Phase-specific mechanical and proteomic analyses reveal how tendon responds to its mechanical environment during postnatal development to meet functional requirements.

The membrane type I-matrix metalloproteinase is essential for the release of collagen fibrils from plasma membrane fibripositors, which is required for the transition from embryonic to postnatal tendon development.

Tendon fibroblast cells lay down a collagen matrix template during embryogenesis, and the expansion of this matrix drives post-natal tissue growth.

Conditional deletion of TGFβ signaling results in tenocyte dedifferentiation in vivo demonstrating a key role for TGFβ signaling in the maintenance of the tendon cell fate.

Single-cell RNA sequencing to delineate the comprehensive postnatal RC enthesis growth from as early as postnatal day 1 to postnatal day 56.

Functional attachments between muscles and tendons require pentameric Thrombospondin-4, revealing novel roles both as an integrin ligand and extracellular matrix scaffold.

Ultrastructural, biochemical, and behavioral assessments reveal that the Crtap^-/- mouse model of severe, recessive Osteogenesis Imperfecta presents with defects in tendon structure and strength that correlate with severe motor deficits.

Adult Scleraxis-lineage cells are not required for successful tendon healing but are required for maintenance of tendon homeostasis.

Perturbation of mechanical force at muscle attachments and its effects on tendon morphogenesis provides insights into the mechanisms underlying cellular responses to tensional force and resulting extracellular matrix production.

Integrin and actin associated proteins are resolved into four layers within myofibril attachments, an architecture requiring balanced positive and negative regulation of integrin adhesion with integrated mechanotransduction and actin pathways.