Recombination rates reported in an ultra-high-resolution whole-genome recombination map, described in Comeron et al., 2012 (FBrf0219727), were used by FlyBase to calculate the genetic map position of genes that have been localized to the D. melanogaster Release 6 genome assembly. Comeron et al. analyzed 139 million informative SNPs and mapped 106,964 recombination events at a resolution down to 2 kb to generate the recombination map. Raw cross over values were reported as centiMorgans (cM) per megabase pair (Mb) per female meiosis per 100 kb interval for chromosomes X, 2 and 3. From this raw data, FlyBase calculated the cumulative sum of cross over frequency (dividing by a corrective factor of 10) to give genetic map positions in cM along the genome assembly in 100 kb increments; sums started at the distal tip of X, 2L or 3L. As the recombination map was originally reported on the Release 5 genome assembly, map values were lifted over to the Release 6 genome assembly using the FlyBase "Coordinates Converter" tool. Note that the Release 5 and 6 genome assemblies differed primarily in regions of heterochromatin where recombination is rare, so the recombination map is not expected to be affected by the change in genome assembly. Genetic map values were then assigned to genes based on their midpoint location.