{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:29:38Z","timestamp":1760146178754,"version":"build-2065373602"},"reference-count":36,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2024,10,12]],"date-time":"2024-10-12T00:00:00Z","timestamp":1728691200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003787","name":"Hebei Natural Science Foundation","doi-asserted-by":"publisher","award":["C2023107012","2023TD41","CARS-47","21326307D"],"award-info":[{"award-number":["C2023107012","2023TD41","CARS-47","21326307D"]}],"id":[{"id":"10.13039\/501100003787","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Central Public-Interest Scientific Institution Basal Research Fund, CAFS","award":["C2023107012","2023TD41","CARS-47","21326307D"],"award-info":[{"award-number":["C2023107012","2023TD41","CARS-47","21326307D"]}]},{"name":"China Agriculture Research System","award":["C2023107012","2023TD41","CARS-47","21326307D"],"award-info":[{"award-number":["C2023107012","2023TD41","CARS-47","21326307D"]}]},{"name":"Key R&amp;D Program of Hebei Province","award":["C2023107012","2023TD41","CARS-47","21326307D"],"award-info":[{"award-number":["C2023107012","2023TD41","CARS-47","21326307D"]}]},{"name":"National Marine Genetic Resource Center","award":["C2023107012","2023TD41","CARS-47","21326307D"],"award-info":[{"award-number":["C2023107012","2023TD41","CARS-47","21326307D"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Japanese flounder is usually gonochoristic, with gonads that are either testes or ovaries. Here, we report an unusual case of hermaphroditism in Japanese flounder captured from the Bohai Sea. In the intersex flounder, the membrane of the upper ovary was closely connected to the abdominal muscles and internal organs, and the eggs filled the entire abdomen. The lower ovary was small and closely connected to the testes. The testes contained few fully mature sperm. Both eggs and sperm were capable of fertilization. The levels of several reproduction-related hormones (17\u03b2-estradiol, 11-ketotestosterone, 17\u03b1, 20\u03b2-dihydroxyprogesterone, luteinizing hormone, follicle-stimulating hormone, and testosterone) in the intersex flounder were intermediate, between those in females and males. The results showed that the heterozygosity of the intersex flounder was 0.632, and there were 28 single-nucleotide polymorphisms in the cyp21a gene. Compared with that of wild flounder, the activity of 21-hydroxylase was reduced by approximately 20.0%, and expressions of cyp19a, amh, and dmrt1 differed. We present the first report of its kind, detailing the anatomy, hormonal endocrinology, molecular biology, and physiology of the intersex Japanese flounder.<\/jats:p>","DOI":"10.3390\/ani14202948","type":"journal-article","created":{"date-parts":[[2024,10,14]],"date-time":"2024-10-14T06:46:33Z","timestamp":1728888393000},"page":"2948","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Synchronously Mature Intersex Japanese Flounder (Paralichthys olivaceus): A Rare Case"],"prefix":"10.3390","volume":"14","author":[{"given":"Tian","family":"Han","sequence":"first","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"China Ocean College, Hebei Agricultural University, Qinhuangdao 066009, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Cao","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lize","family":"San","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zixiong","family":"Xu","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guixing","family":"Wang","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhongwei","family":"He","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yufeng","family":"Liu","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1572-8371","authenticated-orcid":false,"given":"Yuqin","family":"Ren","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yufen","family":"Wang","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-4118-329X","authenticated-orcid":false,"given":"Xiaoyan","family":"Zhang","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1370-822X","authenticated-orcid":false,"given":"Jilun","family":"Hou","sequence":"additional","affiliation":[{"name":"China State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"},{"name":"Hebei Key Laboratory of the Bohai Sea Fish Germplasm Resources Conservation and Utilization, Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao 066100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,10,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1159\/000342009","article-title":"Diversity and plasticity of sex determination and diferentiation in fishes","volume":"7","author":"Kobayashi","year":"2013","journal-title":"Sex. Dev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1159\/000223079","article-title":"Evolutionary perspectives on hermaphroditism in fishes","volume":"3","author":"Avise","year":"2009","journal-title":"Sex. Dev."