A High Quality Genome for , a Close Relative of House Mice with Unique Social and Ecological Adaptations.

Genomic data for the closest relatives of house mice ( species complex) are surprisingly limited. Here, we present the first complete genome for a behaviorally and ecologically unique member of the sister clade to house mice, the mound-building mouse, Using read cloud sequencing and assembly we produced a 2.50 Gbp genome with a scaffold N50 of 2.27 Mbp. We constructed >25 000 gene models, of which the majority had high homology to other species. To evaluate the utility of the genome for behavioral and ecological genomics, we extracted 196 vomeronasal receptor (VR) sequences from our genome and analyzed phylogenetic relationships between VRs and orthologs from and the Algerian mouse, While most VRs clustered with orthologs in and , 10 VRs with evidence of rapid divergence in are strong candidate modulators of species-specific chemical communication. A high quality assembly and genome for will help to resolve discordant ancestry patterns in house mouse genomes, and will provide an essential foundation for genetic dissection of phenotypes that distinguish commensal from non-commensal species, and the social and ecological characteristics that make unique.