Aristotle already observed in the fourth century B.C. that some animals can regrow their tails after losing them, but the mechanisms that support this kind of regeneration remain difficult to understand.

Using single-cell genomics, scientists at the Wellcome Trust / Cancer Research UK Gurdon Institute at the University of Cambridge developed an innovative strategy to show what happens in different tadpole cells when they regenerate their tails.

Recent advances at Cambridge in next-generation single-cell sequencing mean that scientists can now track which genes are turned on throughout a whole organism or tissue, at the resolution of individual cells. This technique, known as single-cell genomics, makes it possible to distinguish between cell types in more detail based on their characteristic selection of active genes.

These groundbreaking discoveries are beginning to reveal a map of cellular identities and lineages, as well as the factors involved in controlling how cells choose between alternative pathways during embryo development to produce the range of cell types in adults.

Using this technology, Can Aztekin and Dr Tom Hiscock under the direction of Dr Jerome Jullien made a detailed analysis of cell types involved in regeneration after damage in African clawed frog tadpoles (Xenopus laevis). Details were published in the journal Science.

Dr Tom Hiscock said: Tadpoles can regenerate their tails throughout their life; but there is a two-day period at a precise stage in development where they lose this ability. We exploited this natural phenomenon to compare the cell types present in tadpoles capable of regeneration and those no longer capable.

The researchers found that the regenerative response of stem cells is orchestrated by a single sub-population of skin cells, which they named Regeneration-Organizing Cells, or ROCs.

Can Aztekin said: Its an astonishing process to watch unfold. After tail amputation, ROCs migrate from the body to the wound and secrete a cocktail of growth factors that coordinate the response of tissue precursor cells. These cells then work together to regenerate a tail of the right size, pattern and cell composition.

In mammals, many tissues such as the skin epidermis, the intestinal epithelium and the blood system, undergo constant turnover through life. Cells lost through exhaustion or damage are replenished by stem cells. However, these specialised cells are usually dedicated to tissue sub-lineages, while the ability to regenerate whole organs and tissues has been lost in all but a minority of tissues such as liver and skin.

Professor Benjamin Simons, a co-author of the study said: Understanding the mechanisms that enable some animals to regenerate whole organs represents a first step in understanding whether a similar phenomenon could be reawakened and harnessed in mammalian tissues, with implications for clinical applications.

This research was funded by the University of Cambridge, the Cambridge Trust andthe Wellcome Trust;and supported by theEuropean Molecular Biology Organization, the Royal Society,theEuropean Molecular Biology Laboratory, and Cancer Research UK.

Source: University of Cambridge Research

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Scientists find a cell that helps tadpoles tails regrow - Vryheid Herald