scholarly journals The knirps and knirps-related genes organize development of the second wing vein in Drosophila

Development ◽  
1998 ◽  
Vol 125 (21) ◽  
pp. 4145-4154 ◽  
Author(s):  
K. Lunde ◽  
B. Biehs ◽  
U. Nauber ◽  
E. Bier
Keyword(s):  
Target Gene ◽  
Positional Information ◽  
Transcription Unit ◽  
Expression Domain ◽  
Anterior Border ◽  
Wing Vein ◽  
Cis Acting ◽  
Gap Gene ◽  
Wing Imaginal Discs ◽  
Wing Discs

The neighboring homologous knirps (kni) and knirps-related (knrl) genes in Drosophila encode transcription factors in the steroid hormone receptor superfamily. During early embryogenesis, kni functions as a gap gene to control expression of segmentation genes within the abdominal region of the embryo. In this study, we present evidence that kni and knrl link A/P positional information in larval wing imaginal discs to morphogenesis of the second longitudinal wing vein (L2). We show that kni and knrl are expressed in similar narrow stripes corresponding to the position of the L2 primordium. The kni and knrl L2 stripes abut the anterior border of the broad central expression domain of the Dpp target gene spalt major (salm). We provide evidence that radius incompletus (ri), a well-known viable mutant lacking the L2 vein, is a regulatory mutant of the kni/knrl locus. In ri mutant wing discs, kni and knrl fail to be expressed in the L2 primordium. In addition, the positions of molecular breakpoints in the kni/knrl locus indicate that the ri function is provided by cis-acting sequences upstream of the kni transcription unit. Epistasis tests reveal that the kni/knrl locus functions downstream of spalt major (salm) and upstream of genes required to initiate vein-versus-intervein differentiation. Mis-expression experiments suggest that kni and knrl expressing cells inhibit neighboring cells from becoming vein cells. Finally, kni and knrl are likely to refine the L2 position by positively auto-regulating their own expression and by providing negative feedback to repress salm expression. We propose a model in which the combined activities of kni and knrl organize development of the L2 vein in the appropriate position.

Expression and regulation of the abd-A gene of Drosophila

Development ◽  
1990 ◽  
Vol 110 (4) ◽  
pp. 1197-1207 ◽  
Author(s):  
A. Macias ◽  
J. Casanova ◽  
G. Morata
Keyword(s):  
Transcription Unit ◽  
Normal Domain ◽  
Bithorax Complex ◽  
Posterior Border ◽  
Expression Domain ◽  
Anterior Border ◽  
Good Correspondence ◽  
Abnormal Distribution ◽  
Normal Expression ◽  
Specific Polyclonal Antibody

We have developed a specific polyclonal antibody that recognizes the protein products of the abdominal-A (abd-A) gene, a member of the bithorax complex of Drosophila. The normal expression domain extends from parasegments 7 to 13, in good correspondence with previous genetic and molecular results. However, while the anterior border of expression is precisely demarcated by a parasegmental boundary, the posterior border does not coincide with a lineage boundary. Within the normal domain, the expression of abd-A shows intrametameric modulation; the amount of product is higher in posterior compartments and in the most anterior cells of the anterior compartments and then gradually decreases. We have examined the effect on abd-A expression of a number of mutations, some mapping within and others outside the abd-A transcription unit. Those mapping to the transcription unit eliminate or severely reduce the amount of abd-A antigen, while those mapping outside produce an abnormal distribution of abd-A protein. Finally, we show that the abd-A gene is down-regulated in part of the Abdominal-B (Abd-B) domain, precisely in those regions where the Abd-B gene is expressed at high levels.

scholarly journals Feedback control of morphogen gradient scale

2019 ◽  
Author(s):  
Yilun Zhu ◽  
Yuchi Qiu ◽  
Weitao Chen ◽  
Qing Nie ◽  
Arthur D. Lander
Keyword(s):  
Gene Expression ◽  
Mathematical Modeling ◽  
Alternative Model ◽  
Genetic Manipulation ◽  
Morphogen Gradient ◽  
Expression Domain ◽  
Minimal Loss ◽  
Wing Imaginal Discs ◽  
Wing Discs ◽  
Gradient Scaling

