It should be noted that many of the mapping studies claiming sex effects in model organisms suffer from the same limitations as those described above for human studies. However, the experimental toolbox available for studies of model organisms allows for a more thorough dissection of sex-specific genetic architecture, which has, in many cases, directly implicated specific genes or chromosomes in genotype–sex interactions. Overall, genotype–sex interaction effects on diverse biological processes are common in model organisms and often account for a significant proportion of the phenotypic variability. The extent of sex-specific genetic architecture in the human genome has yet to be determined, although we predict that humans are similar to other organisms in this respect.
