ladybird, a tandem of homeobox genes that maintain late wingless expression in terminal and dorsal epidermis of the Drosophila embryo

Development ◽  
1997 ◽  
Vol 124 (1) ◽  
pp. 91-100 ◽  
Author(s):  
K. Jagla ◽  
T. Jagla ◽  
P. Heitzler ◽  
G. Dretzen ◽  
F. Bellard ◽  
...  
Keyword(s):  
Homeobox Gene ◽  
The Body ◽  
Drosophila Embryo ◽  
Anal Plate ◽  
Regulatory Interactions ◽  
Cdna Sequences ◽  
Complete Inactivation ◽  
Segment Polarity ◽  
Regulatory Feedback Loop ◽  
Dorsal Epidermis

ladybird early and ladybird late genes, tandemly located in the Drosophila 93E homeobox gene cluster, encode highly related homeodomain-containing transcription factors. Here we report the cloning of the complete cDNA sequences of both genes and a study of their expression and regulatory interactions with the segment polarity gene wingless in the epidermis. ladybird genes are co-expressed with wingless in epidermal cells close to the posterior parasegmental boundaries and in terminal regions of the body. In mutant embryos with altered wingless function, transcription of ladybird early and ladybird late is changed; it disappears completely from the epidermis in wingless-embryos, indicating wingless-dependence. After 6 hours of development, wingless expression is maintained by gooseberry in the ventral epidermis. However, in the dorsal epidermis and the terminal regions of the body, expression of wingless is independent of gooseberry but requires a wingless-ladybird regulatory feedback loop. Loss of ladybird function reduces the number of wingless-expressing cells in dorsal epidermis and leads to complete inactivation of wingless in the anal plate. Consequently, mutant ladybird embryos fail to develop anal plates and ubiquitous embryonic expression of either one or both ladybird genes leads to severe defects of the dorsal cuticle. Lack of late wingless expression and anal plate formation can be rescued with the use of a heat-shock-ladybird transgene.

The molecular basis for metameric pattern in the Drosophila embryo

Development ◽  
1987 ◽  
Vol 101 (1) ◽  
pp. 1-22 ◽  
Author(s):  
M. Akam
Keyword(s):  
Molecular Basis ◽  
Subsequent Development ◽  
The Body ◽  
Drosophila Embryo ◽  
Homeotic Genes ◽  
Simple Pattern ◽  
Segment Polarity ◽  
Maternal Determinants ◽  
Segment Pattern ◽  
Pair Rule

The metameric organization of the Drosophila embryo is generated in the first 5 h after fertilization. An initially rather simple pattern provides the foundation for subsequent development and diversification of the segmented part of the body. Many of the genes that control the formation of this pattern have been identified and at least twenty have been cloned. By combining the techniques of genetics, molecular biology and experimental embryology, it is becoming possible to unravel the role played by each of these genes. The repeating segment pattern is defined by the persistent expression of engrailed and of other genes of the ‘segment polarity’ class. The establishment of this pattern is directed by a transient molecular prepattern that is generated in the blastoderm by the activity of the ‘pair-rule’ genes. Maternal determinants at the poles of the egg coordinate this prepattern and define the anteroposterior sequence of pattern elements. The primary effect of these determinants is not known, but genes required for their production have been identified and the product of one of these, bicoid is known to be localized at the anterior of the egg. One early consequence of their activity is to define domains along the A-P axis within which a series of ‘cardinal’ genes are transcribed. The activity of the cardinal genes is required both to coordinate the process of segmentation and to define the early domains of homeotic gene expression. Further interactions between the homeotic genes and other classes of segmentation genes refine the initial establishment of segment identities.

