Evolution of ITS Ribosomal RNA Secondary Structures in Fungal and Algal Symbionts of Selected Species of Cladonia sect. Cladonia (Cladoniaceae, Ascomycotina)

  title={Evolution of ITS Ribosomal RNA Secondary Structures in Fungal and Algal Symbionts of Selected Species of Cladonia sect. Cladonia (Cladoniaceae, Ascomycotina)},
  author={Sara Beiggi and Michele D. Piercey-Normore},
  journal={Journal of Molecular Evolution},
Evolutionary studies in lichen associations follow that of the fungal symbiont (mycobiont), which is the symbiont after which the lichen is named and forms the majority of the thallus. However, evolution of the algal partner (photobiont) is important to maintain compatibility between symbionts and to optimize productivity of the lichen association. The internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA (rDNA) were examined for primary DNA sequence patterns and for patterns… 

Molecular phylogeny and ultrastructure of the lichen microalga Asterochloris mediterranea sp. nov. from Mediterranean and Canary Islands ecosystems.

A detailed characterization comprising chloroplast morphology, and ultrastructural and phylogenetic analyses of a novel phycobiont species, here described as Asterochloris mediterranea sp.

Phylogeny of the family Cladoniaceae (Lecanoromycetes, Ascomycota) based on sequences of multiple loci

A new phylogeny of Cladoniaceae is constructed using five loci from a worldwide sample of 643 specimens representing 304 species and proposes the new genera Pulchrocladia and Rexia, as segregates of Cladia, five new combinations, and the resurrection of the genus Heterodea.

The complexity of symbiotic interactions influences the ecological amplitude of the host: A case study in Stereocaulon (lichenized Ascomycota)

According to the analyses, the distribution of phycobionts is primarily driven by myc Cobionts and vice versa, and species‐level lineages, which accept more symbiotic partners, have wider climatic niches, overlapping with the niches of their partners.

Convergent evolution in Cladonia gracilis and allies

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Genetic diversity and species delimitation of the zeorin-containing red-fruited Cladonia species (lichenized Ascomycota) assessed with ITS rDNA and β-tubulin data

Chemical patterns of the presence/absence of porphyrilic and/or isousnic acid which may help to characterize two lineages are detected and incongruence between the two molecular markers studied is shown.

The lichen symbiosis re-viewed through the genomes of Cladonia grayi and its algal partner Asterochloris glomerata

The diversity of the genes affecting the symbiosis suggests that lichens evolved by accretion of many scattered regulatory and structural changes rather than through introduction of a few key innovations.

The genetic structure of the cosmopolitan three-partner lichen Ramalina farinacea evidences the concerted diversification of symbionts.

The observations support a model in which ecological diversification and speciation of lichen symbionts in different habitats could include a transient phase consisting of associations with more than one photobiont in individual thalli.

Cladonia pyxidata and C. pocillum; genetic evidence to regard them as conspecific

Soil pH shows a statistically significant difference between the extreme morphologies of the two species suggesting a possible link between morphology and environmental conditions.




The Microthamniales are inferred to be an array of independent lineages that radiate nearly simultaneously and may also include some autosporic coccoid taxa previously classified in the Chlorophyceae in the rRNA phylogenies.

The lichen-forming ascomycete Evernia mesomorpha associates with multiple genotypes of Trebouxia jamesii.

Low fungal specificity for multiple algal genotypes and a hypothesized algal switch may be important life history strategies for E. mesomorpha to adapt to changing environmental conditions.

Lichen Guilds Share Related Cyanobacterial Symbionts

A phylogenetic analysis resulted in a consensus tree in which all Nostoc formed a monophyletic group with 100% support, and the cyanobionts of the Nephroma guild form a well-supported subgroup within the Nostoc clade.

Unusual compact rDNA gene arrangements within some members of the Ascomycota: evidence for molecular co-evolution between ITS1 and ITS2.

Correlation analysis revealed that the sizes of ITS1 and ITS2 show a strong positive correlation, suggesting that the 2 rDNA regions have co-evolved, and supports biochemical evidence indicating that the ITS2 segments interact to facilitate the maturation of the rRNA precursor.

Phylogeny of the Genus Cladonia s.lat. (Cladoniaceae, Ascomycetes) Inferred from Molecular, Morphological, and Chemical Data

Phylogenetic relationships within the genus Cladonia, including Cladina, were reconstructed based upon simultaneous analyses of DNA sequences and morphological and chemical data, and a new provisional classification for the genus is proposed.

Species Relationships in the Lichen Alga Trebouxia (Chlorophyta, Trebouxiophyceae): Molecular Phylogenetic Analyses of Nuclear-Encoded Large Subunit rRNA Gene Sequences

Short partial sequences that encompass both domains of the 265 rRNA may be sufficient for resolving close relationships and allow unambiguous species identifications in Trebouxia.

Identification of Photobionts from the lichen family Physciaceae using algal-specific ITS rDNA sequencing

A diversity within the genus Trebouxia Puymaly and Physciaceae photobionts that is higher than expected on the basis morphology alone is indicated and seems to be rather selective and contained photobIONts that were very closely related within one morphospecies of TreBouxia.

The Internal Transcribed Spacer 2 Exhibits a Common Secondary Structure in Green Algae and Flowering Plants

A common secondary structure that is conserved despite wide intra- and interfamilial primary sequence divergence is revealed and may contribute significantly to the value of ITS-2 sequences in phylogenetic analyses at several taxonomic levels, but particularly in characterizing populations and species.

Phylogenetic Species, Reproductive Mode, and Specificity of the Green Alga Trebouxia Forming Lichens with the Fungal Genus Letharia

One phylogenetic species of T. jamesii was found to have a recombining population structure, as two alleles of two loci were found in all four pairwise combinations among the haploid genotypes of that species, suggesting that Trebouxia, a genus in which sexual structures have never been observed, is nevertheless recombining.