Presentation description

Fluid gender identity, the change over time in a person's gender expression, is prevalent topic within the last decade. While gender identity and its fluidity are likely unique to humans, we can study animal sex plasticity. In humans and other mammals, it is believed that gonadal sex is innate and determined early in development by factors stemming from chromosomal inheritance. It is not influenced by the environment. However, sexual differentiation of the brain (masculinization) appears to result from hormonal and other possible influences later in life. In many fishes, gonadal and behavioral sex determination is regulated by their social environment, and gender plasticity extends throughout life. Fish, therefore, are excellent systems for investigating the physiological mechanisms that underlie how social and environmental information shapes the sexual differentiation of the brain. This research program and project address the general question of how sexual differentiation of brains is specified and its effects on gender behavior. We study bluehead wrasses (Thalassoma bifasciatum), which have emerged as a model for addressing brain mechanisms of plasticity in behavioral sex phenotypes. By knowing the mechanisms that underlie behavioral sex transformation in the bluehead wrasse, we hope to further our understanding of how the environment influences gender fluidity in other organisms, possibly including humans.