Regulation of globin gene expression at the molecular level.

(1) Globin gene regulatory factors, and the DNA sites on which they act, are being sought. (2) Positive and negative regulatory factors that influence globin gene expression have been identified. The positive factor(s) is globin gene specific. (3) Assays are being developed using cloned globin genes to (a) purify the positive globin regulatory factor(s) in a cell-free transcription assay, and (b) identify the DNA sites that act as control regions by microinjection of "full-length" and shortened genomic genes into MEL cells. (4) Globin genes from mouse and human thalassemia cells are being studied as models of abnormal globin gene expression.