Insights from Amphioxus into the Evolution of Vertebrate Cartilage

Central to the story of vertebrate evolution is the origin of the vertebrate head, a problem difficult to approach using paleontology and comparative morphology due to a lack of unambiguous intermediate forms. Embryologically, much of the vertebrate head is derived from two ectodermal tissues, the neural crest and cranial placodes. Recent work in protochordates suggests the first chordates possessed migratory neural tube cells with some features of neural crest cells. However, it is unclear how and when these cells acquired the ability to form cellular cartilage, a cell type unique to vertebrates. It has been variously proposed that the neural crest acquired chondrogenic ability by recruiting proto-chondrogenic gene programs deployed in the neural tube, pharynx, and notochord. To test these hypotheses we examined the expression of 11 amphioxus orthologs of genes involved in neural crest chondrogenesis. Consistent with cellular cartilage as a vertebrate novelty, we find that no single amphioxus tissue co-expresses all or most of these genes. However, most are variously co-expressed in mesodermal derivatives. Our results suggest that neural crest-derived cartilage evolved by serial cooption of genes which functioned primitively in mesoderm

Oral health awareness in adult patients with diabetes: a questionnaire study

Objective To investigate oral health awareness, oral hygiene and attitudes towards general dental practitioners' (GDP) involvement in diabetes screening in adults with diabetes. Design Self-completion questionnaire. Setting General medical practices in Warwickshire. Subjects and methods Adults with diabetes attending clinics run by practice or diabetes nurses in general medical practices. Results Two hundred and twenty-nine of 615 (37.2%) questionnaires were completed in 14 general medical practices. The majority of respondents (79.8%, 178/223) visited a dentist once or twice a year, but oral care varied; 67.2% (133/198) reported brushing at least twice a day, whereas only 15.3% (29/190) flossed daily. Awareness of oral health risks was limited: 69.1% (150/217) had never received any oral health advice related to their diabetes. Over half of respondents supported the idea of dentists offering screening for diabetes (121/226, 53.5%). Conclusions Many adults with diabetes have poor awareness of oral care and health complications associated with diabetes, and are receiving limited advice from healthcare professionals. Training and advice for both healthcare professionals and patients concerning the importance of good oral health in patients with diabetes is needed. The role of dentists in diabetes screening and support requires further investigation