scholarly journals Separate elements cause lineage restriction and specify boundaries of Hox-1.1 expression

Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 279-287 ◽  
Author(s):  
A.W. Puschel ◽  
R. Balling ◽  
P. Gruss
Keyword(s):  
Transgenic Mice ◽  
Hox Genes ◽  
Positional Information ◽  
Regulatory Elements ◽  
Specific Region ◽  
Regulatory Sequences ◽  
Anteroposterior Axis ◽  
Positional Identity ◽  
Developmental Programme ◽  
Responsive Element

The Hox genes are a class of putative developmental control genes that are thought to be involved in the specification of positional identity along the anteroposterior axis of the vertebrate embryo. It is apparent from their expression pattern that their regulation is dependent upon positional information. In a previous analysis of the Hox-1.1 promoter in transgenic mice, we identified sequences that were sufficient to establish transgene expression in a specific region of the embryo. The construct used, however, did not contain enough regulatory sequences to reproduce all aspects of Hox-1.1 expression. In particular, neither a posterior boundary nor a restriction of expression to prevertebrae was achieved. Here we show correct regulation by Hox-1.1 sequences in transgenic mice and identify the elements responsible for different levels of control. Concomitant with the subdivision of mesodermal cells into different lineages during gastrulation and organogenesis, Hox-1.1 expression is restricted to successively smaller sets of cells. Distinct elements are required at different stages of development to execute this developmental programme. One position-responsive element (130 bp nontranslated leader) was shown to be crucial for the restriction of expression not only along the anteroposterior axis of the embryo, setting the posterior border, but also along the dorsoventral axis of the neural tube and to the lineage giving rise to the prevertebrae. Thus, Hox-1.1 expression is established in a specific region of the embryo and in a specific lineage of the mesoderm by restricting the activity of the promoter by the combined effect of several regulatory elements.

Dietary regulation of pancreatic amylase in transgenic mice mediated by a 126-base pair DNA fragment

1992 ◽  
Vol 262 (6) ◽  
pp. G971-G976 ◽  
Author(s):  
R. M. Schmid ◽  
M. H. Meisler
Keyword(s):  
Transgenic Mice ◽  
Base Pair ◽  
Insulin Response ◽  
Regulatory Elements ◽  
Regulatory Sequences ◽  
Pancreatic Amylase ◽  
Amylase Gene ◽  
Dietary Regulation ◽  
Dna Fragment ◽  
Responsive Element

Expression of the mouse pancreatic amylase gene Amy-2.2 is increased approximately 10-fold in response to increasing the carbohydrate content of the diet from 9.6 to 74%. The DNA sequence mediating this response has been localized to the 5' flanking region of the amylase gene by analysis of hybrid constructs in transgenic mice. The results define a 127-base pair dietary response unit that includes two previously described regulatory elements, an insulin-responsive element and a pancreatic enhancer. Fragments containing these two elements alone fail to respond to diet, demonstrating a requirement for additional regulatory sequences. Another mouse amylase gene Amy-2.1 is only minimally responsive to insulin and to diet. The data are consistent with the hypothesis that the insulin-response element is necessary but not sufficient for regulation of amylase by dietary carbohydrate.

Transducing positional information to the Hox genes: critical interaction of cdx gene products with position-sensitive regulatory elements

Development ◽  
1998 ◽  
Vol 125 (22) ◽  
pp. 4349-4358 ◽  
Author(s):  
J. Charite ◽  
W. de Graaff ◽  
D. Consten ◽  
M.J. Reijnen ◽  
J. Korving ◽  
...  
Keyword(s):  
Binding Sites ◽  
Hox Genes ◽  
Regulatory Element ◽  
Ectopic Expression ◽  
Positional Information ◽  
Regulatory Elements ◽  
Gene Products ◽  
Anteroposterior Patterning

