| dc.contributor.author | Edgell, David R. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:28Z | |
| dc.date.available | 1997 | |
| dc.date.issued | 1997 | en_US |
| dc.identifier.other | AAINQ24737 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55473 | |
| dc.description | DNA replication is a fundamental process of living things. This thesis examines the origins and evolution of DNA replication proteins found in the three primary domains of life, the eubacteria, the archaebacteria, and the eukaryotes. | en_US |
| dc.description | First, DNA-dependent DNA polymerases of archaebacteria and eukaryotes were studied. A PCR-based approach was used to amplify and sequence various family B DNA polymerases from thermoacidophilic archaebacteria and early-diverging eukaryotes. Phylogenetic analysis of these and other sequences indicated that the DNA polymerases of archaebacteria and eukaryotes have evolved by a series of independent gene duplications, but the order of the duplication events remains unclear. Unexpectedly, one eukaryotic DNA polymerase, $\varepsilon,$ appears more related to archaebacterial DNA polymerases than to any other eukaryotic polymerase. | en_US |
| dc.description | Second, the replication proteins of eubacteria and eukaryotes that perform analogous functions at the replication fork were examined by computer-based methods to resolve issues of evolution by duplication and homology. It was found that many replication proteins of eukaryotes are members of gene families, whereas eubacterial replication proteins are not. Eukaryotic replication proteins likely evolved by gene duplication after the split of the eukaryotic and eubacterial lineages. Archaebacterial genomes also encode many proteins that are members of gene families and that are homologous to eukaryotic replication proteins. | en_US |
| dc.description | The question of homology of eubacterial and eukaryotic replication proteins was addressed by comparisons of amino acid alignments of proteins performing analogous functions. There is no evidence from amino acid alignments that eubacterial and eukaryotic replication proteins are homologs. Thus, there is little evidence to support the notion that DNA replication proteins evolved from a single set of replication proteins present in the last common ancestor of eubacteria, archaebacteria, and eukaryotes. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1997. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Molecular. | en_US |
| dc.subject | Biology, Genetics. | en_US |
| dc.subject | Biology, Microbiology. | en_US |
| dc.subject | Biology, Zoology. | en_US |
| dc.title | Origins and evolution of the archaebacterial and eukaryotic DNA replication apparatus. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
