Table 2. Hierarchical Clustering Basted on DNA Content Yields Distinct Functional Categories within the Chlamydomonas Cell Cycle Mutants.

DNA Content	Typical Annotations	Gene (No.)	Orthologous Genes in Arabidopsis
1C	Growth related; DNA replication	50	76%
2C	APC subunits; DNA replication; CDKB	13	84%
4C/8C	Spindle formation	25	80%

Clustering all tested mutants according to their DNA content profile provides three major functional groups, each highly occupied. Listed in the table are the groups, including the number of genes in each one, and their functions as suggested by characteristic annotations. Mutants that had an intermediate phenotype were counted in the nearest category that fits their DNA profile (1/2C were either included in 1C or 2C; 1/2/4C were included in 4C/8C).