Genetic determinants of respiratory phenotypes in mice

Individual variation in breathing pattern has been recognized for over a century and a half, but only recently have we been able to assign specific genetic determinants that regulate this variation. An understanding of these potential genetic determinants is on the horizon with the eventual sequencing of genomes from different mammalian species, including mouse and human genomes. Given that breathing characteristics are obviously complex traits, the interactions between various genetic determinants are numerous and evolve from different regulatory pathways. In a simple model system of mammalian respiration, genes that regulate neural pathways must interact with genes that regulate lung function. These gene interactions are then subject to serving the maintenance of metabolic homeostasis. The purpose of this chapter is to explore different breathing characteristics in inbred mice, and to query the role of lung mechanics in regulating variation in the magnitude and pattern of breathing. Specifically, we address the hypothesis implicating genetic determinants that regulate differential breathing phenotypes in certain mouse strains may evolve from factors controlling variation in lung mechanics.