Maternal-effect mutations altering the anterior-posterior pattern of the Drosophila embryo

1986 ◽  
Vol 195 (5) ◽  
pp. 302-317 ◽  
Author(s):  
Trudi Sch�pbach ◽  
Eric Wieschaus
Keyword(s):  
Maternal Effect ◽  
Drosophila Embryo ◽  
Anterior Posterior

scholarly journals THE GENETICS OF THE DORSAL-BICAUDAL-D REGION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 113 (3) ◽  
pp. 665-678
Author(s):  
Ruth Steward ◽  
Christiane Nüsslein-Volhard
Keyword(s):  
Maternal Effect ◽  
Complementation Group ◽  
Drosophila Embryo ◽  
Temperature Sensitive ◽  
X Ray ◽  
Dominant Phenotype ◽  
Maternal Effect Genes ◽  
D Region ◽  
Complementation Groups ◽  
Anterior Posterior

ABSTRACT The chromosomal region 36C on 2L contains two maternal-effect loci, dorsal (dl) and Bicaudal-D (Bic-D), which are involved in establishing polarity of the Drosophila embryo along the dorsal-ventral and anterior-posterior axes, respectively. To analyze the region genetically, we isolated X-ray-induced dorsal alleles, which we recognized by virtue of the haplo-insufficient temperature-sensitive dorsal-dominant phenotype in progeny of single females heterozygous for a mutagenized chromosome. From the 20,000 chromosomes tested, we isolated three deficiencies, two inversions with breakpoint in dl and one apparent dl point mutant. One of the deficiencies, Df(2L)H20 (36A6,7; 36F1,2) was used to screen for EMS-induced lethal- and maternal-effect mutants mapping in the vicinity of dl and Bic-D. We isolated 44 lethal mutations defining 11 complementation groups. We also recovered as maternal-effect mutations four dl alleles, as well as six alleles of quail and one allele of kelch, two previously identified maternal-effect genes. Through complementation tests with various viable mutants and deficiencies in the region, a total of 18 loci were identified in an interval of about 30 cytologically visible bands. The region was subdivided into seven subregions by deficiency breakpoints. One lethal complementation group as well as the two maternal loci, Bic-D and quail, are located in the same deficiency interval as is dl.

scholarly journals Effects of the maternal factor Zelda on zygotic enhancer activity in the Drosophila embryo

2018 ◽  
Author(s):  
Xiao-Yong Li ◽  
Michael B. Eisen
Keyword(s):  
Binding Sites ◽  
Expression Patterns ◽  
Drosophila Embryo ◽  
Temporal Expression ◽  
Reporter Construct ◽  
Limited Effect ◽  
Enhancer Activity ◽  
Maternal Factor ◽  
Anterior Posterior

AbstractThe maternal factor Zelda is broadly bound to zygotic enhancers during early fly embryogenesis, and has been shown to be important for the expression of a large number of genes. However, its function remains poorly understood. Here, we carried out detailed analysis of the functional role of Zelda on the activities of a group of enhancers that drive patterned gene expression along the anterior -posterior axis. We found that among these enhancers, only one lost its activity entirely when all its Zelda bind sites were mutated. For all others, mutations of all of their Zelda binding sites only had limited effect, which varied temporally and spatially. These results suggest that Zld may exert a quantitative effect on a broad range of enhancers, which presumably is critical to generate highly diverse spatial and temporal expression patterns for different genes in the developmental gene network in fly embryo. Lastly, we found that the observed effect of Zelda site mutations was much stronger when a mutant enhancer was tested using a BAC based reporter construct than a simple reporter construct, suggesting that the effect of Zld is dependent on chromatin environment.

