Blood, 1 February 2002, Vol. 99, No. 3, pp. 1082-1084
BRIEF REPORT
Regulation of fetal versus embryonic gamma globin genes:
appropriate developmental stage expression patterns in the
presence of HS2 of the locus control region
Timothy Yu,
David M. Thomas,
Wei Zhu,
Morris Goodman, and
Deborah L. Gumucio
From the Department of Cell and Developmental Biology,
University of Michigan Medical School, Ann Arbor, and the Department of
Anatomy and Cell Biology, Wayne State Medical School, Detroit, MI.
The 
genes provide the major contribution to beta-like
globin chain production in the fetal liver of humans. However, the expression of genes in the fetus is a recent evolutionary trend seen only in the primate lineage. In a previous study, it was shown
that galago and human genes retain their characteristic stage-specific expression patterns in transgenic mice (galago is
expressed exclusively in the embryo, whereas human is expressed in
the fetus). In that experiment, human and galago genes were linked
to hypersensitive site 3 (HS3) of the locus control region. To rule out
the possibility that HS3 is required for these differential expression
profiles, additional transgenic lines were tested in which human or
galago genes were linked to HS2. Once again, the galago gene
was embryonic and the human gene was fetal, indicating that the
stage specificity of these genes is driven by elements located within
the 4-kb fragments that contain the human and galago genes proper.
