The Wnt and Delta-Notch signalling pathways interact to direct pair-rule gene expression viacaudalduring segment addition in the spiderParasteatoda tepidariorum

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.

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The zygotic control of Drosophila pair-rule gene expression. I. A search for new pair-rule regulatory loci

Development ◽

10.1242/dev.107.3.663 ◽

1989 ◽

Vol 107 (3) ◽

pp. 663-672 ◽

Cited By ~ 2

Author(s):

S.H. Vavra ◽

S.B. Carroll

Keyword(s):

Gene Expression ◽

Regulatory System ◽

Wild Type ◽

Periodic Patterns ◽

Pair Rule Gene ◽

New Type ◽

Regulatory Loci ◽

Direct Inspection ◽

Pair Rule ◽

Zygotic Control

The examination of pair-rule gene expression in wild-type and segmentation mutant embryos has identified many, but not necessarily all, of the elements of the regulatory system that establish their periodic patterns. Here we have conducted a new type of search for previously unknown regulators of these genes by examining pair-rule gene expression in blastoderm embryos lacking parts of or entire chromosomes. This method has the advantage of direct inspection of abnormal pair-rule gene patterns without relying upon mutagenesis or interpretation of larval phenotypes for the identification of segmentation genes. From these experiments we conclude that: (i) most zygotically required regulators of the fushi tarazu (ftz), even-skipped (eve) and hairy (h) pair-rule genes have been identified, except for one or more loci we have uncovered on chromosome arm 2L; (ii) the repression of the ftz and eve genes in the anterior third of the embryo is under maternal, not zygotic control; and (iii) there are no general zygotically required activators of pair-rule gene expression. The results suggest that the molecular basis of pair-rule gene regulation can be pursued with greater confidence now that most key trans-acting factors are already in hand.

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Conservation and variation in pair-rule gene expression and function in the intermediate-germ beetleDermestes maculatus

Development ◽

10.1242/dev.154039 ◽

2017 ◽

Vol 144 (24) ◽

pp. 4625-4636 ◽

Cited By ~ 11

Author(s):

Jie Xiang ◽

Katie Reding ◽

Alison Heffer ◽

Leslie Pick

Keyword(s):

Gene Expression ◽

Pair Rule Gene ◽

And Function ◽

Pair Rule

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Deciphering the onychophoran ‘segmentation gene cascade’: Gene expression reveals limited involvement of pair rule gene orthologs in segmentation, but a highly conserved segment polarity gene network

Developmental Biology ◽

10.1016/j.ydbio.2013.07.010 ◽

2013 ◽

Vol 382 (1) ◽

pp. 224-234 ◽

Cited By ~ 45

Author(s):

Ralf Janssen ◽

Graham E. Budd

Keyword(s):

Gene Expression ◽

Gene Network ◽

Segmentation Gene ◽

Segment Polarity ◽

Pair Rule Gene ◽

Gene Orthologs ◽

Segment Polarity Gene ◽

Pair Rule ◽

Polarity Gene

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

10.1101/052241 ◽

2016 ◽

Cited By ~ 7

Author(s):

Erik Clark ◽

Michael Akam

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Gene Regulatory Network ◽

Regulatory Network ◽

Frequency Doubling ◽

Anteroposterior Patterning ◽

Regulatory Interactions ◽

Pair Rule Gene ◽

Gene Regulatory ◽

Pair Rule

ABSTRACTThe 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 fourteen 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.

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The zygotic control of Drosophila pair-rule gene expression. II. Spatial repression by gap and pair-rule gene products

Development ◽

10.1242/dev.107.3.673 ◽

1989 ◽

Vol 107 (3) ◽

pp. 673-683 ◽

Cited By ~ 6

Author(s):

S.B. Carroll ◽

S.H. Vavra

Keyword(s):

Gene Expression ◽

Expression Patterns ◽

Control Mechanisms ◽

Gap Gene ◽

Gap Genes ◽

Gene Mutant ◽

Pair Rule Gene ◽

Regulatory Effects ◽

Pair Rule ◽

Zygotic Control

We examined gene expression patterns in certain single and double pair-rule mutant embryos to determine which of the largely repressive pair-rule gene interactions are most likely to be direct and which interactions are probably indirect. From these studies we conclude that: (i) hairy+ and even-skipped (eve+) regulate the fushi tarazu (ftz) gene; (ii) eve+ and runt+ regulate the hairy gene; (iii) runt+ regulates the eve gene; but, (iv) runt does not regulate the ftz gene pattern, and hairy does not regulate the eve gene pattern. These pair-rule interactions are not sufficient, however, to explain the periodicity of the hairy and eve patterns, so we examined specific gap gene mutant combinations to uncover their regulatory effects on these two genes. Our surprising observation is that the hairy and eve genes are expressed in embryos where the three key gap genes hunchback (hb), Kruppel (Kr), and knirps (kni) have been removed, indicating that these gap genes are not essential to activate the pair-rule genes. In fact, we show that in the absence of either hb+ or kni+, or both gap genes, the Kr+ product represses hairy expression. These results suggest that gap genes repress hairy expression in the interstripe regions, rather than activate hairy expression in the stripes. The molecular basis of pair-rule gene regulation by gap genes must involve some dual control mechanisms such that combinations of gap genes affect pair-rule transcription in a different manner than a single gap gene.

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Evolution of neuroblast identity: seven-up and prospero expression reveal homologous and divergent neuroblast fates in Drosophila and Schistocerca

Development ◽

10.1242/dev.121.12.3989 ◽

1995 ◽

Vol 121 (12) ◽

pp. 3989-3996 ◽

Cited By ~ 4

Author(s):

J. Broadus ◽

C.Q. Doe

Keyword(s):

Gene Expression ◽

Central Nervous System ◽

Gene Function ◽

Fushi Tarazu ◽

Pair Rule Gene ◽

Key Features ◽

Insect Central Nervous System ◽

Or Gene ◽

Species Specific ◽

Pair Rule

In the Drosophila CNS, early neuroblast formation and fate are controlled by the pair-rule class of segmentation genes. The distantly related Schistocerca (grasshopper) embryo has a similar arrangement of neuroblasts, despite lack of known pair-rule gene function. Does divergent pair-rule gene function lead to different neuroblast identities, or can different patterning mechanisms produce homologous neuroblasts? We use four molecular markers to compare Drosophila and Schistocerca neuroblast identity: seven-up, prospero, engrailed, and fushi-tarazu/Dax. In both insects some early-forming neuroblasts share key features of neuroblast identity (position, time of formation, and temporally accurate gene expression); thus, different patterning mechanisms can generate similar neuroblast fates. In contrast, several later-forming neuroblasts show species-specific differences in position and/or gene expression; these neuroblast identities seem to have diverged, suggesting that evolution of the insect central nervous system can occur through changes in embryonic neuroblast identity.

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