Project description:Age and skeletal maturity impacts the capacity for bone regeneration. Using a mouse model of large-scale rib resection, we demonstrated that skeletally immature mice regenerate the rib around 14 days post resection, whereas skeletally mature mice never fully regenerate the rib. Here, we performed bulk RNA sequencing analysis of rib calluses from skeletally immature and mature mice at baseline, 0, 2, 5, and 14 days post-resection to characterize the age-related changes in gene expression profiles during the early and late stages repair of bone repair.
Project description:Age and skeletal maturity impacts the capacity for bone regeneration. Using a mouse model of large-scale rib resection, we demonstrated that skeletally immature mice regenerate the rib around 14 days post resection, whereas skeletally mature mice never fully regenerate the rib. Here, we performed single-cell RNA sequencing analysis of rib calluses from skeletally immature and mature mice at 5 and 14 days post-resection to characterize the age-related changes in cell population frequencies and their gene expression profiles during the early and late stages repair of bone repair.
Project description:Despite the extreme morphological variability of the canine species, data on limb development are limited and the time windows for the appearance of the limb ossification centres (OCs) reported in veterinary textbooks, considered universally valid for all dogs, are based on dated studies. The aim of this study was to acquire up-to-date information regarding the arm, forearm and leg bone development in skeletally-immature large-sized dogs from 6 weeks to 16 weeks of age. Nine litters of 5 large-sized breeds (Boxer, German Shepherd, Labrador Retriever, Saarloos Wolfdog, White Swiss Shepherd Dog) were included, for a total of 54 dogs, which were subject to radiographic examination on a bi-weekly basis. The appearance of 18 limb OCs was recorded and 14 radiographic measurements were performed; their relationship with age and body weight was investigated and any breed differences were analysed using different statistical non-parametric tests. The number of OCs present was significantly different at 6 and 8 weeks of age between the investigated breeds. The appearance of the OCs occurred earlier in the Saarloos Wolfdog, while the Labrador Retriever was the later breed. In Boxers and Labrador Retrievers, various OCs showed a delayed appearance compared to the data reported in the literature. The number of OCs was strongly and positively correlated to body weight. Breed differences were also observed in the relative increase of the measured OCs and were not limited to dogs of different morphotypes. Statistically significant differences were most frequently observed between Saarloos Wolfdogs and the other breeds. The OCs that showed a greater variability in their development were the olecranon tuber, the patella and the tibial tuberosity. Their increase was more strongly correlated with the dog's age and body weight. Our data strongly suggest that differences in limb development exist in dog breeds of similar size and morphotype.
