clk-1 mutants of the nematode C. elegans have been phenotypically characterized in previous work and found to have decreased rates of development and of periodic adult behaviours, such as defecation, pumping and swimming (Wong et al., 1995). In this study, the defecation periods in older wild type and clk-1 mutant worms were found to be similar despite their differences in young adults. Transgenic strains which express high levels of clk-1 were characterized phenotypically. Over-expression of the clk-1 gene has no observed effect on physiological rates as measured conventionally in young adults but rather has an effect on defecation rates in an age-dependent manner. A proportion of ageing transgenic animals over-expressing clk-1 did not have decreased defecation period, as seen in ageing wild type and clk-1 mutants. This suggests that the action of CLK-1, which functions in controlling physiological rates, is reduced in older wild type worms. As previously characterized, clk-1 mutants have lengthened life spans compared to wild type (Wong et al., 1995). Consistent with this effect, we found transgenic strains with high clk-1 expression to have a shortened average life span. Furthermore, no effect on average life span was found in transgenic control strains in which clk-1 expression was not altered, confirming that the presence of the transgene and the phenotype marking its presence do not influence the observed effects in strains with high clk-1 expression. Together, the findings from both the studies on physiological rates and life span suggest that clk-1 plays a role in determining the rate at which worms age.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.21551 |
| Date | January 1998 |
| Creators | Felkai, Stephanie. |
| Contributors | Hekimi, Siegfried (advisor) |
| Publisher | McGill University |
| 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 | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001659113, proquestno: MQ50766, Theses scanned by UMI/ProQuest. |
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