Figure 1.

M:F ratios as a function of Z chromosome position for brain, heart, and liver tissues. (a) Individual M:F ratios in the brain, graphed by gene position on the Z chromosome. (b-d) The running average of 30 M:F ratios is plotted at the median gene position, for brain, heart, and liver. The curves all show a dip, or valley, surrounding the MHM locus of Zp, comprising a cluster of dosage compensated genes in a region deficient in genes with high M:F ratios, as well as an elevated region (one or two peaks) at the distal end of Zq with an unusual concentration of non-compensated genes.