Chromatin structure and the expression of globin-encoding genes.

The developmental regulation of globin gene expression in the chicken has been studied. All of the genes are regulated by a small number of general erythroid factors. In addition, expression of individual members of the family must be controlled in a lineage (stage)-specific manner. In some cases, the relevant factors may be stage specific, but in others they are not confined to one stage, but exert their control through developmentally regulated changes in their abundance within the nucleus. Chromatin structural elements, such as locus control regions and insulators, are also involved in control of eukaryotic gene expression. Because so much is understood about regulation of individual genes, the globin family has proven valuable in investigating control of transcription at the level of chromatin structure.