Differential Gene Expression in TRAP-positive Cells During Mouse Embryonic Skeletal Development

Graduate #10
Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology

Melissa Carr-Reynolds - University of Connecticut Health
Co-Author(s): Department of Molecular Medicine, UConn Health, Farmington, CT

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Chondroclasts are cartilage-resorbing cells whereas osteoclasts are bone-resorbing cells. Both play a role in endochondral ossification, which occurs during embryonic bone development. Endochondral ossification is specific to the long bones of the skeleton. These include the bones of the arms and legs, ribs, phalanges and the vertebral column. The goal of the project is to test the hypothesis that these two very similar cell types are distinguished by a pattern of differentially expressed genes during embryonic development (E14.5, E1.5, E18.5 and 20.5). Previous microarray analysis has identified a cluster of 851 genes that are differentially expressed between these two cell types in a fracture model of mouse. The first step is to validate a subset of the genes from those differentially expressed genes of tartrate-resistant acid phosphatase (TRAP) positive cells localized in mineralized bone (osteoclasts) and mineralized cartilage (chondroclasts). Laser capture microdissection was done in order to isolate RNA from the two cell types. Lastly, qRT-PCR and immunohistochemistry analysis is done to compare the expression of the subset of differentially expressed genes. These experiments test whether the genes that are differentially expressed during fracture are also differentially expressed during developmental. In the future, we will investigate particular signaling pathways that may be involved in the differential phenotype of both cells. These experiments will allow us to be able to identify genes that are important in defining the osteoclast and chondroclast cells in development, as well as fracture healing.

Not Submitted

Funder Acknowledgement(s): The Connecticut Institute of Clinical and Translational Science (CICATS)

Faculty Advisor: Marc Hansen, mhansen@uchc.edu