In situ hybridization reveals co-expression of embryonic and adult alpha globin genes in the earliest murine erythrocyte progenitors

Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 1041-1049 ◽  
Author(s):  
A. Leder ◽  
A. Kuo ◽  
M.M. Shen ◽  
P. Leder
Keyword(s):  
In Situ Hybridization ◽  
Embryonic Development ◽  
Fetal Liver ◽  
Globin Gene ◽  
Yolk Sac ◽  
Globin Genes ◽  
Globin Mrna ◽  
Mature Adult ◽  
Alpha Globin

Murine erythropoiesis begins with the formation of primitive red blood cells in the blood islands of the embryonic yolk sac on day 7.5 of gestation. By analogy to human erythropoiesis, it has been thought that there is a gradual switch from the exclusive expression of the embryonic alpha-like globin (zeta) to the mature adult form (alpha) in these early mouse cells. We have used in situ hybridization to assess expression of these two globin genes during embryonic development. In contrast to what might have been expected, we find that there is simultaneous expression of both zeta and alpha genes from the very onset of erythropoiesis in the yolk sac. At no time could we detect expression of embryonic zeta globin mRNA without concomitant expression of adult alpha globin mRNA. Indeed, adult alpha transcripts exceed those of embryonic zeta in the earliest red cell precursors. Moreover, the pattern of hybridization reveals co-expression of both genes within the same cells. Even in the fetal liver, which supersedes the yolk sac as the major site of murine fetal erythropoiesis, there is a brief co-expression of zeta and alpha genes followed by the exclusive expression of the adult alpha genes. These data indicate an important difference in hematopoietic ontogeny between mouse and that of human, where zeta expression precedes that of alpha. In addition to resolving the embryonic expression of these globin genes, our results suggest that the embryonic alpha-like globin gene zeta may be physiologically redundant, even during the earliest stages of embryonic development.

scholarly journals Substitution of the Human β-Spectrin Promoter for the Human Aγ-Globin Promoter Prevents Silencing of a Linked Human β-Globin Gene in Transgenic Mice

1998 ◽  
Vol 18 (11) ◽  
pp. 6634-6640 ◽  
Author(s):  
Denise E. Sabatino ◽  
Amanda P. Cline ◽  
Patrick G. Gallagher ◽  
Lisa J. Garrett ◽  
George Stamatoyannopoulos ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Fetal Liver ◽  
Globin Gene ◽  
Gene Promoter ◽  
Yolk Sac ◽  
Globin Genes ◽  
Erythroid Cells ◽  
Globin Mrna ◽  
Globin Promoter ◽  
In Erythroid Cells

ABSTRACT During development, changes occur in both the sites of erythropoiesis and the globin genes expressed at each developmental stage. Previous work has shown that high-level expression of human β-like globin genes in transgenic mice requires the presence of the locus control region (LCR). Models of hemoglobin switching propose that the LCR and/or stage-specific elements interact with globin gene sequences to activate specific genes in erythroid cells. To test these models, we generated transgenic mice which contain the human Aγ-globin gene linked to a 576-bp fragment containing the human β-spectrin promoter. In these mice, the β-spectrin Aγ-globin (βsp/Aγ) transgene was expressed at high levels in erythroid cells throughout development. Transgenic mice containing a 40-kb cosmid construct with the micro-LCR, βsp/Aγ-, ψβ-, δ-, and β-globin genes showed no developmental switching and expressed both human γ- and β-globin mRNAs in erythroid cells throughout development. Mice containing control cosmids with the Aγ-globin gene promoter showed developmental switching and expressed Aγ-globin mRNA in yolk sac and fetal liver erythroid cells and β-globin mRNA in fetal liver and adult erythroid cells. Our results suggest that replacement of the γ-globin promoter with the β-spectrin promoter allows the expression of the β-globin gene. We conclude that the γ-globin promoter is necessary and sufficient to suppress the expression of the β-globin gene in yolk sac erythroid cells.

