Figure 4. Bone marrow cells migrate specifically to the FDL repair site in vivo.

Representative sections of repaired flexor tendons from C57Bl6/J mice that were myeloablated, and reconstituted with bone marrow from GFP transgenic mice. Tendons were repaired after bone marrow cells had engrafted, and tissues were harvested between three and 28 days post-repair. Sections were counterstained with the nuclear dye DAPI (blue) and bone marrow derived cells were identified based on the expression of GFP. Contralateral sham controls (A) did not have any GFP expressing cells indicating a lack of bone marrow cells in un-injured tendon, while bone marrow derived cells are present at the FDL repair site at (B) three, (C) seven, (D) 14, (E) 21, and (F) 28 days post-repair. Tendon tissue is outlined in orange and marked as ‘T’. All images are 10x magnification. Scale bars represent 200 microns.