Dax, a locust Hox gene related to fushi-tarazu but showing no pair-rule expression

Development ◽  
1994 ◽  
Vol 120 (6) ◽  
pp. 1561-1572 ◽  
Author(s):  
R. Dawes ◽  
I. Dawson ◽  
F. Falciani ◽  
G. Tear ◽  
M. Akam
Keyword(s):  
Schistocerca Gregaria ◽  
Posterior Part ◽  
Homeobox Gene ◽  
Early Embryo ◽  
Neural Precursor Cells ◽  
Germ Band ◽  
Fushi Tarazu ◽  
Hox Gene ◽  
Two Phases ◽  
Pair Rule

We describe an unusual Antennapedia class homeobox gene from the grasshopper Schistocerca gregaria (Orthoptera, African Plague Locust). Its sequence is not sufficiently similar to that of any other insect Hom-Hox gene to identify it unambiguously, but short conserved elements suggest a relationship to the segmentation gene fushi-tarazu, (ftz). We term it Sg Dax (divergent Antennapedia class homeobox gene). Antibodies raised against the protein encoded by this gene reveal two phases of expression during embryogenesis. In the early embryo, it is a marker for the posterior part of the forming embryonic primordium, and subsequently for the posterior part of the growing germ band. In older embryos, it labels a subset of neural precursor cells in each trunk segment, very similar to that defined by the expression of fushi tarazu (ftz) in Drosophila. We suggest that Schistocerca Dax and Drosophila ftz are homologous members of a gene family whose members are diverging relatively rapidly, both in terms of sequence and role in early development.

The degree of determination of the early embryo of Schistocerca gregaria (Forskål) (Orthoptera: Acrididae)

Development ◽  
1971 ◽  
Vol 25 (3) ◽  
pp. 277-299
Author(s):  
S. K. Moloo
Keyword(s):  
Early Development ◽  
Schistocerca Gregaria ◽  
Early Embryo ◽  
Germ Band ◽  
Early Cleavage ◽  
Band Formation ◽  
Zygote Nucleus ◽  
Young Embryo ◽  
Blastoderm Stage

The degree of determination of the young embryo of S. gregaria has been investigated using ligation, thermocautery and centrifugation techniques. From the overall results, it is suggested that the early development of the embryo is mediated by two physiological centres. The formation of the germ rudiment is controlled by an activation centre located in the periplasm round the posterior end of the egg. This centre is already present at the zygote nucleus stage and is essential during the very early cleavage period. The differentiation of the germ band is induced by the activity of a second centre, the differentiation centre, located in the presumptive thorax. It apparently becomes established at least by the late blastoderm stage and its activity continues during the period of germ-band formation. During the late cleavage and early blastoderm stages, the egg is labile and the embryo is therefore able to normalize its development after part or parts of the germinal Anlage have been cauterized, removed or displaced. The differentiation centre completes its functions by the beginning of gastrulation. Thereafter, the embryo is determined. The embryo can regulate its size at least up to the gastrulation stage provided that a certain minimum amount of usable yolk is available. The development of the serosa is not under the control of either centre. This structure seems to be capable of regeneration providing that a part of the extra-embryonic blastoderm remains intact.

Interactions between the pair-rule genes runt, hairy, even-skipped and fushi tarazu and the establishment of periodic pattern in the Drosophila embryo

Development ◽  
1988 ◽  
Vol 104 (Supplement) ◽  
pp. 51-60 ◽  
Author(s):  
Philip Ingham ◽  
Peter Gergen
Keyword(s):  
Double Mutant ◽  
Early Embryo ◽  
Drosophila Embryo ◽  
Periodic Pattern ◽  
Fushi Tarazu ◽  
Blastoderm Stage ◽  
Pair Rule

The pair-rule genes of Drosophila play a fundamental role in the generation of periodicity in the early embryo. We have analysed the transcript distributions of runt, hairy, even-skipped and fushi tarazu in single and double mutant ernbryos. The results indicate a complex set of interactions between the genes during the blastoderm stage of embryogenesis.

The pattern of cell death in fushi tarazu, a segmentation gene of Drosophila

Development ◽  
1988 ◽  
Vol 104 (3) ◽  
pp. 447-451 ◽  
Author(s):  
L. Magrassi ◽  
P.A. Lawrence
Keyword(s):  
Cell Death ◽  
Wild Type ◽  
Germ Band ◽  
Fushi Tarazu ◽  
Larval Cuticle ◽  
Dividing Cells ◽  
In The Wild ◽  
Indirect Consequence ◽  
Dying Cells ◽  
Pair Rule

The pair-rule mutant, fushi tarazu, causes deletion of alternate metameres. Here we show that there is cell death in the mutant which begins at the completion of germ band extension. We map the dying cells in the epidermis; they occur scattered all over those regions that, in the wild type, would form the even-numbered parasegments and are also found in posterior parts of the odd-numbered parasegments. In the affected zones, dying and dividing cells are intermingled; we suggest that cells from these zones may still give descendents that contribute to the larval cuticle. Cell death is not limited to those cells that would normally express ftz+, suggesting that it is some indirect consequence of the abnormal situation in the mutant embryo.

