The highly heterozygous European amphioxus ( <i>Branchiostoma lanceolatum</i> ) at the edge of panmixia

The highly heterozygous European amphioxus (Branchiostoma lanceolatum) at the edge of panmixia | bioRxiv Skip to main content Home About Submit ALERTS / RSS Search for this keyword Advanced Search New Results The highly heterozygous European amphioxus ( Branchiostoma lanceolatum ) at the edge of panmixia View ORCID Profile Marina Brasó-Vives , View ORCID Profile Diego A. Hartasánchez , View ORCID Profile Angélica Pulido , View ORCID Profile Stéphanie Bertrand , View ORCID Profile Hector Escriva , View ORCID Profile Marc Robinson-Rechavi doi: https://doi.org/10.64898/2026.01.13.699254 Marina Brasó-Vives 1 Department of Ecology and Evolution, University of Lausanne , Lausanne, Switzerland 2 Swiss Institute of Bioinformatics (SIB) , Lausanne, Switzerland Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Marina Brasó-Vives For correspondence: marina.brasovives{at}unil.ch Diego A. Hartasánchez 3 Department of Computational Biology, University of Lausanne , Lausanne, Switzerland 4 Aging Research Center, Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav) , Mexico City, Mexico Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Diego A. Hartasánchez Angélica Pulido 1 Department of Ecology and Evolution, University of Lausanne , Lausanne, Switzerland 2 Swiss Institute of Bioinformatics (SIB) , Lausanne, Switzerland Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Angélica Pulido Stéphanie Bertrand 5 Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins, BIOM , F-66650, Banyuls-sur-Mer, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Stéphanie Bertrand Hector Escriva 5 Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins, BIOM , F-66650, Banyuls-sur-Mer, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Hector Escriva Marc Robinson-Rechavi 1 Department of Ecology and Evolution, University of Lausanne , Lausanne, Switzerland 2 Swiss Institute of Bioinformatics (SIB) , Lausanne, Switzerland Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Marc Robinson-Rechavi For correspondence: marina.brasovives{at}unil.ch Abstract Full Text Info/History Metrics Supplementary material Data/Code Preview PDF Abstract Amphioxus (Cephalochordata) are small marine chordates that have broad ecological ranges, yet as adults form local settlements and exhibit limited mobility. Genomic surveys of two amphioxus species have suggested that they rank among the most genetically diverse metazoans. Here, we present the first accurate assessment of genomic diversity in the European amphioxus ( Branchiostoma lanceolatum ) and investigate the processes underlying this diversity. We leverage whole-genome sequencing data from multiple individuals sampled at two geographically distant Atlantic and Mediterranean locations. Consistent with previous estimates in other amphioxus species, we measure exceptionally high genomic diversity, with an average heterozygosity of 2.73% in B. lanceolatum . Despite the large geographic separation between sampling sites, population differentiation is minimal, indicating extensive gene flow among distant adult settlements. Phylogenetic analyses combined with population genetic simulations confirm that this elevated genomic diversity is primarily driven by a large effective population size. Although adult amphioxus have limited mobility, our results indicate that long-distance larval dispersal mediated by ocean currents is sufficient to generate a near-panmictic population structure across their broad ecological range. Author Summary Amphioxus are small marine animals that are close relatives of vertebrates. Although they appear simple and are very similar among species, previous studies have suggested that their genome may be more diverse than expected. In this study, we accurately measured genetic diversity across the entire genome of European amphioxus collected from the Atlantic Ocean and the Mediterranean Sea. We found that this species exhibits a genetic diversity among the highest reported in animals. Despite being collected from far-apart locations, individuals are genetically very similar. This suggests that amphioxus populations are strongly interconnected. While adults move very little, their larvae drift with ocean currents, enabling them to travel long distances before settling. This widespread mixing helps to maintain a single, large, interconnected population. Our results demonstrate that even species that appear simple and sedentary can exhibit extraordinary genetic diversity when they have large populations and effective long-distance dispersal mechanisms. Understanding how such diversity is generated and maintained is essential for comprehending evolution and marine biodiversity. Competing Interest Statement The authors have declared no competing interest. Footnotes We revised the refence list and detected some typesetting errors. We have now corrected them. https://doi.org/10.5281/zenodo.21503009 Funder Information Declared Swiss National Science Foundation , 207853 Agence Nationale de la Recherche , ANR-21-CE13-0034 Copyright The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license . Back to top Previous Next Posted August 18, 2026. Download PDF Supplementary Material Data/Code Email Thank you for your interest in spreading the word about bioRxiv. NOTE: Your email address is requested solely to identify you as the sender of this article. Your Email * Your Name * Send To * Enter multiple addresses on separate lines or separate them with commas. You are going to email the following The highly heterozygous European amphioxus (Branchiostoma lanceolatum) at the edge of panmixia Message Subject (Your Name) has forwarded a page to you from bioRxiv Message Body (Your Name) thought you would like to see this page from the bioRxiv website. Your Personal Message CAPTCHA This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Share The highly heterozygous European amphioxus ( Branchiostoma lanceolatum ) at the edge of panmixia Marina Brasó-Vives , Diego A. Hartasánchez , Angélica Pulido , Stéphanie Bertrand , Hector Escriva , Marc Robinson-Rechavi bioRxiv 2026.01.13.699254; doi: https://doi.org/10.64898/2026.01.13.699254 Share This Article: Copy Citation Tools The highly heterozygous European amphioxus ( Branchiostoma lanceolatum ) at the edge of panmixia Marina Brasó-Vives , Diego A. Hartasánchez , Angélica Pulido , Stéphanie Bertrand , Hector Escriva , Marc Robinson-Rechavi bioRxiv 2026.01.13.699254; doi: https://doi.org/10.64898/2026.01.13.699254 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Area Evolutionary Biology Subject Areas All Articles Animal Behavior and Cognition (8164) Biochemistry (19027) Bioengineering (15171) Bioinformatics (45808) Biophysics (22958) Cancer Biology (20248) Cell Biology (27495) Clinical Trials (138) Developmental Biology (14233) Ecology (21529) Epidemiology (2067) Evolutionary Biology (25940) Genetics (16436) Genomics (23979) Immunology (19176) Microbiology (43488) Molecular Biology (18483) Neuroscience (95839) Paleontology (717) Pathology (3064) Pharmacology and Toxicology (5253) Physiology (8339) Plant Biology (16378) Scientific Communication and Education (2123) Synthetic Biology (4675) Systems Biology (10451) Zoology (2436)

Related documents

• Morphological analyses allow to separate Branchipus species (Branchiopoda, Anostraca) from different geographic regions#643956
• The slug within the bivalve: molecular and morphological systematics of the family Juliidae (Gastropoda: Panpulmonata: Sacoglossa)#203610
• Vorticidad y socavación fluvial alrededor de las estructuras hidráulicas: una revisión#422435
• Distribuição e conservação de anfíbios no cerrado em cenários atuais e futuros#1040668
• Trajetórias de crescimento de Cedrela spp. em florestas neotropicais úmida e sazonalmente seca#1017174