SUMMARYGradients of the morphogen decapentaplegic (Dpp) pattern Drosophila wing imaginal discs, establishing gene expression boundaries at specific locations. As discs grow, Dpp gradients expand, keeping relative boundary positions approximately stationary. Such scaling fails in mutants for Pentagone (pent), a gene repressed by Dpp that encodes a diffusible protein that expands Dpp gradients. Although these properties fit a recent mathematical model of automatic gradient scaling, we show here that Pent lacks a property essential to that model—the ability to spread with minimal loss throughout the morphogen field. Instead, Pent’s actions appear confined to within a few cell diameters of its site of synthesis, and can be phenocopied by manipulating non-diffusible targets of Pent strictly within the Pent expression domain. Through genetic manipulation and mathematical modeling we develop an alternative model of scaling, driven by feedback down-regulation of Dpp receptors and co-receptors. Among the model’s predictions is a size limit beyond which scaling fails—something we observe directly in wing discs.

Reconstitution of the vitamin D-responsive osteocalcin transcription unit in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (8) ◽  
pp. 3517-3523
Author(s):  
D P McDonnell ◽  
J W Pike ◽  
D J Drutz ◽  
T R Butt ◽  
B W O'Malley
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Vitamin D ◽  
Transcription Factors ◽  
Promoter Activity ◽  
Transcription Unit ◽  
Proximal Promoter ◽  
Regulatory Sequences ◽  
Cis Acting ◽  
Osteocalcin Gene ◽  
Definition Of

The human osteocalcin gene is regulated in mammalian osteoblasts by 1,25(OH)2D3-dependent and -independent mechanisms. The sequences responsible for this activity have been mapped to within the -1339 region of the gene. We show here that this enhancer region functions analogously in Saccharomyces cerevisiae cells engineered to produce active 1,25(OH)2D3 receptor. When fused to the proximal promoter elements of the yeast iso-1-cytochrome c gene, the enhancer demonstrated substantial promoter activity. This activity was elevated further by 1,25(OH)2D3 when the reporter constructs were assayed in cells containing the 1,25(OH)2D3 receptor. This system affords a model for 1,25(OH)2D3 action and represents a simple assay system that will enable definition of the important cis-acting regulatory sequences within the osteocalcin gene and identification of their cognate transcription factors.

scholarly journals Successive specification of Drosophila neuroblasts NB 6-4 and NB 7-3 depends on interaction of the segment polarity genes wingless, gooseberry and naked cuticle

Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3253-3261 ◽  
Author(s):  
Nirupama Deshpande ◽  
Rainer Dittrich ◽  
Gerhard M. Technau ◽  
Joachim Urban
Keyword(s):  
Cell Fate ◽  
Cell Lineage ◽  
Positional Information ◽  
Dorsoventral Patterning ◽  
Expression Domain ◽  
Direct Role ◽  
Segment Polarity Genes ◽  
Segment Polarity ◽  
Unique Identity

The Drosophila central nervous system derives from neural precursor cells, the neuroblasts (NBs), which are born from the neuroectoderm by the process of delamination. Each NB has a unique identity, which is revealed by the production of a characteristic cell lineage and a specific set of molecular markers it expresses. These NBs delaminate at different but reproducible time points during neurogenesis (S1-S5) and it has been shown for early delaminating NBs (S1/S2) that their identities depend on positional information conferred by segment polarity genes and dorsoventral patterning genes. We have studied mechanisms leading to the fate specification of a set of late delaminating neuroblasts, NB 6-4 and NB 7-3, both of which arise from the engrailed (en) expression domain, with NB 6-4 delaminating first. In contrast to former reports, we did not find any evidence for a direct role of hedgehog in the process of NB 7-3 specification. Instead, we present evidence to show that the interplay of the segmentation genes naked cuticle (nkd) and gooseberry (gsb), both of which are targets of wingless (wg) activity, leads to differential commitment to NB 6-4 and NB 7-3 cell fate. In the absence of either nkd or gsb, one NB fate is replaced by the other. However, the temporal sequence of delamination is maintained, suggesting that formation and specification of these two NBs are under independent control.

