ANALYSIS OF THE DEVELOPMENTAL AND TRANSCRIPTIONAL POTENTIATION FUNCTIONS OF 5'HS2 OF THE MURINE BETA-GLOBIN LOCUS-CONTROL REGION IN TRANSGENIC MICE

We analyze the role of 5'HS2 of the mouse beta-globin LCR in the trans criptional and developmental regulation of beta-globin gene expression . Previous studies have shown that the human beta-globin gene behaves as an adult gene in transgenic mice, being expressed in fetal liver an d bone marrow-derived erythroblasts but not in yolk sac-derived embryo nic erythroid cells. We show that linkage of mLCR5'HS2 to a human beta -globin gene alters this pattern of expression during ontogeny, result ing in expression of the linked beta-globin gene at all stages of muri ne erythroid development. Expression was independent of integration po sition and correlated with transgene copy number. Our results provide the first test of a phylogenetically homologous LCR in transgenic mice and demonstrate evolutionary conservation of both developmental and t ranscriptional potentiation functions between mammalian beta-globin LC Rs. (C) 1994 Academic Press, Inc.