ArticleFrontiers in zoology2018
Convergent evolution of the ladder-like ventral nerve cord in Annelida.
Article in Frontiers in zoology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 31 papers.
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31 citing papers in PubMed.
- An Increase in Animal Diversity was Facilitated by Ecologically-Driven Brain Complexity Throughout the Cambrian.BioEssays : news and reviews in molecular, cellular and developmental biology · 2026Review
- Mitochondrial genomes of Terebelliformia: gene rearrangements, phylogenetic relationships, and evolutionary insights.BMC genomics · 2026Article
- The wiring diagram of an entire animal.eLife · 2025Article
- Sex-specific differential gene expression during stolonization in the branching syllid Ramisyllis kingghidorahi (Annelida, Syllidae).BMC genomics · 2025Article
- The development of the adult nervous system in the annelid Owenia fusiformis.Neural development · 2024Article
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- Palps across the tree - the neuronal innervation and development of sensory head appendages in Annelida.Frontiers in neuroscience · 2023Article
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- Histamine and gamma-aminobutyric acid in the nervous system of Pygospio elegans (Annelida: Spionidae): structure and recovery during reparative regeneration.BMC zoology · 2022Article
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- Sensory cells and the organization of the peripheral nervous system of the siboglinid Oligobrachia haakonmosbiensis Smirnov, 2000.BMC zoology · 2022Article
- Ultrastructure of cerebral eyes in Oweniidae and Chaetopteridae (Annelida) - implications for the evolution of eyes in Annelida.Zoological letters · 2022Article
- Detailed morphology of tentacular apparatus and central nervous system in Owenia borealis (Annelida, Oweniidae).Zoological letters · 2021Article
- May the palps be with you - new insights into the evolutionary origin of anterior appendages in Terebelliformia (Annelida).BMC zoology · 2021Article
- Revisiting kinorhynch segmentation: variation of segmental patterns in the nervous system of three aberrant species.Frontiers in zoology · 2021Article
- Myogenesis of Siboglinum fiordicum sheds light on body regionalisation in beard worms (Siboglinidae, Annelida).Frontiers in zoology · 2021Article
- Molecular and morphological analysis of the developing nemertean brain indicates convergent evolution of complex brains in Spiralia.BMC biology · 2021Article
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10 authors.
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Abstract
backgroundA median, segmented, annelid nerve cord has repeatedly been compared to the arthropod and vertebrate nerve cords and became the most used textbook representation of the annelid nervous system. Recent phylogenomic analyses, however, challenge the hypothesis that a subepidermal rope-ladder-like ventral nerve cord (VNC) composed of a paired serial chain of ganglia and somata-free connectives represents either a plesiomorphic or a typical condition in annelids.
resultsUsing a comparative approach by combining phylogenomic analyses with morphological methods (immunohistochemistry and CLSM, histology and TEM), we compiled a comprehensive dataset to reconstruct the evolution of the annelid VNC. Our phylogenomic analyses generally support previous topologies. However, the so far hard-to-place Apistobranchidae and Psammodrilidae are now incorporated among the basally branching annelids with high support. Based on this topology we reconstruct an intraepidermal VNC as the ancestral state in Annelida. Thus, a subepidermal ladder-like nerve cord clearly represents a derived condition.
conclusionsBased on the presented data, a ladder-like appearance of the ventral nerve cord evolved repeatedly, and independently of the transition from an intraepidermal to a subepidermal cord during annelid evolution. Our investigations thereby propose an alternative set of neuroanatomical characteristics for the last common ancestor of Annelida or perhaps even Spiralia.
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