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Presenting Author(s) Kazuna Sato
Abstract Title "Neural" stem cell marker, Musashi express ion in Xenopus and axolotl limb.
Full author List Sato, K., Karcavich, R.E, Smith R.C.* and Chernoff, E.A.G.
Text of abstract

We are studying the function of Musashi, an RNA-binding protein in limb and spinal cord regeneration. Musashi-1 maintains Notch signalling by preventing translation of the Notch inhibitor Numb. This keeps neural stem cells immature and undifferentiated. Musashi-1 has been identified in the ependymal cells/radial glia in developing central nervous system (CNS) and in adult neural stem cells/progenitor cells in the mouse (Kaneko et al., 2000, Dev. Neurosci 22, 139-153.). It is strongly expressed in developing amphibian CNS (work of Peter Good). We find that Musashi is strongly expressed in regenerating amphibian

CNS and also in limb. In Xenopus laevis (a frog) and Ambystoma mexicanum (the axolotl, a salamander), we found that Musashi-1 (called nrp-1 in Xenopus) is strongly expressed in ependymal cells in regeneration-competent spinal cord. In Xenopus spinal cord, Musashi-1/ nrp-1 is highly expressed in regeneration-competent tissue, but grows weak as cord regeneration fails. After a lesion of spinal cord, Musashi-1 expression increases in regenerating spinal cord in both Xenopus and axolotl. In amphibian limbs, Musashi-1 expression is strongly correlated with regeneration-competence. In stage 53 Xenopus tadpoles, hind limb regenerates completely after amputation. At stage 59 hind limb cannot regenerate after amputation. Musashi-1/ nrp-1 is expressed strongly in stage 53 limb but not in stage 59 limb. To understand the timing, stage 53 is before the thyroid hormone (T3 and T4) secretion peak preceding metamorphosis ; stage 59 is during the thyroid hormone peak. We cloned Musashi-1 in the axolotl, an amphibian that does not normally metamorphose, and regenerates limbs as an adult. Musashi-1 is strongly expressed in fully developed axolotl limbs. This suggests that Musashi-1 is more broadly related to regeneration-competence and may promote stem cell properties in limb as it maintains neural stem cell properties during spinal cord regeneration.
Which session is your work most relevant to: Limb regeneration