Cardinal characters on a slippery slope – A re-evaluation of phylogeny, character evolution, and evolutionary rates in the jelly lichens (Collemataceae s. str)

Abstract

PostprintThis is the accepted version of a paper published in Molecular Phylogenetics and Evolution. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination. Citation for the original published paper (version of record):Otálora, M., Aragón, G., Martínez, I., Wedin, M. (2013) Cardinal characters on a slippery slope -A re-evaluation of phylogeny, character evolution, and evolutionary rates in the jelly lichens (Collemataceae s. str.). Evolution, http://dx.doi.org/10. 1016/j.ympev.2013.04.004 Access to the published version may require subscription. Here we reconstruct the phylogeny of Collemataceae using Bayesian and maximum likelihood analyses based on mitochondrial (mtSSU rDNA) and nuclear (nuLSU rDNA, Betatubulin and MCM7) markers of 70 Collemataceae species. We studied the evolution of four morphological and ecological characters traditionally used to delimit genera and infra-generic Molecular Phylogenetics andgroups. Finally, we tested if differences in branch-lengths between clades are due to differences in rates of molecular evolution. Eleven strongly supported groups were recovered in the resulting well-resolved and well-supported phylogeny. The presence/absence of a eucortex, which is currently used as the cardinal character to define genera in the group, does not characterize monophyletic groups corresponding to the genera as currently circumscribed.Ancestral state reconstruction indicates that the most recent common ancestor of the jelly lichens most likely was saxicolous/terricolous, lacked a tomentum, and had transversally septate ascospores. Although the cortex state could not be reconstructed for the ancestor of the family, our observations indicate that a lack of cortex may have an evolutionary advantage in saxicolous/terricolous species in semi-arid environments, as non-corticate species tends to be larger and occur in higher frequency and abundance in such regions, compared to corticate species. A significant evidence for faster evolutionary rates was found in a lineage mainly including taxa that occur in the wet tropics and humid temperate regions, compared to other lineages. We suggest that this can explain the greater diversity of Collemataceae in tropical and humid areas.Key words: Accelerated evolutionary rates, ancestral state reconstruction, Collemataceae, cortex, habitat, lichen-forming fungi. 4 IntroductionLichens are fungi utilizing photosynthetic algae or cyanobacteria for the exploitation of carbohydrates. The symbiotic association allows both the fungal and algal partners to colonize a range of habitats which otherwise would be inhabitable to them. Molecular phylogenetic studies have recently led to significant advances in the understanding of relationships between fungal groups including lichen fungi (Lutzoni et al., 2004; Miadlikowska et al., 2006;Hibbett et al., 2007; Ekman et al., 2008). These and other studies have provided strong evidence that many commonly used morphological and anatomical characters traditionally...

A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families

“…1E–F). Strongly supported monophyletic circumscription of Scytinium , Lathagrium , and Enchylium (based on the combined nucLSU, mitSSU, MCM7 , and beta-tubulin in Otálora et al, 2013a, 2013b) was not revealed in this study. Moreover, members of these three newly delimited genera of the former Collema/Leptogium complex are intermixed with high bootstrap support (mostly from the 5+4+3+2-gene dataset).…”

“…and Leptogium s. str (Otálora et al, 2013a, 2013b) and their sister relationship in the absence of Paracollema (not sampled in this study; Fig. 1E–F).…”

“…3 and 4; Supplemental Table S5). Instances of highly supported relationships contradicting published multigene phylogenies were very rare and usually involved different combination of molecular markers used in previous studies, e.g., discrepancies in delimitation of new genera in the Collema / Leptogium complex based on MCM7 and beta-tubulin in addition to nucLSU and mitSSU loci (Otálora et al, 2013a, 2013b versus Fig. 1E–F).…”

“…Recently, protein-coding markers (usually RPB1 and RPB2 , but also beta-tubulin, GAPDH , and MCM7 ) have been more frequently used for phylogenetic inference within Lecanoromycetes (e.g., Baloch et al, 2010; Crespo et al, 2010; Hofstetter et al, 2007; Lumbsch et al, 2007b; Miadlikowska et al, 2006; Myllys et al, 2005; Otálora and Wedin, 2013; Otálora et al 2013a; Parnmen et al, 2012; Reeb et al, 2004; Rivas Plata et al, 2012a, 2012b; Schmitt et al, 2010). Only five studies (Hofstetter et al, 2007; Lumbsch et al, 2004; Miadlikowska et al, 2006; Reeb et al, 2004; Wedin et al, 2005) were designed specifically to reconstruct phylogenetic relationships within the Lecanoromycetes at the family and higher ranks as a framework for the evaluation of existing classifications.…”

Cyanobacteria in Terrestrial Symbiotic Systems

“…The cyanobionts of gelatinous cyanolichens or so-called jelly lichens Otálora et al 2013Otálora et al , 2014 are not organized into a distinct photobiont layer but occur more freely within the medulla (Fig. 2).…”