Both locus control region and proximal regulatory elements direct the developmental regulation of beta-globin gene cluster

Using ligation-mediated PCR and in vivo footprinting methods to study the s tatus of DNA-protein interaction at hypersensitive site 2 of locus control region and beta(maj) promoter of erythroid cells of fetal liver and adult b one marrow we found that during different developmental periods, the status of DNA-protein interaction at both hypersensitive site 2 and beta(maj) pro moter changed significantly, and indicated that locus control region might function through a looping mechanism to regulate the expression of downstre am genes, and that distal regulatory elements (locus control region, hypers ensitive sites) as well as proximal regulatory elements (promoter enhancer) of beta-globin gene cluster participate in the regulation of developmental specificity. (C) 2000 Wiley-Liss, Inc.