Histograms showing the distribution of RNs along the length of KYS maize SCs 5, 6, 7, and 9. Each SC is represented on the x-axis in micrometers with the short arm to the left and the position of the kinetochore marked by a black dot. Beneath the x-axis, the locations of knobs are marked by horizontal, thick red lines, and the position of the NOR on SC 6 is marked by a horizontal, thin black line. The histogram bars on the y-axis represent the total number of RNs observed in each 0.2-μm segment of SC length for 203 SC 5’s, 176 SC 6’s, 178 SC 7’s, and 234 SC 9’s. A red smoothing line is superimposed over each histogram to show the general trend of RN distribution. These histograms are used with permission from GENETICS (Anderson et al. 2003). RN, recombination nodule; SC, synaptonemal complex.