Characterization of Mycobionts of Photomorph Pairs in the Peltigerineae (Lichenized Ascomycetes) Based on Internal Transcribed Spacer Sequences of the Nuclear Ribosomal DNA

• Published in: Fungal genetics and biology 1997-04, Vol.21 (2), p.228-237
• Main Authors: Goffinet, Bernard, Bayer, Randall J.
• Format: Article
• Language: English
• Subjects: Ascomycota - genetics; Base Composition; chemotaxonomy; DNA; DNA Primers; DNA, Fungal - chemistry; DNA, Fungal - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; evolution; genbank/u73491; genbank/u73492; genbank/u73493; genbank/u73494; genbank/u73495; genbank/u73496; genbank/u92880; genbank/u92881; Genetic Variation - genetics; ITS; lichen; lichens; Lichens - genetics; Molecular Sequence Data; molelcular sequence data; Mutation; nephrma expallidum; Nephroma; nephroma arcticum; nrDNA; nucleotide sequences; Peltigera; Peltigerales; Peltigerineae; photomorph; polymerase chain reaction; Polymerase Chain Reaction - methods; ribosomal DNA; RNA, Ribosomal, 5.8S - genetics; Sequence Analysis, DNA; symbionts; Symbiosis; taxonomy
• ISSN: 1087-1845; 1096-0937
• DOI: 10.1006/fgbi.1997.0977

Goffinet, B., and Bayer, R. J. 1997. Characterization of mycobionts of photomorph pairs in the Peltigerineae (lichenized ascomycetes) based on internal transcribed spacer sequences of the nuclear ribosomal DNA.Fungal Genetics and Biology21,228–237. The The “one fungus–two photomorphs” hypothesis suggests that certain lichenized fungi can establish a symbiotic relationship with either a eukaryotic or a prokaryotic photobiont. Such pairs of photomorphs are well know from cephalodiate Peltigerineae. Using an ascomycete-specific primer we amplified the internal transcribed spacer region of the nrDNA repeat of the mycobiont from total “lichen DNA” extracts ofPeltigera malacea,photomorphs ofP. aphthosa, P. britannica,andP. leucophlebia, Nephroma expallidum,and photomorphs ofN. arcticum.Comparisons of5.8Ssequences suggest that the sequences obtained belong to the mycobiont and thus, that the ascomycete-specific primer is adequate for amplifying fungal DNA from total lichen–DNA extracts. The strict identity of nucleotide sequences of the internal transcribed spacer region of the nrDNA repeat between joined-photomorphs supports the one fungus–two photomorphs hypothesis. Photomorphs may thus primarily reflect phenotypic plasticity of photomorphic fungi in response to changing environmental conditions. The cyanomorph recently reported forP. leucophlebiais shown to be based on a misidentified specimen ofP. aphthosa.Comparisons of the ITS sequences further supports recognizingP. aphthosa, P. britannica,andP. leucophlebiaat the species rather than the infraspecific level.