Endogenous Elevations of Short Chain Fatty Acids Up-Regulate Embryonic Globin Gene Expression during Primitive Erythropoiesis.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1210-1210
Author(s):  
Lauren Sterner ◽  
Toru Miyazaki ◽  
Larry Swift ◽  
Ann Dean ◽  
Jane Little
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Fetal Liver ◽  
Globin Gene ◽  
Short Chain Fatty Acids ◽  
Yolk Sac ◽  
Globin Genes ◽  
Wild Type ◽  
Alpha Type ◽  
Globin Gene Expression

Abstract We examined the effects of short chain fatty acids (SCFAs) on globin gene expression during development. We studied globin gene expression in transgenic mice that have endogenous elevations in the SCFA propionate due to a knockout (KO) of the gene for propionyl CoA carboxylase subunit A (PCCA, Miyazaki et al. JBC, 2001 Sep 21;276(38):35995–9). Serum propionate levels measured by gas chromatography were 2.5 to 3.6 mgms/ml in 2 adult PCCA KO mice and were undetectable in 2 wild type (wt) or heterozygous control adult mice. Embryonic PCCA KO offspring had propionate levels of 2.3 and 5.0 μgms/100 mgms of fetal liver, at day 16.5 (E16.5), while wt or heterozygotes at E14.5 had levels <1 μgm/100 mgms. Analysis of expression from alpha (α), beta major (βmaj), embryonic beta-type epsilon-y (εy), embryonic beta-type beta H1 (βH1) and embryonic alpha-type zeta (ζ) globin genes plus 18S ribosomal RNA as a control was undertaken using real-time PCR with gene-specific primers and taqman probes. cDNA was reverse-transcribed from the mRNA of yolk sac (YS) and fetal liver of PCCA KO and wt progeny of more than one litter from timed pregnancies. Individual PCCA embryos at E10 (n=10), E12 (n=9), and E14 (n=7) were analyzed for globin gene expression, normalized to18S expression and were compared to age-matched wt embryos (n>=4 for each time point). As expected, embryonic alpha- and beta-type globin gene expression (ζ and βH1 plus εy) predominated in E 10 YS, and definitive globin gene expression, α and βmaj, predominated in E12 or E14 fetal liver. Expression from embryonic alpha-type globin was calculated as normalized ζ/(ζ+α) and from embryonic beta-type globins as normalized (βH1+εy)/(βH1+εy+βmaj), see table. Embryonic globin gene expression was statistically significantly increased in PCCA KO E12 YS at 1.3 fold relative to wt ζ and in PCCA KO E14 YS at 1.8 fold and 2.1 fold relative to wt ζ or βH1 and εy respectively (p<.05). No increase in embryonic globin mRNA was seen in adult PCCA KO animals. We conclude that elevations of SCFAs during normal murine development causes a persistence of both embryonic alpha-type and embryonic beta-type globin gene expression during primitive, but not definitive, erythropoiesis, suggesting that SCFAs cannot reactivate silenced murine embryonic globin genes in the absence of erythroid stress. Embryonic Globin Gene Expression in Mice with Endogenous Elevations of SCFAs % Expression PCCA KO wild type p value, t test E10 ζ Yolk Sac 53+/− 2 nd E10 βH1 & ε y Yolk Sac 99 +/− 0.3 nd E12 ζ Yolk Sac 32 +/− 3 25 +/− 1 p < .05 E12 βH1 & ε y Yolk Sac 77 +/− 6 74 +/− 3 ns E14 ζ Yolk Sac 7 +/− 1.5 4 +/− 1.4 p < .05 E14 βH1 & ε y Yolk Sac 13 +/− 6 6 +/− 0.5 p < .05 E12 ζ Fetal Liver 11 +/− 4 9 +/− 2 ns E12 βH1 & ε y Fetal Liver 13 +/− 5 13+/− 3 ns E14 ζ Fetal Liver 1 +/− 0.4 0.7 +/− 0.2 ns E14 βH1 & εy Fetal Liver 6 +/− 1.8 4 +/− 1 ns

scholarly journals Developmental silencing of the embryonic zeta-globin gene: concerted action of the promoter and the 3'-flanking region combined with stage-specific silencing by the transcribed segment.

