Spatial and temporal expression of Sox9 during murine incisor development

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Oral Biology

Background:

• Mouse incisors exhibit continuous growth, driven by stem cells in the dental epithelium and mesenchyme.
• The transcription factor Sox9 is crucial for stem cell maintenance in various tissues like hair follicles and neural crest.

Purpose of the Study:

• To investigate the expression pattern of Sox9 during mouse incisor development.
• To determine if Sox9 is involved in the processes underlying continuous incisor growth.

Main Methods:

• In situ hybridization was used to detect Sox9 mRNA expression.
• Immunohistochemistry was employed to visualize Sox9 protein localization.
• Expression patterns were analyzed across different developmental stages, from embryonic day (E) 13.5 to postnatal day (PN) 10.

Main Results:

• Sox9 mRNA and protein exhibited similar spatiotemporal expression patterns.
• Strong Sox9 expression was observed in the dental epithelium at E13.5 and E14.5.
• From E16.5 to PN10, Sox9 was detected in the labial cervical loop (including basal epithelium, stellate reticulum, outer enamel epithelium) and adjacent mesenchymal cells.

Conclusions:

• The expression of Sox9 in key structures of the developing mouse incisor suggests its potential involvement in incisor development.
• Sox9 may play a role in regulating the stem cells responsible for continuous incisor growth.