CHARACTERIZATION AND COMPARISON OF THE HUMAN AND MOUSE DIST1 ALPHA-GLOBIN COMPLEX REVEALS A TIGHTLY PACKED MULTIPLE GENE-CLUSTER CONTAININGDIFFERENTIALLY EXPRESSED TRANSCRIPTION UNITS/
Mf. Kielman et al., CHARACTERIZATION AND COMPARISON OF THE HUMAN AND MOUSE DIST1 ALPHA-GLOBIN COMPLEX REVEALS A TIGHTLY PACKED MULTIPLE GENE-CLUSTER CONTAININGDIFFERENTIALLY EXPRESSED TRANSCRIPTION UNITS/, Genomics, 32(3), 1996, pp. 341-351
In this paper, we describe the detailed analysis of about 75 kb of gen
omic DNA flanking the 5' end of the mouse alpha-globin region and comp
lete the transcription map of the human region. Previously, we establi
shed the homology of the human and mouse alpha-globin upstream flankin
g regions (alpha UFR) and characterized in detail the mouse alpha-glob
in major regulatory element (alpha MRE) and the mMPG DNA repair gene.
Here, we extend our analysis with the construction of a detailed restr
iction map, the mapping and isolation of two nonglobin genes, named mD
ist1 and mProx1, the distribution of 18 DNase hypersensitive sites (HS
Ss) in erythroid and fibroblast cells, and the analysis of the mDist1,
mMPG, and mProx1 expression levels in several adult tissues and durin
g fetal development. In addition, the hDist1 gene is exactly localized
1.9 kb from the hMPG gene. The mapping results show that the Dist1, M
PG, and Prox1 genes, to gether with the alpha-globin genes and the (al
pha MRE, form a tightly packed multiple gene cluster that is 50% more
compact in mouse than in human. The expression results show that each
of the genes present in this locus displays a characteristic expressio
n pattern in adult tissues and during fetal development. The 18 DNase
HSSs observed were scattered over this region. Interestingly, all the
erythroid-sensitive HSSs were associated with the Prox1 transcription
unit, whereas the only two pairs of fibroblast-sensitive HSSs present
in this locus were located in the promoter regions of the mProx1 and m
Dist1/mMPG genes. The possible role of the erythroid- and fibro-blast
sensitive sites in the regulation of the mouse alpha-globin and nonglo
bin gene expression is discussed. The characterization of the mouse al
pha UFR identifies most, if not all, of the structural elements possib
ly involved in the regulation of m alpha-globin gene expression and sh
eds Light on the organization and evolution of the telomere-associated
, GC-rich isochore family H3. (C) 1996 Academic Press, Inc.