{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T17:00:11Z","timestamp":1790874011739,"version":"4.1.0"},"reference-count":60,"publisher":"National Academy of Sciences","issue":"40","license":[{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2026,10,6]]},"abstract":"<jats:p>\n                    Sexual reproduction is generally considered costly for unicellular organisms and is typically induced in yeast only under nutrient limitation. However, wild strains of\n                    <jats:italic toggle=\"yes\">Schizosaccharomyces japonicus<\/jats:italic>\n                    isolated from fruit flies in Japan exhibit constitutive sporulation even under nutrient-rich conditions. Here, we investigated the ecological and evolutionary significance of this unusual phenotype. We demonstrate that spores produced under nutrient-rich conditions survive passage through the digestive tract of\n                    <jats:italic toggle=\"yes\">Drosophila melanogaster<\/jats:italic>\n                    , whereas vegetative cells do not. Although constitutive sporulation reduces competitive growth during laboratory serial passaging, fly-mediated transmission strongly enriches high-sporulation (hc\n                    <jats:sup>90<\/jats:sup>\n                    ) strains, indicating positive selection by insect predation. Experimental evolution using a chemically mutagenized library further confirmed that passage through fruit flies enriches mutants capable of nutrient-independent sporulation. Whole-genome and genetic analyses revealed that the hc\n                    <jats:sup>90<\/jats:sup>\n                    phenotype is associated with combinations of mutations in six meiotic regulatory genes\u2014\n                    <jats:italic toggle=\"yes\">byr2, mcs4, ste6, ste11, tor2,<\/jats:italic>\n                    and\n                    <jats:italic toggle=\"yes\">win1<\/jats:italic>\n                    \u2014suggesting epistatic interactions rather than single-gene effects. Suppressor mutations arising during laboratory cultivation frequently targeted\n                    <jats:italic toggle=\"yes\">ste11<\/jats:italic>\n                    , reinforcing its central role in regulating this trait. Field surveys showed that genetically diverse hc\n                    <jats:sup>90<\/jats:sup>\n                    strains are widely distributed across Japan from insects, flowers, moss, and soil. Together, our findings indicate that long-term yeast\u2013insect interactions can maintain costly sexual reproduction as an adaptive strategy for survival and dispersal. This study provides direct experimental evidence linking microbial reproductive strategies to ecological selection by animal hosts.\n                  <\/jats:p>","DOI":"10.1073\/pnas.2607475123","type":"journal-article","created":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T16:09:36Z","timestamp":1790870976000},"update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":0,"title":["Constitutive sporulation in wild fission yeast enhances insect-mediated survival"],"prefix":"10.1073","volume":"123","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5391-6595","authenticated-orcid":false,"given":"Hironori","family":"Niki","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02xg1m795","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Gene Function and Phenomics, National Institute of Genetics","place":["Mishima, Japan"]},{"name":"Graduate Institute for Advanced Studies, Graduate University for Advanced Studies","place":["Mishima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8275-1323","authenticated-orcid":false,"given":"Shunsuke","family":"Noda","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02xg1m795","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Gene Function and Phenomics, National Institute of Genetics","place":["Mishima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keigo","family":"Fujiwara","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02xg1m795","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Gene Function and Phenomics, National Institute of Genetics","place":["Mishima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takuya","family":"Miyake","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02xg1m795","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Gene Function and Phenomics, National Institute of Genetics","place":["Mishima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Koichiro","family":"Akiyama","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02xg1m795","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Gene Function and Phenomics, National Institute of