Reparative regeneration of histogenetically different bones

Abstract

The bone plates that forming the turtle shell differ in histogenesis. Thus, the costal and neural plates of the carapace (dorsal shield) have mesenchymal origin and develop by indirect perichondral osteogenesis from vertebrae and ribs. The bone plates of the plastron - abdominal shield, are known to be formed from neuroectodermal cells of the neural crest and develop by intramembrane osteogenesis in the dermis of the skin. The aim of the study was to compare the reparative regeneration of histogenetically different bone tissue of the carapace and plastron of freshwater red-eared turtles Trachemys scripta. The experiment was performed on freshwater red-eared turtles Trachemys scripta aged 3 months. 2 defects of carapace and plastron bone plates with a diameter of 5 mm and a depth of up to "soft tissues” were formed with further histological examination. It was found that the regeneration of the bone plates of the plastron is characterized by the formation of bone tissue in a larger volume and at an earlier date. After 30 days a layer of continuous newly formed bone tissue is formed. By 90 days the proportion of bone tissue in the carapace regenerate was 40,5% of the defect area, while in the plastron the regenerate occupied 47,4%. Thus, intramembranous formed bone tissue of neuroectodermal histogenesis has a more pronounced regenerative potential compared to perichondral formed bone of mesenchymal origin.