The interfollicular epidermis of adult mouse tail comprises two distinct cell lineages that are differentially regulated by Wnt, Edaradd, and Lrig1.
Current models of how mouse tail interfollicular epidermis (ife) is maintained overlook the coexistence of two distinct terminal differentiation programs: parakeratotic (scale) and orthokeratotic (interscale). lineage tracing and clonal analysis revealed that scale and interscale are maintained by unipotent cells in the underlying basal layer, with scale progenitors dividing more rapidly than interscale progenitors. Although scales are pigmented and precisely aligned with hair follicles, melanocytes and follicles were not necessary for scale differentiation. Epidermal Wnt signaling was required for scale enlargement during development and for postnatal maintenance of scale-interscale boundaries. Loss of Edaradd inhibited ventral scale formation, whereas loss of Lrig1 led to scale enlargement and fusion. In wild-type skin, Lrig1 was not expressed in IFE but was selectively upregulated in dermal fibroblasts underlying the interscale. We conclude that the different IFE differentiation compartments are maintained by distinct stem cell populations and are regulated by epidermal and dermal signals.
Centre for Stem Cells and Regenerative Medicine, King's College London, 28th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK.
Céline
C
Gomez
Wesley
W
Chua
Ahmad
A
Miremadi
Sven
S
Quist
Denis J
DJ
Headon
Fiona M
FM
Watt
D053687:Adult Stem Cells / Q000166:cytology / Q000378:metabolism; D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D019070:Cell Lineage; D053362:Edar-Associated Death Domain Protein / Q000235:genetics / Q000378:metabolism*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D018859:Hair Follicle / Q000166:cytology / Q000378:metabolism*; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D013623:Tail; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D060449:Wnt Signaling Pathway
D053362:Edar-Associated Death Domain Protein; C101671:Lrig1 protein, mouse; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D051153:Wnt Proteins