1996 ◽  
Vol 16 (6) ◽  
pp. 2637-2646 ◽  
Author(s):  
S A Liebhaber ◽  
Z Wang ◽  
F E Cash ◽  
B Monks ◽  
J E Russell
Keyword(s):  
Gene Silencing ◽  
Fetal Liver ◽  
Globin Gene ◽  
Gene Promoter ◽  
Gene Promoters ◽  
Globin Genes ◽  
Alpha Globin ◽  
Flanking Region ◽  
Zeta Globin Gene ◽  
The Individual

Globin gene switching is a well-described model of eucaryotic developmental control. In the case of the human alpha-globin gene cluster, migration of erythropoietic activity from the embryonic yolk sac to the fetal liver is parallaled by the zeta-globin gene silencing and enhanced expression of the alpha-globin genes. To map critical cis determinants of this switch, the human zeta-globin gene, the alpha-globin gene, and chimeric recombinants were introduced into the mouse genome. Consistent with previous studies, expression of the individual alpha- and zeta-globin transgenes was found to be developmentally appropriate. Contrary to current models, however, the alpha- and zeta-globin gene promoters were not sufficient to establish this control. Instead, full silencing of the zeta-globin gene required the combined activities of this promoter, transcribed region, and 3'-flanking sequences. Individually, the silencing activities of the zeta-globin gene promoter and 3'-flanking region were minimal but increased markedly when both regions were present. The zeta-globin transcribed region appeared to contribute to gene silencing by a mechanism specifically activated in definitive erythroblasts in the fetal liver. These data demonstrate that a complex set of controls, requiring at least three determinants and involving at least two independent mechanisms, is necessary for full developmental silencing of the human zeta-globin gene.

scholarly journals Genome Architecture of the Human β-Globin Locus Affects Developmental Regulation of Gene Expression

2005 ◽  
Vol 25 (20) ◽  
pp. 8765-8778 ◽  
Author(s):  
Susanna Harju ◽  
Patrick A. Navas ◽  
George Stamatoyannopoulos ◽  
Kenneth R. Peterson
Keyword(s):  
Gene Expression ◽  
Gene Order ◽  
Yeast Artificial Chromosome ◽  
Fetal Liver ◽  
Globin Gene ◽  
Regulation Of Gene Expression ◽  
Globin Genes ◽  
Wild Type ◽  
Globin Mrna ◽  
Definitive Erythropoiesis

ABSTRACT To test the role of gene order in globin gene expression, mutant human β-globin locus yeast artificial chromosome constructs were used, each having one additional globin gene encoding a “marked” transcript (εm, γm, or βm) integrated at different locations within the locus. When a βm-globin gene was placed between the locus control region (LCR) and the ε-globin gene, βm-globin expression dominated primitive and definitive erythropoiesis; only βm-globin mRNA was detected during the fetal and adult definitive stages of erythropoiesis. When an Aγm-globin gene was placed at the same location, Aγm-globin was expressed during embryonic erythropoiesis and the fetal liver stage of definitive erythropoiesis but was silenced during the adult stage. The downstream wild-type γ-globin genes were not expressed. When an εm-globin gene was placed between the δ- and β-globin genes, it remained silent during embryonic erythropoiesis; only the LCR-proximal wild-type ε-globin gene was expressed. Placement of a βm-globin gene upstream of the Gγ-globin gene resulted in expression of βm-globin in embryonic cells and in a significant decrease in expression of the downstream wild-type β-globin gene. These results indicate that distance from the LCR, an inherent property of spatial gene order, is a major determinant of temporal gene expression during development.

