflects traits and distribution of genome sequences and are regulated by ways of release
and/or clearance. eoDNA enables the horizontal transfer of gene sequences from one cell to
another, over various distances. The ability of eoDNA to partake in horizontal gene transfer
makes it an important facet in the field of epigenetic variation. Clinical implementation of
eoDNA diagnostics requires that all of the subgroups of eoDNA be properly investigated. It
is suggested that eoDNA is the result of the metabolic fraction of DNA that is released by the
cell. Various observations indicate that eoDNA may also be incorporated into the genome of
a cell, from where it may affect cell function. Therefore horizontal gene transfer in higher
organisms is a real possibility. In this study, variations and increases in eoDNA levels over
time correlate with stressors that are subjected to 143B human osteosarcoma cells. It seems
viable to assume that a stressor is met by a change in the molecular machinery of a cell,
required to neutralise the onset of metabolic instability. This may be done by amplification of
necessary cistrons, producing metabolic DNA, that may then be observed after its release as
eoDNA. The presence of hydrolysing enzymes gives an updated real time picture of the state
of eoDNA. The eogenics hypothesis emanating from this study, suggests that amplification
and horizontal transfer of cistrons affect tissue and organ function over long periods of time,
in order for an organism to evolve one or more a specialized genomes. / Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2011.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nwu/oai:dspace.nwu.ac.za:10394/6929 |
| Date | January 2011 |
| Creators | Peters, Dimetrie Leslie |
| Publisher | North-West University |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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