Pattern formation in the Drosophila embryo: allocation of cells to parasegments by even-skipped and fushi tarazu

Development ◽  
1989 ◽  
Vol 105 (4) ◽  
pp. 761-767 ◽  
Author(s):  
P.A. Lawrence ◽  
P. Johnston
Keyword(s):  
Pattern Formation ◽  
Drosophila Embryo ◽  
Germ Band ◽  
Fushi Tarazu ◽  
Cellular Resolution ◽  
Blastoderm Stage ◽  
Pair Rule ◽  
Drosophila Embryos

The first sign of metamerization in the Drosophila embryo is the striped expression of pair-rule genes such as fushi tarazu (ftz) and even-skipped (eve). Here we describe, at cellular resolution, the development of ftz and eve protein stripes in staged Drosophila embryos. They appear gradually, during the syncytial blastoderm stage and soon become asymmetric, the anterior margins of the stripes being sharply demarcated while the posterior borders are undefined. By the beginning of germ band elongation, the eve and ftz stripes have narrowed and become very intense at their anterior margins. The development of these stripes in hairy-, runt-, eve-, ftz- and engrailed- embryos is illustrated. In eve- embryos, the ftz stripes remain symmetric and lack sharp borders. Our results support the hypothesis (Lawrence et al. Nature 328, 440–442, 1987) that individual cells are allocated to parasegments with respect to the anterior margins of the eve and ftz stripes.

Analysis of function of the pair-rule genes hairy, even-skipped and fushi tarazu in mosaic Drosophila embryos

Development ◽  
1989 ◽  
Vol 107 (4) ◽  
pp. 847-853 ◽  
Author(s):  
P.A. Lawrence ◽  
P. Johnston
Keyword(s):  
Genetic Interactions ◽  
Nuclear Transplantation ◽  
Fushi Tarazu ◽  
Segmentation Gene ◽  
Hairy Cells ◽  
Analysis Of Function ◽  
Mutant Cells ◽  
Pair Rule ◽  
Drosophila Embryos

We report the first attempt of its kind to study genetic interactions using young Drosophila embryos that are mosaic for wildtype and mutant cells. Using nuclear transplantation we make mosaic embryos in which a patch of cells lacks a particular segmentation gene, A. With antibodies, we than look at the expression of another gene that is known to be downstream of gene A, with respect to the cells in the patch. We have examples of patches of hairy cells (where we monitor the effect on fushi tarazu (ftz) expression), even-skipped (monitoring ftz) and ftz (monitoring engrailed and Ultrabithorax). Our main finding is that the dependence of engrailed expression on the ftz gene is strictly cell-autonomous. This result goes some way towards explaining the dependence of Ultrabithorax expression on ftz, a dependence we show to be locally cell-autonomous within parts of parasegments 6 and 8 but non autonomous within parasegment 7.

Mouse Hox-3.4: homeobox sequence and embryonic expression patterns compared with other members of the Hox gene network

Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 329-339 ◽  
Author(s):  
S.J. Gaunt ◽  
P.L. Coletta ◽  
D. Pravtcheva ◽  
P.T. Sharpe
Keyword(s):  
Gene Network ◽  
Common Ancestor ◽  
Expression Patterns ◽  
Homeobox Gene ◽  
Predicted Amino Acid Sequence ◽  
Chromosome 15 ◽  
Hox Gene ◽  
The Central Nervous System ◽  
Genomic Organisation

A putative mouse homeobox gene (Hox-3.4) was previously identified 4kb downstream of the Hox-3.3 (Hox-6.1)* gene (Sharpe et al. 1988). We have now sequenced the Hox-3.4 homeobox region. The predicted amino acid sequence shows highest degree of homology in the mouse with Hox-1.3 and -2.1. This, together with similarities in the genomic organisation around these three genes, suggests that they are comembers of a subfamily, derived from a common ancestor. Hox-3.4 appears to be a homologue of the Xenopus Xlhbox5 and human cp11 genes (Fritz and De Robertis, 1988; Simeone et al. 1988). Using a panel of mouse-hamster somatic cell hybrids we have mapped the Hox-3.4 gene to chromosome 15. From the results of in situ hybridization experiments, we describe the distribution of Hox-3.4 transcripts within the 12 1/2 day mouse embryo, and we compare this with the distributions of transcripts shown by seven other members of the Hox gene network. We note three consistencies that underlie the patterns of expression shown by Hox-3.4. First, the anterior limits of Hox-3.4 transcripts in the embryo are related to the position of the Hox-3.4 gene within the Hox-3 locus. Second, the anterior limits of Hox-3.4 expression within the central nervous system are similar to those shown by subfamily homologues Hox-2.1 and Hox-1.3, although the tissue-specific patterns of expression for these three genes show many differences. Third, the patterns of Hox-3.4 expression within the spinal cord and the testis are very similar to those shown by a neighbouring Hox-3 gene (Hox-3.3), but they are quite different from those shown by Hox-1 genes (Hox-1.2, -1.3 and -1.4).

