Data from: Cellular morphology of leg musculature in the water bear Hypsibius exemplaris (Tardigrada) unravels serial homologies

• Main Authors: Gross, Vladimir, Mayer, Georg
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2019
• Subjects: Hypsibius exemplaris; Lobopod; Functional morphology; F-actin; Ecdysozoa; Tardigrade; water bear
• Online Access: https://doi.org/10.5061/dryad.kv1cr18

Tardigrades ( water bears) are microscopic, segmented ecdysozoans with four pairs of legs. Lobopodous limbs that are similar to those seen in tardigrades are hypothesised to represent the ancestral state of Panarthropoda (Tardigrada + Onychophora + Arthropoda), and their evolutionary history is important to our understanding of ecdysozoan evolution. Equally important is our understanding of the functional morphology of these legs, which requires knowledge of their musculature . Tardigrade musculature is well documented but open questions remain. For example, while the muscular organisation of each trunk segment and its legs is unique, three of the four trunk segments are nevertheless relatively homonomous. To what extent, then, do leg muscles show segmental patterns? Specifically, which leg muscles are serially repeated and which are unique? The present study addresses these questions using a combination of techniques intended to visualise both the overall layout and fine structure of leg muscles in the eutardigrade Hypsibius exemplaris . In doing so, we propose serial homologies for all leg muscles in each of the four legs and reveal new details of their cellular structure and attachment sites. We compare our results to those of previous studies and address the functional implications of specialised muscle cell morphologies. CLSM stacks and segmentation labels CLSM stacks used for this study together with segmentation labels that were used to generate the 3D reconstructions. SupplementaryFile1_CLSM_stacks_labels.zip