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Casas, L., Saborido-Rey, F., Ryu, T., Michell, C., Ravasi, T., and Irigoien, X. (2016). Sex change in clownfish: Molecular insights from transcriptome analysis. Sci. Rep., 6.","DOI":"10.1038\/srep35461"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1139\/cjz-2012-0272","article-title":"Reproductive strategies in hermaphroditic gastropods: Conceptual and empirical approaches","volume":"91","author":"Nakadera","year":"2013","journal-title":"Can. J. Zool."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"960","DOI":"10.1093\/biolre\/ioad036","article-title":"A case of hermaphroditism in the gonochoristic sea urchin, Strongylocentrotus purpuratus, reveals key mechanisms of sex determination","volume":"108","author":"Pieplow","year":"2023","journal-title":"Biol. Reprod."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/S0044-8486(02)00057-1","article-title":"Sex determination and sex differentiation in fish: An overview of genetic, physiological, and environmental influences","volume":"208","author":"Robert","year":"2002","journal-title":"Aquaculture"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1093\/oxfordjournals.jhered.a111246","article-title":"Male sex reversal in gynogenetic XX females of common carp Cyprinus carpio L. by a recessive mutation in a sex-determining gene","volume":"83","author":"Komen","year":"1992","journal-title":"J. Hered."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3042","DOI":"10.1210\/en.2017-00156","article-title":"New Insights Into the Role of Estrogens in Male Fertility Based on Findings in romatase-Deficient Zebrafish","volume":"158","author":"Tang","year":"2017","journal-title":"Endocrinology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4756","DOI":"10.3390\/md12094756","article-title":"Mugilid fish are sentinels of exposure to endocrine disrupting compounds in coastal and estuarine environments","volume":"12","author":"Bizarro","year":"2014","journal-title":"Mar. Drugs"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.1126\/science.1176013","article-title":"Mutations in two independent pathways are sufficient to create hermaphroditic nematodes","volume":"326","author":"Baldi","year":"2009","journal-title":"Science"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"111814","DOI":"10.1016\/j.plantsci.2023.111814","article-title":"Sex determination in papaya: Current status and perspectives","volume":"335","year":"2023","journal-title":"Plant Sci."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Senthilkumaran, B., and Kar, S. (2021). Advances in Reproductive Endocrinology and Neuroendocrine Research Using Catfish Models. Cells, 10.","DOI":"10.3390\/cells10112807"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1530\/JOE-19-0384","article-title":"The P450 side-chain cleavage enzyme Cyp11a2 facilitates steroidogenesis in zebrafish","volume":"244","author":"Li","year":"2020","journal-title":"J. Endocrinol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1016\/j.marpolbul.2017.06.027","article-title":"Transcription of ribogenesis genes in fish gonads: Applications in the identification of stages of oogenesis and in environmental monitoring of intersex condition","volume":"121","author":"Valencia","year":"2017","journal-title":"Mar. Pollut. Bull."},{"key":"ref_15","first-page":"1939","article-title":"Induction of XX pseudo-males, and larger-scale reproduction of all-female population in yellow catfish","volume":"12","author":"Liu","year":"2022","journal-title":"Acta Hydrobiol. Sin."},{"key":"ref_16","first-page":"94","article-title":"Expression characteristics and function of Anti-M\u00fcllerian hormone receptor II gene (amhr2) in Paralichthys olivaceus","volume":"1","author":"Li","year":"2024","journal-title":"J. Thorac. Oncol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Hattori, R.S., Kumazawa, K., Nakamoto, M., Nakano, Y., Yamaguchi, T., Kitano, T., Yamamoto, E., Fuji, K., and Sakamoto, T. (2022). Y-specific amh allele, amhy, is the master sex-determining gene in Japanese flounder Paralichthys olivaceus. Front. Genet., 13.","DOI":"10.3389\/fgene.2022.1007548"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"718","DOI":"10.1007\/s10126-023-10235-2","article-title":"Sex-Associated SNP Confirmation of Sex-Reversed Male Farmed Japanese Flounder Paralichthys olivaceus","volume":"25","author":"Maekawa","year":"2023","journal-title":"Mar. Biotechnol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/(SICI)1098-2795(200005)56:1<1::AID-MRD1>3.0.CO;2-3","article-title":"Aromatase inhibitor and 17a-methyltestosterone cause sex-reversal from genetical females to phenotypic males and suppression of P450 aromatase gene expression in Japanese flounder (Paralichthys