Differential expression of alpha- and beta-globin genes in erythroleukemic cell lines

1990 ◽  
Vol 10 (7) ◽  
pp. 3591-3595
Author(s):  
N Beru ◽  
P B Maples ◽  
O Hermine ◽  
E Goldwasser
Keyword(s):  
Cell Lines ◽  
Globin Gene ◽  
Restriction Enzymes ◽  
Erythroid Differentiation ◽  
Globin Genes ◽  
Beta Globin ◽  
Globin Mrna ◽  
Beta Globin Gene ◽  
Alpha Globin ◽  
Erythroleukemic Cell

The IW32, NN10, and IW201 cell lines are erythroleukemic cell lines isolated from the spleens of mice infected with the Friend virus. IW32 and NN10 cells can be induced toward erythroid differentiation and hemoglobin synthesis by hemin or butyrate. Both cell lines contain some mature alpha- and beta-globin mRNA before induction, and addition of the inducers greatly increases the amount of globin message. Unlike IW32 and NN10 cells, IW201 cells are only partially inducible. Uninduced 201 cells contain a small amount of alpha-globin mRNA but no detectable beta-globin message. After induction, the cells contain markedly increased amounts of alpha-globin mRNA but still do not express the beta-globin gene. Southern blot analysis with 10 restriction enzymes shows that the restriction map of the beta-globin gene in IW201 cells is indistinguishable from that in IW32 and NN10 cells.

“Definitive” Erythropoiesis Has Distinct Developmental Origins and Globin Expression Patterns in the Mammalian Embryo.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2539-2539
Author(s):  
Kathleen E. McGrath ◽  
Jenna M Frame ◽  
George Fromm ◽  
Anne D Koniski ◽  
Paul D Kingsley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fetal Liver ◽  
Globin Gene ◽  
Yolk Sac ◽  
Globin Genes ◽  
Beta Globin ◽  
Erythroid Cells ◽  
Erythroid Progenitors ◽  
Low Levels ◽  
Globin Gene Expression

Abstract Abstract 2539 Poster Board II-516 A transient wave of primitive erythropoiesis begins at embryonic day 7.5 (E7.5) in the mouse as yolk sac-derived primitive erythroid progenitors (EryP-CFC) generate precursors that mature in the circulation and expand in numbers until E12.5. A second wave of erythroid progenitors (BFU-E) originates in the yolk sac beginning at E8.25 that generate definitive erythroid cells in vitro. These BFU-E colonize the newly forming liver beginning at E10.5, prior to the initial appearance there of adult-repopulating hematopoietic stem cells (HSCs) between E11.5-12.5. This wave of definitive erythroid yolk sac progenitors is proposed to be the source of new blood cells required by the growing embryo after the expansion of primitive erythroid cells has ceased and before HSC-derived hematopoiesis can fulfill the erythropoietic needs of the embryo. We utilized multispectral imaging flow cytometry both to distinguish erythroid lineages and to define specific stages of erythroid precursor maturation in the mouse embryo. Consistent with this model, we found that small numbers of definitive erythrocytes first enter the embryonic circulation beginning at E11.5. All maturational stages of erythroid precursors were observed in the E11.5 liver, consistent with these first definitive erythrocytes having rapidly completed their maturation in the liver. The expression of βH1 and εy-beta globin genes is thought to be limited to primitive erythroid cells. Surprisingly, examination of globin gene expression by in situ hybridization revealed high levels of βH1-, but not εy-globin, transcripts in the parenchyma of E11.5-12.5 livers. RT-PCR analysis of globin mRNAs confirmed the expression of βH1- and adult β1-, but not εy-globin, in E11.5 liver-derived definitive (ckit+, Ter119lo) proerythroblasts sorted by flow cytometry to remove contaminating primitive (ckit-, Ter119+) erythroid cells. A similar pattern of globin gene expression was found in individual definitive erythroid colonies derived from E9.5 yolk sac and from early fetal liver. In vitro differentiation of definitive erythroid progenitors from E9.5 yolk sac revealed a maturational “switch” from βH1- and β1-globins to predominantly β1-globin. βH1-globin transcripts were not observed in proerythroblasts from bone marrow or E16.5 liver or in erythroid colonies from later fetal liver. ChIP analysis revealed that hyperacetylated domains encompass all beta globin genes in primitive erythroid cells but only the adult β1- and β2-globin genes in E16.5 liver proerythroblasts. Consistent with their unique gene expression, E11.5 liver proerythroblasts have hyperacetylated domains encompassing the βh1-, β1- and β2-, but not εy-globin genes. We also examined human globin transgene expression in mice carrying a single copy of the human beta globin locus. Because of the overlapping presence and changing proportion of primitive and definitive erythroid cells during development, we analyzed sorted cell populations whose identities were confirmed by murine globin gene expression. We confirmed that primitive erythroid cells express higher levels of γ- than ε-globin and little β-globin. E11.5 proerythroblasts and cultured E9.5 progenitors express γ- and β-, but not ε-globin. E16.5 liver proerythroblasts express β- and low levels of γ-globin, while adult marrow proerythroblasts express only β-globin transcripts. In summary, two forms of definitive erythropoiesis emerge in the murine embryo, each with distinct globin expression patterns and chromatin modifications of the β-globin locus. While both lineages predominantly express adult globins, the first, yolk sac-derived lineage uniquely expresses low levels of the embryonic βH1-globin gene as well as the human γ-globin transgene. The second definitive erythroid lineage, found in the later fetal liver and postnatal marrow, expresses only adult murine globins as well as low levels of the human γ-globin transgene only in the fetus. Our studies reveal a surprising complexity to the ontogeny of erythropoiesis. Disclosures: No relevant conflicts of interest to declare.

