|KIM, EUI SOO - Iowa State University|
|SOHN, SEA HWAN - Jinju National University|
|HONG, YEONG - Chung-Ang University|
Submitted to: Korean Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2015
Publication Date: 3/20/2015
Publication URL: http://handle.nal.usda.gov/10113/62619
Citation: Kim, E., Sohn, S., Lillehoj, H.S., Hong, Y.H. 2015. Genomic regions associated with necrotic enteritis resistance in Fayoumi and White Leghorn chickens. Korean Journal of Poultry Science. 42(1):27-32.
Interpretive Summary: Necrotic enteritis (NE) is an acute infection caused by the bacteria, Clostridium prefringens, that is characterized by severe death of cells in the intestinal mucosa and has recently became a significant problem for the poultry industry because of restrictions on antibiotic usage and high-density production conditions. In the United States, NE has caused enormous economic losses in the poultry industry (accounting for > $2 billion/year), largely due to the impaired growth of chickens and costs associated with medical treatments. Very limited information is available on the mechanisms of genetic variations in chicken breeds. In this paper, ARS scientists collaborated with scientists from South Korean universities to identify genetic markers which are associated with NE susceptibility and resistance. By comparing two different breeds of chickens that show high and low levels of NE susceptibility, this study identified the areas of the host genome which play important roles in muscle development that could be associated with NE resistance. Analysis of data revealed that the genes associated with muscle function play an important role in NE resistance. The results of this study can facilitate genetic selection strategy for NE resistant chickens and would lead to better understanding of the molecular basis of short-term evolution of disease resistance against NE.
Technical Abstract: In this study, we used two breeds of chicken to identify genomic regions corresponding to necrotic enteritis (NE) resistance. We scanned the genomes of a resistant and susceptible line of Fayoumi and White Leghorn chicken using a chicken 60K Illumina SNP panel. A total of 235 loci with divergently fixed alleles were identified across the genome in both breeds; particularly, several clusters of multiple loci with fixed alleles were found in five narrow regions. Moreover, consensus 15-SNP haplotypes that were shared by the resistant lines of both breeds were identified on chromosomes 3, 7, and 9. Genes responsible for NE resistance were identified in chicken lines selected for resistance and susceptibility. Annotation of the regions spanning clustered divergently fixed regions revealed a set of interesting candidate genes such as phosphoinositide-3-kinase, regulatory subunit 5, p101 (PIK3R5) and inositol 1,4,5-trisphosphate receptor 1 (ITPR1), which participate in immune response. Consensus haplotypes were found in regions containing possibly relevant genes, such as myostatin and myosin, which play important roles in muscle development. Thus, genome scans of divergent selection in multiple chicken lines and breeds can be used to identify genomic regions associated with NE resistance.