Browsing Department of Animal Biology by Subject "11β-Hydroxylase"
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ItemDynamic expression of 11β-hydroxylase during testicular development, recrudescence and after hCG induction, in vivo and in vitro in catfish, Clarias batrachus( 2015-01-05) Rajakumar, Anbazhagan ; Senthilkumaran, BalasubramanianCytochrome P450 11β-hydroxylase (11β-h), is involved in the production of 11-hydroxytestosterone, an immediate precursor for 11-ketotestosterone (11-KT), a potent androgen in teleosts. To understand the role of 11β-h in gonadal development, maturation, function and recrudescence in an annually reproducing teleost, the present study was conducted using Clarias batrachus. Four forms of 11β-h cDNA, regular type (2.253. kb), variant 1 (1.290. kb), variant 2 (1.223. kb) and variant 3 (1.978. kb) were identified from the testis of catfish which expressed ubiquitously with high levels in testis. 11β-h transcripts were detected as early as 0. days post hatch further, stage- and sex-dependent increase in the 11β-h transcripts were seen during gonadal differentiation/development. In addition, high expression of 11β-h (regular type) in pre-spawning phase was detected. Corroboratively, levels of 11-KT in serum and testicular tissue was high during pre-spawning and spawning phases, which might facilitate initiation and normal progression of spermatogenesis. The expression of 11β-h was high after human chorionic gonadotropin induction in vivo (all forms), and in vitro (regular type). Immunohistochemical and immunofluorescence localization showed the presence of 11β-h in Sertoli and interstitial/Leydig cells of the testis. These results suggest that 11β-h is involved in late stages of testicular development, together with the regulation of seasonal reproductive cycle in catfish.
ItemThiourea-induced alteration in the expression patterns of some steroidogenic enzymes in the air-breathing catfish Clarias gariepinus( 2005-04-01) Rasheeda, M. K. ; Sreenivasulu, G. ; Swapna, I. ; Raghuveer, K. ; Wang, D. S. ; Thangaraj, K. ; Gupta, A. D. ; Senthilkumaran, B.Previous study from our laboratory on thiourea-induced thyroid hormone depletion in mature male catfish demonstrated that thyroid hormones play a significant role in testicular function. In the present study, we aimed to analyze the changes in the expression pattern of several steroidogenic enzyme genes after thyroid hormone depletion using semi quantitative RT-PCR in both adult male and female catfish. There was a marked decrease in the 11 β-hydroxylase expression in the testis and liver while no change was observed in case of kidney. A significant decrease in 11 β-hydroxysteroid dehydrogenase transcript level in testis, liver and kidney were observed in the thiourea treated males. The results obtained corroborated with our earlier findings of testicular regression after thyroid hormone depletion. In females, expression of aromatase transcript increased in experimental group compared to control. There was no considerable change observed in the transcript level of 3β-hydroxysteroid dehydrogenase, P450 17α-hydroxylase/C17-20-lyase, and 20β-hydroxysteroid dehydrogenase in both males and females. Thus, thyroid hormones might exert modulating effect on steroidogenic enzyme genes at the transcription level. © Springer Science+Business Media B.V. 2006.