length of 50 or 30 Mb and then estimated the variance explained by each segment ( hS2) in a joint analysis (Online Methods). We found that the regression of hS2 on the total gene length per segment (Lg(S)) remained significant for height, P = 1.7×10−3 for 50 Mb segments and P = 1.2×10−4 for 30 Mb segments (Supplementary Fig. 5). The regressions of hS2 on the number of genes, the total length of exons and the number of exons on each segment were also significant in some cases, but none of them was significant when fitted after Lg(S) while Lg(S) was always significant fitted after any of them (Supplementary Table 4). These results suggest that, at least for height, genomic regions explain variation in proportion to their genic content.