Expression of engrailed during segmentation in grasshopper and crayfish

Development ◽  
1989 ◽  
Vol 107 (2) ◽  
pp. 201-212 ◽  
Author(s):  
N.H. Patel ◽  
T.B. Kornberg ◽  
C.S. Goodman
Keyword(s):  
Monoclonal Antibody ◽  
Cell Proliferation ◽  
Cell Division ◽  
Embryonic Stage ◽  
Germ Band ◽  
Segmentation Genes ◽  
Pair Rule ◽  
Drosophila Embryos ◽  
The Way

We have used a monoclonal antibody that recognizes engrailed proteins to compare the process of segmentation in grasshopper, crayfish, and Drosophila. Drosophila embryos rapidly generate metameres during an embryonic stage characterized by the absence of cell division. In contrast, many other arthropod embryos, such as those of more primitive insects and crustaceans, generate metameres gradually and sequentially, as cell proliferation causes caudal elongation. In all three organisms, the pattern of engrailed expression at the segmented germ band stage is similar, and the parasegments are the first metameres to form. Nevertheless, the way in which the engrailed pattern is generated differs and reflects the differences in how these organisms generate their metameres. These differences call into question what role homologues of the Drosophila pair-rule segmentation genes might play in other arthropods that generate metameres sequentially.

The spatial and temporal distribution of polarizing activity in the flank of the pre-limb-bud stages in the chick embryo

Development ◽  
1991 ◽  
Vol 111 (3) ◽  
pp. 725-731 ◽  
Author(s):  
A. Hornbruch ◽  
L. Wolpert
Keyword(s):  
Posterior Part ◽  
Temporal Distribution ◽  
Early Embryo ◽  
Limb Bud ◽  
Posterior Edge ◽  
Limb Buds ◽  
Avian Embryos ◽  
Low Levels ◽  
Clear Change ◽  
Somitic Mesoderm

The presence of polarizing activity in the limb buds of developing avian embryos determines the pattern of the anteroposterior axis of the limbs in the adult. Maps of the spatial distribution and the strength of the signal within limb buds of different stages are well documented. Polarizing activity can also be found in Hensen's node in the early embryo. We have mapped the distribution of polarizing activity as it emerges from Hensen's node and spreads into the flank tissue of the embryo. There is a clear change in the local pattern of expression of polarizing activity between stage 8 and 18. Almost no activity is measured for stages 8 and 9. More or less uniform levels of around 10% are spread along the flank lateral to the unsegmented somitic mesoderm from somite position 12 to 22 in stage 10 embryos. Some 6 to 8 h later at stage 12, there is a distinct peak of activity at somite position 18, the middle of the wing field. This peak increases at stages 13 to 15 and its position traverses to the posterior edge of the wing field. Full strength of activity is reached shortly before the onset of limb bud formation at stage 16 to 17. Stages 16 to 18 were investigated for polarizing activity in the wing and the leg field. Low levels of polarizing activity are present in the anterior leg field at stages 16 and 17 but have disappeared by stage 18 and all activity is confined to the posterior part of the leg bud.

Transcriptional regulation of cytoskeletal functions and segmentation by a novel maternal pair-rule gene, lilliputian

Development ◽  
2001 ◽  
Vol 128 (5) ◽  
pp. 801-813 ◽  
Author(s):  
A.H. Tang ◽  
T.P. Neufeld ◽  
G.M. Rubin ◽  
H.A. Muller
Keyword(s):  
Transcriptional Control ◽  
Fragile X ◽  
Transcriptional Regulator ◽  
Regulator Gene ◽  
Embryonic Patterning ◽  
Fushi Tarazu ◽  
Fragile X Mental Retardation ◽  
Pair Rule Gene ◽  
Mutant Phenotypes ◽  
Pair Rule

Transcriptional control during early Drosophila development is governed by maternal and zygotic factors. We have identified a novel maternal transcriptional regulator gene, lilliputian (lilli), which contains an HMG1 (AT-hook) motif and a domain with similarity to the human fragile X mental retardation FMR2 protein and the AF4 proto-oncoprotein. Embryos lacking maternal lilli expression show specific defects in the establishment of a functional cytoskeleton during cellularization, and exhibit a pair-rule segmentation phenotype. These mutant phenotypes correlate with markedly reduced expression of the early zygotic genes serendipity alpha, fushi tarazu and huckebein, which are essential for cellularization and embryonic patterning. In addition, loss of lilli in adult photoreceptor and bristle cells results in a significant decrease in cell size. Our results indicate that lilli represents a novel pair-rule gene that acts in cytoskeleton regulation, segmentation and morphogenesis.

Sign in / Sign up

Export Citation Format

Share Document