Abstract
Proteoglycan heterogeneity was studied during the maturation of embryonic-chick limb cartilage in vivo. During differentiation of limb-bud cartilage the aggregated forms of proteoglycans increased stages 24-35, while the nonaggregated or monomeric forms decreased. Only 1 link protein was found in stage 24 limb buds, while 2 were present at stage 35. The synthesis of link proteins may be a regulatory factor in limb chondrogenesis.