Morphological and Functional Alterations in Testes and Efferent Ducts of Homogametic Rainbow Trout Oncorhynchus mykiss Walbaum
In the present study we analyzed the morphology of testes and efferent ducts as well as the localization of androgen receptors (AR) in the tissues of XY, YY, and XX male rainbow trout Oncorhynchus mykiss Walbaum. Testes of the XX trout differed distinctly from those of XY and YY males; the interstitial space was very narrow and lumina of the tubules were densely filled with spermatozoa. There was no efferent duct. The nuclei of Leydig cells and endothelial cells of blood vessels were positively stained for AR, and this was confirmed by quantitative image analysis. Differences in the AR immunoexpression levels indicate the differences in the levels of androgens produced by the Leydig cells, possibly based on the chromosomal constitution of the testes concerned.
efferent ducts rainbow trout androgen receptors leydig cells testis immunohistochemistry