Characteristics and sex dimorphism of 17β-hydroxysteroid dehydrogenase family genes in the olive flounder Paralichthys olivaceus
Characteristics and sex dimorphism of 17β-hydroxysteroid dehydrogenase family genes in the olive flounder Paralichthys olivaceus
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橄榄鲽牙鲆 17β-羟基类固醇脱氢酶家族基因的特征和性别二态性
DOI：
10.1016/j.jsbmb.2020.105597
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发表时间：
2020
影响因子：
4.1
通讯作者：
You Feng
中科院分区：
文献类型：
--
作者：
Zou Congcong;Wang Lijuan;Zou Yuxia;Wu Zhihao;Wang Wenxiang;Liang Shaoshuai;Wang Ling;You Feng
性类固醇激素在鱼类性别分化、性腺发育和第二性征中起重要作用。橄榄牙鲆是一种重要的经济鱼类，具有明显的两性异形。然而，性激素在比目鱼性行为中的作用机制仍不清楚。本研究共鉴定了比目鱼性激素合成代谢关键酶Hsd 17 b家族10个基因，包括Hsd 17 b3、-4、-7、-8、-9、-10、-12 a、-12 b、-14和-15，Hsd 17 b基因分布在8条染色体上，Hsd 17 b12 a和-12 b分别位于第19和第7染色体上。据推测，这两个基因只是高度相似，而不是来自同一基因的不同转录本。根据结构域和基序分析结果，它们都属于SDR超家族，并含有保守的Hsd 17 b基序TGxxxGxG、PGxxxT、NNAG和YxxxK。氨基酸序列分析表明Hsd 17 b1、-4、-7、-12 a和-14为亲水性蛋白。Hsd 17 b1、-3和-12b蛋白的稳定性较低。Hsd 17 b家族基因在不同组织中的表达模式不同，Hsd 17 b10、-12a和-12b在牙鲆卵巢中高表达。在整个性腺发育过程中，Hsd 17 b3在睾丸中高表达，Hsd 17 b1、-12 a和-12 b在卵巢中高表达，提示它们可能在睾丸睾酮合成或卵巢雌激素合成中起重要作用。Hsd 17 b3活性在I-V期睾丸中均显著高于卵巢（P < 0.05，P < 0.01）。在HEK 293 T细胞中的转染分析显示，Hsd 17 b1和Hsd 17 b3位于细胞质和细胞核中。另外，用三苯氧胺攻击后，精巢中Hsd 17 b3的表达量显著降低（P < 0.01），卵巢中Hsd 17 b3的表达量无显著变化。卵巢组织中Hsd 17 b1的表达在注射氟啶后显著上调（P < 0.05）。这些研究结果介绍了比目鱼Hsd 17 bin亚家族的特点，这有助于我们了解鱼类性腺发育中性类固醇激素的合成调控。
Sex steroid hormones play important roles in fish sex differentiation, gonadal development and secondary sexual characteristics. Olive flounderParalichthys olivaceusis a valuable commercial marine fish species and has marked sexual dimorphism. However, the mechanisms of action of sex hormones in flounder sex are still unclear. In this study, a total of tenHsd17bfamily genes, includingHsd17b3, -4, -7, -8, -9, -10, -12a, -12b, -14and -15, were identified in the flounder, which encoded critical enzymes acting on sex steroid synthesis and metabolism.Hsd17bgenes were distributed on eight chromosomes.Hsd17b12aand -12bwere located on chromosomes 19 and 7, respectively. It was speculated that these two genes were just highly similar rather than different transcripts derived from the same gene. According to the results of domain and motif analyses, they all belonged to the SDR superfamily and contained conservedHsd17bmotifs TGxxxGxG, PGxxxT, NNAG and YxxxK. Analysis of amino acid sequences predicted that Hsd17b1, -4, -7, -12a and -14 were hydrophilic proteins. The stability of Hsd17b1, -3 and -12b proteins was predicted to be low. The variousHsd17bfamily genes differed in tissue expression pattern, andHsd17b10, -12aand -12bwere highly expressed in the flounder ovary. Moreover, throughout gonadal development,Hsd17b3was highly expressed in the testis, andHsd17b1, -12aand -12bwere highly expressed in the ovary, suggesting that they might play an important role in testosterone synthesis in the testis or estrogen synthesis in the ovary. Activities of Hsd17b3 at stages I-V were all significantly higher in the testis than in the ovary (P < 0.05, P < 0.01). Transfection analysis in HEK293T cells showed that Hsd17b1 and -3 were located in both the cytoplasm and nucleus. Additionally, after challenging fish with tamoxifen,Hsd17b3expression level in the testis decreased significantly (P < 0.01), and in the ovary no significant change was observed. Moreover, the expression ofHsd17b1in the ovary was significantly upregulated after injection with flutamide (P < 0.05). These findings introduce the characteristics of the flounderHsd17bin subfamily, which contribute to our understanding of the regulation of sex steroid hormone synthesis in fish gonadal development.