Quantitative trait loci associated with the humoral innate immune response in chickens were confirmed in a cross between Green-Legged Partridgelike and White Leghorn

Abstract

Natural antibodies (NA) create a crucial barrier at the initial steps of the innate humoral immune response. The main role of NA in the defense system is to bind the pathogens at early stages of infection. Different pathogens are recognized by the presence of highly conserved antigen determinant [e.g., lipopolysaccharide (LPS) in gram-negative bacteria or lipoteichoic acid (LTA) in gram-positive bacteria]. In chickens, a different genetic background of NA binds LPS and LTA antigens, encoded by different QTL. The main objective of this work was to confirm known QTL associated with LPS and LTA NA. For this purpose a chicken reference population was created by crossing 2 breeds: a commercial layer, White Leghorn, and a Polish indigenous chicken, Green-Legged Partridgelike. The chromosomal regions analyzed harbored to GGA3, GGA5, GGA6, GGA8, GGA9, GGA10, GGA14, GGA15, GGA18, and GGAZ. The data collected consisted of the NA titers binding LPS and LTA (determined by ELISA at 12 wk of age) as well as the genotypes (30 short tandem repeat markers; average of 3 markers/chromosome, collected for generations F(0), F(1), and F(2)). The analyses were performed with 3 statistical models (paternal and maternal half-sib, line cross, and linkage analysis and linkage disequilibrium) implemented in GridQTL software (http://www.gridqtl.org.uk/). The QTL study of humoral innate immune response traits resulted in the confirmation of 3 QTL associated with NA titers binding LPS (located on GGA9, GGA18, and GGAZ) and 2 QTL associated with NA titers binding LTA (located on GGA5 and GGA14). A set of candidate genes within the regions of the validated QTL has been proposed.

Identification of candidate genes and mutations inQTLregions for immune responses in chicken

“…; Slawińska et al . ). The current study showed that the selected SNPs were located within regions originally suggested by those linkage analyses.…”

“…; Slawińska et al . ). Validated QTL on the GGA9, GGA14 and GGA18 chromosomes were fine mapped using two statistical tools: meta QTL analysis and joined QTL analysis (Slawinska & Siwek ).…”

A genome-wide association study identifies major loci affecting the immune response against infectious bronchitis virus in chicken

“…The remaining eight QTLs for the antibody response against IBV were novel and specific QTLs in this study. They were not only different from the QTLs for the antibody response against Newcastle disease virus, they also differed from the QTLs for immune responses against other stimuli, such as Brucella abortus (Zhou et al, 2003), E. coli (Yunis et al, 2002a,b), keyhole lympet hemocyanin (Siwek et al, 2003), sheep red blood cells (Dorshorst et al, 2011), infectious bursal disease virus (Ewald et al, 2007) and lipoteichoic acid (Slawinska et al, 2011). Nevertheless, all the QTLs linked to the antibody response against IBV were not independent of body weights in chickens ( Supplementary Table 3), and birds with the favored genotype of the QTLs linked to the antibody response against IBV had significantly lower body weights (unpublished results).…”

Insights into the genetic history of Green‐legged Partridgelike fowl: mtDNA and genome‐wide SNP analysis

“…In recent times, it has been used to study the genetic background of general immune responsiveness to KLH, LTA and LPS antigens (Siwek et al . 2010; Sławińska et al . 2011; Siwek et al .…”

“…The breed requires minimal veterinary health care, tolerates very low temperatures, is an excellent forager and is reputed to lay eggs low in cholesterol (Krawczyk et al 2005;Krawczyk & Szefer 2012). In recent times, it has been used to study the genetic background of general immune responsiveness to KLH, LTA and LPS antigens (Siwek et al 2010;Sławi nska et al 2011;Siwek et al 2012).…”