Probing Drosophila gene function by antisense RNA

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 422-425 ◽  
Author(s):  
Reinhard Schuh ◽  
Herbert Jäckle
Keyword(s):  
Antisense Rna ◽  
Germ Line ◽  
Conventional Technique ◽  
Transcription Unit ◽  
The Body ◽  
Mutant Phenotype ◽  
Drosophila Embryo ◽  
Alternative Approach ◽  
Pattern Forming ◽  
Germ Line Transformation

The conventional technique for assigning a particular genetic function to a cloned transcription unit has relied on the rescue of the mutant phenotype by germ line transformation. An alternative approach is to mimic a mutant phenotype by the use of antisense RNA injections to produce phenocopies. This approach has been successfully used to identify genes involved in early pattern forming processes in the Drosophila embryo. At the time when antisense RNA is injected, the embryo develops as a syncytium composed of about 5000 nuclei which share a common cytoplasm. The gene interactions required to establish the body plan occur before cellularization at the blastoderm stage. Thus the nuclei and their exported transcripts are accessible to the injected antisense RNA. The antisense RNA interferes with the endogenous RNA by an as yet unidentified mechanism. The extent of interference is only partial and produces phenocopies with characteristics of weak mutant alleles. In our lab and others, this approach has been successfully used to identify several genes required for normal Drosophila pattern formation.Key words: Drosophila segmentation, phenocopy, antisense RNA, Krüppel gene.

scholarly journals Novel patterns of homeotic protein accumulation in the head of the Drosophila embryo

Development ◽  
1989 ◽  
Vol 105 (1) ◽  
pp. 167-174 ◽  
Author(s):  
J.W. Mahaffey ◽  
R.J. Diederich ◽  
T.C. Kaufman
Keyword(s):  
Nerve Cord ◽  
Protein Product ◽  
Drosophila Embryo ◽  
Protein Accumulation ◽  
Homeotic Genes ◽  
Gene Products ◽  
Ventral Region ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Dorsal Epidermis

Antibodies that specifically recognize proteins encoded by the homeotic genes: Sex combs reduced, Deformed, labial and proboscipedia, were used to follow the distribution of these gene products during embryogenesis. The position of engrailed-expressing cells was used as a reference and staining conditions were established that could distinguish, among cells expressing engrailed, one of the homeotic proteins or both. Our observations demonstrate two important facts about establishing identity in the head segments. First, in contrast to the overlapping pattern of homeotic gene expression in the trunk segments, we observe a non-overlapping pattern in the head for those homeotic proteins required during embryogenesis. In contrast, the spatial accumulation of the protein product of the non-vital proboscipedia locus overlaps partially with the distribution of the Deformed and Sex combs reduced proteins in the maxillary and labial segments, respectively. Second, two of the proteins, Sex combs reduced and Deformed, have different dorsal and ventral patterns of accumulation. Dorsally, these proteins are expressed in segmental domains while, within the ventral region, a parasegmental register is observed. The boundary where this change in pattern occurs coincides with the junction between the ventral neurogenic region and the dorsal epidermis. After contraction of the germ band, when the nerve cord has completely separated from the epidermis, the parasegmental pattern is observed only within the ventral nerve cord while a segmental register is maintained throughout the epidermis.

scholarly journals Odd-paired controls frequency doubling in Drosophila segmentation by altering the pair-rule gene regulatory network

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Erik Clark ◽  
Michael Akam
Keyword(s):  
Gene Expression ◽  
Gene Regulatory Network ◽  
Regulatory Network ◽  
Frequency Doubling ◽  
Drosophila Embryo ◽  
Anteroposterior Patterning ◽  
Regulatory Interactions ◽  
Pair Rule Gene ◽  
Gene Regulatory ◽  
Pair Rule

The Drosophila embryo transiently exhibits a double-segment periodicity, defined by the expression of seven 'pair-rule' genes, each in a pattern of seven stripes. At gastrulation, interactions between the pair-rule genes lead to frequency doubling and the patterning of 14 parasegment boundaries. In contrast to earlier stages of Drosophila anteroposterior patterning, this transition is not well understood. By carefully analysing the spatiotemporal dynamics of pair-rule gene expression, we demonstrate that frequency-doubling is precipitated by multiple coordinated changes to the network of regulatory interactions between the pair-rule genes. We identify the broadly expressed but temporally patterned transcription factor, Odd-paired (Opa/Zic), as the cause of these changes, and show that the patterning of the even-numbered parasegment boundaries relies on Opa-dependent regulatory interactions. Our findings indicate that the pair-rule gene regulatory network has a temporally modulated topology, permitting the pair-rule genes to play stage-specific patterning roles.

