Genetics of evolved load resistance in the skeletons of unusually large mice from Gough Island

Researchers have uncovered the genetic basis for extreme skeletal load resistance in the largest wild house mice on record, found on Gough Island. Unlike laboratory studies that typically focus on one or two bones, this study analyzed seven bones—femur, tibia, scapula, humerus, radius, ulna, and mandible—in 760 mice from a cross between Gough Island mice and a smaller mainland strain. The findings reveal 153 quantitative trait loci (QTL) associated with load resistance, distributed across nearly all chromosomes, with minimal overlap with QTL for bone length, width, or body weight. Notably, these mice exhibit bone geometries that enhance load resistance without increased bone mineral density, suggesting distinct evolutionary adaptations. This study provides a rare genetic portrait of how natural selection shapes skeletal structure in extreme environments.

Payseur, B. A., Anderson, S., James, R. T., Parmenter, M. D., Gray, M. M., & Vinyard, C. J. (2023). Genetics of evolved load resistance in the skeletons of unusually large mice from Gough Island. Genetics, 225(1). https://doi.org/10.1093/genetics/iyad137