Genetic Control of Gonadotrop Differentiation in the Platyfish, Xiphophorus maculatus (Poeciliidae)

Science  17 Aug 1973:
Vol. 181, Issue 4100, pp. 678-680
DOI: 10.1126/science.181.4100.678


A sex-linked gene controlling the age at which the gonadotrops of the pituitary gland differentiate has been discovered in Xiphophorus maculatus. Males homozygous for early differentiation become sexually mature between 10 and 16 weeks; those homozygous for late maturation between 22 and 40 weeks. Heterozygotes are intermediate. Since growth rate decreases when testes mature. the two classes of males differ significantly in adult size.