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Restoration of anterior regeneration in a planarian with limited regenerative ability


Variability of regenerative potential among animals has long perplexed biologists1. On the basis of their exceptional regenerative abilities, planarians have become important models for understanding the molecular basis of regeneration2. However, planarian species with limited regenerative abilities are also found3,4. Despite the importance of understanding the differences between closely related, regenerating and non-regenerating organisms, few studies have focused on the evolutionary loss of regeneration5, and the molecular mechanisms leading to such regenerative loss remain obscure. Here we examine Procotyla fluviatilis, a planarian with restricted ability to replace missing tissues6, using next-generation sequencing to define the gene expression programs active in regeneration-permissive and regeneration-deficient tissues. We found that Wnt signalling is aberrantly activated in regeneration-deficient tissues. Notably, downregulation of canonical Wnt signalling in regeneration-deficient regions restores regenerative abilities: blastemas form and new heads regenerate in tissues that normally never regenerate. This work reveals that manipulating a single signalling pathway can reverse the evolutionary loss of regenerative potential.

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Figure 1: Procotyla fluviatilis fails to regenerate heads after amputation in posterior body regions.
Figure 2: Comparative transcriptomics reveal differentially expressed genes following amputation in Reg+ and Reg tissues.
Figure 3: Disruption of Wnt signalling via RNAi rescues regeneration in Reg tissues.

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Gene Expression Omnibus

Data deposits

Sequence read archive (SRA) data reported in this paper were deposited at NCBI as a BioProject under accession number PRJNA205293. RNA-seq analyses have been deposited in the NCBI Gene ExpressionOmnibus under accession number GSE48497.


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We thank Newmark laboratory members for comments, A. Vieira for technical assistance, A. Hernandez and the W. M. Keck Center for Comparative and Functional Genomics for sequencing assistance, and the National Forest Service, Illinois Department of Natural Resources, USA, and Montgomery County (Maryland) Department of Parks, USA, for field collection permits. We also thank A. Boney, J. Brubacher, T. Chong, M. Issigonis, H. Iyer and B. Lambrus for assistance in field collections. This work was supported by National Institute of General Medicine Sciences fellowship F32GM097921 (J.M.S.). P.A.N. is an investigator of the Howard Hughes Medical Institute.

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Authors and Affiliations



Both authors contributed to the design of the experimental strategy. J.M.S. conducted all experiments, analysed the data and drafted the manuscript, which was critically reviewed and revised by P.A.N. Both authors discussed the results and commented on the final version of the manuscript.

Corresponding author

Correspondence to James M. Sikes.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Figures 1-5 and Supplementary Tables 1-3. The figures demonstrate the differences in regenerative potential of P. fluviatilis tissues, the upregulation of mitotic activity following amputation in regeneration-proficient and regeneration-deficient tissues, the effects of RNAi knockdown of Wnt signaling molecules during anterior and posterior regeneration, sequence alignments, nucleotide sequences used to generate dsRNA, and tables illustrate gene upregulation assayed by RNAseq, effects of RNAi, and oligonucleotide sequences. (PDF 11196 kb)

Behaviour of PF-Beta-catenin-1 (RNAi) knockdown tail fragment, 14 days of regeneration

Anterior-directed movements occur in Pf-β-catenin1(RNAi) animals after rescued regeneration, suggesting complete and functional head regeneration. (Time lapse covers a period of 1.3 min.) (MOV 2444 kb)

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Sikes, J., Newmark, P. Restoration of anterior regeneration in a planarian with limited regenerative ability. Nature 500, 77–80 (2013).

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