Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Previous Article in Special Issue
Cells 2013, 2(1), 1-18; doi:10.3390/cells2010001
Concept Paper

The “Stars and Stripes” Metaphor for Animal Regeneration-Elucidating Two Fundamental Strategies along a Continuum

1,*  and 2
Received: 27 September 2012; in revised form: 17 December 2012 / Accepted: 17 December 2012 / Published: 27 December 2012
(This article belongs to the Special Issue Tissue and Organ Regeneration)
View Full-Text   |   Download PDF [426 KB, uploaded 27 December 2012]
Abstract: A number of challenges have hindered the development of a unified theory for metazoan regeneration. To describe the full range of complex regeneration phenomena in Animalia, we suggest that metazoans that regenerate missing body parts exhibit biological attributes that are tailored along a morpho-spatial regeneration continuum, illustrated in its polar scenarios by the USA “stars and stripes” flag. Type 1 organisms (“T1, ‘stars’”) are typical colonial organisms (but contain unitary taxa) that are able to regenerate “whole new stars”, namely, whole bodies and colonial modules, through systemic induction and sometimes multiple regeneration foci (hollow regeneration spheres, resembling the blastula) that compete for dominance. They regenerate soma and germ constituents with pluripotent adult stem cells and exhibit somatic-embryogenesis mode of ontogeny. Type 2 organisms (“T2, ‘stripes’”) are capable of limited regeneration of somatic constituents via fate-restricted stem cells, and regenerate through centralized inductions that lead to a single regeneration front. T2 organisms are unitary and use preformistic mode of ontogeny. T1 and T2 organisms also differ in interpretation of what constitutes positional information. T2 organisms also execute alternative, less effective, regeneration designs (i.e., scar formation). We assigned 15 characteristics that distinguish between T1/T2 strategies: those involving specific regeneration features and those operating on biological features at the whole-organism level. Two model organisms are discussed, representing the two strategies of T1/T2 along the regeneration continuum, the Botrylloides whole body regeneration (T1) and the mouse digit-tip regeneration (T2) phenomena. The above working hypothesis also postulates that regeneration is a primeval attribute of metazoans. As specified, the “stars and stripes” paradigm allows various combinations of the biological features assigned to T1 and T2 regeneration strategies. It does not consider any concentration gradient or thresholds and does not refer to the “epimorphosis” and “morphallaxis” terms, regeneration types across phyla or across body plans. The “stars and stripes” paradigm also ignores, at this stage of analysis, cases of regeneration loss that may obscure biological trajectories. The main advantage of the “stars and stripes” paradigm is that it allows us to compare T1/T2 regeneration, as well as other modes of regeneration, through critical determining characteristics.
Keywords: asexual reproduction; blastema; botryllid ascidians; digit tip; epimorphosis; morphallaxis; somatic embryogenesis; regeneration; whole body asexual reproduction; blastema; botryllid ascidians; digit tip; epimorphosis; morphallaxis; somatic embryogenesis; regeneration; whole body
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Rinkevich, B.; Rinkevich, Y. The “Stars and Stripes” Metaphor for Animal Regeneration-Elucidating Two Fundamental Strategies along a Continuum. Cells 2013, 2, 1-18.

AMA Style

Rinkevich B, Rinkevich Y. The “Stars and Stripes” Metaphor for Animal Regeneration-Elucidating Two Fundamental Strategies along a Continuum. Cells. 2013; 2(1):1-18.

Chicago/Turabian Style

Rinkevich, Baruch; Rinkevich, Yuval. 2013. "The “Stars and Stripes” Metaphor for Animal Regeneration-Elucidating Two Fundamental Strategies along a Continuum." Cells 2, no. 1: 1-18.



Cells EISSN 2073-4409 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert