XVI International Botanical Congess

A cDNA coding for a cyclin dependent kinase (CDK) was identified for the marine microalga Dunaliella tertiolecta. This cDNA, 1061 bp long, contains an open reading frame of 314 amino acids and is most homologous cdc2 in higher plants and animals (with >57% identity and >68% similarity). Several domains highly conserved in cdc2 and other CDKs were identified from this sequence. However, the PSTAIRE and GDSEID motifs characteristic of cdc2 were replaced with PSTTLRE and GDCELQ. This gene seems to occur as a single copy in this species and the transcription appeared to be constitutive. The present results suggest that the universal eukaryotic cell cycle control may be conserved in microalgae with unique structural characteristics.