Genetics","place":["Mishima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8738-7759","authenticated-orcid":false,"given":"Taisuke","family":"Seike","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02278tr80","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology","place":["Iizuka, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2026,10,1]]},"reference":[{"key":"e_1_3_4_1_2","doi-asserted-by":"publisher","DOI":"10.1086\/599084"},{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-018-04054-6"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1534\/genetics.111.135731"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10577-007-1151-0"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1093\/bbb\/zbae019"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1098\/rstb.2011.0081"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0968-0004(06)80022-8"},{"key":"e_1_3_4_8_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00387025"},{"key":"e_1_3_4_9_2","doi-asserted-by":"publisher","DOI":"10.1101\/gad.5.11.1990"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1534\/genetics.111.127126"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1093\/genetics\/156.1.423"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature03405"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pgen.1004910"},{"key":"e_1_3_4_14_2","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.2017.2733"},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2022.1039939"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.1111\/1365-2435.14054"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2013342118"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0002873"},{"key":"e_1_3_4_19_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-023-36942-x"},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.90148.3"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1002\/ece3.10184"},{"key":"e_1_3_4_22_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01741-12"},{"key":"e_1_3_4_23_2","doi-asserted-by":"publisher","DOI":"10.1111\/evo.14265"},{"key":"e_1_3_4_24_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.funeco.2018.04.005"},{"key":"e_1_3_4_25_2","doi-asserted-by":"publisher","DOI":"10.1128\/microbiolspec.FUNK-0081-2016"},{"key":"e_1_3_4_26_2","first-page":"218","article-title":"Schizosaccharomyces japonicus n. sp","volume":"4","author":"Yukawa M.","year":"1931","unstructured":"M. Yukawa, T. Maki, Schizosaccharomyces japonicus n. sp. Bull. Sci. Fak. Terkult. Kyushu Imp. Univ. 4, 218\u2013225 (1931).","journal-title":"Bull. Sci. Fak. Terkult. Kyushu Imp. Univ."},{"key":"e_1_3_4_27_2","first-page":"185","article-title":"Yeasts associated with living plants in the sandy coastal area of the sea of the Japan in the North-eastern Provinces of Japan","volume":"7","author":"Hayashibe M.","year":"1974","unstructured":"M. Hayashibe, N. Sando, S. Awano, J. Kurasawa, S. Takahashi, Yeasts associated with living plants in the sandy coastal area of the sea of the Japan in the North-eastern Provinces of Japan. Bull. Yamagata Univ. Agric. Sci. 7, 185\u2013207 (1974).","journal-title":"Bull. Yamagata Univ. Agric. Sci."},{"key":"e_1_3_4_28_2","first-page":"1","article-title":"Ascosporogenous yeasts isolated from tree exudates in Japan","volume":"52","author":"Kodama K.","year":"1974","unstructured":"K. Kodama, T. Kyono, Ascosporogenous yeasts isolated from tree exudates in Japan. J. Ferment. Technol. 52, 1\u20139 (1974).","journal-title":"J. Ferment. Technol."},{"key":"e_1_3_4_29_2","doi-asserted-by":"publisher","DOI":"10.1002\/yea.2996"},{"key":"e_1_3_4_30_2","doi-asserted-by":"publisher","DOI":"10.1002\/yea.1662"},{"key":"e_1_3_4_31_2","first-page":"350","article-title":"Elevated sporulation efficiency in fission yeast Schizosaccharomyces japonicus strains isolated from Drosophila","volume":"7","author":"Seike T.","year":"2021","unstructured":"T. Seike, N. Sakata, F. Matsuda, C. Furusawa, Elevated sporulation efficiency in fission yeast Schizosaccharomyces japonicus strains isolated from Drosophila. J. Fungi (Basel, Switzerland) 7, 350 (2021).","journal-title":"J. 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Seike Raw sequencing reads of Schizosaccharomyces japonicus strain TN33. DDBJ Sequence Read Archive (DRA). https:\/\/ddbj.nig.ac.jp\/search\/entry\/sra-run\/DRR811518. Deposited 2 December 2025."},{"key":"e_1_3_4_58_2","unstructured":"T. Seike Raw sequencing reads of Schizosaccharomyces japonicus strain TN83. DDBJ Sequence Read Archive (DRA). https:\/\/ddbj.nig.ac.jp\/search\/entry\/sra-run\/DRR811519. Deposited 2 December 2025."},{"key":"e_1_3_4_59_2","unstructured":"T. Seike Raw sequencing reads of Schizosaccharomyces japonicus strain TN84. DDBJ Sequence Read Archive (DRA). https:\/\/ddbj.nig.ac.jp\/search\/entry\/sra-run\/DRR811520. Deposited 2 December 2025."},{"key":"e_1_3_4_60_2","unstructured":"Broad Institute University of Massachusetts Medical School Schizosaccharomyces japonicus yFS275 genome assembly SJ5. GenBank. https:\/\/www.ncbi.nlm.nih.gov\/datasets\/genome\/GCA_000149845.2\/. Deposited 11 October 2006."}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.2607475123","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T16:10:15Z","timestamp":1790871015000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/10.1073\/pnas.2607475123"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,1]]},"references-count":60,"journal-issue":{"issue":"40","published-print":{"date-parts":[[2026,10,6]]}},"alternative-id":["10.1073\/pnas.2607475123"],"URL":"https:\/\/doi.org\/10.1073\/pnas.2607475123","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,1]]},"assertion":[{"value":"2026-03-05","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-08-26","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-10-01","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e2607475123"}}