Genome Assembly and Sex Chromosomes in the Gila Monster (Heloderma suspectum)

Webster, Timothy H. School of Life Sciences Arizona State University Tempe, AZ USA

Department of Anthropology University of Utah Salt Lake City UT USA

Denbrock, Grant A. DeNardo, Dale F. School of Life Sciences Arizona State University Tempe, AZ USA

Wilson, Melissa A. School of Life Sciences Arizona State University Tempe, AZ USA

Center for Evolution and Medicine Arizona State University Tempe, AZ USA mwilsons@asu.edu

The Gila Monster (Heloderma suspectum) is one of the Desert Southwest’s most iconic animals. In coping with the environmental extremes of the desert environment, the Gila Monster uses a unique suite of adaptations. This makes them particularly valuable for understanding evolutionary processes. Unfortunately, potential work has been limited by the lack of an available genome for this species. Here, we describe our efforts to generate a draft reference genome for the Gila Monster and undertake population and comparative genomic analyses. By sequencing and analyzing the Gila Monster genome, we will contribute critical knowledge and resources that will not only promote the conservation of the species, but enable the Gila Monster to become an effective study system for addressing broad questions regarding evolutionary processes associated with adapting to challenging environments. As an example of our ongoing work, we highlight a detailed assessment of the Gila Monster sex chromosomes. Both XX/XY and ZZ/ZW sex determination is present within the squamate (lizards and snakes) clade, and phylogenetically Gila Monsters are ideally located to aid in our understanding of the evolution of squamate sex determination. Our results give insight into the evolutionary history of sex chromosomes and sex determination not only in Gila monsters but also across other squamates.