Neurogenic expression of snail is controlled by separable CNS and PNS promoter elements

Development ◽  
1994 ◽  
Vol 120 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Y.T. Ip ◽  
M. Levine ◽  
E. Bier
Keyword(s):  
Regulatory Region ◽  
Neural Element ◽  
Proneural Gene ◽  
Lacz Expression ◽  
Proneural Genes ◽  
Growing Body ◽  
Mesoderm Formation ◽  
Separate Control ◽  
Early Neurogenesis ◽  
Developing Nervous System

The Drosophila snail (sna) gene is first expressed in cells giving rise to mesoderm and is required for mesoderm formation. sna is subsequently expressed in the developing nervous system. sna expression during neurogenesis evolves from segmentally repeated neuroectodermal domains to a pan-neural pattern. We have identified a 2.8 kb regulatory region of the sna promoter that drives LacZ expression in a faithful neuronal pattern. Deletion analysis of this region indicates that the pan-neural element is composed of separable CNS and PNS components. This finding is unexpected since all known genes controlling early neurogenesis, including the proneural genes (i.e. da and AS-C), are expressed in both the CNS and PNS. We also show that expression of sna during neurogenesis is largely independent of the proneural genes da and AS-C. The separate control of CNS and PNS sna expression and independence of proneural gene regulation add to a growing body of evidence that current genetic models of neurogenesis are substantially incomplete.

Neurogenic genes control gene expression at the transcriptional level in early neurogenesis and in mesectoderm specification

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 219-224 ◽  
Author(s):  
M.D. Martin-Bermudo ◽  
A. Carmena ◽  
F. Jimenez
Keyword(s):  
Posttranscriptional Regulation ◽  
Drosophila Embryo ◽  
Transcriptional Level ◽  
Proneural Gene ◽  
Proneural Genes ◽  
Protein Levels ◽  
Neurogenic Genes ◽  
The Central Nervous System ◽  
Early Neurogenesis ◽  
The Relationship

The development of the central nervous system in the Drosophila embryo is initiated by the acquisition of neural potential by clusters of ectodermal cells, promoted by the activity of proneural genes. Proneural gene function is antagonized by neurogenic genes, resulting in the realization of the neural potential in a single cell per cluster. To analyse the relationship between proneural and neurogenic genes, we have studied, in specific proneural clusters and neuroblasts of wild-type and neurogenic mutants embryos, the expression at the RNA and protein levels of lethal of scute, the most important known proneural gene in central neurogenesis. We find that the restriction of lethal of scute expression that accompanies the restriction of the neural potential to the delaminating neuroblast is regulated at the transcriptional level by neurogenic genes. These genes, however, do not control the size of proneural clusters. Moreover, available antibodies do not provide evidence for an hypothetical posttranscriptional regulation of proneural proteins by neurogenic genes. We also find that neurogenic genes are required for the specification of the mesectoderm. This has been shown for neuralized and Notch, and could also be the case for Delta and for the Enhancer of split gene complex. Neurogenic genes would control at the transcriptional level the repression of proneural genes and the activation of single-minded in the anlage of the mesectoderm.

The ventral nervous system defective gene controls proneural gene expression at two distinct steps during neuroblast formation in Drosophila

Development ◽  
1994 ◽  
Vol 120 (6) ◽  
pp. 1517-1524 ◽  
Author(s):  
J.B. Skeath ◽  
G.F. Panganiban ◽  
S.B. Carroll
Keyword(s):  
Gene Expression ◽  
Nervous System ◽  
Cluster Formation ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Drosophila Embryo ◽  
Proneural Gene ◽  
Lacz Reporter ◽  
Proneural Genes ◽  
Proneural Cluster

Within the Drosophila embryo, the formation of many neuroblasts depends on the functions of the proneural genes of the achaete-scute complex (AS-C): achaete (ac), scute (sc) and lethal of scute (l'sc), and the gene ventral nervous system defective (vnd). Here, we show that vnd controls neuroblast formation, in part, through its regulation of the proneural genes of the AS-C. vnd is absolutely required to activate ac, sc and l'sc gene expression in proneural clusters in specific domains along the medial column of the earliest arising neuroblasts. Using ac-lacZ reporter constructs, we determined that vnd controls proneural gene expression at two distinct steps during neuroblast formation through separable regulatory regions. First, vnd is required to activate proneural cluster formation within the medial column of every other neuroblast row through regulatory elements located 3′ to ac; second, through a 5′ regulatory region, vnd functions to increase or maintain proneural gene expression in the cell within the proneural cluster that normally becomes the neuroblast. By following neuroblast segregation in vnd mutant embryos, we show that the neuroectoderm forms normally and that the defects in neuroblast formation are specific to particular proneural clusters.

