{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T15:42:38Z","timestamp":1782920558622,"version":"3.54.5"},"reference-count":22,"publisher":"Cambridge University Press (CUP)","issue":"4","license":[{"start":{"date-parts":[[2024,4,12]],"date-time":"2024-04-12T00:00:00Z","timestamp":1712880000000},"content-version":"unspecified","delay-in-days":7438,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Helminthol."],"published-print":{"date-parts":[[2003,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Triploid, parthenogenetic forms of the lungfluke, <jats:italic>Paragonimus westermani<\/jats:italic>, occur in Japan, Korea and China. The origin(s) of triploidy has been debated over the years. Sequences of two regions in the mitochondrial DNA, i.e. partial lrRNA (16S), and a portion of the non-coding region, were obtained from natural populations of <jats:italic>P. westermani<\/jats:italic>. All triploid individuals (Japan, Korea, China) and a single tetraploid individual (China) had identical sequences in the 16S region studied. Some sequence variation was observed among diploids, with those from Taiwan being distinct from the remainder. Both neighbour joining and parsimony trees using the 16S region placed diploid individuals from southwestern Japan close to the triploids and the tetraploid. The fragment amplified from the mitochondrial non-coding region showed dimorphism. One form (type A) consisted of 239bp comprising two identical tracts of 70bp separated by a tract of 93bp. The second form (Type B) consisted of only a single 70bp tract. All diploid individuals from Taiwan, China and Korea possessed type A, while those from Japan were polymorphic; individuals from Oita and Hyogo had type B, those from Chiba had type A, but both types were found in Mie. On the other hand, all of the triploid individuals and two tetraploid individuals possessed type B. Both the form present in the non-coding region and the 16S sequence suggest an affinity between a south-eastern group of diploid populations in Japan and the triploid form. A possible mechanism responsible for the origin of the triploid is discussed.<\/jats:p>","DOI":"10.1079\/joh2003185","type":"journal-article","created":{"date-parts":[[2004,2,26]],"date-time":"2004-02-26T22:45:03Z","timestamp":1077835503000},"page":"279-285","source":"Crossref","is-referenced-by-count":20,"title":["The origin of the triploid in <i>Paragonimus westermani<\/i> on the basis of variable regions in the mitochondrial DNA"],"prefix":"10.1017","volume":"77","author":[{"given":"T.","family":"Agatsuma","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Iwagami","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Y.","family":"Sato","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"Iwashita","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.J.","family":"Hong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.Y.","family":"Kang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.Y.","family":"Ho","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K.E.","family":"Su","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K.","family":"Kawashima","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T.","family":"Abe","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2024,4,12]]},"reference":[{"key":"S0022149X00702549_ref020","doi-asserted-by":"publisher","DOI":"10.1007\/BF00932031"},{"key":"S0022149X00702549_ref004","first-page":"302","article-title":"Population genetic studies on isozymes of Paragonimus westermani from Taiwan and Japan, with special reference to the origin of the triploid P. westermani.","volume":"36","author":"Agatsuma","year":"1987","journal-title":"Japanese Journal of Parasitology"},{"key":"S0022149X00702549_ref008","doi-asserted-by":"publisher","DOI":"10.1017\/S0022149X00013407"},{"key":"S0022149X00702549_ref017","first-page":"35","article-title":"Study on chromosome C-banding in Paragonimus westermani: comparison of the diploid and triploid types (in Chinese)","volume":"8","author":"Tan","year":"1990","journal-title":"Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi"},{"key":"S0022149X00702549_ref007","doi-asserted-by":"publisher","DOI":"10.1007\/BF00931578"},{"key":"S0022149X00702549_ref012","doi-asserted-by":"publisher","DOI":"10.1016\/0169-4758(91)90080-8"},{"key":"S0022149X00702549_ref022","doi-asserted-by":"publisher","DOI":"10.1016\/S0020-7519(99)00072-7"},{"key":"S0022149X00702549_ref003","first-page":"69","volume-title":"Paragonimus in Asia: biology, genetic variation and speciation (II).","author":"Agatsuma","year":"1989"},{"key":"S0022149X00702549_ref021","doi-asserted-by":"publisher","DOI":"10.2307\/3284204"},{"key":"S0022149X00702549_ref016","volume-title":"Helminthic zoonoses.","author":"Miyazaki","year":"1991"},{"key":"S0022149X00702549_ref001","first-page":"57","volume-title":"Paragonimus in Asia: biology, genetic variation and speciation (I). 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