Amphioxus sp5 is a member of a conserved SP complement, and is modulated by Wnt/β-catenin signalling
Abstract
A cluster of three Specificity Protein (Sp) genes (Sp1-4, Sp5 and Sp6-9) is thought to be ancestral in both chordates and the wider Eumetazoa. Sp5 and Sp6-9 gene groups are associated with embryonic growth zones, such as tailbuds, and are both Wnt/β-catenin signalling pathway members and targets. Currently, there are conflicting reports as to the number and identity of Sp genes in the cephalochordates, the sister group to the vertebrates and urochordates. We confirm the SP complement of Branchiostoma belcheri and Branchiostoma lanceolatum, as well as their genomic arrangement, protein domain structure and residue frequency. We assay Sp5 expression in B. lanceolatum embryos, and determine its response to pharmacologically increased β-catenin signalling. Branchiostoma possesses three Sp genes, located on the same genomic scaffold. Phylogenetic and domain structure analyses are consistent with their identification as SP1-4, SP5 and SP6-9, although SP1-4 contains a novel glutamine-rich N-terminal region. SP5 is expressed in axial mesoderm and neurectoderm, and marks the cerebral vesicle and presumptive pharynx. Early exposure to increased β-catenin caused ubiquitous SP5 expression in late gastrula, while later treatment at gastrula stages reduced SP5 expression in the posterior growth zone during axis elongation. Amphioxus possess a typical invertebrate eumetazoan SP complement, and SP5 expression in embryos is well conserved with vertebrate homologues. Its expression in the tailbud, a posterior growth zone, is consistent with expression seen in other bilateri
Citation
Dailey , S C , Kozmikova , I & Somorjai , I M L 2017 , ' Amphioxus sp5 is a member of a conserved SP complement, and is modulated by Wnt/β-catenin signalling ' , International Journal of Developmental Biology , vol. 61 , no. 10/11/12 , pp. 723-732 . https://doi.org/10.1387/ijdb.170205is
Publication
International Journal of Developmental Biology
Status
Peer reviewed
ISSN
0214-6282Type
Journal article
Rights
© UPV/EHU Press / the Authors. This work has been made available online in accordance with the publisher’s policies. This is the author created accepted version manuscript following peer review and as such may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1387/ijdb.170205is
Description
CD was funded by a MASTS (Marine Alliance for Science & Technology Scotland) PhD Studentship. Work in the IMLS lab is in part funded by the European Union Horizon 2020 research and innovation programme under grant agreement numbers 654428 (“CORBEL”) and 730984 (“ASSEMBLE+), and the Wellcome Trust ISSF grant number 204821/Z/16/Z. I.K. was supported by grant 15-21285J from the Czech Science Foundation. This work was supported by the Branchiostoma lanceolatum genome consortium, which provided access to the Branchiostoma lanceolatum genome sequence.Collections
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