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- Hogvall, Mattias, et al.
(författare)
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Analysis of the Wnt gene repertoire in an onychophoran provides new insights into the evolution of segmentation
- 2014
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Ingår i: EvoDevo. - : Springer Science and Business Media LLC. - 2041-9139. ; 5, s. 14-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Onychophora are a probable sister group to Arthropoda, one of the most intensively studied animal phyla from a developmental perspective. Pioneering work on the fruit fly Drosophila melanogaster and subsequent investigation of other arthropods has revealed important roles for Wnt genes during many developmental processes in these animals. Results: We screened the embryonic transcriptome of the onychophoran Euperipatoides kanangrensis and found that at least 11 Wnt genes are expressed during embryogenesis. These genes represent 11 of the 13 known subfamilies of Wnt genes. Conclusions: Many onychophoran Wnt genes are expressed in segment polarity gene-like patterns, suggesting a general role for these ligands during segment regionalization, as has been described in arthropods. During early stages of development, Wnt2, Wnt4, and Wnt5 are expressed in broad multiple segment-wide domains that are reminiscent of arthropod gap and Hox gene expression patterns, which suggests an early instructive role for Wnt genes during E. kanangrensis segmentation.
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| 4. |
- Hogvall, Mattias, et al.
(författare)
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Gene expression analysis of potential morphogen signalling modifying factors in Panarthropoda
- 2018
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Ingår i: EvoDevo. - : BMC. - 2041-9139. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Morphogen signalling represents a key mechanism of developmental processes during animal development. Previously, several evolutionary conserved morphogen signalling pathways have been identified, and their players such as the morphogen receptors, morphogen modulating factors (MMFs) and the morphogens themselves have been studied. MMFs are factors that regulate morphogen distribution and activity. The interactions of MMFs with different morphogen signalling pathways such as Wnt signalling, Hedgehog (Hh) signalling and Decapentaplegic (Dpp) signalling are complex because some of the MMFs have been shown to interact with more than one signalling pathway, and depending on genetic context, to have different, biphasic or even opposing function. This complicates the interpretation of expression data and functional data of MMFs and may be one reason why data on MMFs in other arthropods than Drosophila are scarce or totally lacking.Results: As a first step to a better understanding of the potential roles of MMFs in arthropod development, we investigate here the embryonic expression patterns of division abnormally delayed (dally), dally-like protein (dlp), shifted (shf) and secreted frizzled-related protein 125 (sFRP125) and sFRP34 in the beetle Tribolium castaneum, the spider Parasteatoda tepidariorum, the millipede Glomeris marginata and the onychophoran Euperipatoides kanangrensis. This pioneer study represents the first comprehensive comparative data set of these genes in panarthropods.Conclusions: Expression profiles reveal a high degree of diversity, suggesting that MMFs may represent highly evolvable nodes in otherwise conserved gene regulatory networks. Conserved aspects of MMF expression, however, appear to concern function in segmentation and limb development, two of the key topics of evolutionary developmental research.
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| 6. |
- Hogvall, Mattias, 1984-
(författare)
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Investigation of Hox gene expression and Wnt-signalling in basally branching ecdysozoans
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One of the most important processes in the development of an animal is the determination and patterning of the primary body axis, the anterior-posterior (AP) axis. After the AP axis has been established the embryo grows and elongates through posterior elongation.Several evolutionary conserved sets of genes and signalling pathways are involved in AP axis formation and posterior elongation, including Wnt-signalling. Wnt-signalling was involved in AP axis determination and posterior elongation even before the evolution of the Bilateria. In segmented animals, Wnt-signalling is also involved in maintaining segmental boundaries and in giving each segment its polarity. Hox genes, conversely, play a significant role in the regionalisation of the AP axis in Bilateria. This role as regionalisation factors probably emerged within the bilaterian in stem-group and it has been speculated that Wnt genes may have had this function prior to the rise of the Hox genes.The goal of this work is to shed light on the expression and function of Wnt-signalling and Hox gene patterning in basally branching ecdysozoans, Priapulida and Onychophora, two phyla that are underrepresented in current research, but represent key phyla for the understanding of ecdysozoan evolution.Wnt genes are likely to have retained a prominent function in posterior regionalisation and elongation in Priapulida. Investigation of Hox gene expression patterns proved to be difficult in Priapulida, but preliminary results suggest partially conserved function in AP axis patterning.In Onychophora, Wnt-signalling appears to be involved in segment formation, intrasegmental patterning and segment/parasegment border maintenance. Some of the onychophoran Wnt genes are expressed in Hox-like patterns suggesting a role in AP-axis patterning, a function that Wnt genes may thus have retained throughout their evolution.Finally, I have also investigated some of the factors involved in Wnt-signalling (or morphogen processing in general). These genes, the morphogen-interfering factors (MIFs), have been poorly investigated in general. I studied their expression in an onychophoran and a number of other emerging arthropod model organisms in order to obtain a more solid basis for comparison. These data, although difficult to interpret, suggest that the interaction of Wnts and MIFs is diverse and complex among Panarthropoda.
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