Characterization, expression, and regulatory effects of nr0b1a and nr0b1b in spotted scat (Scatophagus argus)
Characterization, expression, and regulatory effects of nr0b1a and nr0b1b in spotted scat (Scatophagus argus)
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DOI：
10.1016/j.cbpb.2021.110644
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发表时间：
2021-07-12
影响因子：
2.2
通讯作者：
Li, Guangli
中科院分区：
文献类型：
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作者：
Shi, Hongjuan;Ru, Xiaoying;Li, Guangli
核受体B亚家族成员1(Nr0b1)属于核受体超家族。它在哺乳动物的性别决定、性别分化和性腺发育中起着关键作用。在本研究中，在斑点叉尾虾(Scatophagus Argus)中发现了重复基因nr0b1a和nr0b1b。系统发育和同时性分析表明，与nr0b1a不同，nr0b1b在nrOb1基因复制事件后在几种硬骨鱼中保留，但在其他鱼类、两栖动物、爬行动物、鸟类和哺乳动物中继而丢失。在序列分析中，在斑点Scat Nr0b1a、Nr0b1b和非哺乳动物Nr0b1a/Nr0b1中只发现了1.5个与LxxLL相关的重复基序，与哺乳动物Nr0b1中的3.5个重复基序不同。定量聚合酶链式反应显示，nr0b1a和nr0b1b分别在IV~V期睾丸和II~IV期卵巢中高表达。外源E_2诱导XY斑点猴雌雄反转。定量聚合酶链式反应分析表明，性别反转的XY鱼的nr0b1b基因表达水平高于对照XY鱼，而nr0b1a的表达水平无明显差异。荧光素酶分析表明，斑点Scat Nr0b1a和Nr0b1b不单独激活cyp19a1a基因转录。与哺乳动物一样，斑点scat Nr0b1a抑制了Nr5a1介导的cyp19a1a的表达，尽管其N末端只有1.5个LxxLL相关的重复基序，而Nr0b1b则刺激了Nr5a1介导的cyp19a1a转录。这些结果表明nr0b1a和nr0b1b在斑点状卵巢中具有不同的表达模式和调控作用，进一步表明nr0b1b可能通过调节Nr5a1介导的cyp19a1a的表达而参与卵巢发育。
Nuclear receptor subfamily 0 group B member 1 (Nr0b1) belongs to the nuclear receptor (NR) superfamily. It plays critical roles in sex determination, sex differentiation, and gonadal development in mammals. In this study, the duplicated genes nr0b1a and nr0b1b were identified in spotted scat (Scatophagus argus). Phylogenetic and synteny analyses revealed that, unlike nr0b1a, nr0b1b was retained in several species of teleosts after an nrObl gene duplication event but was secondarily lost in other fish species, amphibians, reptiles, birds, and mammals. In a sequence analysis, only 1.5 LXXLL-related repeat motifs were identified in spotted scat Nr0b1a, Nr0b1b, and non-mammalian Nr0b1a/Nr0b1, different from the 3.5 repeat motifs in mammalian Nr0b1. By qPCR, nr0b1a and nr0b1b were highly expressed in testes from stages IV to V and in ovaries from stages II to IV, respectively. Maleto-female sex reversal was induced in XY spotted scat by the administration of exogenous E2. A qPCR analysis showed that nr0b1b mRNA expression was higher in sex-reversed XY fish than in control XY fish, with no difference in nr0b1a. A luciferase assay showed that spotted scat Nr0b1a and Nr0b1b did not individually activate cyp19a1a gene transcription. As in mammals, spotted scat Nr0b1a suppressed Nr5a1-mediated cyp19a1a expression, despite containing only 1.5 LXXLL-related repeat motifs in its N-terminal region, while Nr0b1b stimulated Nr5a1 -mediated cyp19a1a transcription. These results demonstrated that nr0b1a and nr0b1b in spotted scat have distinct expression patterns and regulatory effects and further indicate that nr0b1b might be involved in ovarian development by regulating Nr5a1-mediated cyp19a1a expression.