Immunological evidence for progesterone and estradiol receptors in the freshwater crayfish Austropotamobius pallipes

In this article, we present evidencefor progesterone and estradiol receptors (PRand ER, respectively) in the female of the crayfishAustropotamobius pallipes. To our knowledge, this isthe first report of sex steroid receptors in crustaceans.By using immunohistochemistry and Western blottingapproaches and employing three different antibodiesagainst PR (human PR, chicken PR-hinge region, andchicken PR A/B domain) and antibodies againsthuman ER, we showed the presence of PR in theovary and hepatopancreas and ER in the hepatopancreasof the freshwater crayfish A. pallipes. Theimmunological characteristics and the tissue localizationsuggest a relatedness with both PR and ER invertebrates along with their involvement in the modulationof reproductive functions in this crustaceans.