[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-134683-en":3,"doc-seo-134683-105":30,"detail-sidebar-cat-0-en-105":92},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":27,"seo_description":14,"update_tm":28,"read_time":29},134683,687197207919,"Theodora","https://ap-avatar.wpscdn.com/avatar/a000253d6f5f7c60be?x-image-process=image/resize,m_fixed,w_180,h_180&k=1779446848396160552",8,"Research & Report","The Narrow Footprint of Ancient Balancing Selection Revealed by Heterokaryon Incompatibility Genes in Aspergillus fumigatus","In fungi, fusion between individuals can trigger localized cell death via heterokaryon incompatibility, commonly linked to balancing selection driven by negative frequency-dependent selection. This study examines Aspergillus fumigatus, using hyphal compatibility assays with complementation of auxotrophic mutations to identify het genes. Genetic mapping reveals five loci with fine-mapping and causal validation by heterologous expression, showing trans-species polymorphisms and similar allele frequencies. Yet population-genome scans show no elevated Tajima’s D, and balanced polymorphisms localize to a few hundred base pairs flanking coding regions.","The Narrow Footprint of Ancient Balancing Selection Revealed by Heterokaryon Incompatibility Genes in Aspergillus fumigatus  \nBen Auxier ,1,* Jianhua Zhang,1,2 Francisca Reyes Marquez,1 Kira Senden,1 Joost van den Heuvel,1 Duur K. Aanen, 1 Eveline Snelders, 1 and Alfons J.M. Debets 1  \n1Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands  \n2Present address: Center for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands  \n*Corresponding author: E-mail: [ben.auxier@wur.nl](ben.auxier@wur.nl).  \nAssociate editor: Harmit Malik  \nAbstract  \nIn fungi, fusion between individuals leads to localized cell death, a phenomenon termed heterokaryon incompatibility. Generally, the genes responsible for this incompatibility are observed to be under balancing selection resulting from negative frequency-dependent selection. Here, we assess this phenomenon in Aspergillus fumigatus, a human pathogenic fungus with a very low level of linkage disequilibrium as well as an extremely high crossover rate. Using complementation ofauxotrophic mutations as an assay for hyphal compatibility, we screened sexual progeny for compatibility to identify genes involved in this process, called het genes. In total, 5/148 (3.4%) offspring were compatible with a parent and 166/2,142 (7.7%) sibling pairs were compatible, consistent with several segregating incompatibility loci. Genetic mapping identified five loci, four of which could be fine mapped to individual genes, of which we tested three through heterologous expression, confirming their causal relationship. Consistent with long-term balancing selection, trans-species polymorphisms were apparent across several sister species, as well as equal allele frequencies within A. fumigatus. Surprisingly, a sliding window genome-wide population-level analysis of an independent dataset did not show increased Tajima’s D near these loci, in contrast to what is often found surrounding loci under balancing selection. Using available de novo assemblies, we show that these balanced polymorphisms are restricted to several hundred base pairs flanking the coding sequence. In addition to identifying the first het genes in an Aspergillus species, this work highlights the interaction of long-term balancing selection with rapid linkage disequilibrium decay. Key words: allorecognition, cell death, balancing selection.  \nIntroduction  \nThe ability to differentiate self from nonself is a ubiquitous factor of multicellular life. Best studied in mammalian major histocompatibility loci, this process prevents fusion between genetically distinct organisms, in effect delimiting an individual (Billingham et al. 1953; Boehm 2006). Distinguishing self from nonself is also important for fungi, as the fungal mycelium (the threadlike structure of filamentous fungi) benefits from fusions within its own mycelial network (Bastiaans et al. 2015). However, fusion events between mycelia of different individuals allow for the propagation of selfish genetic elements such as viruses (Anagnostakis 1983), plasmids and mitochondria (Debets et al. 1994), and nuclei (Bastiaanset al. 2016; Grum-Grzhimaylo et al. 2021). To discriminate between self and nonself fusions, fungal species possess a robust multigenic incompatibility system based on the alleles of het genes, which trigger cell death when gene products from two alleles are found in the same cytoplasm (Glass  \nand Dementhon 2006). Within a fungal population, these het genes are highly polymorphic and segregation of alleles from multiple unlinked genes results in two randomly selected fungal individuals being virtually guaranteed to have a distinct combination of het-gene alleles (Nauta and Hoekstra 1994; Czárán et al. 2014; Gonçalves and Glass 2020).  \nA common observation of such het genes is that they appear to be under balancing selection. First shown in het-c of Neurospora crassa, this balancing selectio","cbCaifN2rQJ548NT","https://ap.wps.com/l/cbCaifN2rQJ548NT","pdf",1397582,1,14,"English","en",105,"# Abstract\n# Introduction\n## Self–nonself recognition in fungi\n## Multigenic incompatibility and het genes\n## Balancing selection and negative frequency-dependent selection","[{\"question\":\"What is heterokaryon incompatibility and why does it matter in fungi?