204
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Free-living flatworms under the knife: past and present

      review-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Traditionally, regeneration research has been closely tied to flatworm research, as flatworms (Plathelminthes) were among the first animals where the phenomenon of regeneration was discovered. Since then, the main focus of flatworm regeneration research was on triclads, for which various phenomena were observed and a number of theories developed. However, free-living flatworms encompass a number of other taxa where regeneration was found to be possible. This review aims to display and to compare regeneration in all major free-living flatworm taxa, with special focus on a new player in the field of regeneration, Macrostomum lignano (Macrostomorpha). Findings on the regeneration capacity of this organism provide clues for links between regeneration and (post-)embryonic development, starvation, and asexual reproduction. The role of the nervous system and especially the brain for regeneration is discussed, and similarities as well as particularities in regeneration among free-living flatworms are pointed out.

          Related collections

          Most cited references157

          • Record: found
          • Abstract: found
          • Article: not found

          Fundamentals of planarian regeneration.

          The principles underlying regeneration in planarians have been explored for over 100 years through surgical manipulations and cellular observations. Planarian regeneration involves the generation of new tissue at the wound site via cell proliferation (blastema formation), and the remodeling of pre-existing tissues to restore symmetry and proportion (morphallaxis). Because blastemas do not replace all tissues following most types of injuries, both blastema formation and morphallaxis are needed for complete regeneration. Here we discuss a proliferative cell population, the neoblasts, that is central to the regenerative capacities of planarians. Neoblasts may be a totipotent stem-cell population capable of generating essentially every cell type in the adult animal, including themselves. The population properties of the neoblasts and their descendants still await careful elucidation. We identify the types of structures produced by blastemas on a variety of wound surfaces, the principles guiding the reorganization of pre-existing tissues, and the manner in which scale and cell number proportions between body regions are restored during regeneration.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Not your father's planarian: a classic model enters the era of functional genomics.

            Freshwater planarians were a classic model for studying the problems of development and regeneration. However, as attention shifted towards animals with more rigid developmental processes, the planarians, with their notoriously plastic ontogeny, declined in significance as a model system. This trend was exacerbated with the introduction of genetic and molecular approaches, which did not work well in planarians. More recently, the heightened interest in stem-cell biology, along with the successful application of molecular, cellular and genomic approaches in planarians, is re-establishing these fascinating organisms as models for studying regeneration and developmental plasticity.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Identification of genes needed for regeneration, stem cell function, and tissue homeostasis by systematic gene perturbation in planaria.

              Planarians have been a classic model system for the study of regeneration, tissue homeostasis, and stem cell biology for over a century, but they have not historically been accessible to extensive genetic manipulation. Here we utilize RNA-mediated genetic interference (RNAi) to introduce large-scale gene inhibition studies to the classic planarian system. 1065 genes were screened. Phenotypes associated with the RNAi of 240 genes identify many specific defects in the process of regeneration and define the major categories of defects planarians display following gene perturbations. We assessed the effects of inhibiting genes with RNAi on tissue homeostasis in intact animals and stem cell (neoblast) proliferation in amputated animals identifying candidate stem cell, regeneration, and homeostasis regulators. Our study demonstrates the great potential of RNAi for the systematic exploration of gene function in understudied organisms and establishes planarians as a powerful model for the molecular genetic study of stem cells, regeneration, and tissue homeostasis.
                Bookmark

                Author and article information

                Contributors
                +43-512-5076192 , +43-512-5072930 , bernhard.egger@uibk.ac.at
                Journal
                Dev Genes Evol
                Development Genes and Evolution
                Springer-Verlag (Berlin/Heidelberg )
                0949-944X
                1432-041X
                5 December 2006
                February 2007
                : 217
                : 2
                : 89-104
                Affiliations
                Ultrastructural Research and Evolutionary Biology, University of Innsbruck, Innsbruck, Austria
                Author notes

                Communicated by R.J. Sommer

                Article
                120
                10.1007/s00427-006-0120-5
                1784541
                17146688
                3586495b-a2ba-4211-b418-6c83cb24073e
                © Springer-Verlag 2006
                History
                : 28 August 2006
                : 24 October 2006
                Categories
                Review
                Custom metadata
                © Springer-Verlag 2007

                Developmental biology
                platyhelminthes,planarian,catenulida,acoela,rhabditophora
                Developmental biology
                platyhelminthes, planarian, catenulida, acoela, rhabditophora

                Comments

                Comment on this article