Rabbit Genetic Resources Can Provide Several Animal Models to Explain at the Genetic Level the Diversity of Morphological and Physiological Relevant Traits

The rabbit (Oryctolagus cuniculus) is a unique multipurpose domestic species that has relevant economic impacts in several contexts. This review is focused on rabbit genetic resources that have been mainly bred for the fixation of differentiating features (e.g., exterior traits) that have been already genetically characterized. Several naturally occurring rabbit mutants could be useful as animal models for the investigation of the biological mechanisms determining their characterizing aspects, with translational potentials. A historical overview of the origin of the domesticated rabbit populations and of their genetic differentiation into many breeds is summarized. Then, a detailed analysis of the genetic features that characterize the different breeds is reported, starting from coat color and coat structure affecting genes (MC1R, ASIP, TYR, MLPH, TYRP1, KIT, LIPH, and FGF5), determining major loci described by classical genetic studies. Mutations in these genes have implications in pigmentation features, hair growth, and related defects. Other gene mutations affecting body size or shapes (HMGA2) and other physiological disfunctions (RORB and BCO2) are also described Additional studies are needed to complete the genetic characterization of some of these loci and to investigate the large genetic variability available in fancy breeds and commercial meat and fur lines.