[i] ^aIncludes a set of 420 genes identified by classical genetic studies and curated at CoGe (website).

[ii] ^bInclude all non-histone maize chromatin genes curated by http://www.ChromDB.org.

[iii] ^cIncludes all genes with putative cell wall function identified by Penning et al. (2009).

[iv] ^dIncludes the set of maize genes curated by GRASSIUS.

[v] ^eIncludes genes that show increased signal in some genotypes and decreased signal in others.