{"abstract":[{"text":"Sex-linked and autosomal loci experience different selective pressures and\r\nevolutionary dynamics. X (or Z) chromosomes are often hemizygous, as Y (or W)\r\nchromosomes often degenerate. Such hemizygous regions can be under greater\r\nefficacy of selection, as recessive mutations are immediately exposed to selection in\r\nthe heterogametic sex (the so-called Faster-X or Faster-Z effect). However, in young\r\nnon-recombining regions, Y/W chromosomes often have many functional genes, and\r\nmany X/Z-linked loci are therefore diploid. The sheltering of recessive mutations on\r\nthe X/Z by the Y/W homolog is expected to drive a Slower-X (Slower-Z) effect for\r\ndiploid X/Z loci, i.e. a reduction in the efficacy of selection. While the Faster-X effect\r\nhas been studied extensively, much less is known empirically about the evolutionary\r\ndynamics of diploid X or Z chromosomes. Here, we took advantage of published\r\npopulation genomic data in the female-heterogametic human parasite Schistosoma\r\njaponicum to characterize the gene content and diversity levels of the diploid and\r\nhemizygous regions of the Z chromosome. We used different metrics of selective\r\npressures acting on genes to test for differences in the efficacy of selection in\r\nhemizygous and diploid Z regions, relative to autosomes. We found consistent\r\npatterns suggesting reduced Ne, and reduced efficacy of purifying selection, on both\r\nhemizygous and diploid Z regions. Moreover, relaxed selection was particularly\r\npronounced for female-biased genes on the diploid Z, as predicted by Slower-Z\r\ntheory.\r\n","lang":"eng"}],"OA_place":"repository","author":[{"full_name":"Mrnjavac, Andrea","id":"353FAC84-AE61-11E9-8BFC-00D3E5697425","first_name":"Andrea","last_name":"Mrnjavac"},{"orcid":"0000-0002-4579-8306","first_name":"Beatriz","last_name":"Vicoso","full_name":"Vicoso, Beatriz","id":"49E1C5C6-F248-11E8-B48F-1D18A9856A87"}],"corr_author":"1","oa_version":"None","citation":{"ista":"Mrnjavac A, Vicoso B. Evidence of a Slower-Z effect in Schistosoma japonicum. bioRxiv, <a href=\"https://doi.org/10.1101/2024.07.02.601697\">10.1101/2024.07.02.601697</a>.","ama":"Mrnjavac A, Vicoso B. Evidence of a Slower-Z effect in Schistosoma japonicum. <i>bioRxiv</i>. doi:<a href=\"https://doi.org/10.1101/2024.07.02.601697\">10.1101/2024.07.02.601697</a>","chicago":"Mrnjavac, Andrea, and Beatriz Vicoso. “Evidence of a Slower-Z Effect in Schistosoma Japonicum.” <i>BioRxiv</i>, n.d. <a href=\"https://doi.org/10.1101/2024.07.02.601697\">https://doi.org/10.1101/2024.07.02.601697</a>.","apa":"Mrnjavac, A., &#38; Vicoso, B. (n.d.). Evidence of a Slower-Z effect in Schistosoma japonicum. <i>bioRxiv</i>. <a href=\"https://doi.org/10.1101/2024.07.02.601697\">https://doi.org/10.1101/2024.07.02.601697</a>","short":"A. Mrnjavac, B. Vicoso, BioRxiv (n.d.).","mla":"Mrnjavac, Andrea, and Beatriz Vicoso. “Evidence of a Slower-Z Effect in Schistosoma Japonicum.” <i>BioRxiv</i>, doi:<a href=\"https://doi.org/10.1101/2024.07.02.601697\">10.1101/2024.07.02.601697</a>.","ieee":"A. Mrnjavac and B. Vicoso, “Evidence of a Slower-Z effect in Schistosoma japonicum,” <i>bioRxiv</i>. ."},"publication":"bioRxiv","related_material":{"record":[{"relation":"dissertation_contains","id":"18531","status":"public"},{"relation":"later_version","id":"19370","status":"public"}]},"type":"preprint","_id":"18549","date_published":"2024-07-04T00:00:00Z","title":"Evidence of a Slower-Z effect in Schistosoma japonicum","date_updated":"2025-03-10T08:27:44Z","month":"07","day":"04","status":"public","year":"2024","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1101/2024.07.02.601697"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_processing_charge":"No","publication_status":"draft","language":[{"iso":"eng"}],"department":[{"_id":"BeVi"}],"doi":"10.1101/2024.07.02.601697","oa":1,"date_created":"2024-11-13T09:12:08Z","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode","image":"/images/cc_by_nc_nd.png","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)","short":"CC BY-NC-ND (4.0)"}}