C>A substitution in NT 46 of the 3’ UTR region (the α complex protected region) of the alpha-1 globin gene: a non-deletional mutation or polymorphism?

2019 ◽  
Vol 73 (1) ◽  
pp. 14-16
Author(s):  
Paloma Ropero ◽  
Fernando Ataúlfo González ◽  
Jorge M Nieto ◽  
Ana Villegas ◽  
Julian Sevilla ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Messenger Rna ◽  
Globin Gene ◽  
Regulation Of Gene Expression ◽  
Erythroid Cell ◽  
Subcellular Localisation ◽  
Translation Efficiency ◽  
Globin Genes ◽  
Globin Mrna ◽  
Alpha Globin

AimsUntranslated regions (UTRs) play an important role in post-transcriptional regulation of gene expression, including by modulating messenger RNA (mRNA) transport out of the nucleus, translation efficiency, subcellular localisation and stability. Any mutation in this region could alter the stability of mRNA and thereby affect protein synthesis. We analysed if a mutation located in the α complex protected region of the α1 globin gene could cause non-deletional α-thalassaemia by affecting post-transcriptional stability (mRNA stability).MethodsA total of 14 patients without anaemia, normal or slight microcytosis and hypochromia (medium concentration haemoglobin [MCH] <27 pg) were studied. Haemoglobin subtypes were screened using capillary zone electrophoresis and ion-exchange high-performance liquid chromatography (VARIANT II β-Thalassaemia Short Program). The most common α-globin mutations were identified by multiplex PCR (Alpha-Globin StripAssay kit) and the molecular characterisation by automatic sequencing of alpha globin genes.ResultsAll of them shown a novel transversion mutation in nt 778 (C>A), which is located in the 3' UTR in the α complex protected region [HBA1: c.*+46C>A].ConclusionsThis mutation is in the αRNAmin binding site, so a single nucleotide substitution in this region can decrease mRNA stability by potentially compromising the binding of α-complex protein to αRNAmin, favouring the decay of α-globin mRNA via erythroid cell-enriched endoribonuclease cleavage. In this case, it is a non-deletional α-thalassaemia. However, in silico and empirical studies predicted that it could be a silent polymorphism. Functional studies should be carried out to confirm whether it is a pathological mutation or a silent polymorphism.

scholarly journals IN SITU LOCALIZATION OF GLOBIN MESSENGER RNA FORMATION

1974 ◽  
Vol 63 (2) ◽  
pp. 402-413 ◽  
Author(s):  
P. R. Harrison ◽  
D. Conkie ◽  
N. Affara ◽  
J. Paul
Keyword(s):  
In Situ Hybridization ◽  
Messenger Rna ◽  
Fetal Liver ◽  
Liver Cells ◽  
Mrna Levels ◽  
Messenger Rnas ◽  
Erythroid Cells ◽  
Globin Mrna ◽  
Fetal Liver Cells

