Influence of Bisphenol A and 17β‐Trenbolone Exposure in Oryzias Congeners

摘要

Japanese medaka is specified as a model fish in the test guidelines of the Organisation for Economic Co‐operationand Development. Recently, populations of Japanese medaka in Japan were divided into two species, the northern Oryziassakaizumii and the southern O. latipes. Previously, we reported that induction concentrations for sex reversal by exposure to17α‐methyltestosterone differed significantly between these two species, indicating that they respond differently toendocrine‐disrupting chemica. In the present study, we examined the effects of exposure to two more endocrine‐disruptingchemicals (bisphenol A and 17β‐trenbolone) in O. sakaizumii, and compared the results with those previously reported forO. latipes. Exposure to both bisphenol A and 17β‐trenbolone induced testis–ova formation or sex reversal in O. sakaizumii.Exposure to 17β‐trenbolone also increased expression of gonadal soma‐derived factor (gsdf). Least‐observed‐effect concentrationsfor gonadal sex differentiation and gsdf expression were lower for O. latipes than for O. sakaizumii after exposureto bisphenol A, and were lower for O. sakaizumii than for O. latipes after exposure to 17β‐trenbolone. These resultsdemonstrate that O. sakaizumii and O. latipes respond differently to androgenic and estrogenic endocrine‐disruptingchemicals.