Neural Crest Cells Give Rise to Non-Myogenic Mesenchymal Tissue in the Adult Murid Ear Pinna

This study provides a detailed cellular analysis of the development of the ear pinna in mice, revealing that various cell types in the adult pinna, including connective tissue fibroblasts, elastic cartilage, dermal papilla cells, dermal sheath cells, vasculature, and adipocytes, are derived from cranial neural crest cells. However, skeletal muscle and hair follicles are not. The research also examines the short ear mouse mutant, finding that a lack of proper elastic cartilage development in the distal pinna is linked to impaired chondroprogenitor proliferation and correlates with the locations of vasculature-conveying foramen. While there is an increase in adipocytes in the adult pinna, this is not a developmental issue but rather a condition that arises in adulthood. The study concludes that chondrogenesis, the process of cartilage development, remains impaired in the adult mid-distal ear pinna of these mutants, providing a foundation for further research into the development of the ear pinna and elastic cartilage.