Studies of pattern formation in the vertebrate central nervous system indicate that anteroposterior positional information is generated in the embryo by signalling gradients of an as yet unknown nature. We searched for transcription factors that transduce this information to the Hox genes. Based on the assumption that the activity levels of such factors might vary with position along the anteroposterior axis, we devised an in vivo assay to detect responsiveness of cis-acting sequences to such differentially active factors. We used this assay to analyze a Hoxb8 regulatory element, and detected the most pronounced response in a short stretch of DNA containing a cluster of potential CDX binding sites. We show that differentially expressed DNA binding proteins are present in gastrulating embryos that bind to these sites in vitro, that cdx gene products are among these, and that binding site mutations that abolish binding of these proteins completely destroy the ability of the regulatory element to drive regionally restricted expression in the embryo. Finally, we show that ectopic expression of cdx gene products anteriorizes expression of reporter transgenes driven by this regulatory element, as well as that of the endogenous Hoxb8 gene, in a manner that is consistent with them being essential transducers of positional information. These data suggest that, in contrast to Drosophila Caudal, vertebrate cdx gene products transduce positional information directly to the Hox genes, acting through CDX binding sites in their enhancers. This may represent the ancestral mode of action of caudal homologues, which are involved in anteroposterior patterning in organisms with widely divergent body plans and modes of development.

scholarly journals Common core sequences are found in skeletal muscle slow- and fast-fiber-type-specific regulatory elements.

1996 ◽  
Vol 16 (5) ◽  
pp. 2408-2417 ◽  
Author(s):  
M Nakayama ◽  
J Stauffer ◽  
J Cheng ◽  
S Banerjee-Basu ◽  
E Wawrousek ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Spatial Organization ◽  
Molecular Mechanisms ◽  
Fiber Type ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Upstream Region ◽  
Regulatory Sequences ◽  
Fast Fiber ◽  
Core Elements

The molecular mechanisms generating muscle diversity during development are unknown. The phenotypic properties of slow- and fast-twitch myofibers are determined by the selective transcription of genes coding for contractile proteins and metabolic enzymes in these muscles, properties that fail to develop in cultured muscle. Using transgenic mice, we have identified regulatory elements in the evolutionarily related troponin slow (TnIs) and fast (TnIf) genes that confer specific transcription in either slow or fast muscles. Analysis of serial deletions of the rat TnIs upstream region revealed that sequences between kb -0.95 and -0.5 are necessary to confer slow-fiber-specific transcription; the -0.5-kb fragment containing the basal promoter was inactive in five transgenic mouse lines tested. We identified a 128-bp regulatory element residing at kb -0.8 that, when linked to the -0.5-kb TnIs promoter, specifically confers transcription to slow-twitch muscles. To identify sequences directing fast-fiber-specific transcription, we generated transgenic mice harboring a construct containing the TnIs kb -0.5 promoter fused to a 144-bp enhancer derived from the quail TnIf gene. Mice harboring the TnIf/TnIs chimera construct expressed the transgene in fast but not in slow muscles, indicating that these regulatory elements are sufficient to confer fiber-type-specific transcription. Alignment of rat TnIs and quail TnIf regulatory sequences indicates that there is a conserved spatial organization of core elements, namely, an E box, a CCAC box, a MEF-2-like sequence, and a previously uncharacterized motif. The core elements were shown to bind their cognate factors by electrophoretic mobility shift assays, and their mutation demonstrated that the TnIs CCAC and E boxes are necessary for transgene expression. Our results suggest that the interaction of closely related transcriptional protein-DNA complexes is utilized to specify fiber type diversity.

scholarly journals Myosin light chain 3F regulatory sequences confer regionalized cardiac and skeletal muscle expression in transgenic mice.

1995 ◽  
Vol 129 (2) ◽  
pp. 383-396 ◽  
Author(s):  
R Kelly ◽  
S Alonso ◽  
S Tajbakhsh ◽  
G Cossu ◽  
M Buckingham
Keyword(s):  
Skeletal Muscle ◽  
Transgenic Mice ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Muscle Development ◽  
Regulatory Elements ◽  
Left Ventricular ◽  
Mouse Heart ◽  
Regulatory Sequences ◽  
Enhancer Element

