Sex differences in neurological and psychiatric disorders are pervasive, with just about any disease involving the brain featuring skewed sex ratios. Most sex differences in physiology and disease are caused by sex hormones originating from the testes or ovaries. However, we have discovered that certain sex differences are also influenced by genes located on the sex chromosomes, which act independently of the gonads. In this presentation, I will discuss rodent models that have been developed to enhance our understanding of the factors contributing to sex bias in physiology. Additionally, I will outline a strategy for investigating the effects of sex chromosomes on disease phenotypes in mice. Among these models, I will introduce the Four Core Genotypes model, where the type of gonad (testes or ovaries) in an animal is independent of its complement of sex chromosomes (XX or XY). This model allows comparing mice that have different sex chromosomes but the same type of gonad, to find traits that are influenced by the complement of sex chromosomes.
Arthur P. Arnold (AB, Grinnell College; PhD, The Rockefeller University) studies mechanisms causing sex differences in physiology and disease. His research has included the discovery of large structural sexual dimorphisms in the CNS, development of several animal models for studying sex differences, and studies of mechanisms by which sex-biasing factors operate, including sex chromosome effects. He is Distinguished Research Professor in the Department of Integrative Biology & Physiology at UCLA, and a fellow of the AAAS and the John Simon Guggenheim Memorial Foundation. Dr. Arnold was founding President of the Society of Behavioral Neuroendocrinology, and received its Lehrman Lifetime Achievement Award in 2010. He was co-founder of the Organization for the Study of Sex Differences and was founding Editor-in-Chief of OSSD’s journal, Biology of Sex Differences.