Temperature and pathogen exposure act independently to drive host phenotypic trajectories

Tobias E. Hector, Carla M. Sgrò, Matthew D. Hall

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)

Abstract

Natural populations are experiencing an increase in the occurrence of both thermal stress and disease outbreaks. How these two common stressors interact to determine host phenotypic shifts will be important for population persistence, yet a myriad of different traits and pathways are a target of both stressors, making generalizable predictions difficult to obtain. Here, using the host Daphnia magna and its bacterial pathogen Pasteuria ramosa, we tested how temperature and pathogen exposure interact to drive shifts in multivariate host phenotypes. We found that these two stressors acted mostly independently to shape host phenotypic trajectories, with temperature driving a faster pace of life by favouring early development and increased intrinsic population growth rates, while pathogen exposure impacted reproductive potential through reductions in lifetime fecundity. Studies focussed on extreme thermal stress are increasingly showing how pathogen exposure can severely hamper the thermal tolerance of a host. However, our results suggest that under milder thermal stress, and in terms of life-history traits, increases in temperature might not exacerbate the impact of pathogen exposure on host performance, and vice versa.

Original languageEnglish
Article number20210072
Number of pages7
JournalBiology Letters
Volume17
Issue number6
DOIs
Publication statusPublished - 16 Jun 2021

Keywords

  • infectious disease
  • life-history
  • pathogen
  • phenotypic trajectory
  • stress
  • temperature

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