Investigating Peripheral Innervation and Epithelial Development in Embryonic Chicken Lungs

Abstract

Studies have begun to determine the impact of peripheral nerve development on epithelial morphogenesis in branching organs, such as the salivary gland and lung. While most of these studies have used embryonic mice as the model organism, studying this interplay in embryonic chicken lungs is an uncharted research area. Thus, this thesis investigates the interaction between peripheral innervation and epithelial development using embryonic chicken lungs as a model system. First, I characterized nerve development in relation to the epithelium, both qualitatively and quantitatively, using whole-mount fluorescent staining. Subsequently, I used two different drugs to manipulate the acetylcholine neurotransmitter pathway; this pathway has been previously studied in embryonic mouse lungs and salivary glands. I performed these pharmacological manipulations through in vitro cultured explant experiments, and in ovo microinjection experiments. Lastly, I used RNA-sequencing to examine the differential expression of nerve-related genes between the following stages of embryonic lung development: E5 (1-3 buds) and E6 (several buds and extended branches). By studying the impact of peripheral innervation on epithelial development in embryonic chicken lungs, mechanisms that can serve as prevention and treatment targets for underdeveloped lung diseases can be identified.