Transcriptional Control of Pituitary Gene Expression

Abstract

Cascades of interacting regulatory genes controlling developmental pathways have been defined in organisms such as Drosophila (Chalfie and Au, 1989; Cohen and Jurgens, 1991; Gehring, 1987; Ingham, 1988; Ingham and Martinez Arias, 1992; Moses, 1991; Nusslein-Volhard and Wieschaus 1980; Nusslein-Volhard et al., 1987; Perkins and Perrimon, 1991; St. Johnston and Nusslein-Volhard, 1992) and the nematode Caenorhabditis elegans (Davidson, 1990; Sternberg and Horvitz, 1991). The developmental regulators include transcription factors, kinases, phosphatases, growth factors, receptors, and cell-adhesion molecules. In Drosophila, products of maternally expressed genes control expression of zygotic segmentation genes, the products of which regulate homeotic gene expression; regulation is also exerted between genes of the same class. As a result the embryo is divided into a meshwork of metameric units, each expressing a unique combination of homeotic genes. These genes contain a conserved homeobox, encoding a 60-amino-acid home-odomain that functions in DNA binding. By acting as transcription factors, the homeodomain proteins orchestrate activation of a unique combination of target genes that causes the cells to enter a specific morphogenetic pathway.KeywordsGrowth HormonePituitary CellThyroid Hormone ReceptorGrowth Hormone GeneCombine Pituitary Hormone DeficiencyThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.