Expression of secreted Wnt pathway components reveals unexpected complexity of the planarian amputation response |
| |
Authors: | Kyle A. Gurley Sarah A. Elliott Oleg Simakov Thomas W. Holstein |
| |
Affiliation: | a Department of Neurobiology and Anatomy, Howard Hughes Medical Institute, University of Utah School of Medicine, 401 MREB, 20N 1900E, Salt Lake City, UT 84132, USAb EMBL Heidelberg, Developmental Biology, Meyerhofstraße 1, 69117 Heidelberg, Germanyc Center for Integrative Bioinformatics Vienna (CIBIV), Max F. Perutz Laboratories (MFPL), Dr Bohr Gasse 9, 1030 Vienna; Vienna University; University of Veterinary Medicine; Medical University; Vienna, Austriad Molecular Evolution and Genomics, Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany |
| |
Abstract: | Regeneration is widespread throughout the animal kingdom, but our molecular understanding of this process in adult animals remains poorly understood. Wnt/β-catenin signaling plays crucial roles throughout animal life from early development to adulthood. In intact and regenerating planarians, the regulation of Wnt/β-catenin signaling functions to maintain and specify anterior/posterior (A/P) identity. Here, we explore the expression kinetics and RNAi phenotypes for secreted members of the Wnt signaling pathway in the planarian Schmidtea mediterranea. Smed-wnt and sFRP expression during regeneration is surprisingly dynamic and reveals fundamental aspects of planarian biology that have been previously unappreciated. We show that after amputation, a wounding response precedes rapid re-organization of the A/P axis. Furthermore, cells throughout the body plan can mount this response and reassess their new A/P location in the complete absence of stem cells. While initial stages of the amputation response are stem cell independent, tissue remodeling and the integration of a new A/P address with anatomy are stem cell dependent. We also show that WNT5 functions in a reciprocal manner with SLIT to pattern the planarian mediolateral axis, while WNT11-2 patterns the posterior midline. Moreover, we perform an extensive phylogenetic analysis on the Smed-wnt genes using a method that combines and integrates both sequence and structural alignments, enabling us to place all nine genes into Wnt subfamilies for the first time. |
| |
Keywords: | Stem cells Regeneration Tissue remodeling Wnt signaling pathway Planarians |
本文献已被 ScienceDirect 等数据库收录! |
|