QTL for natural antibodies in two population

The aim of this study is to identify QTL associated with levels of natural antibodies in two population of laying hens. One experimental (H/L) F2 population originates from a cross (ISA Warren) between two divergently selected lines for either high (H line) or low (L line) primary antibody response to sheep red blood cells (SRBC) at 5 weeks of age. Another experimental (F/P) F2 population was created from a cross of laying hens differing for behavioral traits. For the genotypic analysis, in both populations, Genome Scan has been performed using 174 microsatellite markers, equally distributed over the chicken genome. Total antibody titers to lipopolisacharide (LPS) and lipoteicholic acid (LTA) were determined by ELISA. LPS and LTA represent “homotopes” antigenic determinants of gram negative and gram positive bacteria. Paternal half-sib and line-cross analysis models were used to detect QTL involved in response to these two homotopes. There seem little overlap in QTL between two population and both homotopes.