Interpreting relationships among MHC, parasites, and secondary sexual colouration in a natural system

Abstract

Differences in guppy (Poecilia reticulata) colour patterns can be driven by opposing selection pressures of predation and female mate choice, but the effect of parasitism has received less attention. We sought to test the Hamilton-Zuk hypothesis, which posits that immunocompetence can be selected for through sexual selection on ornamentations acting as honest signals of fitness. By studying 21 wild guppy populations in Trinidad, we analyzed relationships among parasitic infections by Gyrodactylus, male sexual ornamentation (colouration), and genetic variation at the Major Histocompatibility Complex (MHC) at both individual and population levels. We found population level support for a correlation between MHC functional supertype diversity and Gyrodactylus prevalence, as well as particular MHC supertypes that were correlated with Gyrodactylus prevalence. However, these relationships were not supported at the individual level. Further, much of this variation was explained by processes acting at a broader geographic scale, within river drainage which comprise divergent guppy lineages; suggesting that evolutionary history and processes such as genetic drift and gene flow also contribute substantially to these relationships. Our results highlight that MHC diversity is correlated to the level of diversity of parasite communities, yet, by considering a single parasite type, we only found limited support for the Hamilton–Zuk hypothesis. Rather, the long-term evolutionary history and contemporary demographic processes are more important factors shaping MHC diversity across populations. Our work demonstrates the importance of examining whole parasite communities within broader evolutionary contexts.

This readme file was generated on 2025-09-27 by Allegra Love

General information

1. Title of dataset:

2. Dataset DOI: NA

3. Long-term contact Name: Kiyoko Gotanda ORCID: 0000-0002-3666-0700 Institution: Brock University Email: kgotanda@brocku.ca

4. Author Name: Allegra Love ORCID: 0000-0002-4637-6850 Institution: University of Guelph Redpath Museum, McGill Unviersity Department of Biology, McGill University

Name: Jackie Lighten ORCID: 0000-0002-4228-1037 Institution: Marine Gene Probe Laboratory, Department of Biology, Dalhousie University

Name: Cock van Oosterhout ORCID: 0000-0002-5653-738X Institution: School of Environmental Sciences, University of East Anglia

Name: Alexander S.T. Papdopulos ORCID: 0000-0001-6589-754X Institution: Marine Gene Probe Laboratory, Department of Biology, Dalhousie University

Name: Stanley D. King ORCID: NA Institution: Marine Gene Probe Laboratory, Department of Biology, Dalhousie University

Name: Ian G. Paterson ORCID: NA Institution:

Name: Lari C. Delaire ORCID: NA Institution: Redpath Museum, McGill Unviersity Department of Biology, McGill University

Name: Lyndsey Baillie ORCID: NA Institution: Marine Gene Probe Laboratory, Department of Biology, Dalhousie University

Name: Ian R. Bradbury ORCID: 0000-0002-8152-4943 Institution: Department of Fisheries and Oceans

Name: Janay A. Fox ORCID: 0000-0002-7895-2357 Institution: Redpath Museum, McGill Unviersity Department of Biology, McGill University

Name: Felipe Perez-Jvostov ORCID: 0000-0003-0822-5039 Institution: Department of Biology, McGill University

Name: Felipe Dargent ORCID: 0000-0002-4510-0086 Institution: Department of Biology, McGill University

Name: Marilyn Scott ORCID: 0000-0002-3553-4550 Institution: Institute of Parasitology, Macdonald Campus of McGill University

Name: Gregor F. Fussmann ORCID: 0000-0001-9576-0122 Institution: Department of Biology, McGill University

Name: Andrew P. Hendry ORCID: 0000-0002-4807-6667 Institution: Redpath Museum, McGill Unviersity Department of Biology, McGill University

Name: Paul Bentzen ORCID: 0000-0003-4288-7730 Institution: Marine Gene Probe Laboratory, Department of Biology, Dalhousie University

Name: Kiyoko M. Gotanda ORCID: 0000-0002-3666-0700 Institution: Redpath Museum, McGill Unviersity Department of Biology, McGill University Department of Biological Sciences, Brock University

5. Description of the dataset: Data used in analysis from "Interpreting relationships among MHC, parasites, and secondary sexual colouration in a natural system".

6. Date of data collection: 2009-2010

7. Geographic location of the data collection: Trinidad and Tobago, see figure 1.

8. Funding information: Funding for this research was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC). AL was supported by a Natural Sciences and Engineering Research Council (NSERC) Postgraduate scholarship—Doctoral (#PGSD - 588909 - 2024). KMG was supported by an NSERC Vanier, Banting, and Discovery Grant.

Sharing/access information

1. Licenses/restrictions placed on the dataset: CC-BY 4.0

2. Links to publications that cite or use the dataset: TBD

3. Links/relationships to related datasets: MHC sequencing data used to generate richness metrics for the associated publication has been submitted to the GenBank database (KR870052-KR870125) and the NCBI database (KF321642.1–KF321728.1 (PopSet: 544451456), and KT003989.1–KT004363.1 (PopSet: 1033321404).

4. Data sources: NA

5. Dataset citation: TBD

Folder and file overview

1. File List:

[code]: [contains all scripts to run analysis and generate figures]

[code/01-data-prep.rmd]: [Uses raw data files to generate data files that are used in analysis]

[code/02-data-analysis.rmd]: [Uses data outputs from code/01-data-prep.rmd to run analyses as outlined in the manuscript. Saves results from these analyses in output/ for use in figure generation]

[code/03-figures.rmd]: [generates figures in manuscript, saves to Figures/]

[Figures]: [for figures generated in code/03-figures.rmd]

[output]: [for files generated from data prep and analysis.]

[data]: [place files from data repository here, required to run scripts]

2. Relationship between files, if important:

Must run files in code/ in numerical order (e.g., 01-data-prep.rmd needs to be run to run 02-data-analysis.rmd)