{"doi":"10.1086/732256","title":"The Dominance of Coinfecting Parasites’ Indirect Genetic Effects on Host Traits","abstract":"Indirect genetic effects (IGEs) exist when there is heritable variation in one organism’s ability to alter a second organism’s traits. For example, parasites have antigens that can induce a host immune response, as well as disparate strategies to evade or suppress host immunity; among-parasite genetic variation in these antigens generates among-host variation in immune traits. Here, we experimentally show that the cestode parasite Schistocephalus solidus exerts an IGE on an immune trait (peritoneal fibrosis) in its threespine stickleback host: stickleback developed strong fibrosis after exposure to some parasite genotypes but not others. A complication arises during coinfection, when two or more parasite genotypes may impose conflicting IGEs on the same host trait. What parasite-controlled trait will the host express? Will the host trait reflect the more immune-stimulatory parasite genotype or the more immune-evasive genotype? These alternatives can be quantified by estimating the dominance coefficient, as if a coinfected host were a heterozygote. We experimentally estimated the dominance of S. solidus IGEs by coinjecting antigens from different parasite genotypes. Contrary to our a priori hypotheses, coinjected antigens induced an overdominant effect, stronger than either parasite’s antigens alone. We present a mathematical model showing that the value of this IGE dominance is biologically important, affecting the evolutionary dynamics of parasites in a density- and frequency-dependent manner. The model indicates that overdominance would be detrimental to immigrants when resident prevalence is high. This combination of experimental data and modeling provides an example of a parasite IGE on host traits and the evolutionary significance of IGE dominance.","journal":"The American Naturalist","year":2024,"id":438722,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":10,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9495,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1168851,"name":"Sophia Arruda","orcid":null,"position":1,"is_corresponding":false},{"id":1168852,"name":"Christian Polania","orcid":null,"position":2,"is_corresponding":false},{"id":1168853,"name":"Lauren Simonse","orcid":null,"position":3,"is_corresponding":false},{"id":1168540,"name":"Arshad Ahmed Padhiar","orcid":"0000-0001-8273-1111","position":4,"is_corresponding":false},{"id":1093251,"name":"Maria L. Rodgers","orcid":"0000-0002-0271-1303","position":5,"is_corresponding":false},{"id":1248861,"name":"Andrea J. Roth-Monzón","orcid":"0000-0003-4633-0702","position":6,"is_corresponding":false},{"id":291569,"name":"Daniel I. Bolnick","orcid":"0000-0003-3148-6296","position":0,"is_corresponding":true}],"reference_count":84,"raw_metadata":null,"created_at":"2026-07-19T02:00:43.618468Z","pmid":"39486034","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}