RUI: The Ancestral Modulation Hypothesis: Predicting Hormonal Regulation Of Sex-Biased Traits

Reed College, Portland OR

Investigators

Abstract

This award funds research on the evolutionary and biological basis of physical and behavioral traits that are biased toward male expression or female expression. Understanding the multi-level processes that produce such traits will help explain the diversity of traits that are observed across individuals and species. This project will investigate genetic levels, molecular levels, and physiological levels that contribute to sex-biased traits. By understanding each level, the work will address a general framework for understanding how these processes evolve. In common discourse, description of the vast diversity of traits associated primarily with females or primarily with males is often compromised in the effort to illustrate general biological concepts. Part of this award will produce educational outreach materials to emphasize the full spectrum of natural trait variation across individuals and species. Multiple educational levels will be targeted through outreach to K-12, undergraduate introductory courses, and a Master’s level course. The researchers will address the biological control of physical and behavioral traits that are biased toward male expression or female expression. The work will occur at five different levels of biological organization: global hormone levels, metabolic enzyme levels for converting hormones at the cellular level, hormone receptor levels at the cellular level, the distribution of genomic binding sites for receptors, and the transcriptional response. Two genera of fishes will be used that include evolutionary transitions of phenotype from males to females or vice-versa. Using the evolutionary history of the traits for predictive power, the research will test whether the biological control mechanisms use different pathways based on the ancestral condition of the phenotype. The prediction is that novel traits will use existing mating-type biased pathways while evolutionarily transitioned traits will modify pathways that are typically present in the opposite mating-type. By bridging proximate and ultimate mechanisms, the tested model provides a framework for exploring additional mechanisms for bias and further nuanced phenotypes to better understand the assorted mating-type biased traits in the natural world. This award was co-funded by the Physiological Mechanisms and Biomechanics Program in the Division of Integrative Organismal Systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.