Microsporidia are unicellular fungi that are intracellular parasites of animals, including
humans. They are both complex and simple, armed with a sophisticated infection
apparatus and possessing the smallest eukaryotic nuclear genomes. The microsporidian
Encephalitozoon cuniculi has a genome size of 2.9 Mb, which is smaller than many
bacterial genomes. Genome reduction and compaction in size, content, and form has been
interpreted as an adaptation to parasitism. One of the effects of genome size reduction
concerns intron evolution — E. cuniculi has retained only a few extremely short
spliceosomal introns.
This thesis examines the splicing of introns in the spore stage. The introns were retained
in spores, suggesting life-stage specific splicing and splicing inhibition. How the short
introns are recognized was also examined. Unique splicing signal motifs were predicted,
and were used to find additional introns. The intron density was doubled for this species,
and I also obtained data that counter current views about intron evolution in compacted
genomes with low intron densities. I also predict that E. cuniculi introns are recognized
in a unique way by the spliceosome.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU./4173 |
| Date | 11 1900 |
| Creators | Lee, Renny |
| Publisher | University of British Columbia |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | 1466989 bytes, application/pdf |
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