Fig. 6.
Differences between GC content of 50-kb segments containing duplicated (identical Alu, including 50-bp flanks) and the remaining "unique" Alu from the June 2002 version of the human genome. With the exception of chromosome Y, duplicated Alus are in significantly more GC-rich DNA.Yd = 39.5; Yu = 39.0; P > 0.1 (two-tailed t test)
Xd = 41.5; Xu = 39.4; P < 0.001 (two-tailed t test)
Ad = 43.0; Au = 41.1; P < 0.001 (two-tailed t test)
Y, X, and A denote average GC content on chromosomes Y and X and autosomes in 50-kb nonoverlapping windows with duplicated (d) and unique (u) Alu.