A historical perspective of nutrient change impact on an infectious disease in Daphnia

Abstract

Changes in food quality can play a substantial role in the vulnerability of hosts to infectious diseases. In this study, we focused on the genetic differentiation of the water flea Daphnia magna towards food of different quality (by manipulating C:N:P ratios) and its impact on the interaction with a virulent infectious disease, "White Fat Cell Disease (WFCD)". Via a resurrection ecology approach, we isolated two Daphnia subpopulations from different depths in a sediment core, which were exposed to parasites and a nutrient ratio gradient in a common garden experiment. Our results showed a genetic basis for sensitivity towards food deprivation. Both fecundity and host survival was differently affected when fed with low-quality food. This strongly impacted the way both subpopulations interacted with this parasite. A historical reconstruction of nutrient changes in a sediment core reflected an increase in organic material and phosphorus concentration (more eutrophic conditions) over time in the studied pond. These results enable us to relate patterns of genetic differentiation in sensitivity towards food deprivation to an increasing level of eutrophication of the subpopulations, which ultimately impacts parasite virulence effects. This finding was confirmed via a dynamic energy budgets (DEB), in which energy was partitioned for the host and the parasite. The model was tailored to our study by integrating (1) increased growth and a fecundity shift in the host upon parasitism and (2) differences of food assimilation in the subpopulations showing that a reduced nutrient assimilation resulted in increased parasite virulence. The combination of our experiment with the DEB model shows that it is important to consider genetic diversity when studying the impact of nutritional stress on species interactions, especially in the context of changing environments and emerging infectious diseases.

Dead or alive: sediment DNA archives as tools for tracking aquatic evolution and adaptation

“…The multi-faceted aspect of eutrophication on freshwater foodwebs and species interactions has been addressed by coupling resurrected Daphnia with bacterial infections (Pasteuria ramosa) against a background of changing food quality associated with increased nutrient load. Reyserhove et al 52 show that genetic differentiation in Daphnia is affected by food availability, and ultimately influences parasite virulence. Finally, an example from the marine realm: as described earlier, resting stages of the dinoflagellate Pentapharsodinium dalei can survive ca.…”

Back to the future in a petri dish: Origin and impact of resurrected microbes in natural populations

“…These and other types of anthropogenic change may lead to spatial or temporal mismatches between antagonists, resulting in host shifts and the rapid spread of disease across susceptible host populations not historically exposed to particular pathogens (Penczykowski et al, 2016). For instance, an increased level of eutrophication (i.e., nutrient "pollution") in time can lead to increased pathogen prevalence and virulence, which may promote evolution toward elevated virulence (Aalto, Decaestecker, & Pulkkinen, 2015;Decaestecker et al, 2007;Forde, Thompson, & Bohannan, 2004;Johnson et al, 2010 (Aalto et al, 2015;Reyserhove et al, 2017). Together, the analyses of stratified egg banks are a key instrument to link evolutionary dynamics in natural populations with environmental change (Frisch et al, 2013(Frisch et al, , 2016Hairston et al, 1999Hairston et al, , 2001.…”

“…Lake sediments serve as archives of environmental change, where paleolimnological methods can be used to reconstruct changes in an elemental context (Bennion, Fluin, & Simpson, ; Battarbee, Anderson, Jeppesen, & Leavitt, ; see Burge et al., this issue). It is estimated that if environmental nutrient enrichment or increased temperature is translated into higher population sizes, then increased host–pathogen interactions, in terms of within‐host competition and pathogen transmission, may intensify the coevolutionary arms race and virulence outcome between hosts and pathogens (Aalto et al., ; Reyserhove et al., ). Together, the analyses of stratified egg banks are a key instrument to link evolutionary dynamics in natural populations with environmental change (Frisch et al., , ; Hairston et al., , ).…”

Food nutrient availability affects epibiont prevalence and richness in natural Daphnia populations

“…Zooplankton, for example, have been found to be negatively affected by both the relative limitation or excess of either N or P in their food resources (Boersma & Elser , Zhou and Declerck ). For instance, a high phytoplankton N : P ratio can serve as low quality food for zooplankton due to relative excess of nitrogen (Reyserhove et al , b ), or limitation by phosphorus (Andersen and Hessen ; Sterner et al ; Acharya et al ; Zhou et al ).…”

“…In particular, we studied how phytoplankton N : P ratio impacts Daphnia epibiont prevalence, association intensity, and species richness in natural Daphnia populations and in experimental Daphnia cohorts. We focus on this food quality variable as it is particularly relevant in the context of increasing N to P supply rates to aquatic ecosystems (Peñuelas et al , 2013) and as nutrient availability (both N and P) have been suggested to impact Daphnia – endoparasite interactions (Aalto et al ; Reyserhove et al , b ; Narr et al ). We expect that the effect of stoichiometric imbalance in the elemental supply of the environment will have an effect on the species composition and relative abundance of the epibionts.…”