Paper
Document
Download
Flag content
21

Post-embryonic development and aging of the appendicular skeleton in Ambystoma mexicanum

21
TipTip
Save
Document
Download
Flag content

Abstract

Abstract Background The axolotl is a key model to study appendicular regeneration. The limb complexity resembles that of humans in structure and tissue components; however, axolotl limbs develop post-embryonically. In this work, we evaluated the post-embryonic development of the appendicular skeleton and its changes with aging. Results The juvenile limb skeleton is formed mostly by Sox9 / Col1a2 cartilage cells. Ossification of the appendicular skeleton starts when animals reach a length of 10 cm, and cartilage cells are replaced by a primary ossification center, consisting of cortical bone and an adipocyte-filled marrow cavity. Vascularization is associated with the ossification center and the marrow cavity formation. We identified the contribution of Col1a2 -descendants to bone and adipocytes. Moreover, ossification progresses with age towards the epiphyses of long bones. Axolotls are neotenic salamanders, and still ossification remains responsive to L-thyroxine, increasing the rate of bone formation. Conclusions In axolotls, bone maturation is a continuous process that extends throughout their life. Ossification of the appendicular bones is slow and continues until the complete element is ossified. The cellular components of the appendicular skeleton change accordingly during ossification, creating a heterogenous landscape in each element. The continuous maturation of the bone is accompanied by a continuous body growth.

Paper PDF

This paper's license is marked as closed access or non-commercial and cannot be viewed on ResearchHub. Visit the paper's external site.