Ascl3 expression marks a progenitor population of both acinar and ductal cells in mouse salivary glands.
Ascl3, also know as Sgn1, is a member of the mammalian achaete scute (Mash) gene family of transcription factors, which have been implicated in cell fate specification and differentiation. In the mouse salivary gland, expression of Ascl3 is restricted to a subset of duct cells. Salivary gland function depends on the secretory acinar cells, which are responsible for saliva formation, and duct cells, which modify the saliva and conduct it to the oral cavity. The salivary gland ducts are also the putative site of progenitor cells in the adult gland. Using a Cre recombinase-mediated reporter system, we followed the fate of Ascl3-expressing cells after the introduction of an EGFP-Cre expression cassette into the Ascl3 locus by homologous recombination. Lineage tracing shows that these cells are progenitors of both acinar and ductal cell types in all three major salivary glands. In the differentiated progeny, expression of Ascl3 is down-regulated. These data directly demonstrate a progenitor-progeny relationship between duct cells and the acinar cell compartment, and identify a population of multipotent progenitor cells, marked by expression of Ascl3, which is capable of generating both gland cell types. We conclude that Ascl3-expressing cells contribute to the maintenance of the adult salivary glands.
Center for Oral Biology and Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
Tara
T
Bullard
Laurie
L
Koek
Elisa
E
Roztocil
Paul D
PD
Kingsley
Lily
L
Mirels
Catherine E
CE
Ovitt
D000375:Aging; D000483:Alleles; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002451:Cell Compartmentation; D019070:Cell Lineage; D047108:Embryonic Development; D049452:Green Fluorescent Proteins / Q000378:metabolism; D019426:Integrases / Q000378:metabolism; D051379:Mice; D018987:Salivary Ducts / Q000166:cytology / Q000196:embryology; D012469:Salivary Glands / Q000166:cytology* / Q000196:embryology / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology*; D013361:Sublingual Gland / Q000166:cytology / Q000196:embryology
D051792:Basic Helix-Loop-Helix Proteins; D049452:Green Fluorescent Proteins; D019426:Integrases; C446484:Ascl3 protein, mouse; C485184:enhanced green fluorescent protein; C045073:Cre recombinase