Abstract
The pattern of inheritance indicates that the gene for aconitase-1 is sex linked in the frog, Rana clamitans, and that the male is the heterogametic sex. Unlike mammals, both male and female frogs carry and express two alleles for this sex-linked gene. Therefore, the sex chromosomes in these frogs and probably others behave like an autosomal pair, with one homologue carrying a male-determining element.