AsianScientist (Nov. 17, 2017) – A group of researchers at the University of Tokyo have identified a molecule, IL-11, that allows tadpoles to regenerate their tails. They published their findings in Nature Communications.
Some animal species, such as the tadpole of the African clawed frog (Xenopus laevis), have the remarkable ability to reconstruct lost appendages. When the tadpole loses its tail due to injury or other cause, it creates a new population of undifferentiated cells, called blastema, around the tail’s stump.
These cells proliferate and subsequently differentiate to form a new tail comprising a functional spinal cord, muscles and other tissues. The molecular mechanisms that underlie this process of undifferentiated-cell generation and proliferation, and subsequent regeneration of the tail, however, remained a mystery.
In this study, a team of researchers led by Professor Takeo Kubo at the University of Tokyo found that the interleukin-11 (IL-11) gene expresses itself selectively in the blastema cells that appear following the amputation of the tail. IL-11 induces and maintains several undifferentiated-cell lines, which form tissues needed for tadpole-tail regeneration.
Moreover, when the group forced the expression of IL-11 in intact tadpole tails, it induced the expression of marker genes for immature progenitor cells that differentiate into nerve, notochord (larval structure located ventral to spinal cord) and muscle tissues.
These findings suggest that the research group has succeeded in reproducing the earliest stage of organ regeneration by inducing cell differentiation in the lab. The results also demonstrate, for the first time, that only a single factor—IL-11—is responsible for inducing and maintaining undifferentiated progenitor cells of several tissues.
This study should help scientists better understand the entire molecular and cellular process of the ability, limited to a few select species, to regenerate organs.
“I wanted to reveal molecular mechanisms common to various kinds of regenerative phenomena when I started my research,” said Assistant Professor Hiroshi Tsujioka at Osaka University who carried out the experiments as a graduate student at the University of Tokyo. “In future studies, it will be important to examine whether IL-11 also induces and maintains undifferentiated cells in other regenerative phenomena.”
Source: University of Tokyo; Photo: Pixabay.
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