Meeting Abstract
Androgenic hormones act through androgen receptors (AR) to mediate many physiological processes in vertebrates. While the prevailing dogma is that ARs are expressed in nearly all nucleated cells, few studies have tested this idea to determine how the potential for androgenic signaling differs across peripheral tissues. Even less understood is how co-factors that interact with AR can act as dynamic rheostats to increase or decrease the capacity for androgenic signaling in tissues that perform diverse functions. Thus, little is known about how androgenic signaling capacity differs at the tissue and species level. We address these two questions by using two oscine passerines (northern cardinal and white-breasted nuthatch) and one sub-oscine passerine (blue-crowned manakin). Our findings not only show that AR expression differs among species, but there is also substantial variation among tissues. Meanwhile, our findings are consistent with the long-standing notion that AR is expressed in most tissues, but most enriched in tissues that perform essential reproductive functions. Additionally, co-factor expression differs between tissues. Tissue-level differences in co-factor expression likely provide alternative routes to modulate androgen targets outside of increased receptor sensitivity. Taken together, we provide the first detailed description that nearly all tissues across the body exhibit the capacity for androgen signaling, with substantial variation between species and tissues. We suspect that such variation is a product of different selection regimens, including sexual selection and drift, shaping androgenic signaling mechanisms in peripheral tissues.
