Figure 1

Point centromeres are derived from regional centromeres and appeared only once during evolution. (a) The 16 CENs from S. cerevisiae were used to train a HMM. The blue bar indicates the number of predicted point CENs in the genome and the red bar represents the number of known chromosomes. (b) HMM from (a) was used to search the genome of fungi with known point CENs, known regional CENs and predicted point CENs. Blue and red bars are as described in (a) except gray bars, which indicate the predicted number of chromosomes, based on synteny within other Saccharomyces species. (c) Sequence comparison of the CDEI, CDEII and CDEIII elements from budding yeast with point centromeres. (d) Frequency distribution of the CDEII length (measured in bp) in each budding yeast with point centromeres. (e) Evolutionary conservation of CBF3 subunits in fungi with point and regional CENs. (f) Phylogenetic analysis of 17 different fungi, including the 7 budding yeast with point centromeres and the 3 budding yeast with regional centromeres using 3 highly conserved reference proteins (α-tubulin, the signal recognition protein SRP54 and the DNA replication factor PCNA). Blue branches represent fungi with point centromeres and black branches those with regional centromeres.