Molecular associations of gallinacin genes with immune response against Salmonella typhimurium in chickens

Candidate gallinacin genes (GAL) were assessed in Fayoumi (F), Rhode Island Red (R) and their crosses (½R½F and ½F½R) using PCR-RFLP technique to detect the associations between GAL 2, GAL 3, GAL 4 and GAL 5 genes and caecal S. typhimurium bacterial count (CSTBC) and IgA, IgY and IgM antibody titers. The solutions of genotypes of GAL genes were calculated by the method of Generalized Least Squares (GLS). The SNPs genotypes of GAL 3 and GAL 5 genes showed significant counts of caecal S. typhimurium. The SNP of gallinacin 3, 4 and 5 genes had significant effects on IgA, IgY and IgM antibody titers. For GAL 3 gene, the chicks of genotype CC in R breed had lower significant CSTBC and higher significant IgA and IgM antibody titers than chicks of TT genotype, while the chicks of TC genotype had lower significant CSTBC in chicks of ½R½F crossbred and higher significant antibody titers of IgA and IgM in chicks of ½F½R crossbred. For GAL 4 gene, the chicks of genotype GG in R breed had lower significant CSTBC and higher significant IgA, IgY and IgM antibody titers, but the chicks of genotype AG had higher significant IgA, IgY and IgM antibody titers in chicks of ½R½F crossbred than chicks of GG and AA genotypes. For GAL 5 gene, the genotype CC in chicks of R breed had lower significant CSTBC and higher significant IgA and IgY antibody titers. In chicks of ½F½R crossbred, the chicks of genotype AA had lower significant CSTBC and higher significant IgA and IgY antibody titers than chicks of CA genotype. In practice, GAL genes could be used as markers assisted selection to improve immune response against S. typhimurium in genetic improvement programs of chickens.