Diverse effect of in ovo treatment with metaloestrogen: selenium on chick testis histology and estrogen signaling

With the observed in the last years increasing disruption of poultry males’ fertility, there is a need to improve knowledge on the morphology and functioning of the avian reproductive system. A number of molecular and endocrine interrelationships indicate that testicular dysfunction may be one of the reasons for the production of poor semen quality. Because selenium (Se) is known to be an essential element for spermatogenesis, thus the aim of the present study was to determine the effect of Se treatment in ovo on cellular and molecular status (expression of aromatase, estrogen receptors and estrogen level) of testes of chicks. The study was performed on chick embryons exposed to Se at a dose of 0.6 µg/egg. We revealed diverse changes in testis histology after Se-treatment including developmental changes reflected by cell migration or vacuolization of the marginal stroma. We showed for the first time the expression of GPER in the testes of chicks and changes in the expression of aromatase, GPER, ERα and ERβ after treatment with Se. Simultaneously with these, decreased testicular estradiol concentration indicated an altered receptor protein and/or binding by Se only to GPER, ERα that in turn affects hormone concentration and action. Further studies are needed to evaluate other effects of Se supplementation especially of immature birds or mature ones and eggs laying by them per se.