Dataset Information

Hidden Genetic Diversity in an Asexually Reproducing Lichen Forming Fungal Group.

ABSTRACT: Asexual species with vegetative propagation of both symbiont partners (soredia) in lichens may harbor lower species diversity because they may indeed represent evolutionary dead ends or clones. In this study we aim to critically examine species boundaries in the sorediate lichen forming fungi Parmotrema reticulatum-Parmotrema pseudoreticulatum complex applying coalescent-based approaches and other recently developed DNA-based methods. To this end, we gathered 180 samples from Africa, Asia, Australasia, Europe, North and South America and generated sequences of internal transcribed spacer of nuclear ribosomal DNA (ITS) and DNA replication licensing factor MCM7 (MCM7). The dataset was analysed using different approaches such as traditional phylogeny-maximum likelihood and Bayesian-genetic distances, automatic barcode gap discovery and coalescent-based methods-PTP, GMYC, spedeSTEM and *Beast-in order to test congruence among results. Additionally, the divergence times were also estimated to elucidate diversification events. Delimitations inferred from the different analyses are comparable with only minor differences, and following a conservative approach we propose that the sampled specimens of the P. reticulatum-P. pseudoreticulatum complex belong to at least eight distinct species-level lineages. Seven are currently classified under P. reticulatum and one as P. pseudoreticulatum. In this work we discuss one of only few examples of cryptic species that have so far been found in sorediate reproducing lichen forming fungi. Additionally our estimates suggest a recent origin of the species complex-during the Miocene. Consequently, the wide distribution of several of the cryptic species has to be explained by intercontinental long-distance dispersal events.

SUBMITTER: Del-Prado R

PROVIDER: S-EPMC4981466 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Hidden Genetic Diversity in an Asexually Reproducing Lichen Forming Fungal Group.

Del-Prado Ruth R Divakar Pradeep Kumar PK Lumbsch H Thorsten HT Crespo Ana M AM

PloS one 20160811 8

Asexual species with vegetative propagation of both symbiont partners (soredia) in lichens may harbor lower species diversity because they may indeed represent evolutionary dead ends or clones. In this study we aim to critically examine species boundaries in the sorediate lichen forming fungi Parmotrema reticulatum-Parmotrema pseudoreticulatum complex applying coalescent-based approaches and other recently developed DNA-based methods. To this end, we gathered 180 samples from Africa, Asia, Austr ...[more]

PMID: 27513649

Similar Datasets

Project description:BackgroundLichens represent not only the mutualism of fungal and photosynthetic partners but also are composed of microbial consortium harboring diverse fungi known as endolichenic fungi. While endolichenic fungi are known to exert a remarkable influence on lichen ecology through their crucial roles in nutrient cycling, bioprospecting and biodiversity, the enigmatic community structures of these fungal inhabitants remain shrouded in mystery, awaiting further exploration and discovery. To address knowledge gap, we conducted metabarcoding on two lichens using 18S gene amplification, Dirinara applanta and Parmotrema tinctorum, and compared their microbial communities to those found in the pine bark to which the lichens were attached. Our hypothesis was that the endolichenic communities would exhibit distinct diversity patterns, community structures, network structures, and specialist composition compared to the surrounding epiphytic community.ResultsOur investigation has shed light on the clear demarcation between the endolichenic and epiphytic fungal communities, as they exhibit markedly different characteristics that set them apart from each other. This research demonstrated that the endolichenic communities are less diverse as compared to the epiphytic communities. Through community similarity analysis, we observed that two endolichenic communities are more similar to each other in terms of community composition than with the adjacent epiphytic communities. Moreover, we unveiled a striking contrast in the network structures between the endolichenic and epiphytic communities, as the former displayed a more modular and less nested features that is evocative of a potent host-filtration mechanism.ConclusionsThrough our investigation, we have discovered that lichens harbor less intricate and interconnected fungal communities compared to the neighboring epiphytic environment. These observations provide valuable insights into the metagenomic architecture of lichens and offer a tantalizing glimpse into the unique mycobiome.

