Donald D. Brown
Carnegie Institution for Science
Election Year: 1973
Primary Section: 22, Cellular and Developmental Biology
Membership Type: Member
The life cycle of a frog includes a tadpole stage. The transition from tadpole to frog is called metamorphosis and is controlled by the hormone thyroxine. The newly feeding tadpole forms a thyroid gland that gradually produces increasing amounts of thyroid hormone which in turn sequentially triggers the many changes involved in the transition to an adult frog. The thyroid hormone works by controlling gene expression. It does so by binding to a protein receptor which can activate a specific set of genes and influence their expression. We are studying the genes involved in several of the various developmental programs of metamorphosis, especially cell death in the tadpole tail.