Genes that control dorsoventral polarity affect gene expression along the anteroposterior axis of the Drosophila embryo

Development ◽  
1987 ◽  
Vol 99 (3) ◽  
pp. 327-332 ◽  
Author(s):  
S.B. Carroll ◽  
G.M. Winslow ◽  
V.J. Twombly ◽  
M.P. Scott
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Maternal Effect ◽  
Positional Information ◽  
Drosophila Embryo ◽  
Dorsoventral Polarity ◽  
Anteroposterior Axis ◽  
Positional Marker ◽  
Control Pattern ◽  
The Relationship

At least 13 genes control the establishment of dorsoventral polarity in the Drosophila embryo and more than 30 genes control the anteroposterior pattern of body segments. Each group of genes is thought to control pattern formation along one body axis, independently of the other group. We have used the expression of the fushi tarazu (ftz) segmentation gene as a positional marker to investigate the relationship between the dorsoventral and anteroposterior axes. The ftz gene is normally expressed in seven transverse stripes. Changes in the striped pattern in embryos mutant for other genes (or progeny of females homozygous for maternal-effect mutations) can reveal alterations of cell fate resulting from such mutations. We show that in the absence of any of ten maternal-effect dorsoventral polarity gene functions, the characteristic stripes of ftz protein are altered. Normally there is a difference between ftz stripe spacing on the dorsal and ventral sides of the embryo; in dorsalized mutant embryos the ftz stripes appear to be altered so that dorsal-type spacing occurs on all sides of the embryo. These results indicate that cells respond to dorsoventral positional information in establishing early patterns of gene expression along the anteroposterior axis and that there may be more significant interactions between the different axes of positional information than previously determined.

A common translational control mechanism functions in axial patterning and neuroendocrine signaling inDrosophila

Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3325-3334 ◽  
Author(s):  
Ira E. Clark ◽  
Krista C. Dobi ◽  
Heather K. Duchow ◽  
Anna N. Vlasak ◽  
Elizabeth R. Gavis
Keyword(s):  
Gene Expression ◽  
Translational Control ◽  
Ectopic Expression ◽  
Drosophila Embryo ◽  
Control Element ◽  
Molting Cycle ◽  
Axial Patterning ◽  
Cis Acting ◽  
Maternal Mrnas ◽  
Anterior Posterior

Translational repression of maternal nanos (nos) mRNA by a cis-acting Translational Control Element (TCE) in the nos 3′UTR is critical for anterior-posterior patterning of the Drosophila embryo. We show, through ectopic expression experiments, that the nos TCE is capable of repressing gene expression at later stages of development in neuronal cells that regulate the molting cycle. Our results predict additional targets of TCE-mediated repression within the nervous system. They also suggest that mechanisms that regulate maternal mRNAs, like TCE-mediated repression, may function more widely during development to spatially or temporally control gene expression.

scholarly journals Dynamics of hunchback translation in real time and at single mRNA resolution in the Drosophila embryo

Development ◽  
2021 ◽  
pp. dev.196121
Author(s):  
Daisy J. Vinter ◽  
Caroline Hoppe ◽  
Thomas G. Minchington ◽  
Catherine Sutcliffe ◽  
Hilary L. Ashe
Keyword(s):  
Single Molecule ◽  
Translational Regulation ◽  
Mrna Translation ◽  
Drosophila Embryo ◽  
Translational Repression ◽  
Expression Domain ◽  
Culture Cells ◽  
Spatiotemporal Regulation ◽  
Developmental Patterning ◽  
Anterior Posterior

The Hunchback (Hb) transcription factor is critical for anterior-posterior patterning of the Drosophila embryo. Despite the maternal hb mRNA acting as a paradigm for translational regulation, due to its repression in the posterior of the embryo, little is known about the translatability of zygotically transcribed hb mRNAs. Here we adapt the SunTag system, developed for imaging translation at single mRNA resolution in tissue culture cells, to the Drosophila embryo to study the translation dynamics of zygotic hb mRNAs. Using single-molecule imaging in fixed and live embryos, we provide evidence for translational repression of zygotic SunTag-hb mRNAs. While the proportion of SunTag-hb mRNAs translated is initially uniform, translation declines from the anterior over time until it becomes restricted to a posterior band in the expression domain. We discuss how regulated hb mRNA translation may help establish the sharp Hb expression boundary, which is a model for precision and noise during developmental patterning. Overall, our data show how use of the SunTag method on fixed and live embryos is a powerful combination for elucidating spatiotemporal regulation of mRNA translation in Drosophila.

