Kotula-Balak Malgorzata, Zielińska Renata, Glogowski Jan, Kowalski Radosław K, Sarosiek Beata, Bilińska Barbara
Department of Endocrinology and Tissue Culture, Institute of Zoology, Jagiellonian University, Ingardena 6, 30-060 Krakow, Poland.
Comp Biochem Physiol A Mol Integr Physiol. 2008 Feb;149(2):188-96. doi: 10.1016/j.cbpa.2007.11.009. Epub 2007 Nov 28.
The main goal of the present study was to show whether testicular cells of rainbow trout (Oncorhynchus mykiss Walbaum) either hormonally manipulated (XX males) or produced by using gamma irradiation and pressure shock (YY males, "supermales") are able to aromatize androgens into estrogens compared with the control (XY males). The expression of aromatase gene at the level of the protein and its presence in testicular tissue was investigated by means of immunohistochemistry and Western blot analysis, respectively. The positive staining for aromatase was detected in testicular cells of all trout and in efferent duct cells of XY and YY males. However, the staining intensity varied among particular trout, being strong in YY males, moderate in XY males, and weak in XX trout. It was confirmed by quantitative image analysis in which the staining intensity was expressed as relative optical density (ROD) of diaminobenzidine deposits. Significant differences were found between XY and YY trout ((**)p<0.01) and XY and XX trout ((*)p<0.05). Such differences could reflect various levels of estrogens, possibly dependent on the genetic background of the trout studied. It seems likely that differential expression of the enzyme, especially that of weak or strong intensity, causes some alterations in testicular morphology of homogametic trout. Additionally, the results indicate that an imbalance in sex hormone biosynthesis may provoke the functional alterations in testes of YY males, and, in consequence, negatively affect the fertility of "supermales".
本研究的主要目的是表明，与对照组（XY雄性）相比，经激素处理的虹鳟（Oncorhynchus mykiss Walbaum）睾丸细胞（XX雄性）或通过γ射线照射和压力休克产生的睾丸细胞（YY雄性，“超雄”）是否能够将雄激素芳香化为雌激素。分别通过免疫组织化学和蛋白质印迹分析，研究了芳香化酶基因在蛋白质水平的表达及其在睾丸组织中的存在情况。在所有虹鳟的睾丸细胞以及XY和YY雄性的输出管细胞中均检测到芳香化酶的阳性染色。然而，特定虹鳟之间的染色强度有所不同，YY雄性中染色强，XY雄性中染色中等，XX虹鳟中染色弱。通过定量图像分析证实了这一点，其中染色强度表示为二氨基联苯胺沉积物的相对光密度（ROD）。XY和YY虹鳟之间（（**）p<0.01）以及XY和XX虹鳟之间（（*）p<0.05）存在显著差异。这种差异可能反映了雌激素的不同水平，可能取决于所研究虹鳟的遗传背景。似乎这种酶的差异表达，尤其是强弱程度不同，会导致同配性别虹鳟睾丸形态发生一些改变。此外，结果表明性激素生物合成的失衡可能引发YY雄性睾丸的功能改变，进而对“超雄”的生育能力产生负面影响。
