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Updated: Feb 27, 2026
Author Spotlight: Development and Evaluation of a Standardized Rat Model for Calvarial Suture-Bony Composite Defects
Published on: May 10, 2024
Calvarial bone development and suture closure in Dicer-deficient mice
P Atsawasuwan1, M Ouibaidin1, B Dalal1
1Department of Orthodontics, University of Illinois at Chicago, Chicago, Illinois, USA.
Objective:
To evaluate whether lack of Dicer during calvaria development would lead to dysmorphology of calvaria and suture closure in mice.
Materials And Methods:
A conditional Dicer deficient under Osx promoter mouse was employed in this study. The 4- and 10-week-old conditional Dicer-deficient mice control littermates and Osx-cre transgenic mice were studied for calvarial bone morphology and suture closure. Dry skull, microcomputed tomography (μCT), histological and gene expression studies were investigated to evaluate the effect of Dicer deficiency on calvarial bone morphology and their related genes during calvaria development.
Results:
The results elucidated that complete suture closure was observed in 10-week-old conditional Dicer-deficient mice while incomplete closure suture was observed in age-matched Osx-cre control mice. The μCT and histological sections demonstrated complete fusion of posterior frontal suture and dysmorphic calvarial bones in Dicer deficient mice compared to the ones in their littermates and age-matched Osx-cre control mice. Gene expression study demonstrated significantly increased expression of suture and calvarial bone-related genes, that is Tgf-beta family, Bmp3, Msx2, Alx4, Runx2 and Osx in Dicer-deficient mice during suture closure time.
Conclusions:
The results suggest mature miRNAs are important for suture closure and calvarial morphology during calvaria development.
Insights
Dicer deficiency in mice leads to premature suture closure and abnormal calvarial bone development. Mature microRNAs (miRNAs) are crucial for regulating calvarial morphology and suture fusion during development.
Area of Science:
- Developmental Biology
- Genetics
- Craniofacial Biology
Background:
- Dicer is essential for microRNA (miRNA) biogenesis.
- miRNAs play critical roles in cellular differentiation and tissue development.
- The role of Dicer in calvarial bone development and suture closure is not well understood.
Purpose of the Study:
- To investigate the impact of Dicer deficiency on calvarial development and suture closure in mice.
- To determine if Dicer loss leads to calvarial dysmorphology.
Main Methods:
- Conditional Dicer-deficient mice under the Osx promoter were generated.
- Calvarial bone morphology and suture closure were analyzed in 4- and 10-week-old mice using dry skull, microcomputed tomography (μCT), and histological studies.
- Gene expression analysis of suture and calvarial bone-related genes was performed.
Main Results:
- Conditional Dicer deficiency resulted in complete suture closure by 10 weeks of age, unlike controls.
- μCT and histological analyses revealed dysmorphic calvarial bones and fused sutures in Dicer-deficient mice.
- Gene expression studies showed increased levels of key developmental genes (e.g., Tgf-beta family, Runx2, Osx) during suture closure in Dicer-deficient mice.
Conclusions:
- Mature miRNAs are essential for normal calvarial morphology.
- Dicer-mediated miRNA production is critical for regulating suture closure during calvarial development.
