Reproductive death and adaptive ageing in Caenorhabditis elegans
Evolution, Anthropology
Final Report Abstract
The primary goal of this research project was to investigate the possible importance of reproductive death and adaptive ageing. Specifically, we argue that programmed death that increases fitness can occur in some organisms, such as C. elegans, and that this is consistent with the classic evolutionary theory of aging. In such cases, death-promoting mechanisms can enhance inclusive fitness, through group selection. The plausibility of adaptive death is supported by computer modelling studies, and new knowledge about the ecology of this species. To support these arguments we also review the biology of adaptive death. Within this framework I also investigated the role of disease pathology in the context of ageing. In humans we are well aware that we die of disease and not of ageing itself, but this process has been largely ignored in the model organisms used to study ageing. To take a look at this in C. elegans I investigated a major cause of death, namely phalangeal infection. Interestingly, a sub population of worms become infected early by E. coli and die. This infection pattern has large effects on the lifespan of C. elegans. Using RNAi I knocked down two important genes involved in projection from E. coli pharyngeal infection to demonstrate that what had been though of as a anti ageing genes, was in fact an anti-infection gene. Teasing apart such process will help us to understand the dynamics of ageing by removing a black box, which contains all ageing phenotypes. Future work continuing on from this project will be to describe similar ageing limiting processes in my own groups model organism, Daphnia magna, and to look for similar anti-infection genes. The benefit in D. magna is that it is also a host-parasite model. I also plan to continue investigating the role of semelparity and adaptive death using a modeling approach with collaborators.
Publications
- Does senescence promote fitness in Caenorhabditis elegans by causing death? Ageing Research Reviews, 50: 58-71
Lohr, J.N., Galimov, E.R., Gems, D.
(See online at https://doi.org/10.1016/j.arr.2019.01.008) - When and how can death be an adaptation? 2020. Biochemistry (Moscow), 84: 1433-1437
Galimov, E.R., Lohr, J.N., Gems, D.
(See online at https://doi.org/10.1134/S0006297919120010)