The myosin light chain IF/3F locus contains two independent promoters, MLC1F and MLC3F, which are differentially activated during skeletal muscle development. Transcription at this locus is regulated by a 3' skeletal muscle enhancer element, which directs correct temporal and tissue-specific expression from the MLC1F promoter in transgenic mice. To investigate the role of this enhancer in regulation of the MLC3F promoter in vivo, we have analyzed reporter gene expression in transgenic mice containing lacZ under transcriptional control of the mouse MLC3F promoter and 3' enhancer element. Our results show that these regulatory elements direct strong expression of lacZ in skeletal muscle; the transgene, however, is activated 4-5 d before the endogenous MLC3F promoter, at the time of initiation of MLC1F transcription. In adult mice, transgene activity is downregulated in muscles that have reduced contributions of type IIB fibers (soleus and diaphragm). The rostrocaudal positional gradient of transgene expression documented for MLC1F transgenic mice (Donoghue, M., J. P. Merlie, N. Rosenthal, and J. R. Sanes. 1991. Proc. Natl. Acad. Sci. USA. 88:5847-5851) is not seen in MLC3F transgenic mice. Although MLC3F was previously thought to be restricted to skeletal striated muscle, the MLC3F-lacZ transgene is expressed in cardiac muscle from 7.5 d of development in a spatially restricted manner in the atria and left ventricular compartments, suggesting that transcriptional differences exist between cardiomyocytes in left and right compartments of the heart. We show here that transgene-directed expression of the MLC3F promoter reflects low level expression of endogenous MLC3F transcripts in the mouse heart.

scholarly journals Two Pax-binding sites are required for early embryonic brain expression of an Engrailed-2 transgene

Development ◽  
1996 ◽  
Vol 122 (2) ◽  
pp. 627-635 ◽  
Author(s):  
D.L. Song ◽  
G. Chalepakis ◽  
P. Gruss ◽  
A.L. Joyner
Keyword(s):  
Dna Binding ◽  
Transgenic Mice ◽  
Binding Sites ◽  
Regulatory Elements ◽  
Developing Brain ◽  
Molecular Evidence ◽  
Regulatory Sequences ◽  
Pax Genes

The temporally and spatially restricted expression of the mouse Engrailed (En) genes is essential for development of the midbrain and cerebellum. The regulation of En-2 expression was studied using in vitro protein-DNA binding assays and in vivo expression analysis in transgenic mice to gain insight into the genetic events that lead to regionalization of the developing brain. A minimum En-2 1.0 kb enhancer fragment was defined and found to contain multiple positive and negative regulatory elements that function in concert to establish the early embryonic mid-hindbrain expression. Furthermore, the mid-hindbrain regulatory sequences were shown to be structurally and functionally conserved in humans. The mouse paired-box-containing genes Pax-2, Pax-5 and Pax-8 show overlapping expression with the En genes in the developing brain. Significantly, two DNA-binding sites for Pax-2, Pax-5 and Pax-8 proteins were identified in the 1.0 kb En-2 regulatory sequences, and mutation of the binding sites disrupted initiation and maintenance of expression in transgenic mice. These results present strong molecular evidence that the Pax genes are direct upstream regulators of En-2 in the genetic cascade controlling mid-hindbrain development. These mouse studies, taken together with others in Drosophila and zebrafish on the role of Pax genes in controlling expression of En family members, indicate that a Pax-En genetic pathway has been conserved during evolution.

scholarly journals Position-specific activity of the Hox1.1 promoter in transgenic mice

Development ◽  
1990 ◽  
Vol 108 (3) ◽  
pp. 435-442 ◽  
Author(s):  
A.W. Puschel ◽  
R. Balling ◽  
P. Gruss
Keyword(s):  
Transgenic Mice ◽  
Transgene Expression ◽  
Hox Genes ◽  
Specific Activity ◽  
Regulatory Element ◽  
Single Cells ◽  
Expression Patterns ◽  
Positional Information ◽  
Promoter Sequences ◽  
Second Period

