To investigate the effects of bonding experiences on the transcriptome of monogamous P. californicus in the lungs. Our results indicated that the lung transcriptomes of Peromyscus californicus are altered in a manner that depends on pair bonding. Pathways affected include hypoxia response and heart development. Overall design: Comparative gene expression profiling analysis of RNA-Seq data. RNA was isolated from bonded, bond-disrupted, and virgin lung tissues.