scholarly journals Mechanisms of Hox gene colinearity: transposition of the anterior Hoxb1 gene into the posterior HoxD complex

2000 ◽  
Vol 14 (2) ◽  
pp. 198-211 ◽  
Author(s):  
Marie Kmita ◽  
Frank van der Hoeven ◽  
József Zákány ◽  
Robb Krumlauf ◽  
Denis Duboule
Keyword(s):  
Retinoic Acid ◽  
Reporter Gene ◽  
General Property ◽  
Transgene Expression ◽  
Specific Activity ◽  
Hox Gene ◽  
Position Analysis ◽  
Ectopic Activation ◽  
Posterior Position ◽  
Gene Colinearity

Transposition of Hoxd genes to a more posterior (5′) location within the HoxD complex suggested that colinearity in the expression of these genes was due, in part, to the existence of a silencing mechanism originating at the 5′ end of the cluster and extending towards the 3′ direction. To assess the strength and specificity of this repression, as well as to challenge available models on colinearity, we inserted a Hoxb1/lacZtransgene within the posterior HoxD complex, thereby reconstructing a cluster with a copy of the most anterior gene inserted at the most posterior position. Analysis of Hoxb1 expression after ectopic relocation revealed that Hoxb1-specific activity in the fourth rhombomere was totally abolished. Treatment with retinoic acid, or subsequent relocations toward more 3′ positions in theHoxD complex, did not release this silencing in hindbrain cells. In contrast, however, early and anterior transgene expression in the mesoderm was unexpectedly not suppressed. Furthermore, the transgene induced a transient ectopic activation of the neighboringHoxd13 gene, without affecting other genes of the complex. Such a local and transient break in colinearity was also observed after transposition of the Hoxd9/lacZ reporter gene, indicating that it may be a general property of these transgenes when transposed at an ectopic location. These results are discussed in the context of existing models, which account for colinear activation of vertebrate Hox genes.

scholarly journals The Promoter of the Rat Gonadotropin-Releasing Hormone Receptor Gene Directs the Expression of the Human Placental Alkaline Phosphatase Reporter Gene in Gonadotrope Cells in the Anterior Pituitary Gland as well as in Multiple Extrapituitary Tissues

Endocrinology ◽  
2004 ◽  
Vol 145 (2) ◽  
pp. 983-993 ◽  
Author(s):  
Anne Granger ◽  
Valérie Ngô-Muller ◽  
Christian Bleux ◽  
Céline Guigon ◽  
Hanna Pincas ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Reporter Gene ◽  
Transgene Expression ◽  
Pituitary Cells ◽  
Placental Alkaline Phosphatase ◽  
R Gene ◽  
Glycoprotein Hormone ◽  
Steroidogenic Factor 1 ◽  
Functional Sites ◽  
Human Placental Alkaline Phosphatase

Abstract Previous studies dealing with the mechanisms underlying the tissue-specific and regulated expression of the GnRH receptor (GnRH-R) gene led us to define several cis-acting regulatory sequences in the rat GnRH-R gene promoter. These include functional sites for steroidogenic factor 1, activator protein 1, and motifs related to GATA and LIM homeodomain response elements as demonstrated primarily in transient transfection assays in mouse gonadotrope-derived cell lines. To understand these mechanisms in more depth, we generated transgenic mice bearing the 3.3-kb rat GnRH-R promoter linked to the human placental alkaline phosphatase reporter gene. Here we show that the rat GnRH-R promoter drives the expression of the reporter gene in pituitary cells expressing the LHβ and/or FSHβ subunit but not in TSHβ- or GH-positive cells. Furthermore, the spatial and temporal pattern of the transgene expression during the development of the pituitary was compatible with that characterizing the emergence of the gonadotrope lineage. In particular, transgene expression is colocalized with the expression of the glycoprotein hormone α-subunit at embryonic day 13.5 and with that of steroidogenic factor 1 at later stages of pituitary development. Transgene expression was also found in specific brain areas, such as the lateral septum and the hippocampus. A single promoter is thus capable of directing transcription in highly diverse tissues, raising the question of the different combinations of transcription factors that lead to such a multiple, but nevertheless cell-specific, expressions of the GnRH-R gene.

On the Chemistry of Phorbol, XIX [1] Preparation of Tritium-Labelled 12-O-RetinoyIphorbol-13-acetate([20-3H]-RPA)

1988 ◽  
Vol 43 (12) ◽  
pp. 1672-1675 ◽  
Author(s):  
G. L. Tremp ◽  
E. Hecker
Keyword(s):  
Retinoic Acid ◽  
Sodium Borohydride ◽  
Specific Activity ◽  
Diterpene Esters ◽  
Highly Sensitive ◽  
Radioactive Labelling

Abstract In contrast to established principles of radioactive labelling of diterpene esters such as TPA it was impossible to introduce tritium into the highly sensitive 12-0-retinoylphorbol-13-acetate (RPA) via reduction of its cold 20-aldehyde with [3H]-sodium borohydride. As an alternative successful procedure, [20-3H]-phorbol-13-acetate was prepared at first. It was protected in position 20 by reaction with tritylchloride and the tritylether reacted with retinoic acid. In both reactions appropriate phorbol acetates were used as easy to separate cold carriers. After removal of the 20-tritylether group, [20-3H]-RPA of a specific activity was obtained that was sufficient for the compound to be used as a tool in biochemical investigations

Synthesis of high specific activity tritium-labeled [3H]-9-cis-retinoic acid and its application for identifying retinoids with unusual binding properties

1994 ◽  
Vol 37 (3) ◽  
pp. 408-414 ◽  
Author(s):  
Marcus F. Boehm ◽  
Michael R. McClurg ◽  
Charles Pathirana ◽  
David Mangelsdorf ◽  
Steven K. White ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Specific Activity ◽  
High Specific Activity ◽  
Binding Properties

scholarly journals Effect of nuclear matrix attachment regions on transgene expression in tobacco plants.

