Abstract
Summary
Dwarf mice (Snell) from A dw (Albino-dwarf) stock, in which the thyroid-pituitary axis is abnormal, were injected with pituitary tissue extract from the achondroplastic brachycephalic bovine dwarf mutant, which suffers from achondroplasia but is reported to have a normal thyroid-pituitary axis. Controls were (i) dwarf mice injected with pituitary tissue extract from nonachondroplastic cattle of normal size and (ii) uninjected dwarf mice. The extracts from 2 sources were standardized so that both possessed the same concentration of pituitary tissue. As the weight of dwarf mice neared plateau, they were divided into 3 groups: one received pituitary extract from bovine dwarfs, one received pituitary extract from cattle of normal size, and one was untreated. Body weight response was checked by daily weighing. Injection of pituitary extract from bovine dwarfs stimulated mouse growth significantly, as did extract from normal cattle and the responses were identical. This supports the hypothesis that the bovine dwarf mutant and the mouse dwarf mutant are not homologous.
Get full access to this article
View all access options for this article.