Locating the lpk QTL. Quantitative trait loci for PKD phenotypic markers were determined using WinCart QTL . The markers used for analysis are shown along the x-axis (red triangles) and span 86cM from D10Rat43 to D10Rat12. On the y axis, the evidence for linkage is recorded as a logarithm of odds (LOD) score. The QTL illustrated is the cyst to kidney area ratio. The QTL was determined using Composite interval mapping with model 6 (standard model) with a window size of 0.5 cM and walk speed of 1cM a forward and backward regression. A threshold of 7.5 (LR) and 1.6 (LOD – black hashed line) was determined by permutations.