Key points are not available for this paper at this time.
been made in the identification and characterization ohhe specific DNA binding factors that interact with these two classes of regulatory elements.Most recently distant sequences have been identified that may exert their regulatory effect by structural changes in large chromatin domains,IIt is not possible to provide a comprehensive account of these advances in a review of this size.We have, therefore, summarized some essential fi ndings from past investigations and emphasized results of recent studies that we believeliUustrate the important conclusions.There is every reason to assume that the principles governing;control of the globin genes are appli cable to other gene families as welt.n CIS ELEMENTS AND GLOBIN GENE REGULATION Globin Cluster Or.ganizationWe begin by considering the chromosomal organization of the ry, and p globin loci (see Bunn those at the 3' end are expressed latest For example, the human p locus (Figure 1) is arranged in the order embryonic (e), fetal (Gy, Ay), adult ((t locus occurred ,before the AV' es/ Mammalia ;di�t:rgl:!tlce(GMdnhlhleNil ,W8'tJ,7 and'the mechanisms govern� ,
Evans et al. (Thu,) studied this question.