Project description:Despite reproducing without sexual recombination, Meloidogyne incognita is an adaptive and versatile phytoparasitic nematode. This species displays a global distribution, can parasitize a large range of plants, and can overcome plant resistance in a few generations. The mechanisms underlying this adaptability remain poorly known. At the whole-genome level, only a few single nucleotide variations have been observed across different geographical isolates with distinct ranges of compatible hosts. Exploring other factors possibly involved in genomic plasticity is thus important. Transposable elements (TEs), by their repetitive nature and mobility, can passively and actively impact the genome dynamics. This is particularly expected in polyploid hybrid genomes such as the one of M. incognita. Here, we have annotated the TE content of M. incognita, analyzed the statistical properties of this TE landscape, and used whole-genome pool-seq data to estimate the mobility of these TEs across twelve geographical isolates, presenting variations in ranges of compatible host plants. DNA transposons are more abundant than retrotransposons, and the high similarity of TE copies to their consensus sequences suggests they have been at least recently active. We have identified loci in the genome where the frequencies of presence of a TE showed substantial variations across the different isolates. Overall, variations in TE frequencies across isolates followed their phylogenetic divergence, suggesting TEs participate in the species diversification. Compared with the M. incognita reference genome, we detected isolate and lineage-specific de novo insertion of some TEs, including within genic regions or in the upstream regulatory regions. We validated by PCR the insertion of some of these TEs inside genic regions, confirming TE movements have possible functional impacts. Overall, we show DNA transposons can drive genomic plasticity in M. incognita and their role in genome evolution of other parthenogenetic animal deserves further investigation.

Project description:BackgroundFactors promoting diversification in lichen symbioses remain largely unexplored. While Pleistocene events have been important for driving diversification and affecting distributions in many groups, recent estimates suggest that major radiations within some genera in the largest clade of macrolichens (Parmeliaceae, Ascomycota) vastly predate the Pleistocene. To better understand the temporal placement and sequence of diversification events in lichens, we estimated divergence times in a common lichen-forming fungal genus, Melanohalea, in the Northern Hemisphere. Divergence times were estimated using both concatenated gene tree and coalescent-based multilocus species tree approaches to assess the temporal context of major radiation events within Melanohalea. In order to complement our understanding of processes impacting genetic differentiation, we also evaluated the effects of Pleistocene glacial cycles on population demographics of distinct Melanohalea lineages, differing in reproductive strategies.ResultsWe found that divergence estimates, from both concatenated gene tree and coalescent-based multilocus species tree approaches, suggest that diversification within Melanohalea occurred predominantly during the Miocene and Pliocene, although estimated of divergence times differed by up to 8.3 million years between the two methods. These results indicate that, in some cases, taxonomically diagnostic characters may be maintained among divergent lineages for millions of years. In other cases, similar phenotypic characters among non-sister taxa, including reproductive strategies, suggest the potential for convergent evolution due to similar selective pressures among distinct lineages. Our analyses provide evidence of population expansions predating the last glacial maximum in the sampled lineages. These results suggest that Pleistocene glaciations were not inherently unfavorable or restrictive for some Melanohalea species, albeit with apparently different demographic histories between sexually and vegetatively reproducing lineages.ConclusionsOur results contribute to the understanding of how major changes during the Miocene and Pliocene have been important in promoting diversification within common lichen-forming fungi in the northern Hemisphere. Additionally, we provide evidence that glacial oscillations have influenced current population structure of broadly distributed lichenized fungal species throughout the Holarctic.

Dataset Information

Hidden Genetic Diversity in an Asexually Reproducing Lichen Forming Fungal Group.

Publications

Hidden Genetic Diversity in an Asexually Reproducing Lichen Forming Fungal Group.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets