Smed-betacatenin-1 is required for anteroposterior blastema polarity in planarian regeneration.
Planarian flatworms can regenerate heads at anterior-facing wounds and tails at posterior-facing wounds throughout the body. How this regeneration polarity is specified has been a classic problem for more than a century. We identified a planarian gene, Smed-betacatenin-1, that controls regeneration polarity. Posterior-facing blastemas regenerate a head instead of a tail in Smed-betacatenin-1(RNAi) animals. Smed-betacatenin-1 is required after wounding and at any posterior-facing wound for polarity. Additionally, intact Smed-betacatenin-1(RNAi) animals display anteriorization during tissue turnover. Five Wnt genes and a secreted Frizzled-related Wnt antagonist-like gene are expressed in domains along the anteroposterior axis that reset to new positions during regeneration, which suggests that Wnts control polarity through Smed-betacatenin-1. Our data suggest that beta-catenin specifies the posterior character of the anteroposterior axis throughout the Bilateria and specifies regeneration polarity in planarians.
Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA.
Christian P
CP
Petersen
Peter W
PW
Reddien
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning; D015870:Gene Expression; D017238:Genes, Helminth; D006257:Head; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D006706:Homeostasis; D008969:Molecular Sequence Data; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology; D010932:Planarians / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D034622:RNA Interference; D012038:Regeneration; D015398:Signal Transduction; D051153:Wnt Proteins / Q000235:genetics / Q000502:physiology; D051176:beta Catenin / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D015801:Helminth Proteins; D051153:Wnt Proteins; D051176:beta Catenin