CDC local similarity graph. A local similarity graph of the CDC dataset showing significant LSA values as defined by the upper bound cutoff and the additional constraint of absolute LSA values greater than 0.85 (α = 0.001, |LSA| ≥ 0.85). Clusters of local structure are observed with some example correlates of expression shown in graphs a, b, and c, indicated by solid ellipses. However, because only 800 of the approximately 6,000 genes could be classified to a cell cycle position (G1, G2/M, S, S/G2, M/G1) we could only guess at two clusters' functional characteristics. Cluster x has many G1 genes that, according to the Saccharomyces Genome Database http://www.yeastgenome.org webcite, have some functionality relative to helicases and telomeres. The gene, YKR077W (*), accelerates the cell cycle initiation stage (G1) when abundant . Cluster y is a set of genes encoding histone proteins . Histone development is an essential part of genome replication  adequately describing all of cluster y as S phase genes.
Durno et al. BMC Genomics 2013 14(Suppl 1):S3 doi:10.1186/1471-2164-14-S1-S3