Condition-specific associations of TSSs as determined by Shannon entropy. (a) Condition associations for the set of identified TSSs. Shannon entropy was applied to 72,535 ESTs in the (sub-)clusters of 5,665 identified TSSs. There were 33,077 ESTs from embryo, 23,361 from head, 3,903 from Schneider cells, 2,883 from testes, 2,267 from larva pupa, 1,978 from ovary, 699 from mbn2 cells, 471 from fat body, and 3,896 with the diverse label. The degree of association of the TSSs with the spatiotemporal conditions was evaluated using EST frequency, Shannon entropy, and a tripartite classification system (see Materials and methods). The numbers of TSSs with specific associations are shown. (b) Condition associations for random permutations of labels. Condition assignments were repeated on 100 sets of random permutations of the 72,535 condition labels across the 5,665 (sub-)clusters. The total number of sites with specific condition associations was summed for each permutation. Across all 100 sets of permutations, the number of condition-specific sites ranged from 180 to 250. The 1,997 condition-specific TSSs in the identified set significantly deviated from this distribution (P << 0.001).
Rach et al. Genome Biology 2009 10:R73 doi:10.1186/gb-2009-10-7-r73