{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T04:38:31Z","timestamp":1786509511894,"version":"build-2736575974"},"reference-count":10,"publisher":"Hindawi Limited","issue":"2","license":[{"start":{"date-parts":[[2009,4,14]],"date-time":"2009-04-14T00:00:00Z","timestamp":1239667200000},"content-version":"unspecified","delay-in-days":14075,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genet. Res."],"published-print":{"date-parts":[[1970,10]]},"abstract":"<jats:title>SUMMARY<\/jats:title><jats:p>Associative overdominance arises at an intrinsically neutral locus through its non-random association with overdominant loci. In finite populations, even if fitness is additive between loci, non-random association will be created by random genetic drift.<\/jats:p><jats:p>The magnitude of such associative overdominance is roughly proportional to the sum of<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300002391_inline1\"\/>between the neutral and the surrounding over-dominant loci, where<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300002391_inline2\"\/>is the squared standard linkage deviation, defined between any two loci by the relation<\/jats:p><jats:p><jats:disp-formula><jats:graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" position=\"float\" xlink:type=\"simple\" xlink:href=\"S0016672300002391_eqnU1\"\/><\/jats:disp-formula><\/jats:p><jats:p>in which<jats:italic>p<\/jats:italic>and 1 \u2013<jats:italic>p<\/jats:italic>are frequencies of alleles<jats:italic>A<\/jats:italic><jats:sub>1<\/jats:sub>and<jats:italic>A<\/jats:italic><jats:sub>2<\/jats:sub>in the first locus,<jats:italic>q<\/jats:italic>and 1 \u2013<jats:italic>q<\/jats:italic>are frequencies of alleles<jats:italic>B<\/jats:italic><jats:sub>1<\/jats:sub>and<jats:italic>B<\/jats:italic><jats:sub>2<\/jats:sub>in the second locus, and<jats:italic>D<\/jats:italic>is the coefficient of linkage disequilibrium. A theory was developed based on diffusion models which enables us to obtain formulae for<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300002391_inline2\"\/>under various conditions, and Monte Carlo experiments were performed to check the validity of those formulae.<\/jats:p><jats:p>It was shown that if<jats:italic>A<\/jats:italic><jats:sub>1<\/jats:sub>and<jats:italic>A<\/jats:italic><jats:sub>2<\/jats:sub>are strongly overdominant while<jats:italic>B<\/jats:italic><jats:sub>1<\/jats:sub>and<jats:italic>B<\/jats:italic><jats:sub>2<\/jats:sub>are selectively neutral, we have approximately<\/jats:p><jats:p><jats:disp-formula><jats:graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" position=\"float\" xlink:type=\"simple\" xlink:href=\"S0016672300002391_eqnU2\"\/><\/jats:disp-formula><\/jats:p><jats:p>provided that 4<jats:italic>N<jats:sub>e<\/jats:sub><\/jats:italic><jats:italic>c<\/jats:italic>\u226b 1, where<jats:italic>N<jats:sub>e<\/jats:sub><\/jats:italic>is the effective population size and<jats:italic>c<\/jats:italic>is the recombination fraction between the two loci. This approximation formula is also valid between two strongly overdominant as well as weakly overdominant loci, if 4<jats:italic>N<jats:sub>e<\/jats:sub><\/jats:italic><jats:italic>c<\/jats:italic>\u226b 1.<\/jats:p><jats:p>The significance of associative overdominance for the maintenance of genetic variability in natural populations was discussed, and it was shown that<jats:italic>N<jats:sub>e<\/jats:sub>s\u2032<\/jats:italic>, that is, the product between effective population size and the coefficient of associative overdominance, remanis constant with varying<jats:italic>N<jats:sub>e<\/jats:sub><\/jats:italic>, if the total segregational (overdominant) load is kept constant.<\/jats:p><jats:p>The amount of linkage disequilibrium expected due to random drift in experimental populations was also discussed, and it was shown that<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300002391_inline3\"\/>in the first generation, if it is produced by extracting<jats:italic>n<\/jats:italic>chromosomes from a large parental population in which<jats:italic>D<\/jats:italic>= 0.<\/jats:p>","DOI":"10.1017\/s0016672300002391","type":"journal-article","created":{"date-parts":[[2009,9,17]],"date-time":"2009-09-17T07:53:48Z","timestamp":1253174028000},"page":"165-177","source":"Crossref","is-referenced-by-count":98,"title":["Development of associative overdominance through linkage disequilibrium in finite populations"],"prefix":"10.1155","volume":"16","author":[{"given":"Tomoko","family":"Ohta","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Motoo","family":"Kimura","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"98","published-online":{"date-parts":[[2009,4,14]]},"reference":[{"key":"S0016672300002391_ref009","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1093\/genetics\/63.1.229","article-title":"Linkage disequilibrium at steady state determined by random genetic drift and recurrent mutation","volume":"63","author":"Ohta","year":"1969","journal-title":"Genetics"},{"key":"S0016672300002391_ref003","first-page":"494","volume-title":"Heterosis","author":"Comstock","year":"1952"},{"key":"S0016672300002391_ref008","doi-asserted-by":"publisher","DOI":"10.1017\/S001667230000272X"},{"key":"S0016672300002391_ref005","doi-asserted-by":"publisher","DOI":"10.1007\/BF01245622"},{"key":"S0016672300002391_ref007","doi-asserted-by":"publisher","DOI":"10.1007\/BF01245624"},{"key":"S0016672300002391_ref001","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1093\/genetics\/57.2.237","article-title":"Linkage and selection: Theoretical analysis of the deterministic two locus random mating model","volume":"57","author":"Bodmer","year":"1967","journal-title":"Genetics"},{"key":"S0016672300002391_ref002","doi-asserted-by":"publisher","DOI":"10.1266\/jjg.39.289"},{"key":"S0016672300002391_ref010","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1093\/genetics\/59.4.543","article-title":"The stability of linked systems of loci with a small population size","volume":"59","author":"Sved","year":"1968","journal-title":"Genetics"},{"key":"S0016672300002391_ref006","first-page":"229","article-title":"Development of temporary overdominance associated with neutral alieles","volume":"1","author":"Maruyama","year":"1968","journal-title":"Proceedings of XII International Congress of Genetics"},{"key":"S0016672300002391_ref004","doi-asserted-by":"publisher","DOI":"10.1111\/j.1601-5223.1963.tb01896.x"}],"container-title":["Genetical Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0016672300002391","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,10,10]],"date-time":"2021-10-10T22:52:41Z","timestamp":1633906361000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0016672300002391\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1970,10]]},"references-count":10,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1970,10]]}},"alternative-id":["S0016672300002391"],"URL":"https:\/\/doi.org\/10.1017\/s0016672300002391","relation":{},"ISSN":["0016-6723","1469-5073"],"issn-type":[{"value":"0016-6723","type":"print"},{"value":"1469-5073","type":"electronic"}],"subject":[],"published":{"date-parts":[[1970,10]]}}}