No evidence that estrogens affect the development of the immune system in the red-eared slider turtle, Trachemys scripta

This article is part of a Special Issue “Neuroendocrine-Immune Axis in Health and Disease.”Exposure to maternally derived substances during development can affect offspring phenotype. In ovo exposure to maternally derived steroids has been shown to influence traits such as growth and behavior in the offspring. The development of the immune system also can be altered by exposure to both androgens and glucocorticoids in a variety of species, but much less is known about the potential for estrogens to influence the development of this system. We examined the effect of estradiol on the development of both innate and adaptive immune components in the red-eared slider turtle (Trachemys scripta). A bacterial killing assay was used to assess innate immunity, a delayed-type hypersensitivity test for cellular immunity, and total immunoglobulin levels to measure the humoral immune response. We found no effect of in ovo estradiol treatment on any of our immune measures despite using doses that are known to influence other phenotypic parameters during development and varying the timing of dosing across development. Our results suggest that maternally derived estradiol does not affect the development of the immune system in T. scripta.

► We examined in ovo estradiol exposure on development of immunity in a reptile.
► We assessed both innate and adaptive components of immunity.
► We found no effect of estradiol exposure on any immune measure.
► Variation in yolk estradiol levels is unlikely to influence immunity.