On the organisation of the regulatory region of the zebrafish deltaD gene

Development ◽  
2002 ◽  
Vol 129 (20) ◽  
pp. 4773-4784 ◽  
Author(s):  
Stefan Hans ◽  
José A. Campos-Ortega
Keyword(s):  
Genomic Dna ◽  
Transcriptional Control ◽  
Regulatory Region ◽  
Notch Pathway ◽  
Notch Receptor ◽  
Regulatory Sequences ◽  
Early Neurogenesis ◽  
Regulatory Feedback Loop ◽  
E Boxes ◽  
Genomic Regions

deltaD is one of the four zebrafish Delta homologues presently known. Experimental evidence indicates that deltaD participates in a number of important processes during embryogenesis, including early neurogenesis and somitogenesis, whereby the protein it encodes acts as a ligand for members of the Notch receptor family. In accordance with its functional role, deltaD is transcribed in several domains of mesodermal and ectodermal origin during embryogenesis. We have analysed the organisation of the regulatory region of the deltaD gene using fusions to the reporter gene gfp and germline transgenesis. Cis-regulatory sequences are dispersed over a stretch of 12.5 kb of genomic DNA, and are organised in a similar manner to those in the regulatory region of the Delta-like 1 gene of mouse. Germline transformation using a minigene comprising 10.5 kb of this genomic DNA attached to the 3′ end of a full-length cDNA clone rescues the phenotype of embryos homozygous for the amorphic deltaD mutation after eightAR33. Several genomic regions that drive transcription in mesodermal and neuroectodermal domains have been identified. Transcription in all the neural expression domains, with one exception, is controlled by two relatively small genomic regions, which are regulated by the proneural proteins neurogenin 1 and zash1a/b acting as transcriptional activators that bind to so-called E-boxes. Transcriptional control of deltaD by proneural proteins therefore represents a molecular target for the regulatory feedback loop mediated by the Notch pathway in lateral inhibition.

her4, a zebrafish homologue of the Drosophila neurogenic gene E(spl), is a target of NOTCH signalling

Development ◽  
1999 ◽  
Vol 126 (9) ◽  
pp. 1811-1821 ◽  
Author(s):  
C. Takke ◽  
P. Dornseifer ◽  
E. v Weizsacker ◽  
J.A. Campos-Ortega
Keyword(s):  
Feedback Loop ◽  
Bhlh Protein ◽  
Primary Neurons ◽  
Amino Terminal ◽  
Early Neurogenesis ◽  
Regulatory Feedback Loop ◽  
Carboxy Terminal ◽  
Her4 Expression ◽  
Primary Neurogenesis ◽  
Developing Nervous System

her4 encodes a zebrafish bHLH protein of the hairy-E(spl) family. The gene is transcribed in a complex pattern in the developing nervous system and in the hypoblast. During early neurogenesis, her4 expression domains include the regions of the neural plate from which primary neurons arise, suggesting that the gene is involved in directing their development. Indeed, misexpression of specific her4 variants leads to a reduction in the number of primary neurons formed. The amino-terminal region of her4, including the basic domain, and the region between the putative helix IV and the carboxy-terminal tetrapeptide wrpw are essential for this effect, since her4 variants lacking either of these regions are non-functional. However, the carboxy-terminal wrpw itself is dispensable. We have examined the interrelationships between deltaD, deltaA, notch1, her4 and neurogenin1 by means of RNA injections. her4 is involved in a regulatory feedback loop which modulates the activity of the proneural gene neurogenin, and as a consequence, of deltaA and deltaD. Activation of notch1 leads to strong activation of her4, to suppression of neurogenin transcription and, ultimately, to a reduction in the number of primary neurons. These results suggest that her4 acts as a target of notch-mediated signals that regulate primary neurogenesis.

