Fungus, frogs and MHC: the role of sexual selection in the evolution of disease resistance
Final Report Abstract
Choosing a reproductive partner is a difficult and heavy decision, as it directly influences the fitness of the offspring. This is particularly relevant to species experiencing lethal pathogens or that reproduce sporadically and produce little offspring. In this project I explored whether amphibians select reproductive partners based on the resistance genes – a trait that is known to be selected for in other vertebrate groups – and resistance itself. While, due to technical issues, I was not able to explore gene preferences, I observed that individuals choose reproductive partners based on their own, and their reproductive partner’s, resistance level; meaning that they can manipulate the resistance level of their offspring, potentially, making them more fit to deal with local pathogens. Using computer simulations to study how this would translate over time, I observed that species with stricter reproductive partner choice systems (for instance that select for reproductive partners that are very different from themselves) suffered less from a new invading lethal pathogen. In particular, I observed that the population crash due to the lethal pathogen was smaller, and that the population also recovered faster. Some of the most surprising data from this project came from the fact that individuals are not necessarily selecting for the most resistant reproductive partners, and that preference differs with the cues being received (e.g. visual, olfactory) and the population studied. This variation between populations is likely related to possibly different infection histories of the populations; individuals from populations that have no experience with the lethal pathogen might have no benefit from selecting reproductive partners that are resistant to that particular pathogen. Unfortunately, while we know that the particular individuals used in this project were not infected, we don’t know if the pathogen is not present there; specially because this pathogen is known to exist in the surrounding area. This project contributed to expand the knowledge of the role of sexual selection on the evolution of disease resistance. The observations made in this project suggest that the type of reproductive partner choice can be used to identify species that should be conservation priorities, allowing to better allocate the, unfortunately, not endless budget that exists for conservation efforts.
Publications
- (2021). Wildlife pathogen detection: evaluation of alternative DNA extraction protocols. Biology Methods and Protocols, 6(1): bpab018
Mantzana-Oikonomaki, V., Maan, M., Sabino-Pinto, J.
(See online at https://doi.org/10.1093/biomethods/bpab018)
