The rapidly increasing amount of sequence data has brought about a new appreciation for the tremendous influence mobile elements have had in shaping eukaryotic genomes. Despite their ubiquity, however, the factors governing the proliferation of mobile elementsor, in some cases, the lack of proliferationacross diverse taxa remain poorly understood. Analysis of Alu activity in humans and chimpanzees since their divergence indicates a two-fold increase in human Alu activity compared to that of the chimpanzee. This human retrotransposition increase is accompanied by a roughly two-fold higher level of chimpanzee Alu diversity. We prepose a model, wherein smaller effective population sizes in humans brought about a shift in host-element dynamic, ultimately leading to increased Alu activity in humans. We also survey Alu-associated diversity on the human sex chromosomes in order to examine whether Alu elements behave similarly to genetic marker systems. Our results suggest that, comparable to other genetic systems, Alu elements exhibit reduced diversity on the sex chromosomes. Our data provide no evidence for retrotransposon targeted biology influencing Alu insertion frequencies. We go on to synthesize several recent advances in the mobile element field and propose a novel hypothesis concerning how retrotransposon lineages manage to largely lie below the radar of population-level negative selection.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-03232005-161807 |
| Date | 29 March 2005 |
| Creators | Hedges, Dale James |
| Contributors | William Hansel, Michael Hellberg, Mark Batzer, David Pollock, Mohamed Noor |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-03232005-161807/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0087 seconds