Characterization of the bHLH family of transcriptional regulators in the acoel S. roscofensis and their putative role in neurogenesis

Background: The basic helix-loop-helix (bHLH) family of transcription factors is one of the largest superfamilies of regulatory transcription factors and is widely used in eukaryotic organisms. They play an essential role in a range of metabolic, physiological, and developmental processes, including...

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Bibliographic Details
Authors: Perea Atienza, Elena, Sprecher, Simon G., Martínez Serra, Pedro
Format: article
Status:Published version
Publication Date:2018
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/122079
Online Access:https://hdl.handle.net/2445/122079
Access Level:Open access
Keyword:Neurobiologia
Embriologia
Transcripció genètica
Invertebrats
Neurobiology
Embryology
Genetic transcription
Invertebrates
Description
Summary:Background: The basic helix-loop-helix (bHLH) family of transcription factors is one of the largest superfamilies of regulatory transcription factors and is widely used in eukaryotic organisms. They play an essential role in a range of metabolic, physiological, and developmental processes, including the development of the nervous system (NS). These transcription factors have been studied in many metazoans, especially in vertebrates but also in early branching metazoan clades such as the cnidarians and sponges. However, currently very little is known about their expression in the most basally branching bilaterian group, the xenacoelomorphs. Recently, our laboratory has characterized the full complement of bHLH in the genome of two members of the Xenacoelomorpha, the xenoturbellid Xenoturbella bocki and the acoel Symsagittifera roscoffensis. Understanding the patterns of bHLH gene expression in members of this phylum (in space and time) provides critical new insights into the conserved roles of the bHLH and their putative specificities in this group. Our focus is on deciphering the specific roles that these genes have in the process of neurogenesis. Results: Here, we analyze the developmental expression of the whole complement of bHLH genes identified in the acoel S. roscoffensis. Based on their expression patterns, several members of bHLH class A appear to have specific conserved roles in neurogenesis, while other class A genes (as well as members of other classes) have likely taken on more generalized functions. All gene expression patterns are described in embryos and early juveniles. Conclusion: Our results suggest that the main roles of the bHLH genes of S. roscoffensis are evolutionarily conserved, with a specific subset dedicated to patterning the nervous system: SrAscA, SrAscB, SrHes/Hey, SrNscl, SrSrebp, SrE12/ E47 and SrOlig.