Meeting Abstract
Telomeres, the end regions of eukaryotic chromosomes, preserve integrity. Short telomeres will lead to cellular senescence, thus telomeres must be maintained and elongated by the telomerase enzyme. Chronic stress correlates with heightened oxidative stress and DNA damage. Our subjects, Astatotilapia burtoni cichlid males, form a strict primarily size-based social hierarchy. We maintained the social status of individual A. burtoni males for the first 6 months of life. Then by manipulating the relative size of tank mates, they were either forced to switch social status or allowed to maintain it for 4 more weeks. Brain, liver and gut tissues were then assayed for absolute telomere length and telomerase activity. This design allows us to assess both the chronic and acute effects of stress on telomeres. It’s hypothesized that always dominant males will have higher telomerase activity due to constant growth, while always subordinate males will have lower telomerase activity due to limited growth. For those that descend social status, telomerase activity will decrease; for those that ascend social status, telomerase activity will increase with resumed growth. Within 4 weeks, no dramatic change in telomere lengths is expected even with changes in telomerase activity. However, it is difficult to predict the chronic effects of stress on telomere length in fish because they have indeterminate growth, meaning they can delay growth when necessary. Due to growth suppression, always subordinate fish may not suffer a reduction in telomere length that would otherwise be predicted for reduced telomerase activity; likewise, due to increased growth and cell division, always dominant fish may suffer reduced telomere length despite elevated telomerase activity. All possible results will provide further insights into the mechanism of cellular aging and how social stress influences organisms on a molecular level.