Different contributions of pannier and wingless to the patterning of the dorsal mesothorax of Drosophila

Development ◽  
1999 ◽  
Vol 126 (16) ◽  
pp. 3523-3532 ◽  
Author(s):  
M.J. Garcia-Garcia ◽  
P. Ramain ◽  
P. Simpson ◽  
J. Modolell
Keyword(s):  
Transcription Factor ◽  
Concentration Gradient ◽  
Positional Information ◽  
Secreted Protein ◽  
Expression Domain ◽  
Similar Role ◽  
Finger Protein ◽  
Proneural Cluster ◽  
Gata Family ◽  
Permissive Role

In Drosophila, the GATA family transcription factor Pannier and the Wnt secreted protein Wingless are known to be important for the patterning of the notum, a part of the dorsal mesothorax of the fly. Thus, both proteins are necessary for the development of the dorsocentral mechanosensory bristles, although their roles in this process have not been clarified. Here, we show that Pannier directly activates the proneural genes achaete and scute by binding to the enhancer responsible for the expression of these genes in the dorsocentral proneural cluster. Moreover, the boundary of the expression domain of Pannier appears to delimit the proneural cluster laterally, while antagonism of Pannier function by the Zn-finger protein U-shaped sets its limit dorsally. So, Pannier and U-shaped provide positional information for the patterning of the dorsocentral cluster. In contrast and contrary to previous suggestions, Wingless does not play a similar role, since the levels and vectorial orientation of its concentration gradient in the dorsocentral area can be greatly modified without affecting the position of the dorsocentral cluster. Thus, Wingless has only a permissive role on dorsocentral achaete-scute expression. We also provide evidence indicating that Pannier and U-shaped are main effectors of the regulation of wingless expression in the presumptive notum.

scholarly journals Sequences regulating temporal poly(A) site switching in the adenovirus major late transcription unit.

1991 ◽  
Vol 11 (12) ◽  
pp. 5977-5984 ◽  
Author(s):  
J D DeZazzo ◽  
E Falck-Pedersen ◽  
M J Imperiale
Keyword(s):  
Regulatory Element ◽  
Transcription Unit ◽  
Late Infection ◽  
Cis Acting ◽  
Temporal Regulation ◽  
Deletion Mutagenesis ◽  
Late Transcription ◽  
A Site ◽  
Adenovirus Recombinant ◽  
Selection Of

Temporal regulation of poly(A) site choice occurs in an adenovirus recombinant encoding a miniature version of the major late transcription unit with two poly(A) sites, L1 and L3. Using deletion mutagenesis, we have looked directly for cis-acting elements regulating poly(A) site choice in this recombinant. From this work, we draw two main conclusions. First, elements other than the AAUAAA and downstream sequences of the L1 poly(A) site are required for temporal regulation of poly(A) site choice during infection. Second, these regions function in two distinct modes during infection. The two regions enhance selection of the L1 poly(A) site in an additive manner during an early infection, but deletion of either element abolishes the switch in poly(A) site choice during a late infection. This work documents the first example of a regulatory element downstream of a core poly(A) region.

scholarly journals Modulation of Hedgehog target gene expression by the Fused serine–threonine kinase in wing imaginal discs

1998 ◽  
Vol 78 (1-2) ◽  
pp. 17-31 ◽  
Author(s):  
Georges Alves ◽  
Bernadette Limbourg-Bouchon ◽  
Hervé Tricoire ◽  
Jeanine Brissard-Zahraoui ◽  
Claudie Lamour-Isnard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Gene ◽  
Imaginal Discs ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Target Gene Expression ◽  
Wing Imaginal Discs

scholarly journals Expression of wingless in the Drosophila embryo: a conserved cis-acting element lacking conserved Ci-binding sites is required for patched-mediated repression

Development ◽  
1998 ◽  
Vol 125 (8) ◽  
pp. 1469-1476 ◽  
Author(s):  
D. Lessing ◽  
R. Nusse
Keyword(s):  
Binding Sites ◽  
Transmembrane Protein ◽  
Cell Communication ◽  
Signal Transduction Pathway ◽  
Transcription Unit ◽  
Drosophila Virilis ◽  
Negative Regulator ◽  
Drosophila Embryo ◽  
Cis Acting ◽  
Hh Signaling

