title: Morphology, sex steroid level and gene expression analysis in gonadal sex reversal of triploid female (XXX) rainbow trout (Oncorhynchus mykiss).
abstract: In non-mammalian vertebrates, estrogens and expressions of cyp19a1 and foxl2 play critical roles in maintaining ovary differentiation and development, while dmrt1 and sox9 are male-specific genes in testicular differentiation and are highly conserved. In order to deeply understand the morphological change, sex steroids level and molecular mechanism of triploid female gonadal reversal in rainbow trout, we studied the ovary morphology, tendency of estradiol-17β (E2) and testosterone (T) levels and the relative expressions of dmrt1, cyp19a1, sox9 and foxl2 in juvenile and adult fish. Our results demonstrated that the development of triploid female gonads in rainbow trout went through arrested development, oocytes dedifferentiation, ovary reconstruction and sex reversal finally. During early gonadal development (154-334 days post-fertilization), the expressions of foxl2 and cyp19a1 increased linearly, while expressions of dmrt1 and sox9 were extremely suppressed, and E2 level was higher, while T level was lower. During the mid-to-late period of triploid female gonadal development (574-964 days post-fertilization), the expressions of dmrt1 and sox9 remained high and were very close to the quantity of diploid male genes, and T levels were even reaching diploid male plasma concentrations, while expressions of cyp19a1 and foxl2 were decreased, leading to decrease in E2 level. We realized that the development model of rainbow trout triploid female gonads was extremely rare, and the regulatory mechanism was very special. Genes involved in gonadal development and endogenous estrogens are pivotal factors in fish natural sex reversal.
authors.affiliation: Department of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China.
authors.forename: Gefeng
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China.
authors.forename: Tianqing
authors.initials: T
authors.lastname: Huang
authors.affiliation: Harbin Academy of Agricultural Science, Harbin, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Jin
authors.affiliation: Harbin Academy of Agricultural Science, Harbin, China.
authors.forename: Cunhe
authors.initials: C
authors.lastname: Cui
authors.affiliation: Harbin Academy of Agricultural Science, Harbin, China.
authors.forename: Depeng
authors.initials: D
authors.lastname: Li
authors.affiliation: Harbin Academy of Agricultural Science, Harbin, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Sun
authors.affiliation: Department of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China. hanying_606@163.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Han
authors.affiliation: National and Local Joint Engineering Laboratory of Freshwater Fish Breeding, Heilongjiang Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, China. muzhenbo@163.com.
authors.forename: Zhenbo
authors.initials: Z
authors.lastname: Mu
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics; D004958:Estradiol / Q000097:blood; D005260:Female; D029941:Fish Proteins / Q000235:genetics*; D051858:Forkhead Transcription Factors / Q000235:genetics; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D008297:Male; D017686:Oncorhynchus mykiss / Q000097:blood / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010053:Ovary / Q000033:anatomy & histology / Q000378:metabolism*; D055758:SOX9 Transcription Factor / Q000235:genetics; D012733:Sex Differentiation; D013739:Testosterone / Q000097:blood; D014157:Transcription Factors / Q000235:genetics; D057885:Triploidy
chemical_list: C110547:DMRT1 protein; D029941:Fish Proteins; D051858:Forkhead Transcription Factors; D055758:SOX9 Transcription Factor; D014157:Transcription Factors; D013739:Testosterone; D004958:Estradiol; D001141:Aromatase
keywords: Gene expression; Rainbow trout; Sex reversal; Sex steroid; Triploid