Sox9-expressing precursors are the cellular origin of the cruciate ligament of the knee joint and the limb tendons

• Published in: Genesis (New York, N.Y. : 2000) Vol. 48; no. 11; pp. 635 - 644
• Main Authors: Soeda, Tsunemitsu, Deng, Jian Min, de Crombrugghe, Benoit, Behringer, Richard R., Nakamura, Takashi, Akiyama, Haruhiko
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2010
• Subjects: Animals; Anterior Cruciate Ligament - cytology; Anterior Cruciate Ligament - embryology; Anterior Cruciate Ligament - metabolism; Anterior Cruciate Ligament - physiology; Cell Differentiation - genetics; cell fate; Cells, Cultured; CreERT2; cruciate ligament; Embryo, Mammalian; Extremities - embryology; Extremities - physiology; Female; Knee Joint - embryology; Knee Joint - metabolism; limb tendon; Mice; Mice, Transgenic; Organogenesis - genetics; Organogenesis - physiology; Posterior Cruciate Ligament - cytology; Posterior Cruciate Ligament - embryology; Posterior Cruciate Ligament - metabolism; Posterior Cruciate Ligament - physiology; Pregnancy; Sox9; SOX9 Transcription Factor - genetics; SOX9 Transcription Factor - metabolism; Stem Cells - metabolism; Stem Cells - physiology; Tendons - embryology; Tendons - metabolism
• ISSN: 1526-954X; 1526-968X; 1526-968X
• DOI: 10.1002/dvg.20667

Sox9 expression defines cell progenitors in a variety of tissues during mouse embryogenesis. To establish a genetic tool for cell‐lineage tracing and gene‐function analysis, we generated mice in which the CreERT2 gene was targeted to the endogenous mouse Sox9 locus. In Sox9CreERT2/+;R26R embryos, tamoxifen activated Cre recombinase exclusively in Sox9‐expressing tissues. To determine the suitability of this mouse line for developmental stage‐specific gene recombination, we investigated the cellular origins of the cruciate ligaments of the knee joint and the limb tendons, in which precursor cells have not been defined. The cells in these tissues were labeled after tamoxifen treatment before or at the stage of chondrogenic mesenchymal condensation, indicating that ligament and tendon cells originated from Sox9‐expressing cells and that cell fate determination occurred at mesenchymal condensation. This mouse line is a valuable tool for the temporal genetic tracing of the progeny of, and inducible gene modification in Sox9‐expressing cells. genesis 48:635–644, 2010. © 2010 Wiley‐Liss, Inc.