Patterning of the Drosophila embryo depends on the accurate expression of wingless (wg), which encodes a secreted signal required for segmentation and many other processes. Early expression of wg is regulated by the nuclear proteins of the gap and pair-rule gene classes but, after gastrulation, wg transcription is also dependent on cell-cell communication. Signaling to the Wg-producing cells is mediated by the secreted protein, Hedgehog (Hh), and by Cubitus interruptus (Ci), a transcriptional effector of the Hh signal transduction pathway. The transmembrane protein Patched (Ptc) acts as a negative regulator of wg expression; ptc- embryos have ectopic wg expression. According to the current models, Ptc is a receptor for Hh. The default activity of Ptc is to inhibit Ci function; when Ptc binds Hh, this inhibition is released and Ci can control wg transcription. We have investigated cis-acting sequences that regulate wg during the time that wg expression depends on Hh signaling. We show that approximately 4.5 kb immediately upstream of the wg transcription unit can direct expression of the reporter gene lacZ in domains similar to the normal wg pattern in the embryonic ectoderm. Expression of this reporter construct expands in ptc mutants and responds to hh activity. Within this 4.5 kb, a 150 bp element, highly conserved between D. melanogaster and Drosophila virilis, is required to spatially restrict wg transcription. Activity of this element depends on ptc, but it contains no consensus Ci-binding sites. The discovery of an element that is likely to bind a transcriptional repressor was unexpected, since the prevailing model suggests that wg expression is principally controlled by Hh signaling acting through the Ci activator. We show that wg regulatory DNA can drive lacZ in a proper wg-like pattern without any conserved Ci-binding sites and suggest that Ci can not be the sole endpoint of the Hh pathway.

Evolutionary conservation of homeodomain-binding sites and other sequences upstream and within the major transcription unit of the Drosophila segmentation gene engrailed

1989 ◽  
Vol 9 (10) ◽  
pp. 4304-4311
Author(s):  
J A Kassis ◽  
C Desplan ◽  
D K Wright ◽  
P H O'Farrell
Keyword(s):  
Binding Sites ◽  
Regulatory Region ◽  
Divergence Time ◽  
Evolutionary Conservation ◽  
Transcription Unit ◽  
Regulatory Proteins ◽  
Coding Region ◽  
Cis Acting ◽  
Perfect Sequence ◽  
Development Proceeds

The engrailed (en) gene functions throughout Drosophila development and is expressed in a succession of intricate spatial patterns as development proceeds. Normal en function relies on an extremely large cis-acting regulatory region (70 kilobases). We are using evolutionary conservation to help identify en sequences important in regulating patterned expression. Sequence comparison of 2.6 kilobases upstream of the en coding region of D. melanogaster and D. virilis (estimated divergence time, 60 million years) showed that 30% of this DNA occurs in islands of near perfect sequence conservation. One of these conserved islands contains binding sites for homeodomain-containing proteins. It has been shown genetically that homeodomain-containing proteins regulate en expression. Our data suggested that this regulation may be direct. The remaining conserved islands may contain binding sites for other regulatory proteins.

Multiple cis-acting targeting sequences are required for orb mRNA localization during Drosophila oogenesis

1994 ◽  
Vol 14 (4) ◽  
pp. 2235-2242
Author(s):  
V Lantz ◽  
P Schedl
Keyword(s):  
Untranslated Region ◽  
Germ Line ◽  
Critical Role ◽  
Positional Information ◽  
Mrna Localization ◽  
Early Embryo ◽  
Developmental Systems ◽  
Localization Pattern ◽  
Cis Acting ◽  
Anterior Posterior

The targeting of positional information to specific regions of the oocyte or early embryo is one of the key processes in establishing anterior-posterior and dorsal-ventral polarity. In many developmental systems, this is accomplished by localization of mRNAs. The germ line-specific Drosophila orb gene plays a critical role in defining both axes of the developing oocyte, and its mRNA is localized in a complex pattern during oogenesis. We have identified a 280-bp sequence from the orb 3' untranslated region capable of reproducing this complex localization pattern. Furthermore, we have found that multiple cis-acting elements appear to be required for proper targeting of orb mRNA.

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