The Effects of Hypoxia on Branching Morphogenesis of the Embryonic Chicken Lung

Abstract

Oxygen is crucial for the growth and development of all organs. Oxygen concentration plays a special role in the development of the lungs. Hypoxia, a state of oxygen deficiency, can be induced within humans through various pulmonary diseases such as COPD and asthma. Additionally, pregnant mothers who smoke or go into high altitudes may create a hypoxic environment for the fetus. Hypoxia during the developmental phases of lung growth leads to malformation and stunted growth, which can also lead to COPD, BPD, and asthma. As such, an investigation into the effects of hypoxia on the lung may yield valuable information. The development of embryonic chicken lung has been highly characterized, but little is known about the effects of hypoxia on development. This thesis explores the effects of hypoxia on the development of chicken lungs and seeks to identify the physical characteristics that are affected by the lack of oxygen. Lungs were placed under hypoxic conditions for various periods of time and development was tracked and compared to lungs cultured under normoxia. Lung growth under hypoxia was stunted, which appears to have resulted from a hinderance of apical constriction. Hindering apical constriction leads to malformation of the lung as new branches cannot be formed.