Detection and fine mapping of quantitative trait loci for bone traits on chicken chromosome one.

In broiler chickens, bone problems are an important welfare issue that has been linked to genetic selection for rapid growth. The objectives of this study were to identify and fine map quantitative trait loci (QTL) associated with bone traits. The Northeast Agricultural University resource population (NEAURP) being an F(2) population was used in this study, and a total of 17 bone traits were measured. In primary genome scan, the linkage map was constructed with 23 microsatellite markers across the entire chicken chromosome 1. Seventeen QTLs for bone traits were identified and 12 of these were found between LEI0079 and ROS0025 (50.8 cM apart). To fine map the QTLs located between LEI0079 and ROS0025, more markers and more individuals were used and a new partial linkage map was constructed. The confidence intervals for QTLs were sharply narrowed down from 24.5∼52.6 to 2.7∼17.0 Mb. This study identified chromosome regions harbouring significant QTLs affecting bone traits and showed that the use of more markers and individuals could decrease the confidence interval of QTL effectively. The results provide a useful reference for further candidate gene research and MAS for bone traits.