Joint Development Involves a Continuous Influx of Gdf5-Positive Cells.
Synovial joints comprise several tissue types, including articular cartilage, the capsule, and ligaments. All of these compartments are commonly assumed to originate from an early set of Gdf5-expressing progenitors populating the interzone domain. Here, we provide evidence that joints develop through a continuous influx of cells into the interzone, where they contribute differentially to forming joint tissues. Using a knockin Gdf5-CreER(T2) mouse, we show that early labeling of Gdf5-positive interzone cells failed to mark the entire organ. Conversely, multiple Cre activation steps indicated a contribution of these cells to various joint compartments later in development. Spatiotemporal differences between Gdf5 and tdTomato reporter expression support the notion of a continuous recruitment process. Finally, differential contribution of Gdf5-positive cells to various tissues suggests that the spatiotemporal dynamics of Gdf5 expression may instruct lineage divergence. This work supports the influx model of joint development, which may apply to other organogenic processes.
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
Yulia
Y
Shwartz
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
Sergey
S
Viukov
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
Sharon
S
Krief
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: eli.zelzer@weizmann.ac.il.
Elazar
E
Zelzer
D000818:Animals; D019070:Cell Lineage; D049109:Cell Proliferation; D005786:Gene Expression Regulation; D055879:Gene Knock-In Techniques; D055428:Growth Differentiation Factor 5 / Q000378:metabolism*; D019426:Integrases / Q000378:metabolism; D007596:Joints / Q000166:cytology* / Q000378:metabolism*; D051379:Mice; D023421:Models, Animal; D008954:Models, Biological; D009024:Morphogenesis; D055758:SOX9 Transcription Factor / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology
D055428:Growth Differentiation Factor 5; D055758:SOX9 Transcription Factor; C045073:Cre recombinase; D019426:Integrases
Gdf5; Sox9; interzone; lineage tracing; mouse; progenitor cell; skeletogenesis; synovial joint