title: Pre-hatch lung development in the ostrich.
abstract: We studied development of the ostrich lung using light microscopy as well as electron microscopy techniques. At E24, the lung comprised a few epithelial tubes, interspersed with abundant mesenchyme with scattered profiles of incipient blood vessels. Between E24 and E39, the epithelial thickness was reduced by 90% from 13.5 ± 0.41 μm to 1.33 ± 0.014 μm (mean ± SD, respectively). Atria were evident at E32, and by E35, the first portions of the blood-gas barrier (BGB) measuring 3.41 ± 1.12 μm were encountered. Gas exchange tissue was well formed by E39 with atria, infundibulae, air capillaries and a mature blood-gas barrier (BGB). BGB formation proceeded through the complex processes of secarecytosis and peremerecytosis, which entailed decapitation of epithelial cells by cutting or pinching off respectively and by E39, the BGB was thin at 2.21 ± 1.21 μm. Vascular remodeling by intussusceptive angiogenesis was a late stage process mediated by intraluminal pillars in the pulmonary vasculature.
authors.affiliation: Department of Veterinary Anatomy & Physiology, University of Nairobi, Riverside Drive, PO Box 30197-00100 Nairobi, Kenya. makanya@uonbi.ac.ke
authors.forename: A N
authors.initials: AN
authors.lastname: Makanya
authors.forename: T
authors.initials: T
authors.lastname: Koller
authors.forename: R
authors.initials: R
authors.lastname: Hlushchuk
authors.forename: V
authors.initials: V
authors.lastname: Djonov
mesh_terms: D056151:Airway Remodeling; D000818:Animals; D015824:Blood-Air Barrier; D001980:Bronchi / Q000033:anatomy & histology / Q000196:embryology; D002196:Capillaries / Q000033:anatomy & histology / Q000502:physiology; D004847:Epithelial Cells / Q000502:physiology; D008168:Lung / Q000033:anatomy & histology / Q000166:cytology / Q000196:embryology*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D018919:Neovascularization, Physiologic / Q000502:physiology; D010641:Phenotype; D011652:Pulmonary Circulation / Q000502:physiology; D011659:Pulmonary Gas Exchange; D020310:Struthioniformes / Q000502:physiology*; D016707:Tissue Fixation