olivaceus)","volume":"56","author":"Kitano","year":"2000","journal-title":"Mol. Reprod. Dev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"i884","DOI":"10.1093\/bioinformatics\/bty560","article-title":"Fastp: An ultra-fast all-in-one FASTQ preprocessor","volume":"34","author":"Chen","year":"2018","journal-title":"Bioinformatics"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1754","DOI":"10.1093\/bioinformatics\/btp324","article-title":"Fast and accurate short read alignment with Burrows-Wheeler transform","volume":"25","author":"Li","year":"2009","journal-title":"Bioinformatics"},{"key":"ref_22","first-page":"11.10.1","article-title":"From FastQ data to high confidence variant calls: The Genome Analysis Toolkit best practices pipeline","volume":"11","author":"Carneiro","year":"2013","journal-title":"Curr. Protoc. Bioinform."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1086\/519795","article-title":"PLINK: A tool set for whole-genome association and population-based linkage analyses","volume":"81","author":"Purcell","year":"2007","journal-title":"Am. J. Hum. Genet."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2156","DOI":"10.1093\/bioinformatics\/btr330","article-title":"The variant call format and VCFtools","volume":"27","author":"Danecek","year":"2011","journal-title":"Bioinformatics"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"508","DOI":"10.1016\/j.bbrc.2004.07.162","article-title":"Sexually dimorphic expression of a teleost homologue of M\u00fcllerian inhibiting substance during gonadal sex differentiation in Japanese flounder, Paralichthys olivaceus","volume":"322","author":"Yoshinaga","year":"2004","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1126\/science.179.4069.180","article-title":"Unisexual fish: Laboratory synthesis of a \u201cspecies\u201d","volume":"179","author":"Schultz","year":"1973","journal-title":"Science"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"306","DOI":"10.1289\/ehp.1002555","article-title":"The consequences of feminization in breeding groups of wild fish","volume":"119","author":"Harris","year":"2011","journal-title":"Environ. Health Perspect."},{"key":"ref_28","first-page":"963","article-title":"Genetic diversity analysis of the offshore Japanese flounder (Paralichthys olivaceus) population within Qinhuangdao, China","volume":"19","author":"Ma","year":"2012","journal-title":"Jersey Financ. Serv. Comm."},{"key":"ref_29","first-page":"453","article-title":"Annual cycle change of sex steroid hormones in cultured Paralichthys olivaceus","volume":"4","author":"Sun","year":"2013","journal-title":"Mar. Fish."},{"key":"ref_30","unstructured":"Hoar, W., and Randall, D. (1969). Sex differentiation. Fish Physiology, Academic Press."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Sundaray, J.K., Rather, M.A., Kumar, S., and Agarwal, D. (2021). Estrogenic Regulation of Reproduction in Teleosts. Recent Updates in Molecular Endocrinology and Reproductive Physiology of Fish, Springer.","DOI":"10.1007\/978-981-15-8369-8"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Nieschlag, E., and Behre, H.M. (1998). The role of testosterone in spermatogenesis. Testosterone, Springer.","DOI":"10.1007\/978-3-642-72185-4"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1210\/er.2010-0013","article-title":"The molecular biology, biochemistry, and physiology of human steroidogenesis and its disorders","volume":"32","author":"Miller","year":"2011","journal-title":"Endocr. Rev."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2194","DOI":"10.1016\/S0140-6736(17)31431-9","article-title":"Congenital adrenal hyperplasia","volume":"390","author":"Arlt","year":"2017","journal-title":"Lancet"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.beem.2014.11.002","article-title":"Substitution therapy in adult patients with congenital adrenal hyperplasia","volume":"29","author":"Reisch","year":"2015","journal-title":"Best Pract. Res. Clin. Endocrinol. Metab."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.theriogenology.2019.07.020","article-title":"Androgen signaling in male fishes: Examples of anti-androgenic chemicals that cause reproductive disorders","volume":"139","author":"Golshan","year":"2019","journal-title":"Theriogenology"}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/20\/2948\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:12:23Z","timestamp":1760112743000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/20\/2948"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10,12]]},"references-count":36,"journal-issue":{"issue":"20","published-online":{"date-parts":[[2024,10]]}},"alternative-id":["ani14202948"],"URL":"https:\/\/doi.org\/10.3390\/ani14202948","relation":{},"ISSN":["2076-2615"],"issn-type":[{"type":"electronic","value":"2076-2615"}],"subject":[],"published":{"date-parts":[[2024,10,12]]}}}