Quantitative Analysis of Gene Function in the Drosophila Embryo

Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 273-284
Author(s):  
William D Tracey ◽  
Xiangqun Ning ◽  
Martin Klingler ◽  
Sunita G Kramer ◽  
J Peter Gergen
Keyword(s):  
Gene Function ◽  
Model Systems ◽  
Drosophila Embryo ◽  
Direct Role ◽  
Developmental Context ◽  
Maternal Mrna ◽  
Early Drosophila Embryo ◽  
Segment Polarity ◽  
Pair Rule

Abstract The specific functions of gene products frequently depend on the developmental context in which they are expressed. Thus, studies on gene function will benefit from systems that allow for manipulation of gene expression within model systems where the developmental context is well defined. Here we describe a system that allows for genetically controlled overexpression of any gene of interest under normal physiological conditions in the early Drosophila embryo. This regulated expression is achieved through the use of Drosophila lines that express a maternal mRNA for the yeast transcription factor GAL4. Embryos derived from females that express GAL4 maternally activate GAL4-dependent UAS transgenes at uniform levels throughout the embryo during the blastoderm stage of embryogenesis. The expression levels can be quantitatively manipulated through the use of lines that have different levels of maternal GAL4 activity. Specific phenotypes are produced by expression of a number of different developmental regulators with this system, including genes that normally do not function during Drosophila embryogenesis. Analysis of the response to overexpression of runt provides evidence that this pair-rule segmentation gene has a direct role in repressing transcription of the segment-polarity gene engrailed. The maternal GAL4 system will have applications both for the measurement of gene activity in reverse genetic experiments as well as for the identification of genetic factors that have quantitative effects on gene function in vivo.

The roles of hedgehog, wingless and lines in patterning the dorsal epidermis in Drosophila

Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1083-1092 ◽  
Author(s):  
P. Bokor ◽  
S. DiNardo
Keyword(s):  
Cell Types ◽  
Imaginal Discs ◽  
Drosophila Embryo ◽  
Cell Type ◽  
Signaling Center ◽  
Novel Interactions ◽  
Dorsal Epidermis ◽  
Segment Pattern

Rows of cells that flank the parasegment boundary make up a signaling center within the epidermis of the Drosophila embryo. Signals emanating from these cells, encoded by hedgehog (hh) and wingless (wg), are shown to be required for all segment pattern dorsally. Wg activity is required for the differentiation of one cell type, constituting half the parasegment. The gene lines appears to act in parallel to the Wg pathway in the elaboration of this cell type. Hh activity is responsible for three other cell types in the parasegment. Some cell types are specified as Hh activity and interfere with the function of patched, analogous to patterning of imaginal discs. However, some pattern is independent of the antagonism of patched by Hh, and relies instead on novel interactions with lines. Lastly, we provide evidence that decapentaplegic does not mediate patterning by Hh in the dorsal epidermis.

Regulations in the induction of the organized neural system in amphibian embryos

Development ◽  
1990 ◽  
Vol 110 (3) ◽  
pp. 653-659 ◽  
Author(s):  
T. Yamada
Keyword(s):  
Homeobox Gene ◽  
Internal Surface ◽  
Neural System ◽  
The Body ◽  
Convergent Extension ◽  
Kinase C ◽  
Amphibian Embryos ◽  
Series Of Experiments ◽  
System 1 ◽  
Posterior Anterior

