Comparison of the nucleotide sequence and secondary structure of the 5.8S ribosomal RNA gene of Chlamydomonas tetragama with those of green algae

We have determined the nucleotide sequence of a PCR product corresponding t o the 5.8S ribosomal RNA gene in Chlamydomonas tetragama and compared the o btained sequence with those of one red and eleven green algae. A phylogenet ic tree based on the 5.8S rDNAs and comparison of their predicted secondary RNA structure, with attention to a region which has been proposed to base- pair with an internal guide sequence of an intron in the large subunit chlo roplast rRNA, suggested that C. tetragama was not closely related with Chla mydomonas reinhardtii. These results support the previous idea that the gen us Chlamydomonas is heterogenous.