ScienceDaily (Sep. 28, 2009) — A new study resolves a 130-year-old mystery over the developmental origin of specialized skin cells involved in touch sensation.

First described in 1875, Merkel cells are neuroendocrine cells that reside in the vertebrate epidermis, passing mechanical stimuli on to sensory neurons. In mice, they are mainly found in the paws and around the whiskers but, because they express proteins characteristic of both epithelial and neuronal cells, scientists have long debated whether Merkel cells develop from the epidermis or neural crest.

Van Keymeulen et al. traced the lineage of Merkel cells by fluorescently labeling cells derived from either epidermal or neural crest progenitors. This revealed that Merkel cells originally emerge from the embryonic epidermis. In addition, epidermal stem cells in adult mouse skin replenish the Merkel cell population as they slowly die off over time. The researchers also found that a transcription factor called Atoh1 is required for epidermal progenitors to differentiate into Merkel cells—mice lacking Atoh1 in their skin failed to develop any of the mechanotransducing cells.

Atoh1 acts as a tumor suppressor to prevent an aggressive skin cancer called Merkel cell carcinoma, says senior author Cédric Blanpain. His team now wants to investigate the precise function of the transcription factor in Merkel cell differentiation, as well as the signaling pathways that regulate the process.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Rockefeller University Press, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Van Keymeulen, A., et al. Epidermal progenitors give rise to Merkel cells during embryonic development and adult homeostasis. J. Cell Biol, DOI: 10.1083/jcb.200907080

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

enlarge

Merkel cells (red) fail to differentiate from epidermal stem cells in mouse skin lacking Atoh1 (right). (Credit: Van Keymeulen, A., et al. 2009. J. Cell Biol. doi:10.1083/jcb.200907080.)

Related Stories

Merkel Cell Originates From Skin, Not The Neural Crest (Oct. 7, 2009) — Researchers have found that Merkel cells originate in the skin, not the neural crest lineage, as previously ...  > read more

Inner Workings of Virus Responsible for Rare Skin Cancer (Sep. 15, 2011) — Scientists have begun to uncover how the virus that causes most Merkel cell carcinoma -- a rare and aggressive skin cancer -- operates, meaning that a rational chemotherapeutic target for this cancer ...  > read more

Repulsion More Important Than Cohesion in Embryonic Tissue Separation (Apr. 6, 2011) — Until now, adherence was thought to be the principle force responsible for the separation of the ectoderm from the mesoderm in embryonic cells. But by using high resolution imaging, researchers have ...  > read more

Mystery of Disappearing Bird Digit Solved? (Sep. 5, 2011) — What is the origin of digits in birds? The question has long puzzled evolutionary biologists. Using genomic analysis, researchers have now solved a key part of this ...  > read more

Search ScienceDaily