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 nr0b1 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. Male-to-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.

核受体亚家族 0 组 B 成员 1 (Nr0b1) 属于核受体 (NR) 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。在这项研究中，重复基因nr0b1a和nr0b1b在斑点粪便( Scatophagus argus ) 中被鉴定出来。系统发育和同线性分析表明，不像nr0b1a，nr0b1b被保留在硬骨鱼的几个种类的后NR0B1基因重复事件，但在其他鱼类、两栖动物、爬行动物、鸟类和哺乳动物中其次丢失。在序列分析中，在斑点粪便 Nr0b1a、Nr0b1b 和非哺乳动物 Nr0b1a/Nr0b1 中仅鉴定了 1.5 个 LXXLL 相关重复基序，与哺乳动物 Nr0b1 中的 3.5 个重复基序不同。通过qPCR，nr0b1a和nr0b1b分别在IV 到V 期的睾丸和II 到IV 期的卵巢中高表达。通过施用外源性 E2，在 XY 斑点粪便中诱导了男性到女性的性别逆转。qPCR 分析表明，性逆转 XY 鱼的nr0b1b mRNA 表达高于对照 XY 鱼，而nr0b1a没有差异. 荧光素酶测定表明，斑点粪便 Nr0b1a 和 Nr0b1b 不会单独激活cyp19a1a基因转录。与哺乳动物一样，斑点粪便 Nr0b1a 抑制 Nr5a1 介导的cyp19a1a表达，尽管其 N 末端区域仅包含 1.5 个 LXXLL 相关重复基序，而 Nr0b1b 刺激 Nr5a1 介导的cyp19a1a转录。这些结果表明，斑点粪便中的nr0b1a和nr0b1b具有不同的表达模式和调节作用，进一步表明nr0b1b可能通过调节 Nr5a1 介导的cyp19a1a表达参与卵巢发育。