asense is a Drosophila neural precursor gene and is capable of initiating sense organ formation

Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 1-17 ◽  
Author(s):  
M. Brand ◽  
A.P. Jarman ◽  
L.Y. Jan ◽  
Y.N. Jan
Keyword(s):  
Ectopic Expression ◽  
Sense Organ ◽  
Neural Precursor Cells ◽  
Neural Precursor ◽  
Gene Products ◽  
Proneural Gene ◽  
Proneural Genes ◽  
Helix Loop Helix ◽  
Normal Gene ◽  
Proneural Cluster

Neural precursor cells in Drosophila arise from the ectoderm in the embryo and from imaginal disc epithelia in the larva. In both cases, this process requires daughterless and the proneural genes achaete, scute and lethal-of-scute of the achaete-scute complex. These genes encode basic helix-loop-helix proteins, which are nuclear transcription factors, as does the asense gene of the achaete-scute complex. Our studies suggest that asense is a neural precursor gene, rather than a proneural gene. Unlike the proneural achaete-scute gene products, the asense RNA and protein are found in the neural precursor during its formation, but not in the proneural cluster of cells that gives rise to the neural precursor cell. Also, asense expression persists longer during neural precursor development than the proneural gene products; it is still expressed after the first division of the neural precursor. Moreover, asense is likely to be downstream of the proneural genes, because (1) asense expression is affected in proneural and neurogenic mutant backgrounds, (2) ectopic expression of asense protein with an intact DNA-binding domain bypasses the requirement for achaete and scute in the formation of imaginal sense organs. We further note that asense ectopic expression is capable of initiating the sense organ fate in cells that do not normally require the action of asense. Our studies therefore serve as a cautionary note for the inference of normal gene function based on the gain-of-function phenotype after ectopic expression.

REGULATION OF THE put OPERON IN SALMONELLA TYPHIMURIUM: CHARACTERIZATION OF PROMOTER AND OPERATOR MUTATIONS

Genetics ◽  
1986 ◽  
Vol 114 (3) ◽  
pp. 687-703
Author(s):  
Donald R Hahn ◽  
Stanley R Maloy
Keyword(s):  
Regulatory Region ◽  
Lacz Expression ◽  
Proline Utilization ◽  
Single Operator ◽  
Regulatory Mutations ◽  
Operon Regulation ◽  
In Trans ◽  
Operon Expression ◽  
Operator Site

ABSTRACT The two genes required for proline utilization by S. typhimurium form a divergent operon. Expression of the put operon is induced by proline and subject to catabolite repression. Genetic evidence suggests that putA protein autogenously represses transcription of the putA and putP genes. In order to establish the molecular mechanism of put operon regulation we isolated regulatory mutations in the put control region. These mutants were selected using two phenotypes: (1) the ability to degrade a toxic proline analogue, dehydroproline, due to overexpression of putA enzyme activity, or (2) overexpression of lacZ from put::Mud operon fusions. The effect of each mutation on transcription in both directions was determined by measuring lacZ expression from putA and putP operon fusions. These regulatory mutations were cis-dominant when the putA protein was provided in trans, and they map in a region between the two genes. The phenotypes of the mutants suggest that (1) the put regulatory region has a single operator site where the putA protein binds to repress transcription in both directions, and (2) the putA and putP promoters overlap.

scholarly journals Drosophila Tufted Is a Gain-of-Function Allele of the Proneural Gene amos

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1413-1425 ◽  
Author(s):  
Eric C Lai
Keyword(s):  
Molecular Evidence ◽  
Proneural Gene ◽  
Sensory Organs ◽  
Gain Of Function ◽  
Proneural Genes ◽  
Bhlh Proteins ◽  
Do So ◽  
Drosophila Mutant

Abstract Tufted is a classical Drosophila mutant characterized by a large number of ectopic mechanosensory bristles on the dorsal mesothorax. Unlike other ectopic bristle mutants, Tufted is epistatic to achaete and scute, the proneural genes that normally control the development of these sensory organs. In this report, I present genetic and molecular evidence that Tufted is a gain-of-function allele of the proneural gene amos that ectopically activates mechanosensory neurogenesis. I also systematically examine the ability of the various proneural bHLH proteins to cross-activate each other and find that their ability to do so is in general relatively limited, despite their common ability to induce the formation of mechanosensory bristles. This phenomenon seems instead to be related to their shared ability to activate Asense and Senseless.

