Characterization of diatom–cyanobacteria symbioses on the basis of nifH, hetR and 16S rRNA sequences

摘要: Summary Richelia intracellularis is a symbiotic heterocystous cyanobacterium that capable of forming associations with several genera diatoms. nifH, 16S rRNA and hetR sequences were amplified cloned from field populations Richelia associated Hemiaulus hauckii (N. Atlantic), Rhizosolenia clevei Pacific), cultivated isolate Calothrix Chaetoceros station ALOHA (N. Pacific). Sequence identity was highest (98.2%) among the sequences, more divergent for (83.8%) nifH (91.1%) sequences. The DNA amino acid obtained symbionts three different diatom diverged into separate lineages supported by high bootstrap values. data indicate in hosts are distinct species or strains. Furthermore, previously unidentified heterocystous-like sequence groups recently reported subtropical Pacific, het-1, het-2 het-3, linked to R. clevei, H. hauckii symbiont sp. respectively.