Gene expression profiles of two B-complex disparate, genetically inbred Fayoumi chicken lines that differ in susceptibility to Eimeria maxima.

This study was conducted to compare the gene expression profiles, after Eimeria maxima infection, between 2 B-complex congenic lines of Fayoumi chickens that display differences in disease resistance and innate immunity against avian coccidiosis using cDNA microarray. When compared with uninfected controls using a cutoff of >2.0-fold alteration (P < 0.05), M5.1 demonstrated altered expression of 1 (downregulated), 12 (6 up, 6 down), and 18 (5 up, 13 down) mRNA at 3, 4, and 5 d postinfection, respectively. In the M15.2 line, altered expression was observed in 6 (3 up, 3 down), 29 (11 up, 18 down), and 32 (8 up, 24 down) transcripts at the 3 time points, compared with uninfected controls. Comparison of the expression levels between M5.1 and M15.2 chickens after E. maxima infection revealed alterations in 32 (10 up, 22 down), 98 (43 up, 55 down), and 92 (33 up, 59 down) mRNA at the 3 time points. Functional analysis using gene ontology categorized the genes exhibiting the different expression patterns between 2 chicken lines into several gene ontology terms including immunity and defense. In summary, transcriptional profiles showed that more gene expression changes occurred with E. maxima infection in the M15.2 than the M5.1 line. The most gene expression differences between the 2 chicken lines were exhibited at d 4 and 5 after E. maxima infection. These results demonstrate that differential gene expression patterns associated with the host genetic difference in coccidiosis resistance provide insights into the host protective immune mechanisms and present a rational basis to target specific genes and gene products to bolster host defenses against avian coccidiosis.