\",\"answer\":\"Heterokaryon incompatibility is a process where fusion between individuals leads to localized cell death. In fungal populations, it helps distinguish self from nonself and prevents harmful sharing between genetically distinct individuals.\"},{\"question\":\"How did the study identify genes involved in hyphal compatibility in Aspergillus fumigatus?\",\"answer\":\"The study used complementation of auxotrophic mutations as a hyphal compatibility assay and screened sexual progeny for compatibility. Compatible offspring were then used for genetic mapping to locate het genes.\"},{\"question\":\"What genomic pattern did the authors observe around balanced polymorphisms?\",\"answer\":\"Despite evidence consistent with long-term balancing selection, genome-wide sliding-window analysis did not show increased Tajima’s D near the identified loci. Using de novo assemblies, the authors found balanced polymorphisms restricted to several hundred base pairs flanking the coding sequence.\"}]","The Narrow Footprint of Ancient Balancing Selection Revealed by Heterokaryon Incompatibility Genes in Aspergillus fumigatus | PDF",1787285934,35,{"code":4,"msg":31,"data":32},"ok",{"site_id":24,"language":23,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":87,"head_meta":89,"extra_data":91,"updated_unix":28},"the-narrow-footprint-of-ancient-balancing-selection-revealed-by-heterokaryon-incompatibility-genes-in-aspergillus-fumigatus","",{"@graph":36,"@context":86},[37,54,69],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,51],{"item":41,"name":42,"@type":43,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":50},"https://docshare.wps.com/document/research-report/",3,{"item":52,"name":13,"@type":43,"position":53},"https://docshare.wps.com/document/the-narrow-footprint-of-ancient-balancing-selection-revealed-by-heterokaryon-incompatibility-genes-in-aspergillus-fumigatus/134683/",4,{"url":52,"name":13,"@type":55,"author":56,"headline":13,"publisher":58,"fileFormat":61,"inLanguage":23,"description":14,"dateModified":62,"datePublished":63,"encodingFormat":61,"isAccessibleForFree":64,"interactionStatistic":65},"DigitalDocument",{"name":9,"@type":57},"Person",{"url":41,"name":59,"@type":60},"DocShare","Organization","application/pdf","2026-08-23","2026-08-21",true,{"@type":66,"interactionType":67,"userInteractionCount":20},"InteractionCounter",{"@type":68},"ViewAction",{"@type":70,"mainEntity":71},"FAQPage",[72,78,82],{"name":73,"@type":74,"acceptedAnswer":75},"What is heterokaryon incompatibility and why does it matter in fungi?","Question",{"text":76,"@type":77},"Heterokaryon incompatibility is a process where fusion between individuals leads to localized cell death. In fungal populations, it helps distinguish self from nonself and prevents harmful sharing between genetically distinct individuals.","Answer",{"name":79,"@type":74,"acceptedAnswer":80},"How did the study identify genes involved in hyphal compatibility in Aspergillus fumigatus?",{"text":81,"@type":77},"The study used complementation of auxotrophic mutations as a hyphal compatibility assay and screened sexual progeny for compatibility. Compatible offspring were then used for genetic mapping to locate het genes.",{"name":83,"@type":74,"acceptedAnswer":84},"What genomic pattern did the authors observe around balanced polymorphisms?",{"text":85,"@type":77},"Despite evidence consistent with long-term balancing selection, genome-wide sliding-window analysis did not show increased Tajima’s D near the identified loci. Using de novo assemblies, the authors found balanced polymorphisms restricted to several hundred base pairs flanking the coding sequence.","https://schema.org",{"og:url":52,"og:type":88,"og:title":13,"og:site_name":59,"og:description":14},"article",{"robots":90,"canonical":52},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":93},[94,98,102,106,111,116,121,124,129,132,136],{"id":20,"doc_module":4,"doc_module_name":46,"category_name":95,"show_sort_weight":96,"slug":97},"Story & Novel",90,"story-novel",{"id":47,"doc_module":4,"doc_module_name":46,"category_name":99,"show_sort_weight":100,"slug":101},"Literature",80,"literature",{"id":53,"doc_module":4,"doc_module_name":46,"category_name":103,"show_sort_weight":104,"slug":105},"Exam",70,"exam",{"id":107,"doc_module":4,"doc_module_name":46,"category_name":108,"show_sort_weight":109,"slug":110},5,"Comic",60,"comic",{"id":112,"doc_module":4,"doc_module_name":46,"category_name":113,"show_sort_weight":114,"slug":115},6,"Technology",50,"technology",{"id":117,"doc_module":4,"doc_module_name":46,"category_name":118,"show_sort_weight":119,"slug":120},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":122,"slug":123},30,"research-report",{"id":125,"doc_module":4,"doc_module_name":46,"category_name":126,"show_sort_weight":127,"slug":128},9,"Religion & Spirituality",20,"religion-spirituality",{"id":127,"doc_module":4,"doc_module_name":46,"category_name":130,"show_sort_weight":127,"slug":131},"World Cup","world-cup",{"id":133,"doc_module":4,"doc_module_name":46,"category_name":134,"show_sort_weight":133,"slug":135},10,"Lifestyle","lifestyle",{"id":137,"doc_module":4,"doc_module_name":46,"category_name":138,"show_sort_weight":107,"slug":139},19,"General","general"]