Figure 3.—

Meiotic crossing over in mus309^N2 females. Rates of meiotic crossing over in six intervals spanning distal 2L to proximal 2R are shown. The loci used in mapping are above the graph, placed along the x-axis according to physical distance along the chromosome. The gap between pr and cn indicates the position of the centromere and the pericentric heterochromatin, which is not included in the physical distances shown here. Solid lines show the number of map units (m.u.) per megabase pair (Mb) in each interval for wild-type females (shading) and mus309^N2 females (solid). Dashed lines indicate the mean crossover rate across the entire region assayed for each genotype.