与淋病鱼不同,性腺分化后性别是固定的(主要性别决定),雌雄同体鱼种的成虫可以改变性别(第二性决定)。雌雄同体鱼类的第二性决定主要集中在性别改变过程中睾丸组织和卵巢组织之间的差异。然而,尚未进行独立分析卵巢组织或睾丸组织的综合研究。雌雄同体的黑猪显示出digonic性腺(卵巢组织,睾丸组织被结缔组织隔开)。在前两个生殖周期(<2岁)中,Protandrous黑鸽具有稳定的雄性,在第三个生殖周期中,大约50%进入女性(自然性别变化)。在雌二醇-17β(E2)诱导的女性期(卵母细胞维持在初级卵母细胞期)中很少观察到早熟女性,在<2岁的鱼中,E2被撤回后,发现了可逆的女性与男性的性别变化。然而,在<2岁的鱼中,在睾丸切除的鱼中观察到早熟的雌性(卵母细胞进入卵黄形成卵母细胞阶段)。我们使用该特征通过转录组学分析研究卵巢组织中的第二性决定(女性)。细胞增殖分析表明,在非产卵季节(手术后2个月),与对照组(假)鱼(雄性)相比,睾丸切除鱼(雌性)中掺入BrdU(5-溴-2'-脱氧尿苷)的种系细胞显着增加。qPCR分析表明,在垂体和卵巢类固醇生成相关因子中,垂体释放激素(lhb和gtha)没有差异(star,cyp11a1、hsd3b1和cyp19a1a)或女性相关基因(wnt4a,bmp15,gdf9,figla,和foxl2)在完整和睾丸切除鱼之间的卵巢组织中(手术后2个月)。术后2个月发现垂体fshb和卵巢cyp17a1低表达。然而,通过转录组学分析(手术后1个月),我们确实发现了少量基因(289个基因)在两组中显示性命运双态表达.通过qPCR进一步检查这些差异表达基因的表达谱。我们目前的工作确定了卵巢组织中的几个候选基因,这些基因可能与黑猪的第二性决定(女性)的早期有关。数据证实了我们先前的建议,即睾丸组织在黑头猪的第二性决定中起着重要作用。
Unlike gonochoristic fishes, sex is fixed after gonadal differentiation (primary sex determination), and sex can be altered in adults (secondary sex determination) of hermaphroditic fish species. The secondary sex determination of hermaphroditic fish has focused on the differences between testicular tissue and ovarian tissue during the sex change process. However, comprehensive studies analyzing ovarian tissue or testicular tissue independently have not been performed. Hermaphroditic black porgy shows a digonic gonad (ovarian tissue with testicular tissue separated by connective tissue). Protandrous black porgy has stable maleness during the first two reproductive cycles (<2 years old), and approximately 50% enter femaleness (natural sex change) during the third reproductive cycle. Precocious femaleness is rarely observed in the estradiol-17β (E2)-induced female phase (oocytes maintained at the primary oocyte stage), and a reversible female-to-male sex change is found after E2 is withdrawn in <2-year-old fish. However, precocious femaleness (oocytes entering the vitellogenic oocyte stage) is observed in testis-removed fish in <2-year-old fish. We used this characteristic to study secondary sex determination (femaleness) in ovarian tissue via transcriptomic analysis. Cell proliferation analysis showed that BrdU (5-bromo-2\'-deoxyuridine)-incorporated germline cells were significantly increased in the testis-removed fish (female) compared to the control (sham) fish (male) during the nonspawning season (2 months after surgery). qPCR analysis showed that there were no differences in pituitary-releasing hormones (lhb and gtha) in pituitary and ovarian steroidogenesis-related factors (star, cyp11a1, hsd3b1, and cyp19a1a) or female-related genes (wnt4a, bmp15, gdf9, figla, and foxl2) in ovarian tissues between intact and testis-removed fish (2 months after surgery). Low expression of pituitary fshb and ovarian cyp17a1 was found after 2 months of surgery. However, we did find small numbers of genes (289 genes) showing sexual fate dimorphic expression in both groups by transcriptomic analysis (1 month after surgery). The expression profiles of these differentially expressed genes were further examined by qPCR. Our present work identified several candidate genes in ovarian tissue that may be involved in the early period of secondary sex determination (femaleness) in black porgy. The data confirmed our previous suggestion that testicular tissue plays an important role in secondary sex determination in protandrous black porgy.