Some of the recent data on the induction of the neural system in amphibian embryos are reviewed, utilizing a model, according to which two basic events regulate in this system: (1) ectodermal dorsalization, which occurs all over the induced region of the ectoderm and is responsible for the neural and mesectodermal pathways and (2) caudalization, which occurs only on the posterior level of dorsalized ectoderm and is responsible for the posterior mode of induced differentiation, functioning as a gradient with the apex at the posterior end of the embryo. Dorsalization of ectoderm can be caused by treatment with Con A or TPA, both of which are potential mitogens. Not only after the treatment with TPA, but also during normal dorsalization, the activation of protein kinase C occurs in responding cells. The possibility is suggested that an early step of mitogenic transmembrane signal transduction induced by a growth factor regulates dorsalization in intact embryos. Ectodermal dorsalization is responsible for the appearance of neuronal and glial cell lineages, and independent of the ECM network formed on the internal surface of the responding ectoderm during gastrulation. In caudalization, a series of experiments suggests that the regulatory role is played by the transcript of the mesodermal posterior homeobox gene, Xhox 3. The expression of this gene in time and location closely coincides with the pattern of convergent extension, one type of morphogenetic movement, which is expressed in a posterior-anterior gradient. This directed cell motility is responsible for the formation of the body axis of vertebrates, and was shown to be involved in caudalization by earlier induction experiments in urodele embryos.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of the NK-homeobox gene slouch (S59) in somatic muscle patterning

Development ◽  
1999 ◽  
Vol 126 (20) ◽  
pp. 4525-4535 ◽  
Author(s):  
S. Knirr ◽  
N. Azpiazu ◽  
M. Frasch
Keyword(s):  
Muscle Development ◽  
Ectopic Expression ◽  
Homeobox Gene ◽  
Drosophila Embryo ◽  
Loss Of Function ◽  
Cell Fates ◽  
Somatic Muscle ◽  
Gene Encoding ◽  
Body Wall Muscles ◽  
Founder Cells

In the Drosophila embryo, a distinct class of myoblasts, designated as muscle founders, prefigures the mature pattern of somatic body wall muscles. Each founder cell appears to be instrumental in generating a single larval muscle with a defined identity. The NK homeobox gene S59 was the first of a growing number of proposed ‘identity genes’ that have been found to be expressed in stereotyped patterns in specific subsets of muscle founders and their progenitor cells and are thought to control their developmental fates. In the present study, we describe the effects of gain- and loss-of-function experiments with S59. We find that a null mutation in the gene encoding S59, which we have named slouch (slou), disrupts the development of all muscles that are derived from S59-expressing founder cells. The observed phenotypes upon mutation and ectopic expression of slouch include transformations of founder cell fates, thus confirming that slouch (S59) functions as an identity gene in muscle development. These fate transformations occur between sibling founder cells as well as between neighboring founders that are not lineage-related. In the latter case, we show that slouch (S59) activity is required cell-autonomously to repress the expression of ladybird (lb) homeobox genes, thereby preventing specification along the lb pathway. Together, these findings provide new insights into the regulatory interactions that establish the somatic muscle pattern.

scholarly journals Spatiotemporal Expression of Anticoagulation Factor Antistasin in Freshwater Leeches

2019 ◽  
Vol 20 (16) ◽  
pp. 3994 ◽  
Author(s):  
Hee-Jin Kwak ◽  
Jeong-Su Park ◽  
Brenda Irene Medina Jiménez ◽  
Soon Cheol Park ◽  
Sung-Jin Cho
Keyword(s):  
Hedgehog Signaling ◽  
Signal Transduction Pathway ◽  
The Body ◽  
Spatial Expression ◽  
Downstream Target ◽  
Spatiotemporal Expression ◽  
Stage 4 ◽  
Segment Polarity ◽  
Late Stages

Antistasin, which was originally discovered in the salivary glands of the Mexican leech Haementeria officinalis, was newly isolated from Helobdella austinensis. To confirm the temporal expression of antistasin during embryogenesis, we carried out semi-quantitative RT-PCR. Hau-antistasin1 was uniquely expressed at stage 4 of the cleavage and was strongly expressed in the late stages of organogenesis, as were other antistasin members. In order to confirm the spatial expression of antistasin, we performed fluorescence in situ hybridization in the late stages of organogenesis. The expression of each antistasin in the proboscis showed a similar pattern and varied in expression in the body. In addition, the spatial expression of antistasin orthologs in different leeches showed the possibility of different function across leech species. Hau-antistasin1 was expressed in the same region as hedgehog, which is a known mediator of signal transduction pathway. Hau-antistasin1 is probably a downstream target of Hedgehog signaling, involved in segment polarity signal pathway.

Sign in / Sign up

Export Citation Format

Share Document