This study demonstrates the use of an adenovirus vector
system to study the effect of a DNA repair gene on
untransformed human fibroblasts. The bacteriophage T4
pyrimidine dimer DNA glycosylase (den V) gene has been
inserted into the E3 region of human adenovirus type 5. The
resulting recombinant virus Ad Den V was determined to be
producing correctly initiated RNA from the RSV 3' LTR
promoter used in the den V expression cartridge inserted into
the virus. The effect of the den V gene product on human
fibroblasts 'liras examined by assaying for the percent host
cell reactivation (%HCR) of Vag production for UV irradiated
Ad Den V in comparison to that for a control virus. It was
shown that the %HCR was significantly greater for Ad Den V
as compared to the control virus in xeroderma pigmentosum
(XP) cells. UV survival of adenovirus in XP cells exhibited
a two component nature. Introduction of the den V gene into
XP group A cells increased the D0 value of the first
component of the viral survival curve to a level similar to
that of XPC cells, which showed no change in this component
irrespective of the presence of the den V gene. It has been
suggested that the den V gene is able to partially complement
the deficiency in some XP cells because of its small size,
allowing it to gain access to the DNA damage site where as
the cellular repair enzyme complex can not. Since XPC cells
are proficient in their alteration of DNA secondary structure
prior to DNA excision repair, these results are consistant
with the hypothesis that the first component of UV viral
survival curves reflects the pathway involved in accessing
the damaged sites.
The manuscript of a paper has been included as an
appendix. The work theorizes on the origin of mammalian
immune system diversity and bacteriophage lambda, and their
possible relationship to prokaryotic DNA repair genes. / Thesis / Master of Science (MS)
Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/23624 |
Date | 08 1900 |
Creators | Colicos, Michael, A. |
Contributors | Rainbow, Andrew, J., Biology |
Source Sets | McMaster University |
Language | English |
Detected Language | English |
Type | Thesis |
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