Abstract
Sex differences in the lifetime risk and expression of disease are well-known. Paradoxically, preclinical research targeted at improving treatment, increasing health span and reducing the financial burden of health care, has mostly been conducted on male animals and cells. Females are assumed to be the same or scaled versions of males, yet sex differences in the allometric relationship between phenotypic traits and body size, needed to evaluate the validity of this assumption, have not been established. We quantify allometry for 297 phenotypic traits in male and female mice, recorded in >2.1 million measurements from the International Mouse Phenotyping Consortium. We find sex differences in allometric parameters (slope, intercept, residual SD) are common. Thus, the allometric relationship varies between the sexes: females are not scaled males. Our results support a complex, trait-specific patterning of sex differences in phenotypic traits, promoting case-specific approaches to therapeutic intervention and drug dosage scaled by body weight.
Competing Interest Statement
The authors have declared no competing interest.