Ibrahim, Mohamed M.A. (2021-04). THE FUNCTIONAL PROFILES OF CHICKEN EGGS INCUBATED UNDER MONOCHROMATIC LIGHTING. Doctoral Dissertation.
Poultry production remains susceptible to significant infectious disease threats such as Avian Flu, and Newcastle Disease Virus (NDV), which threaten the supply of poultry production. My dissertation research addresses this challenge by leveraging avian circadian biology to improve responses to vaccines to enhance poultry performance. The central hypothesis is that specific visible light wavelengths would enhance circadian rhythm development in ovo, leading to improved immune responses. I addressed an essential question regarding the effect of providing photoperiods with different wavelengths (Blue, Green, and White) on circadian rhythm development and its interplay with the immune response following the NDV challenge in chick embryos using the RNAseq technology. Our results showed that incubating chicken embryos under blue light 450nm was most efficient in entraining the circadian rhythm in lung tissue, compared to white light or dark treatment. Blue light showed a specific impact on skeletal muscle, regulation of striated muscle contraction, Glycerolipid metabolism, and development of neurons. The white light incubation led to a photo-acceleration stimulant effect on epidermal growth factor receptor signaling pathway, ErbB signaling pathway, MAPK signaling pathway, and Insulin signaling pathway were upregulated in white light non-challenged treatment. The response to NDV challenging showed a distinct transcriptome profile between blue and white light. The blue light showed a potent innate immune response, targeting viral replication, clearly pointing to antiviral response. The white light showed less immune response, but more pronounced cell proliferation and metabolic state, suggesting photo-acceleration as the primary process, particularly T cell development, T cell homeostasis, and T lymphocytes' quantity, suggests a rapid or ongoing transition between innate and adaptive immunity. This observation paves the way to photo-accelerated effect of providing white light during chicken egg incubation on organismal development and immune response. It is noteworthy that unvaccinated white light incubated chicks hatched 6-8 h earlier than other blue or dark incubation at the organism level. In conclusion, this study is the first to generated high-resolution RNASeq evidence demonstrating the effect of lighting color background on the circadian rhythm development and modulation of the innate immune response of chicks' embryos challenged with NDV.