The genes orthodenticle and hunchback substitute for bicoid in the beetle Tribolium

@article{Schrder2003TheGO,
  title={The genes orthodenticle and hunchback substitute for bicoid in the beetle Tribolium},
  author={Reinhard Schr{\"o}der},
  journal={Nature},
  year={2003},
  volume={422},
  pages={621-625}
}
In Drosophila, the morphogen Bicoid organizes anterior patterning in a concentration-dependent manner by activating the transcription of target genes such as orthodenticle (otd) and hunchback (hb), and by repressing the translation of caudal. Homologues of the bicoid gene have not been isolated in any organism apart from the higher Dipterans. In fact, head and thorax formation in other insects is poorly understood. To elucidate this process in a short-germband insect, I analysed the function of… 
Divergent functions of orthodenticle, empty spiracles and buttonhead in early head patterning of the beetle Tribolium castaneum (Coleoptera).
TLDR
Tribolium is established as a model system for arthropod head development that does not suffer from the Drosophila specific problems like head involution and strongly reduced head structures and the ancestral mode of insect head segmentation remains to be discovered.
Apparent role of Tribolium orthodenticle in anteroposterior blastoderm patterning largely reflects novel functions in dorsoventral axis formation and cell survival
TLDR
It is posited that the blastoderm function of Tc-Otd depends on its initial homogeneous maternal expression and that this maternal factor does not provide significant positional information for Tribolium blastodermal cell fates.
The divergent roles of the segmentation gene hunchback.
TLDR
Three independent lines of comparative data strongly support the idea that the anterior organizing function of hb originated in the arthropod and/or insect lineage and that its roles in epithelial and CNS patterning are likely to be broadly conserved within protostomes.
Localized maternal orthodenticle patterns anterior and posterior in the long germ wasp Nasonia
TLDR
It is shown that Nasonia otd maternal mRNA is localized at both poles of the embryo, and resulting protein gradients pattern both poles, which means that localized NasonIA otd has two major roles that allow long germ development.
Orthodenticle and empty spiracles genes are expressed in a segmental pattern in chelicerates
TLDR
It is shown that both ems and otd are expressed not only in an anterior head domain but also along the entire anterior–posterior axis during embryonic development, which appears to be a conserved character of chelicerates.
Delimiting the conserved features of hunchback function for the trunk organization of insects
TLDR
The results allow the disentanglement of the conserved role of hunchback in insects from the derived features that have been acquired in the lineage towards Drosophila, and it may be appropriate to revive an alternative name for the class of gap genes, namely `cardinal genes'.
Evolution of Bicoid-dependent hunchback regulation in Diptera
TLDR
A lower cyclorrhaphan fly (Episyrphus balteatus; Syrphidae) is identified with an early patterning mechanism likely to be fundamentally different from Drosophila and potentially similar to lower dipterans indicating that this species might use a patterning mechanisms that is an intermediate between lower and higher flies.
Divergent segmentation mechanism in the short germ insect Tribolium revealed by giant expression and function
Segmentation is well understood in Drosophila, where all segments are determined at the blastoderm stage. In the flour beetle Tribolium castaneum, as in most insects, the posterior segments are added
Analysis of Tribolium head patterning by forward and reverse genetics and transgenic techniques
TLDR
The gap gene like roles of ems and btd are not conserved while at least the head patterning function of otd appears to be similar in fly and beetle, as well as three very interesting lines affecting head development are identified.
Non-canonical functions of hunchback in segment patterning of the intermediate germ cricket Gryllus bimaculatus
TLDR
Findings suggest that Gb'hb functions in a non-canonical manner in segment patterning in Drosophila, and that the canonical hb function may have evolved from the non- canonical hb functions during evolution.
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TLDR
The results are consistent with the idea that an otd/Otx gene specified anterior head structures in the last ancestor common to arthropods and vertebrates.
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TLDR
Cloned the homologue of hb from the flour beetle Tribolium and shows that, on the basis of its expression pattern, most of its functions seem to be conserved between these two species, suggesting that hb may have the same functions in early Drosophila and Tribolia development, despite the different types of embryogenesis in these twospecies.
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TLDR
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TLDR
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TLDR
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TLDR
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