Details

Autor(en) / Beteiligte

• Friedl, Thomas
• Besendahl, Anja
• Pfeiffer, Patrick
• Bhattacharya, Debashish

Titel

The Distribution of Group I Introns in Lichen Algae Suggests That Lichenization Facilitates Intron Lateral Transfer

Ist Teil von

• Molecular phylogenetics and evolution, 2000-03, Vol.14 (3), p.342-352

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2000

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• The nuclear-encoded small subunit ribosomal DNA gene of many lichen-forming green algae in the genus Trebouxia contains a group I intron at Escherichia coli genic position 1512. We studied the evolutionary history of the 1512 intron in Trebouxia spp. (Trebouxiophyceae) by analyzing intron and “host” cell phylogenies. The host trees were constructed by comparing internal transcribed spacer regions of rDNA. Maximum-likelihood, maximum-parsimony, and distance analyses suggest that the 1512 intron was present in the common ancestor of the green algal classes Trebouxiophyceae, Chlorophyceae, and Ulvophyceae. The 1512 intron, however, was laterally transferred at least three times among later-diverging Trebouxia spp. that form lichen partnerships. Intron secondary structure analyses are consistent with this result. Our results support the hypothesis that lichenization may facilitate 1512 group I intron lateral transfer through the close cell-to-cell contact that occurs between the lichen algal and fungal symbionts in the developing lichen thallus.