The mechanical force with the physiological movement works as a biological cue in tendon development during the postnatal phase in mice

Abstract

3.AbstractThe musculoskeletal system provides structural stability and coordinates to enable movement. The tendon has the important role of transmitting the muscle contraction force to bone and resisting an external force. It is well known that muscle contraction is required to maintain tendon differentiation. Although tendon always bears mechanical force from muscle and external, it is hard to evaluate themin vivo. In this study, we tried to define the mechanical force from an original point of view as a limb physiological environment. Here we showed that late-stage embryos have not enough space in the amniotic membrane and disturbed limb movement. In the neonatal phase, to get the physical ability of righting reflex and locomotion increases mechanical force for their limbs. We also clarified this relationship by detecting the expression of tendon developmental factors during the embryo to postnatal phase. We found that the upregulation of Scx and Tnmd is accompanied by the development of physiological movement with increasing mechanical force. Our results reveal the part of the role of mechanical force, including internal and external factors, in the tendon development process.2.Summary statementBiological and morphological events of tendon development in the embryo to postnatal phase are related to external mechanical forces depending on the physical environment and limb movement patterns.