GSE114919
Differential ageing of growth plate cartilage determines skeletal proportions
Bones at different anatomical locations vary dramatically in size.  The mechanisms responsible for these size differences are poorly understood.  Bone elongation occurs at the growth plates and advances rapidly in early life but then progressively slows due to a developmental program termed growth plate senescence. This developmental program includes declines in cell proliferation and hypertrophy, depletion of cells in all growth plate zones, and extensive underlying changes in the expression of growth-regulating genes. Here we use RNA-Seq to compare changes of gene expression with age in the longer bone (tibia, 1- vs 4-wk) with the difference of gene expression between long and short bones (tibia vs phalanx) at 1wk. We found that the developmental program of growth plate senescence is more advanced in the shorter bone and this differential senescence (or aging) underlies the disparities in bone length. Overall design: tibia, 1wk vs 4wk; 1wk, tibia vs phalanx; in both mice and rats, proliferative zone or hypertrophic zone of growth plate (separated by laser capture microdissection)