This thesis describes the derivation of restriction endonuclease maps for HSV-1and HSV2 DNA; a study of the homologous regions between the genomes of HSV-1,HSV-2,EHV-1and PRV, and the effect of homology upon recombination between HSV-1 and HSV2; nucleotide sequences of the L-S joint regions in HSV-1 andHSV-2 DNA; and analysis of two HSV-1/HSV-2 intertypic recombinants which fail to invert normally in one or both segments of the genome. Restriction endonuclease maps were already available of HSV-1 DNA for XbaI, HindIII, EcoRI, BgIII and HpaI, and of HSV-2 DNA for these enzymes and KpnI. Maps of HSV-1DNA for KpnI, BamHI, XhoI and PvuII and of HSV-2DNA for BamHI, were determined using the techniques of simultaneous digestion with two endonucleases, recleavage of isolated restriction fragments, and blot hybridisation. Previously reported size heterogeneity at the L terminus and L-S joint of the two genomes was confirmed. The results suggested that HSV-2 DNA is 1-2 x10(6) larger in molecular weight in the S segment than HSV-1 DNA. HSV-1 and HSV-2 DNA share approximately 50% homology, and PRV DNA possesses not greater than 8% homology with HSV-1 DNA. Hybridisation of 32 P-labelled recombinant plasmids containing HSV-1 or HSV-2 DNA inserts to blot strips of restriction endonuclease digests of HSV-1 or HSV-2 DNA inserts to blot strips of restriction endonuclease digsts of HSV-1 or HSV-2 DNA showed that the two genomes are collinear, within the resolution attained in these experiments. Hybridisation of 32 P-labellea HSV-1 or HSV-2 DNA to similar blot strips allowed seven regions of the genome to be identified which are more homologous than neighbouring regions. EHV-1 and PRV DNA also showed greater homology to these regions of the HSV genome than to others, but no significant homology between HSV DNA and HCMV DNA was detected. Homologous regions probably reflect greater conversation of the structures of polypeptides encoded by them. Five good candidates for conserved HSV-1 polypeptides are major DNA- binding protein, the major capsid protein, the DNA polymerase, and two immediate- early polypeptides, Vmw IE 175 amd Vmw IE 136'(143). Hybridisation of cloned HSV DNA fragments to blot strips of EHV-1 or PRV restriction endonuclease digests showed that homologous regions in the L segment of the EHV-1 genome are collinear with the L segment of the HSV-1 genome in the IL arrangement. Homologous regions between HSV and PRV DNA where shown not be arranged in a simple collinear fashion. The genome structures were analysed of more than a hundred HSV-1/HSV-2 intertypic recombinans produced by marker rescue of HSV-1 tsD with HSV-2 restriction fragments spanning the L-S joint. The recombinants possessed crossovers preferentially in homologous regions. At least two of the genome arrangements (P and IL) recombined, a result which disproves the earlier proposition that only one of these two arrangements is able to take part in the generation of viable recombinants.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:254646 |
Date | January 1981 |
Creators | Davison, Andrew John |
Publisher | University of Glasgow |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | http://theses.gla.ac.uk/38986/ |
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