The bones of the trunk (limbs, vertebrae, etc) are mesodermally-derived and form by endochondral ossification, i.e. via formation of cartilage templates later replaced by bone. In contrast, many cranial bones, including skull cranial vault, jaws and face, form from cranial neural crest (a unique population of progenitor cells) and are classified as intramembranous (dermal) bones that form directly through ossification of condensations in the cranial dermis, a process, which is very poorly understood. Our goal is to analyze formation of cranial intramembranous (dermal) bone on both cellular and tissue levels. Our interests here range from signals that control differentiation of cranial neural crest cells into specialized (skeletal) cell types to formation of dermal bones as a tissue and their subsequent morphogenesis. We have a strong interest in understanding the roles for microRNAs (miRNAs) in craniofacial skeletal development. Recent evidence suggests that some of these numerous genes have important roles in development of vertebrate embryos regulating key signaling molecules and transcription factors. We recently identified a set of miRNAs associated with dermal bone development and we are currently performing functional tests as to their significance. This project is carried out by graduate student Bumjin Namkoong.