Activation of the easter zymogen is regulated by five other genes to define dorsal-ventral polarity in the Drosophila embryo

Development ◽  
1992 ◽  
Vol 115 (2) ◽  
pp. 607-616 ◽  
Author(s):  
R. Chasan ◽  
Y. Jin ◽  
K.V. Anderson
Keyword(s):  
Maternal Effect ◽  
Serine Proteases ◽  
Drosophila Embryo ◽  
Vitelline Membrane ◽  
Mutant Form ◽  
Wild Type ◽  
Zymogen Activation ◽  
Embryonic Polarity ◽  
Dominant Mutant ◽  
Maternal Effect Genes

The product of the Drosophila easter gene, a member of the trypsin family of serine proteases, must be more active ventrally than dorsally to promote normal embryonic polarity. The majority of the easter protein in the embryo is present in the unprocessed zymogen form and appears to be evenly distributed in the extracellular space, indicating that the asymmetric activity of wild-type easter must arise post-translationally. A dominant mutant form of easter that does not require cleavage of the zymogen for activity (ea delta N) is active both dorsally and ventrally. The ea delta N mutant bypasses the requirement for five other maternal effect genes, indicating that these five genes exert their effects on dorsal-ventral patterning solely by controlling the activation of the easter zymogen. We propose that dorsal-ventral asymmetry is initiated by a ventrally-localized molecule in the vitelline membrane that nucleates an easter zymogen activation complex, leading to the production of ventrally active easter enzyme.

fushi tarazu protein expression in the cellular blastoderm of Drosophila detected using a novel imaging technique

Development ◽  
1989 ◽  
Vol 106 (1) ◽  
pp. 95-103 ◽  
Author(s):  
T.L. Karr ◽  
T.B. Kornberg
Keyword(s):  
Transcriptional Regulation ◽  
Protein Expression ◽  
Transcriptional Control ◽  
Imaging Technique ◽  
Drosophila Embryo ◽  
Immunoperoxidase Technique ◽  
Fushi Tarazu ◽  
Post Transcriptional Regulation ◽  
Blastoderm Stage ◽  
Anterior Posterior

The fushi tarazu (ftz) gene is essential for segmentation of the Drosophila embryo. This requirement is reflected at the cellular blastoderm stage of embryogenesis by seven transverse stripes of ftz expression. These stripes correspond to the missing segments of ftz mutant embryos. We describe here novel intermediate patterns of ftz protein expression which were detected in younger embryos by using anti-ftz antibodies and a sensitive fluorescence/immunoperoxidase technique (‘filtered fluorescence imaging’, FFI). Striped patterns of ftz protein evolved continuously, and the different stripes appeared in an ordered sequence, involving both anterior-posterior (A/P) and dorsal-ventral (D/V) progressions. Comparison of these patterns of ftz protein with those of ftz RNA suggests that these novel aspects of the patterning process involve post-transcriptional regulation in addition to the transcriptional control known to be involved in expression of this gene.

scholarly journals Embryonic geometry underlies phenotypic variation in decanalized conditions

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Anqi Huang ◽  
Jean-François Rupprecht ◽  
Timothy E Saunders
Keyword(s):  
Gene Expression ◽  
Aspect Ratio ◽  
Phenotypic Variation ◽  
Drosophila Embryo ◽  
Wild Type ◽  
Gap Gene ◽  
Key Factor ◽  
Segmentation Gene Expression ◽  
Environmental Variations ◽  
Anterior Posterior

During development, many mutations cause increased variation in phenotypic outcomes, a phenomenon termed decanalization. Phenotypic discordance is often observed in the absence of genetic and environmental variations, but the mechanisms underlying such inter-individual phenotypic discordance remain elusive. Here, using the anterior-posterior (AP) patterning of the Drosophila embryo, we identified embryonic geometry as a key factor predetermining patterning outcomes under decanalizing mutations. With the wild-type AP patterning network, we found that AP patterning is robust to variations in embryonic geometry; segmentation gene expression remains reproducible even when the embryo aspect ratio is artificially reduced by more than twofold. In contrast, embryonic geometry is highly predictive of individual patterning defects under decanalized conditions of either increased bicoid (bcd) dosage or bcd knockout. We showed that the phenotypic discordance can be traced back to variations in the gap gene expression, which is rendered sensitive to the geometry of the embryo under mutations.

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