XVI International Botanical Congess

To catalogue the identities and expression levels of genes in a dinoflagellate system, we initiated sequencing and analysis of C. cohnii cDNA libraries. 942 expressed sequence tags (ESTs) were generated from two cDNA libraries. Database comparisons have revealed that: 22% of the ESTs matched known sequences with a high degree of significance, 20% show moderately significant homology, 5% weakly significant, and 52% exhibit no significant homology to identified sequences. Several cDNAs appear multiple times in the libraries and are most likely abundant messages in the cell. Analysis of the codon usage in C. cohnii indicates that all codons are utilized. While there is a slight bias toward G or C in the third position, this bias is much closer to a dicot codon bias than the extreme bias seen in monocots. This sequence collection represents the most extensive analysis reported to date for a dinoflaggellate.