title: Isolation and cultivation of endosymbiotic algae from green hydra and phylogenetic analysis of 18S rDNA sequences.
abstract: Symbiotic associations are of wide significance in evolution and biodiversity. The green hydra is a typical example of endosymbiosis. In its gastrodermal myoepithelial cells it harbors the individuals of a unicellular green algae. Endosymbiotic algae from green hydra have been successfully isolated and permanently maintained in a stable clean lab culture for the first time. We reconstructed the phylogeny of isolated endosymbiotic algae using the 18S rRNA gene to clarify its current status and to validate the traditional inclusion of these endosymbiotic algae within the Chlorella genus. Molecular analyses established that different genera and species of unicellular green algae could be present as symbionts in green hydra, depending on the natural habitat of a particular strain of green hydra.
authors.affiliation: Faculty of Science, University of Zagreb, Division of Biology, Rooseveltov trg 6, HR-10000 Zagreb, Croatia. goran@zg.biol.pmf.hr
authors.forename: Goran
authors.initials: G
authors.lastname: Kovacević
authors.forename: Damjan
authors.initials: D
authors.lastname: Franjević
authors.forename: Biserka
authors.initials: B
authors.lastname: Jelencić
authors.forename: Mirjana
authors.initials: M
authors.lastname: Kalafatić
mesh_terms: D000818:Animals; D018744:DNA, Plant / Q000235:genetics*; D056890:Eukaryota / Q000235:genetics* / Q000502:physiology*; D019143:Evolution, Molecular; D006829:Hydra / Q000502:physiology*; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D013559:Symbiosis
chemical_list: D018744:DNA, Plant; D012337:RNA, Ribosomal, 18S