Transcriptional Analysis of Resistance to Newcastle Disease Virus Infection in Two Genetically Distinct Inbred Chicken Line

Newcastle disease virus (NDV) is the number one poultry disease-causing virus in developing nations with a mortality rate as high as 80% among village raised chicken flocks in the world. Although vaccines can provide protection against NDV infection, genetic approaches can provide an alternative method for enhancing host immune response to NDV infection. Our objective was to identify genes and signaling pathways associated with disease resistance to NDV infection. Two genetically distinct inbred chicken lines (Fayoumi and Leghorn) were challenged with NDV or PBS at 21 days old. At 2 and 6 days post-infection (dpi), tears were collected to measure viral load using qRT-PCR. At 10 dpi, blood serum was processed using ELISA in order to examine antibody response to NDV. Our results found that Fayoumi birds had significantly lower viral loads at both time points, and higher antibody response than Leghorn birds (P < 0.005). These results strongly support that the Fayoumi lines were more resistant to NDV infection, while the Leghorn lines were more susceptible to NDV. Total RNA was extracted from lung tissues collected at 2 dpi from 16 samples (4 per group: Fayoumi infected and uninfected, Leghorn infected and uninfected) and used to conduct the RNA-seq analysis. The on-going RNA-seq analysis will aid in the identification of genes and signaling pathways involved in NDV response and resistance, and further elucidate the molecular mechanisms of host immune response to NDV infection in chickens.