Starvation reveals the cause of infection-induced castration and gigantism

Clayton E. Cressler, William A. Nelson, Troy Day, Edward McCauley

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


Parasites often induce life-history changes in their hosts. In many cases, these infection-induced life-history changes are driven by changes in the pattern of energy allocation and utilization within the host. Because these processes will affect both host and parasite fitness, it can be challenging to determine who benefits from them. Determining the causes and consequences of infectioninduced life-history changes requires the ability to experimentally manipulate life history and a framework for connecting life history to host and parasite fitness. Here, we combine a novel starvation manipulation with energy budget models to provide new insights into castration and gigantism in the Daphnia magna-Pasteuria ramosa host-parasite system. Our results show that starvation primarily affects investment in reproduction, and increasing starvation stress reduces gigantism and parasite fitness without affecting castration. These results are consistent with an energetic structure where the parasite uses growth energy as a resource. This finding gives us new understanding of the role of castration and gigantism in this system, and how life-history variation will affect infection outcome and epidemiological dynamics. The approach of combining targeted life-history manipulations with energy budget models can be adapted to understand life-history changes in other disease systems.

Original languageEnglish (US)
Article number20141087
JournalProceedings of the Royal Society B: Biological Sciences
Issue number1792
StatePublished - Aug 20 2014
Externally publishedYes


  • Castration
  • Gigantism
  • Host-parasite interaction
  • Life history
  • Starvation

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology
  • General Environmental Science
  • General Agricultural and Biological Sciences


Dive into the research topics of 'Starvation reveals the cause of infection-induced castration and gigantism'. Together they form a unique fingerprint.

Cite this