Frequencies of the three genotypes and LOD score profiles of the mouse genome. This is an F2 population derived from the cross of two inbred lines (BT×BTBR). (a) The top panel shows the frequencies of three genotypes with the blue, red and green patterns representing the A1A1, A1A2 and A2A2 genotypes, respectively. (b) The bottom panel shows the LOD score profiles for the mouse genome obtained from the interval mapping of segregation distortion. The profile in red (LOD SDL) represents the LOD score for segregation distortion. The curves in blue and black are the LOD scores for QTL of the 10 week body weight and joint testing of the QTL and segregation distortion.