Deficits in Selective Attention Alter Gait in Frail Older Adults

GeroPsych ◽  
2016 ◽  
Vol 29 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Véronique Cornu ◽  
Jean-Paul Steinmetz ◽  
Carine Federspiel
Keyword(s):  
Older Adults ◽  
Nursing Home ◽  
Selective Attention ◽  
Dual Task ◽  
Nursing Home Residents ◽  
Gait Rehabilitation ◽  
Rehabilitation Programs ◽  
Gait Parameters ◽  
Growing Body ◽  
Task Conditions

Abstract. A growing body of research demonstrates an association between gait disorders, falls, and attentional capacities in older adults. The present work empirically analyzes differences in gait parameters in frail institutionalized older adults as a function of selective attention. Gait analysis under single- and dual-task conditions as well as selective attention measures were collected from a total of 33 nursing-home residents. We found that differences in selective attention performances were related to the investigated gait parameters. Poorer selective attention performances were associated with higher stride-to-stride variabilities and a slowing of gait speed under dual-task conditions. The present findings suggest a contribution of selective attention to a safe gait. Implications for gait rehabilitation programs are discussed.

How Do People Share Their Positive Events?

2016 ◽  
Vol 37 (4) ◽  
pp. 250-259 ◽  
Author(s):  
Cara A. Palmer ◽  
Meagan A. Ramsey ◽  
Jennifer N. Morey ◽  
Amy L. Gentzler
Keyword(s):  
Cluster Analysis ◽  
Communication Technology ◽  
Big Five ◽  
Well Being ◽  
Big Five Personality Traits ◽  
Big Five Personality ◽  
Positive Events ◽  
Growing Body ◽  
Sharing Patterns ◽  
Practical Implications

Abstract. Research suggests that sharing positive events with others is beneficial for well-being, yet little is known about how positive events are shared with others and who is most likely to share their positive events. The current study expanded on previous research by investigating how positive events are shared and individual differences in how people share these events. Participants (N = 251) reported on their likelihood to share positive events in three ways: capitalizing (sharing with close others), bragging (sharing with someone who may become jealous or upset), and mass-sharing (sharing with many people at once using communication technology) across a range of positive scenarios. Using cluster analysis, five meaningful profiles of sharing patterns emerged. These profiles were associated with gender, Big Five personality traits, narcissism, and empathy. Individuals who tended to brag when they shared their positive events were more likely to be men, reported less agreeableness, less conscientiousness, and less empathy, whereas those who tended to brag and mass-share reported the highest levels of narcissism. These results have important theoretical and practical implications for the growing body of research on sharing positive events.

‘The well-known, old, but still unbeaten track’: Women Poets and Irish Periodical Culture in the Mid-Twentieth Century

2012 ◽  
Vol 42 (1) ◽  
pp. 32-52 ◽  
Author(s):  
Anne Mulhall
Keyword(s):  
Twentieth Century ◽  
Literary Culture ◽  
Woman Writer ◽  
Double Bind ◽  
Women Poets ◽  
Substantial Body ◽  
Growing Body ◽  
Critical Attention ◽  
Irish Women ◽  
Under Construction

While neglected Irish male poets of the mid century have seen some recuperation in recent decades, the work of Irish women poets still languishes in obscurity. A growing body of scholarship has identified the need to bring critical attention to bear on this substantial body of work. In this essay I explore the positioning of Irish women poets in mid-century periodical culture, to flesh out the ways in which the terms of this ‘forgetting’ are already established within the overwhelmingly masculinist homosocial suppositions and idioms that characterized contemporary debates about the proper lineage and aesthetic norms for the national literary culture that was then under construction. Within the terms set by those debates, the woman writer was caught in the double bind that afflicted any woman wishing to engage in a public, politicized forum in post-revolutionary Ireland. While women poets engage in sporadic or oblique terms with such literary and cultural debates, more often their voices are absent from these dominant discourses – the logic of this absence has continued in the occlusion of these women poets from the national poetic canon.

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