title: Reintegration of the regenerated and the remaining tissues during joint regeneration in the newt Cynops pyrrhogaster.
abstract: Urodele amphibians, such as newts, can regenerate a functional limb, including joints, after amputation at any level along the proximal-distal axis of the limb. The blastema can regenerate the limb morphology largely independently of the stump after proximal-distal identity has been established, but the remaining and regenerated tissues must be structurally reintegrated (matched in size and shape). Here we used newt joint regeneration as a model to investigate reintegration, because a functionally interlocking joint requires structural integration between its opposing skeletal elements. After forelimbs were amputated at the elbow joint, the joint was regenerated between the remaining and regenerated skeletal elements. The regenerated cartilage was thick around the amputated joint to make a reciprocally interlocking joint structure with the remaining bone. Furthermore, during regeneration, the extracellular matrix of the remaining tissues was lost, suggesting that the remaining tissues might contribute to the morphogenesis of regenerating cartilage. Our results showed that the area of the regenerated cartilage matched the area of the apposed remaining cartilage, thus contributing to formation of a functional structure.
authors: Department of Biophysics Graduate School of Science Kyoto University Kyoto Japan.
authors: Rio
authors: R
authors: Tsutsumi
authors: Department of Biophysics Graduate School of Science Kyoto University Kyoto Japan.
authors: Takeshi
authors: T
authors: Inoue
authors: Human Health Science Graduate School of Medicine Kyoto University Kyoto Japan; Congenital Anomaly Research Center Graduate School of Medicine Kyoto University Kyoto Japan.
authors: Shigehito
authors: S
authors: Yamada
authors: Department of Biophysics Graduate School of Science Kyoto University Kyoto Japan.
authors: Kiyokazu
authors: K
authors: Agata
keywords: EFIC; joint; limb; newt; regeneration; reintegration