During development, positional values have to be assigned to groups of cells. The murine Hox genes are a class of genes that are predicted to be involved at some stage in this process. During embryogenesis they are expressed in distinct overlapping region- and stage-specific patterns and therefore must be regulated in response to positional information. In this study, we have analysed the activity of Hox1.1 promoter sequences in transgenic mice. The use of lacZ as a marker allows a detailed analysis of expression at the single cell level during early embryonic development. We show that 3.6 kbp of promoter and 1.7 kbp of 3′ sequences provide sufficient regulatory information to express a transgene in a spatial and temporal manner indistinguishable from the endogenous Hox1.1 gene during the period of development when Hox1.1 expression is established. The activation occurs in a strict order in specific ectodermal and mesodermal domains. Within each of these domains the transgene is activated over a period of four hours apparently randomly in single cells. In a following second period, Hox1.1 and transgene expression patterns diverge. In this period, transgene expression persists in many mesodermally derived cells that do not express Hox1.1 indicating the absence of a negative regulatory element in the transgene. The anterior boundary of transgene expression is identical to that of Hox1.1. However, no posterior boundary of transgene expression is set, suggesting that a separate element absent from the transgene specifies this boundary.

Transgenic targeting with regulatory elements of the humanCD34 gene

Blood ◽  
2002 ◽  
Vol 100 (13) ◽  
pp. 4410-4419 ◽  
Author(s):  
Hanna S. Radomska ◽  
David A. Gonzalez ◽  
Yutaka Okuno ◽  
Hiromi Iwasaki ◽  
Andras Nagy ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transgenic Mice ◽  
Bone Marrow Cells ◽  
Artificial Chromosome ◽  
Regulatory Elements ◽  
Human Cd34 ◽  
Cell Assays ◽  
Flanking Region ◽  
Responsive Element

The human CD34 gene is expressed on early progenitor and stem cells in the bone marrow. Here we report the isolation of the human CD34 locus from a human P1 artificial chromosome (PAC) library and the characterization and evaluation of this genomic fragment for expression of reporter genes in stable cell lines and transgenic mice. We show that a 160-kb fragment spanning 110 kb of the 5′ flanking region and 26 kb of the 3′ flanking region of theCD34 gene directs expression of the human CD34gene in the bone marrow of transgenic mice. The expression of human CD34 transgenic RNA in tissues was found to be similar to that of the endogenous murine CD34 gene. Colony-forming cell assays showed that bone marrow cells staining positive for human CD34 consist of early progenitor cells in which expression of CD34 decreased with cell maturation. In order to test the construct for its ability to express heterologous genes in vivo, we used homologous recombination in bacteria to insert the tetracycline-responsive transactivator protein tTA. Analysis of transgenic human CD34-tTA mice by cross breeding with a strain carrying Cre recombinase under control of a tetracycline-responsive element demonstrated induction of Cre expression in mice in a pattern consistent with the expression of the human CD34 transgene.

Segmental relationship between somites and vertebral column in zebrafish

Development ◽  
2002 ◽  
Vol 129 (16) ◽  
pp. 3851-3860 ◽  
Author(s):  
Elizabeth M. Morin-Kensicki ◽  
Ellie Melancon ◽  
Judith S. Eisen
Keyword(s):  
Vertebral Column ◽  
Hox Genes ◽  
De Novo ◽  
Expression Patterns ◽  
Axial Skeleton ◽  
Anteroposterior Axis ◽  
Tissue Interactions ◽  
Positional Identity ◽  
Regional Specificity

The segmental heritage of all vertebrates is evident in the character of the vertebral column. And yet, the extent to which direct translation of pattern from the somitic mesoderm and de novo cell and tissue interactions pattern the vertebral column remains a fundamental, unresolved issue. The elements of vertebral column pattern under debate include both segmental pattern and anteroposterior regional specificity. Understanding how vertebral segmentation and anteroposterior positional identity are patterned requires understanding vertebral column cellular and developmental biology. In this study, we characterized alignment of somites and vertebrae, distribution of individual sclerotome progeny along the anteroposterior axis and development of the axial skeleton in zebrafish. Our clonal analysis of zebrafish sclerotome shows that anterior and posterior somite domains are not lineage-restricted compartments with respect to distribution along the anteroposterior axis but support a ‘leaky’ resegmentation in development from somite to vertebral column. Alignment of somites with vertebrae suggests that the first two somites do not contribute to the vertebral column. Characterization of vertebral column development allowed examination of the relationship between vertebral formula and expression patterns of zebrafish Hox genes. Our results support co-localization of the anterior expression boundaries of zebrafish hoxc6 homologs with a cervical/thoracic transition and also suggest Hox-independent patterning of regionally specific posterior vertebrae.

