Spatiotemporal Dynamics Of Mouse Joints Development Via Histo-Raman Profiling

By integrating histological staining and Raman spectroscopy, we revealed the dynamic developmental characteristics of temporomandibular joint (TMJ), knee joint and spinal joint in mouse embryo. In this study, mouse embryos were obtained from 6-8 weeks old C57BL/6 wild-type female mice by mating with male mice. The embryos were selected at E14.5, E16.5 and E18.5 after pregnancy, and were tested by Safranin O and Fast Green staining, Modified Russell-Movat Pentachrome Staining and Raman spectroscopy. At the earliest stage of spinal joint development, a large amount of glycosaminoglycan(GAG) was secreted in the vertebral body at E14.5. The knee joint developed later than the spinal joint, forming joint cavity at E14.5, and GAG secretion in the meniscus at E18.5, and for TMJ, the condylar primordium was formed at E14.5; the articular inferior cavity and TMJ disc were formed at E18.5. Raman spectroscopy showed that the spatial and temporal distribution patterns of the characteristic peak of collagen (1440-1460cm-1) and GAG (1063cm-1) were consistent with the results of histological staining. The spine develops earliest, followed by the knee joint, and the temporomandibular joint develops latest in mouse embryo. The development of TMJ began from E14.5, the lower joint cavity and TMJ disc formed on E18.5. Our data reveal that in embryonic spinal annulus fibrosus and knee meniscus, GAG is the main component, while the TMJ disc is mainly composed of collagen fibers.