2001 ◽  
Vol 48 (3) ◽  
pp. 637-646 ◽  
Author(s):  
W Nowak ◽  
M Gawłowska ◽  
A Jarmołowski ◽  
J Augustyniak
Keyword(s):  
Transgenic Plants ◽  
Reporter Gene ◽  
Transgene Expression ◽  
Binary Vector ◽  
Special Property ◽  
Matrix Attachment Regions ◽  
Plant Populations ◽  
Tobacco Plants ◽  
Gus Reporter ◽  
Loop Domains

Matrix attachment regions (MARs) are thought to participate in the organization and segregation of independent chromosomal loop domains. Although there are several reports on the action of natural MARs in the context of heterologous genes in transgenic plants, in our study we tested a synthetic MAR (sMAR) with the special property of unpairing when under superhelical strain, for its effect on reporter gene expression in tobacco plants. The synthetic MAR was a multimer of a short sequence from the MAR 3' end of the immunoglobulin heavy chain (IgH) enhancer. This sMAR sequence was used to flank the beta-glucuronidase (GUS) reporter gene within the T-DNA of the binary vector pBI121. Vectors with or without the sMARs were then used to transform tobacco plants by Agrobacterium tumefaciens. Transgenic plants containing the sMAR sequences flanking the GUS gene exhibited higher levels of transgene expression compared with transgenic plants which lacked the sMARs. This effect was observed independently of the position of the sMAR at the 5' side of the reporter gene. However, variation of the detected transgene expression was significant in all transformed plant populations, irrespective of the construct used.

Identification of DNA elements cooperatively activating proopiomelanocortin gene expression in the pituitary glands of transgenic mice

1992 ◽  
Vol 12 (9) ◽  
pp. 3978-3990
Author(s):  
B Liu ◽  
G D Hammer ◽  
M Rubinstein ◽  
M Mortrud ◽  
M J Low
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Reporter Gene ◽  
Transgene Expression ◽  
Intermediate Lobe ◽  
Mobility Shift ◽  
Specific Expression ◽  
Dna Elements ◽  
Pomc Gene

The proopiomelanocortin (POMC) gene is highly expressed in adult mouse pituitary anterior lobe corticotrophs and intermediate lobe melanotrophs. To identify the DNA elements important for this tissue-specific expression, we analyzed a series of POMC reporter genes in transgenic mice. A DNA fragment containing rat POMC 5'-flanking sequences from -323 to -34 recapitulated both basal pituitary cell-specific and hormonally stimulated expression in adult mice when fused to a heterologous thymidine kinase promoter. Developmental onset of the reporter gene expression lagged by 1 day but otherwise closely paralleled the normal ontogeny of murine POMC gene expression, including corticotroph activation at embryonic day 14.5 (E14.5) followed by melanotroph activation at E15.5 to E16.5. AtT20 corticotroph nuclear protein extracts interacted with three specific regions of the functional POMC promoter in DNase I protection assays. The positions of these protected sites were -107 to -160 (site 1), -182 to -218 (site 2), and -249 to -281 (site 3). Individual deletions of these footprinted sites did not alter transgene expression; however, the simultaneous deletion of sites 2 and 3 prevented transgene expression in both corticotrophs and melanotrophs. Electrophoretic mobility shift and Southwestern (DNA-protein) assays demonstrated that multiple AtT20 nuclear proteins bound to these footprinted sites. We conclude that the sequences between -323 and -34 of the rat POMC gene promoter are both necessary and sufficient for correct spatial, temporal, and hormonally regulated expression in the pituitary gland. Our data suggest that the three footprinted sites within the promoter are functionally interchangeable and act in combination with promoter elements between -114 and -34. The inability of any reporter gene construction to dissociate basal and hormonally stimulated expression suggests that these DNA elements are involved in both of these two characteristics of POMC gene expression in vivo.

HOX gene activation by retinoic acid

1991 ◽  
Vol 7 (1) ◽  
pp. 329-334 ◽  
Author(s):  
E Boncinelli
Keyword(s):  
Retinoic Acid ◽  
Gene Activation ◽  
Hox Gene

A preparation of high specific activity [11,12-3H]-9-cis-retinoic acid

1995 ◽  
Vol 36 (6) ◽  
pp. 587-594 ◽  
Author(s):  
Jotham W. Coe ◽  
Calvin R. Hawes ◽  
Patrick Towers
Keyword(s):  
Retinoic Acid ◽  
Specific Activity ◽  
High Specific Activity
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