Three-dimensional reconstruction of the central nervous system of Macrobiotus hufelandi (Eutardigrada, Parachela): implications for the phylogenetic position of Tardigrada

  title={Three-dimensional reconstruction of the central nervous system of Macrobiotus hufelandi (Eutardigrada, Parachela): implications for the phylogenetic position of Tardigrada},
  author={Juliane Zantke and Carsten Wolff and Gerhard Scholtz},
The morphology of the central nervous system of the tardigrade species Macrobiotus hufelandi was analysed with anti α-tubulin immunostaining in combination with confocal-laser-scanning-microscopy and computer aided three-dimensional reconstruction. The brain anatomy is unexpectedly complex with distinct tracts and highly intermingled nerve fibres. In contrast to older descriptions, we could not detect a suboesophageal ganglion. Furthermore, we found no evidence for a tripartite/three-segmented… 

Organization of the central nervous system and innervation of cephalic sensory structures in the water bear Echiniscus testudo (Tardigrada: Heterotardigrada) revisited

The central nervous system of the heterotardigrade Echiniscus testudo is reinvestigated using anti‐synapsin and anti‐acetylated α‐tubulin immunohistochemistry in order to visualize the number and position of tracts, commissures, and neuropils, supporting the hypothesis that the dorsal brain is serially homologous with the ventral trunk ganglia.

Axogenesis in the central and peripheral nervous system of the amphipod crustacean Orchestia cavimana.

The formation of the major axon pathways in the embryonic central and peripheral nervous systems of the amphipod crustacean Orchestia cavimana Heller, 1865 are described by means of antibody staining against acetylated alpha-tubulin and provide a basis for future studies of neurogenesis on a deeper cellular and molecular level.

The architecture of the nervous system of Echiniscus testudo (Echiniscoidea, Heterotardigrada)

The hereindescribed organisation is compared with previously published data on the nervous system of Tardigrada, and it is concluded that the lobate organisation of the brain of E. testudo comprises an arrangement due to functional needs rather than to reflect an organisation into arthropod-like proto-, deuto- and trito-cerebrum.

Neural development in the tardigrade Hypsibius dujardini based on anti-acetylated α-tubulin immunolabeling

The revealed pattern of brain development supports a single-segmented brain in tardigrades and challenges previous assignments of homology between tardigade brain lobes and arthropod brain segments.

Neuroanatomy of Halobiotus crispae (Eutardigrada: Hypsibiidae): Tardigrade brain structure supports the clade panarthropoda

A detailed description of the nervous system of the eutardigrade Halobiotus crispae is presented, using immunostainings, confocal laser scanning microscopy, and computer‐aided three‐dimensional reconstructions supported by transmission electron microscope, and the data presented supports a sister group relationship of Tardigrada to Arthropoda or Onychophora.

Immunohistochemical and ultrastructural analysis of the muscular and nervous systems in the interstitial polychaete Polygordius appendiculatus (Annelida)

An investigation of the muscular and nervous systems of Polygordiidae found that a basiepithelial and non-ganglionic organization of the ventral nerve cord as well as an orthogonal nervous system represent plesiomorphic characters.

Brain anatomy of the marine tardigrade actinarctus doryphorus (arthrotardigrada)

The results on the brain anatomy of Actinarctus doryphorus support the monophyly of Panarthropoda and suggest that the head region of extant tardigrades is the result of cephalization of multiple segments.

Selective neuronal staining in tardigrades and onychophorans provides insights into the evolution of segmental ganglia in panarthropods

The organisation of the nervous system in three tardigrade species using antisera directed against tyrosinated and acetylated tubulin, the amine transmitter serotonin, and the invertebrate neuropeptides FMRFamide, allatostatin and perisulfakinin shows correspondences that support the homology of segmental ganglia in tardsigrades and arthropods.

The metameric pattern of Hypsibius dujardini(Eutardigrada) and its relationship to that of other panarthropods

Investigating nervous system, muscle system, and cuticle anatomy of H. dujardini segmental morphologies will facilitate developmental genetic studies in this species that promise to illuminate the relationship of the tardigrade metameric pattern to that of other panarthropods.



Polychaete nervous systems: Ground pattern and variations--cLS microscopy and the importance of novel characteristics in phylogenetic analysis.

Immunohistochemical investigations in Annelida enable more detailed reanalyses of known structures and detection of new characteristics that are useful for phylogenetic analyses and it is shown that hitherto unknown nerves are present in the peripheral nervous system.

The cerebral ganglia of Milnesium tardigradum Doyère (Apochela, Tardigrada): Three dimensional reconstruction and notes on their ultrastructure

Differential interference contrast micrographs from stretched animals, serially sectioned semi-thin and ultrathin sections revealed that the cerebral ganglia of the eutardigradeMilnesium tardigradumlie has an anterior indentation which is penetrated by two muscles that arise from the cuticle of the forehead.

The Nervous Systems of Invertebrates: An Evolutionary and Comparative Approach

The nervous systems of Cnidarians, Onychophora, Echinodermata, Chelicerata and Annelida are studied.

Neurophylogeny: Architecture of the nervous system and a fresh view on arthropod phyologeny.

  • S. Harzsch
  • Biology
    Integrative and comparative biology
  • 2006
A thorough overview is given of characters derived from structure and development of the arthropod brain and the ventral nerve cord from the cellular level to the level of larger neuropil systems that support the new Tetraconata hypothesis suggested by Dohle and provide evidence for a clade that unites malacostracan and remipede crustaceans with the Hexapoda.

Electron microscopic investigation of cephalic sense organs of the tardigradeMacrobiotus hufelandi C.A.S. Schultze

With regard to the possible functions of the four sensory regions, the ALSF is discussed as a mechanoreceptive organ and the type 1 sensory cells in the COSF are suggested to be chemoreceptive and thetype 2 sensory cells to serve as me-chanoreceptors in theCOSF.

Immunolocalization of serotonin in Onychophora argues against segmental ganglia being an ancestral feature of arthropods

These results contradict a priori assumptions of segmental ganglia of the typical euarthropodan type being an ancestral feature of Onychophora and weaken the traditional Articulata hypothesis, which proposes a sistergroup relationship of Annelida and Arthropoda.

Phylogenetic comparison of serotonin‐immunoreactive neurons in representatives of the Chilopoda, Diplopoda, and Chelicerata: Implications for arthropod relationships

The data discussed in this article moderately support the Tetraconata hypothesis, and the proposed ground patterns of the various groups are reconstructed and the characters are plotted on two competing hypotheses of arthropod phylogeny, the traditional Tracheata hypothesis and an alternative hypothesis derived from molecular and recent morphological data, the Tumenata concept.

The structure of the nervous system of the nematode Caenorhabditis elegans.

The structure and connectivity of the nervous system of the nematode Caenorhabditis elegans has been deduced from reconstructions of electron micrographs of serial sections. The hermaphrodite nervous