Retinoic acid-induced down-regulation of the interleukin-2 promoter via cis-regulatory sequences containing an octamer motif

1991 ◽  
Vol 11 (9) ◽  
pp. 4771-4778
Author(s):  
M P Felli ◽  
A Vacca ◽  
D Meco ◽  
I Screpanti ◽  
A R Farina ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Interleukin 2 ◽  
Calcium Ionophore ◽  
Regulatory Elements ◽  
Chloramphenicol Acetyltransferase ◽  
Regulatory Sequences ◽  
Down Regulation ◽  
Octamer Motif ◽  
Responsive Element

Retinoic acid (RA) is known to influence the proliferation and differentiation of a wide variety of transformed and developing cells. We found that RA and the specific RA receptor (RAR) ligand Ch55 inhibited the phorbol ester and calcium ionophore-induced expression of the T-cell growth factor interleukin-2 (IL-2) gene. Expression of transiently transfected chloramphenicol acetyltransferase vectors containing the 5'-flanking region of the IL-2 gene was also inhibited by RA. RA-induced down-regulation of the IL-2 enhancer is mediated by RAR, since overexpression of transfected RARs increased RA sensitivity of the IL-2 promoter. Functional analysis of chloramphenicol acetyltransferase vectors containing either internal deletion mutants of the region from -317 to +47 bp of the IL-2 enhancer or multimerized cis-regulatory elements showed that the RA-responsive element in the IL-2 promoter mapped to sequences containing an octamer motif. RAR also inhibited the transcriptional activity of the octamer motif of the immunoglobulin heavy chain enhancer. In spite of the transcriptional inhibition of the IL-2 octamer motif, RA did not decrease the in vitro DNA-binding capability of octamer-1 protein. These results identify a regulatory pathway within the IL-2 promoter which involves the octamer motif and RAR.

scholarly journals Retinoic acid-induced down-regulation of the interleukin-2 promoter via cis-regulatory sequences containing an octamer motif.

1991 ◽  
Vol 11 (9) ◽  
pp. 4771-4778 ◽  
Author(s):  
M P Felli ◽  
A Vacca ◽  
D Meco ◽  
I Screpanti ◽  
A R Farina ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Interleukin 2 ◽  
Calcium Ionophore ◽  
Regulatory Elements ◽  
Chloramphenicol Acetyltransferase ◽  
Regulatory Sequences ◽  
Down Regulation ◽  
Octamer Motif ◽  
Responsive Element

Retinoic acid (RA) is known to influence the proliferation and differentiation of a wide variety of transformed and developing cells. We found that RA and the specific RA receptor (RAR) ligand Ch55 inhibited the phorbol ester and calcium ionophore-induced expression of the T-cell growth factor interleukin-2 (IL-2) gene. Expression of transiently transfected chloramphenicol acetyltransferase vectors containing the 5'-flanking region of the IL-2 gene was also inhibited by RA. RA-induced down-regulation of the IL-2 enhancer is mediated by RAR, since overexpression of transfected RARs increased RA sensitivity of the IL-2 promoter. Functional analysis of chloramphenicol acetyltransferase vectors containing either internal deletion mutants of the region from -317 to +47 bp of the IL-2 enhancer or multimerized cis-regulatory elements showed that the RA-responsive element in the IL-2 promoter mapped to sequences containing an octamer motif. RAR also inhibited the transcriptional activity of the octamer motif of the immunoglobulin heavy chain enhancer. In spite of the transcriptional inhibition of the IL-2 octamer motif, RA did not decrease the in vitro DNA-binding capability of octamer-1 protein. These results identify a regulatory pathway within the IL-2 promoter which involves the octamer motif and RAR.

Sign in / Sign up

Export Citation Format

Share Document