Globin mRNA levels in 11–15-day mouse fetal liver cells have been estimated by in situ hybridization of a highly labeled DNA copy (cDNA) of adult globin messenger RNAs (mRNAs) (globin cDNA) to fixed preparations of cells. Under the conditions employed, no significant in situ hybridization occurred to lymphoma cells (L 51787), mouse L cells, or hepatocytes; whereas reticulocytes from phenyl hydrazine-treated mice showed extensive in situ hybridization. The proportion of fetal liver cells showing predominantly cytoplasmic in situ hybridization increased from about 30% at the 11th day of development to 80–85% by days 13–15. Unlike more mature cells, proerythroblasts did not show in situ hybridization, except to a slight extent at later stages of development. These studies therefore indicate that globin mRNAs begin to accumulate during or shortly after the proerythroblastbasophilic erythroblast transition. The fact that certain immature erythroid cells from 14-day fetal liver contain substantial amounts of globin mRNAs has been confirmed by comparing the hybridization in solution of globin cDNA to cytoplasmic RNA extracted from total fetal liver cells or from immature erythroid cells obtained by treatment of fetal liver cells with an antiserum raised against erythrocytes.

Endogenous Elevations of Short Chain Fatty Acids (SCFAs) Can Up-Regulate Embryonic Globin Gene Expression.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1770-1770
Author(s):  
Himanshu Bhatia ◽  
Jennifer Hallock ◽  
Lauren Sterner ◽  
Toru Miyazaki ◽  
Ann Dean ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fetal Liver ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Short Chain Fatty Acids ◽  
Yolk Sac ◽  
Globin Genes ◽  
Key Enzyme ◽  
Globin Gene Expression

Abstract Persistence of fetal hemoglobin can ameliorate adult beta (β)-globin gene disorders. Since SCFAs can affect embryonic and fetal globin gene expression, we examined their role during development. Murine globin gene expression, β-type (embryonic βH1, and epsilon-y, εY, and adult βmajor), and alpha (α)-type (embryonic zeta, ζ, &gt;α, adult α), were compared between wildtype (wt) and transgenic mice, in which a key enzyme for SCFA metabolism, PCCA, had been knocked out (PCCA−/−, (Miyazaki et al, 2001). E10.5 PCCA−/− yolk sac (n= 9), showed increased α, βH1 and ζ gene expression, at respectively 2-, 2.6- and 1.6-fold relative to wt (n=13, p&lt;.05), and εY gene expression, at 1.7-fold (p=0.07). The embryonic-to-adult globin gene switch was modestly delayed in yolk sacs from E12.5 PCCA−/− (n=9) vs. wt (n=4) and E 14.5 PCCA−/− (n=6) vs. wt (n=6). % embryonic β-type globin gene expression (% βH1 and εY of total β globin) was 77±6 PCCA−/− and 74±3 wt at E12.5, p=n.s., and 42±13 PCCA−/− and 21±3 wt at E14.5, p&lt;.05; % emvbryonic α-type expression (% ζ of total α) was 32±3 PCCA−/−, 25±1wt at E12.5, p&lt;.05 and 7±2 PCCA−/− and 4±1 wt at E14.5, p&lt;.05). Embryonic globin gene expression in E 12.5 and 14.5 fetal livers was not different between PCCA−/− and wt embryos. Cultures of pooled E14.5 wt fetal liver cells (FLCs, n=4 separate experiments), however, suggested that embryonic globin genes can be activated in FLCs. The percent of total β-type globin gene expression that was embryonic after culture with butyrate (1mM) was 11.6±2.6%, with propionate (2.5 mM) was 3.6±0.2%, and insulin/erythropoietin or basal media was 0.03±0.03% and 0.42±0.26% respectively (p&lt;.05 relative to SCFAs). Dose-response with propionate (n=2 seaparate experiments) suggest inadequate endogenous propionate levels for activation in PCCA −/− fetal liver, as % embryonic β-type globin gene expression rose above basal levels only at concentrations of 1 to 5 mM (2.5 mM maximal) but not at &lt;0.6 mM. We conclude that endogenous SCFAs, at levels achievable in vivo can activate embryonic globin gene expression during development in the murine yolk-sac. However, higher levels than achievable endogenously currently are necessary to produce this effect in murine fetal livers.

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