Osteoblast maturation occurs in overlapping proximal-distal compartments during fin regeneration in zebrafish.
During fin regeneration, osteoblasts must continually differentiate for outgrowth of the bony fin rays. Bone maturity increases in a distal-proximal manner, and osteoblast maturation can be detected similarly when following gene expression. We find that early markers for osteoblast differentiation are expressed in a discrete domain at the distal end of the fin, just proximal to the adjacent germinal compartment of dividing cells. Matrix genes, required at later stages developmentally, are expressed in a population of cells proximally to the early genes. A marker for mature osteoblasts is expressed in cells further proximal. These domains of gene expression are partially overlapping, perhaps revealing additional levels of osteoblast maturity. We suggest a model for growth where new cells are continually added to the distal-most osteoblast compartment, while osteoblasts in more proximal locations differentiate, thus translating developmental time to location on the proximal-distal axis.
Lehigh University, Department of Biological Science, Bethlehem, Pennsylvania 18015, USA.
Andrew M
AM
Brown
Shannon
S
Fisher
M Kathryn
MK
Iovine
D000818:Animals; D001861:Bone Regeneration; D002454:Cell Differentiation / Q000502:physiology*; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D053495:Osteopontin / Q000378:metabolism; D000076182:Sp7 Transcription Factor; D014157:Transcription Factors / Q000378:metabolism; D015027:Zebrafish / Q000502:physiology*; D029961:Zebrafish Proteins / Q000378:metabolism
C502545:Runx2a protein, zebrafish; C502546:Runx2b protein, zebrafish; D000076182:Sp7 Transcription Factor; D014157:Transcription Factors; D029961:Zebrafish Proteins; C541742:sp7 protein, zebrafish; D053495:Osteopontin