Socorro, S.Martins, Rute S. T.Deloffre, Laurence A. M.Mylonas, Constantinos C.Canario, Adelino V. M.2014-05-092014-05-092007Socorro, Silvia; Martins, Rute S.T.; Deloffre, Laurence A.M.; Mylonas, Constantinos C.; Canario, Adelino V. M. A cDNA for European sea bass (Dicentrachus labrax) 11 beta-hydroxylase: Gene expression during the thermosensitive period and gonadogenesis, General and Comparative Endocrinology, 150, 1, 164-173, 2007.0016-6480AUT: ACA00258;http://hdl.handle.net/10400.1/3817Steroid P450 11 -hydroxylase, encoded by the CYP11B gene, is a key mitochondrial enzyme for the production of 11-oxygenated androgens, which have been shown to be potent masculinising steroids in several Wsh species. In this study we have isolated a CYP11B cDNA of 1903 base pairs from the testis of European sea bass (Dicentrarchus labrax) encoding a predicted protein of 552 amino acids. The amino acid identities to other vertebrate 11 -hydroxylase proteins ranged from 66% to 72% to other Wsh; 45% to amphibian and 35–39% to mammalian. Southern blot indicated that a single CYP11B gene is present. Northern blot analysis detected two transcripts in testis and head kidney, one of the same size of the isolated clone and the other of 3.9 kb. Reverse transcriptase-polymerase chain reaction showed abundant mRNA expression only in testis and head kidney, being residual in a range of other tissues. Expression of CYP11B and CYP19A (which encodes for ovarian aromatase) was detected from at least 4 days post-hatching and did not appear to be aVected by rearing temperature (15 and 20 °C) during the Wrst 60 days, a period in which high temperatures promote masculinisation in European sea bass. Throughout, gonadogenesis (60–300 dph), a highly dimorphic pattern of CYP11B expression was consistent with a role of this gene in testicular development.engCYP11BDicentrarchus labraxAromatase11 -HydroxylaseTemperatureSex diVerentiationAndrogensCYP19Ajournal article2014-05-08http://dx.doi.org/10.1016/j.ygcen.2006.07.018