{"doi":"10.22541/au.158214148.82837988","title":"No evidence for accumulation of deleterious mutations and fitness degradation in clonal fish hybrid: Abandoning sex without regrets","abstract":"<jats:p>Despite its inherent costs, sexual reproduction is ubiquitous in nature,\nand the mechanisms to protect it from a competitive displacement by\nasexuality remain unclear. Popular mutation-based explanations, like the\nMuller's ratchet and the Kondrashov's hatchet, assume that purifying\nselection may not halt the accumulation of deleterious mutations in the\nnon-recombining genomes, ultimately leading to their degeneration.\nHowever, empirical evidence is scarce and it remains particularly\nunclear whether mutational degradation proceeds fast enough to ensure\nthe decay of clonal organisms and to prevent them from outcompeting\ntheir sexual counterparts. To test this hypothesis, we jointly analyzed\nthe exome sequences and the fitness-related phenotypic traits of the\nsexually-reproducing fish species and their clonal hybrids, whose\nevolutionary ages ranged from F1 generations to 300 ky. As expected,\nmutations tended to accumulate in the clonal genomes in a time-dependent\nmanner. However, contrary to the predictions, we found no trend towards\nincreased non-synonymity of mutations acquired by clones, nor higher\nradicality of their amino-acid substitutions. Moreover, there was no\nevidence for fitness degeneration in the old clones compared to that in\nthe younger ones. In summary, although a purifying selection may still\nbe relaxed in the asexual genomes, our data indicate that its efficiency\nis not drastically decreased. Even the oldest investigated clone was\nfound to be too young to suffer fitness consequences from a mutation\naccumulation. This suggests that mechanisms other than mutation\naccumulation may be needed to explain the competitive advantage of sex\nin the short term.</jats:p>","journal":null,"year":null,"id":17395,"datarank":0.16479184330021646,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"self_citation_contribution":0.16479184330021646,"citation_network_contribution":0.0,"self_endowment_contribution":0.16479184330021646,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":124627,"name":"Jan Röslein","orcid":null,"position":1,"is_corresponding":false},{"id":124628,"name":"Jan Pačes","orcid":"0000-0003-3059-6127","position":2,"is_corresponding":false},{"id":124629,"name":"Jan Kotusz","orcid":null,"position":3,"is_corresponding":false},{"id":124630,"name":"Karel Halacka","orcid":null,"position":4,"is_corresponding":false},{"id":124631,"name":"Ján Koščo","orcid":null,"position":5,"is_corresponding":false},{"id":124632,"name":"Jakub Fedorčák","orcid":"0000-0002-3839-9438","position":6,"is_corresponding":false},{"id":124633,"name":"Nataliia Iakovenko","orcid":null,"position":7,"is_corresponding":false},{"id":124634,"name":"Karel Janko","orcid":"0000-0002-7866-4937","position":8,"is_corresponding":false},{"id":124626,"name":"Jan Kočí","orcid":"0000-0002-9036-8321","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"24259432","pmcid":null,"openalex_id":"https://openalex.org/W3007324531","authors":[],"funders":[],"total_grants":0,"fwci":0.3524,"citation_percentile":0.6562739,"influential_citations":0,"citation_trend":[{"year":2020,"count":2}],"oa_status":"green","license":"cc-by","oa_locations":[{"url":"https://www.authorea.com/doi/pdf/10.22541/au.158214148.82837988","host_type":"repository"},{"url":"https://doi.org/10.22541/au.158214148.82837988","host_type":"HYBRID"},{"url":"https://www.authorea.com/doi/pdf/10.22541/au.158214148.82837988","host_type":"repository"}],"fields_of_study":["Evolution and Genetic Dynamics","Genetic diversity and population structure","Aquatic Invertebrate Ecology and Behavior","Biology","Environmental Science"],"mesh_terms":[],"keywords":["Biology","Asexuality","Genetic Fitness","Mutation Accumulation","Evolution of sexual reproduction","Genetics","Negative selection","Mutation","Mutation rate","Evolutionary biology","Genome","clone (Java method)","Phenotype","Asexual reproduction","Natural selection","Gene","Selection (genetic algorithm)"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Life below water"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-02T18:42:09.952211Z","pmid":null,"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":[]}