Discovery Seen as “Critical Step” in Understanding Salivary Gland Maintenance
If you spent a few minutes clicking on Nature, Cell, or any other scientific online journal, you’d draw 2 quick conclusions. The discovery of genes and their proteins has become commonplace. Secondly, many discoveries are so obscure in name and vague in biological function, initially it’s hard to imagine where they will lead in the future. Take the case of the protein Ascl3—also called Sgn1. Working with mice in 2001, scientists identified this 174-amino-acid protein in the specialized duct cells of the salivary gland. They determined that the protein structurally belongs to a family of DNA-binding transcription factors known to participate in the process of tissue development and differentiation. Adding further weight to this finding, the scientists later reported that Ascl3 is barely detectable at birth in the salivary gland but increase as the tissue develops. That’s where the data largely remained for years—in need of a scientific push. That push came recently when a team of National Institute of Dental and Craniofacial Research (NIDCR)-supported scientists generated genetically modified mice that produced a fluorescently labeled version of the Ascl3 protein. Focusing on the developing sublingual salivary gland, the scientists monitored the cells that initially flashed the protein tag as well as their descendent cell lines. As published in the August 2008 issue of Developmental Biology, the scientists determined that the tags labeled a population of progenitor cells within the salivary glands that are capable of producing at least 2 cell lineages. The authors said the finding that Ascl3 is a marker for a population of progenitor cells is “a critical step in the progress toward identifying the source of cells that are responsible for salivary gland maintenance and regeneration.”
(Source: NIDCR, Science News in Brief, August 27, 2008)
