title: Staging of regeneration process of an arm of the feather star Oxycomanthus japonicus focusing on the oral-aboral boundary.
abstract: Crinoids have strong regenerative capability and rapidly restore their lost body parts such as arms. We observed the regeneration process of arms of the feather star (stalkless crinoid), Oxycomanthus japonicus, and divided the process into 10 stages. We clarify the position at which the oral and aboral epidermis adhere in wound closure and track the oral-aboral boundary in the regenerate during the entire process of regeneration. We suggest that the concepts of distalization and intercalation, which are proposed to understand animal regeneration integrally, are also applicable to arm regeneration of the feather star. In addition, we clarify that pinnules, appendages extending from the sides of an arm, start to grow in the oral region of the regenerating arm even though a complete pinnule has an oral-aboral axis. The mode of morphogenesis of pinnules in arm regeneration suggests that the oral region functions as the primary patterning tissue for pinnules.
authors.affiliation: Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Kanagawa, Japan. tshibata@bio.miami.edu
authors.forename: Tomoko F
authors.initials: TF
authors.lastname: Shibata
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Oji
authors.forename: Koji
authors.initials: K
authors.lastname: Akasaka
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Agata
mesh_terms: D000818:Animals; D004447:Echinodermata / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D012038:Regeneration / Q000502:physiology*