Int J Stem Cells.  2015 Nov;8(2):128-133. 10.15283/ijsc.2015.8.2.128.

Planarians: an In Vivo Model for Regenerative Medicine

• Karami A
• Tebyanian
• Goodarzi V
• Shiri S

• KMID: 2380807
• DOI: http://doi.org/10.15283/ijsc.2015.8.2.128

Abstract

The emergence of regenerative medicine has raised the hope of treating an extraordinary range of disease and serious injuries. Understanding the processes of cell proliferation, differentiation and pattern formation in regenerative organisms could help find ways to enhance the poor regenerative abilities shown by many other animals, including humans. Recently, planarians have emerged as an attractive model in which to study regeneration. These animals are considering as in vivo plate, during which we can study the behavior and characristics of stem cells in their own niche. A variety of characteristic such as: simplicity, easy to manipulate experimentally, the existence of more than 100 years of literature, makes these animals an extraordinary model for regenerative medicine researches. Among planarians free-living freshwater hermaphrodite Schmidtea mediterranea has emerged as a suitable model system because it displays robust regenerative properties and, unlike most other planarians, it is a stable diploid with a genome size of about 4.8x108 base pairs, nearly half that of other common planarians. Planarian regeneration involves two highly flexible systems: pluripotent neoblasts that can generate any new cell type and muscle cells that provide positional instructions for the regeneration of anybody region. neoblasts represent roughly 25~30 percent of all planarian cells and are scattered broadly through the parenchyma, being absent only from the animal head tips and the pharynx. Two models for neo-blast specification have been proposed; the naive model posits that all neoblasts are stem cells with the same potential and are a largely homogeneous population.

Keyword

Neoblast; Regenerative medicine; Blastema; Differentiation; Schmidtea mediterranea

MeSH Terms

Animals
Base Pairing
Cell Proliferation
Diploidy
Fresh Water
Genome Size
Head
Hope
Humans
Muscle Cells
Pharynx
Planarians*
Regeneration
Regenerative Medicine*
Stem Cells

Figure

• 

  Fig. 1 Model of the neoblast population. Two major classes, the sigma-class and the zeta-class, represent functionally separate neoblast compartments. sNeoblastsare able to self-renew and collectively give rise to a wide range of tissue types. Over the course of S phase, a subset of the sNeoblasts gains markers specific for the zeta-class. These cells give rise to the prog-1-related lineages and to epidermal cells.

Reference

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