title: Comparative analysis of neurogenesis in the myriapod Glomeris marginata (Diplopoda) suggests more similarities to chelicerates than to insects.
abstract: Molecular data suggest that myriapods are a basal arthropod group and may even be the sister group of chelicerates. To find morphological indications for this relationship we have analysed neurogenesis in the myriapod Glomeris marginata (Diplopoda). We show here that groups of neural precursors, rather than single cells as in insects, invaginate from the ventral neuroectoderm in a manner similar to that in the spider: invaginating cell groups arise sequentially and at stereotyped positions in the ventral neuroectoderm of Glomeris, and all cells of the neurogenic region seem to enter the neural pathway. Furthermore, we have identified an achaete-scute, a Delta and a Notch homologue in GLOMERIS: The genes are expressed in a pattern similar to the spider homologues and show more sequence similarity to the chelicerates than to the insects. We conclude that the myriapod pattern of neural precursor formation is compatible with the possibility of a chelicerate-myriapod sister group relationship.
authors.affiliation: Abteilung für Evolutionsgenetik, Institut für Genetik, Universität zu Köln, Weyertal 121, 50931 Köln, Germany.
authors.forename: Hilary
authors.initials: H
authors.lastname: Dove
authors.forename: Angelika
authors.initials: A
authors.lastname: Stollewerk
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001181:Arthropods / Q000033:anatomy & histology / Q000196:embryology*; D051792:Basic Helix-Loop-Helix Proteins; D019521:Body Patterning / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007313:Insecta / Q000033:anatomy & histology / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009420:Nervous System / Q000033:anatomy & histology / Q000196:embryology* / Q000254:growth & development; D010802:Phylogeny; D051880:Receptors, Notch; D013112:Spiders / Q000033:anatomy & histology / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051880:Receptors, Notch; D014157:Transcription Factors; C089199:ac protein, Drosophila; C064045:delta protein