Consisting of three lineages - cephalochordates (amphioxus), tunicates and vertebrates (including us, humans)-, the monophyletic group of chordate animals is defined by the presence, at some stage of their life cycle, of a set of unique and conserved morphological features: a dorsal hollow nerve cord with a notochord just ventral to it, pharyngeal slits and a post-anal tail. Moreover, the last common ancestor of chordates likely possessed a segmented muscular system along the main body axis. Despite these conserved synapomorphies, chordates have largely diversified since their origin around 600 million years ago, especially vertebrates, one of the most successful animal groups on our planet. The evolution of a myriad of morphological novelties are behind chordate and vertebrate diversification since they permitted the adaptation of new species to a vast range of ecological niches (e.g., paired limbs, jaws).
Two evolutionary processes are particularly relevant to chordate evolution: the formation of the chordate body plan, and the origin of vertebrate traits. Traditionally, developmental biology and genetics have relied on the use of a handful of model animals (mostly jawed vertebrates like mouse, chicken, frog and fish), offering a very shallow taxonomic depth to tackle these two points. Although evolutionary developmental (evo-devo) studies soon attempted to increase the taxon sampling, these were impaired by the lack of advanced techniques readily available to assay emerging model animals. Consequently, most of the early molecular genetics’ studies in the field of chordate evo-devo consisted on the analysis of a single or a limited number of genes in few species. Therefore, and despite their importance, the mechanisms underlying the origin and evolution of both ancestral traits and morphological novelties of chordates have remained largely elusive. However, the recent surge and exponential growth of genome assemblies available from a wider taxonomic range, together with the availability of the most recent technological innovations in genome editing and whole genome scale high throughput expression and regulation analysis are quickly changing this scenario, with promising expectations in solving some of the long-standing chordate evo-devo questions.
This Research Topic aims to gather a broad selection of Original Research, Review and Perspective articles in chordate and vertebrate evo-devo, introducing multidisciplinary and integrative approaches that, by using the most recent state-of-the-art technologies in genomics, molecular biology, imaging and bioinformatics, among other fields, are contributing towards a better understanding of the mechanistic basis of the chordate phenotypic diversity. Researchers working on chordate evolution from any perspective are welcome to submit articles to this collection, which may involve one or more of the following topics:
• Emergent animal models in chordate and vertebrate evo-devo studies.
• Phylogenomics, comparative morphology, paleontology and quantitative approaches aiming at describing the phenotypic diversity of chordates and vertebrates.
• Comparative genomics/epigenomics and chordate genome architecture: gene and whole genome duplications and karyotype evolution; programmed chromatin rearrangements and elimination; gene loss; evolution of regulatory landscapes, spatial topology, etc.
• Functional genomics approaches using new genome editing technologies (CRISPR-Cas9, TALENs, etc.) in chordate models.
• Single-cell sequencing and cell type evolution addressing evolution of chordate complex traits.
Consisting of three lineages - cephalochordates (amphioxus), tunicates and vertebrates (including us, humans)-, the monophyletic group of chordate animals is defined by the presence, at some stage of their life cycle, of a set of unique and conserved morphological features: a dorsal hollow nerve cord with a notochord just ventral to it, pharyngeal slits and a post-anal tail. Moreover, the last common ancestor of chordates likely possessed a segmented muscular system along the main body axis. Despite these conserved synapomorphies, chordates have largely diversified since their origin around 600 million years ago, especially vertebrates, one of the most successful animal groups on our planet. The evolution of a myriad of morphological novelties are behind chordate and vertebrate diversification since they permitted the adaptation of new species to a vast range of ecological niches (e.g., paired limbs, jaws).
Two evolutionary processes are particularly relevant to chordate evolution: the formation of the chordate body plan, and the origin of vertebrate traits. Traditionally, developmental biology and genetics have relied on the use of a handful of model animals (mostly jawed vertebrates like mouse, chicken, frog and fish), offering a very shallow taxonomic depth to tackle these two points. Although evolutionary developmental (evo-devo) studies soon attempted to increase the taxon sampling, these were impaired by the lack of advanced techniques readily available to assay emerging model animals. Consequently, most of the early molecular genetics’ studies in the field of chordate evo-devo consisted on the analysis of a single or a limited number of genes in few species. Therefore, and despite their importance, the mechanisms underlying the origin and evolution of both ancestral traits and morphological novelties of chordates have remained largely elusive. However, the recent surge and exponential growth of genome assemblies available from a wider taxonomic range, together with the availability of the most recent technological innovations in genome editing and whole genome scale high throughput expression and regulation analysis are quickly changing this scenario, with promising expectations in solving some of the long-standing chordate evo-devo questions.
This Research Topic aims to gather a broad selection of Original Research, Review and Perspective articles in chordate and vertebrate evo-devo, introducing multidisciplinary and integrative approaches that, by using the most recent state-of-the-art technologies in genomics, molecular biology, imaging and bioinformatics, among other fields, are contributing towards a better understanding of the mechanistic basis of the chordate phenotypic diversity. Researchers working on chordate evolution from any perspective are welcome to submit articles to this collection, which may involve one or more of the following topics:
• Emergent animal models in chordate and vertebrate evo-devo studies.
• Phylogenomics, comparative morphology, paleontology and quantitative approaches aiming at describing the phenotypic diversity of chordates and vertebrates.
• Comparative genomics/epigenomics and chordate genome architecture: gene and whole genome duplications and karyotype evolution; programmed chromatin rearrangements and elimination; gene loss; evolution of regulatory landscapes, spatial topology, etc.
• Functional genomics approaches using new genome editing technologies (CRISPR-Cas9, TALENs, etc.) in chordate models.
• Single-cell sequencing and cell type evolution addressing evolution of chordate complex traits.
