TY - JOUR T1 - Region-specific regulation of stem cell-driven regeneration in tapeworms JF - bioRxiv DO - 10.1101/495234 SP - 495234 AU - Tania Rozario AU - Edward B. Quinn AU - Jianbin Wang AU - Richard E. Davis AU - Phillip A. Newmark Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/06/01/495234.abstract N2 - Tapeworms grow at rates rivaling the fastest-growing metazoan tissues. To propagate they shed large parts of their body; to replace these lost tissues they regenerate proglottids (segments) as part of normal homeostasis. Their remarkable growth and regeneration are fueled by adult somatic stem cells, that have yet to be characterized molecularly. Using the rat intestinal tapeworm, Hymenolepis diminuta, we find that regenerative potential is regionally limited to the neck, where head-dependent extrinsic signals create a permissive microenvironment for stem cell-driven regeneration. Using transcriptomic analyses and RNA interference, we characterize and functionally validate regulators of tapeworm growth and regeneration. We find no evidence that stem cells are restricted to the regeneration-competent neck. Instead, lethally irradiated tapeworms can be rescued when cells from either regeneration-competent or regeneration-incompetent regions are transplanted into the neck. Together, the head and neck tissues provide extrinsic cues that regulate stem cells, enabling region-specific regeneration in this parasite. ER -