Trophic Dynamics and Metabolic Pathways in Host-Parasite Interactions: A Nitrogen Isotope Analysis of Amino Acids in Multiple Tissues

Khaliq, Shaista; Nachev, Milen; Riekenberg, Philip M; Jochmann, Maik A; Vosough, Maryam; Franke, Frederik; Scharsack, Jörn P; Kurtz, Joachim; Sures, Bernd; van der Meer, Marcel TJ; Schmidt, Torsten C

Research article in digital collection | Preprint

Abstract

Trophic interactions are crucial for understanding food web complexity and energy flow in ecosystems. Including parasites in these analyses can alter dynamics and challenge ecological assumptions. Compound-specific isotope analysis (CSIA) offers greater precision than bulk SIA by analyzing individual amino acids, providing deeper insights into nutrient exchange and metabolism in host-parasite systems. In this study, we conducted a 120-day controlled feeding experiment to investigate parasite metabolic pathways, host-parasite trophic dynamics, and trophic fractionation between infected and uninfected sticklebacks. Nitrogen isotope composition (δ15N) was measured in host (Gasterosteus aculeatus) liver and muscle tissues, and its parasite (Schistocephalus solidus). Parasite serine δ15N values were higher by 4.4 ± 2.4‰ compared to host liver, indicating a strong metabolic link. Lower proline concentrations and increased alanine δ15N values (5‰) indicate support of parasite growth through conversion to hydroxyproline and increased gluconeogenesis. The trophic position difference between parasite and host tissues was < 0.5, suggesting direct assimilation of host-derived products. Infected host tissues exhibited ~ 5‰ increase in glycine δ15N over time compared to control tissues, likely reflecting the host’s increased metabolic demand for immune support during infection. This study highlights the complex metabolic interactions in host-parasite systems.

Details about the publication

Name of the repositoryResearch Square
Version1
StatusPublished
Release year2024 (04/12/2024)
Language in which the publication is writtenEnglish
DOI10.21203/rs.3.rs-5415197/v1
Link to the full texthttps://www.researchsquare.com/article/rs-5415197/v1
KeywordsHost-parasite interactions; food webs; metabolic pathways; stable isotope; GC-C-IRMS

Authors from the University of Münster

Kurtz, Joachim
Research Group Animal Evolutionary Ecology (Prof. Kurtz)
Scharsack, Jörn
Research Group Animal Evolutionary Ecology (Prof. Kurtz)