Jiang J Q, Wang D S, Senthilkumaran B, Kobayashi T, Kobayashi H K, Yamaguchi A, Ge W, Young G, Nagahama Y
Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
J Mol Endocrinol. 2003 Oct;31(2):305-15. doi: 10.1677/jme.0.0310305.
The Japanese eel (Anguilla japonica) and Nile tilapia (Oreochromis niloticus) 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) cDNAs were isolated from their respective testes cDNA libraries. The cDNAs predict two peptides of 436 and 406 amino acid residues that share about 42% homology with mammalian 11beta-HSD type 2 proteins. Analysis of the tissue distribution pattern by RT-PCR reveals that 11beta-HSD2 is expressed in a wide variety of tissues in tilapia, with higher expression in kidney and gill of both sexes, and with the highest expression in testis. 11beta-Dehydrogenase activity of the eel 11beta-HSD2 was confirmed by demonstrating the conversion of cortisol to cortisone by the recombinant protein after transient expression of this cDNA clone in COS-1 cells. Bands of approximately 2.7 and approximately 3.8 Kb were detected in Northern blot of eel and tilapia testes respectively, which is consistent with the cloned cDNA sizes of the two species. Northern blot analysis also revealed that the expression of the eel testis 11beta-HSD2 gene could be induced by human chorionic gonadotropin (hCG) injection, implying a role of 11beta-HSD2 in hCG-induced 11-ketotestosterone production and spermatogenesis in the Japanese eel.
从日本鳗鲡（Anguilla japonica）和尼罗罗非鱼（Oreochromis niloticus）各自的睾丸cDNA文库中分离出了11β-羟基类固醇脱氢酶2型（11β-HSD2）的cDNA。这些cDNA预测了由436和406个氨基酸残基组成的两种肽，它们与哺乳动物的11β-HSD2型蛋白具有约42%的同源性。通过RT-PCR分析组织分布模式发现，11β-HSD2在罗非鱼的多种组织中均有表达，在雌雄两性的肾脏和鳃中表达较高，在睾丸中表达最高。在COS-1细胞中瞬时表达该cDNA克隆后，通过证明重组蛋白将皮质醇转化为可的松，证实了鳗鲡11β-HSD2的11β-脱氢酶活性。在鳗鲡和罗非鱼睾丸的Northern印迹中分别检测到约为2.7 kb和约3.8 kb的条带，这与两个物种克隆的cDNA大小一致。Northern印迹分析还显示，注射人绒毛膜促性腺激素（hCG）可诱导鳗鲡睾丸11β-HSD2基因的表达，这意味着11β-HSD2在hCG诱导的日本鳗鲡11-酮睾酮生成和精子发生中发挥作用。
