The puzzle of lichen symbiosis : Pieces from Thamnolia
Symbiosis brought important evolutionary novelties to life on Earth. Lichens, the symbiotic entities formed by fungi, photosynthetic organisms and bacteria, represent an example of a successful adaptation in surviving hostile environments. Yet many aspects of the lichen symbiosis remain unexplored....
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Uppsala universitet, Systematisk biologi
2017
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ftuppsalauniv:oai:DiVA.org:uu-319639 2023-05-15T18:40:19+02:00 The puzzle of lichen symbiosis : Pieces from Thamnolia Onuț-Brännström, Ioana 2017 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-319639 eng eng Uppsala universitet, Systematisk biologi Uppsala Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1503 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-319639 urn:isbn:978-91-554-9887-0 info:eu-repo/semantics/openAccess Thamnolia lichen symbiosis photobiont mycobiont phylogeography MAT-loci barcoding NGS genome transcriptome Ice Age Natural Sciences Naturvetenskap Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2017 ftuppsalauniv 2023-02-23T21:37:03Z Symbiosis brought important evolutionary novelties to life on Earth. Lichens, the symbiotic entities formed by fungi, photosynthetic organisms and bacteria, represent an example of a successful adaptation in surviving hostile environments. Yet many aspects of the lichen symbiosis remain unexplored. This thesis aims at bringing insights into lichen biology and the importance of symbiosis in adaptation. I am using as model system a successful colonizer of tundra and alpine environments, the worm lichens Thamnolia, which seem to only reproduce vegetatively through symbiotic propagules. When the genetic architecture of the mating locus of the symbiotic fungal partner was analyzed with genomic and transcriptomic data, a sexual self-incompatible life style was revealed. However, a screen of the mating types ratios across natural populations detected only one of the mating types, suggesting that Thamnolia has no potential for sexual reproduction because of lack of mating partners. Genetic data based on molecular markers revealed the existence of three morphologically cryptic Thamnolia lineages. One lineage had a clear recombination structure and was found in the tundra region of Siberia, shorelines of Scandinavia, and Aleutian Islands. The other lineage was allopatric with the previous, and was highly clonal; only two haplotypes were found across the alpine region of central and southeastern Europe. However, the third lineage was sympatric with the other two, had a worldwide distribution, and although highly clonal, showed a recombinant population structure. Our data could not reveal whether the signs of recombination resulted from rare recombination events due to the extreme low frequency of the other mating type or ancestral variation before the loss of sexual reproduction. However, investigation of Thamnolia’s green algal population showed that in different localities, different algal genotypes were associated with the same fungal genotype. Furthermore, data suggest that Thamnolia carried several algal genotypes ... Doctoral or Postdoctoral Thesis Tundra Aleutian Islands Siberia Uppsala University: Publications (DiVA) |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
Thamnolia lichen symbiosis photobiont mycobiont phylogeography MAT-loci barcoding NGS genome transcriptome Ice Age Natural Sciences Naturvetenskap |
spellingShingle |
Thamnolia lichen symbiosis photobiont mycobiont phylogeography MAT-loci barcoding NGS genome transcriptome Ice Age Natural Sciences Naturvetenskap Onuț-Brännström, Ioana The puzzle of lichen symbiosis : Pieces from Thamnolia |
topic_facet |
Thamnolia lichen symbiosis photobiont mycobiont phylogeography MAT-loci barcoding NGS genome transcriptome Ice Age Natural Sciences Naturvetenskap |
description |
Symbiosis brought important evolutionary novelties to life on Earth. Lichens, the symbiotic entities formed by fungi, photosynthetic organisms and bacteria, represent an example of a successful adaptation in surviving hostile environments. Yet many aspects of the lichen symbiosis remain unexplored. This thesis aims at bringing insights into lichen biology and the importance of symbiosis in adaptation. I am using as model system a successful colonizer of tundra and alpine environments, the worm lichens Thamnolia, which seem to only reproduce vegetatively through symbiotic propagules. When the genetic architecture of the mating locus of the symbiotic fungal partner was analyzed with genomic and transcriptomic data, a sexual self-incompatible life style was revealed. However, a screen of the mating types ratios across natural populations detected only one of the mating types, suggesting that Thamnolia has no potential for sexual reproduction because of lack of mating partners. Genetic data based on molecular markers revealed the existence of three morphologically cryptic Thamnolia lineages. One lineage had a clear recombination structure and was found in the tundra region of Siberia, shorelines of Scandinavia, and Aleutian Islands. The other lineage was allopatric with the previous, and was highly clonal; only two haplotypes were found across the alpine region of central and southeastern Europe. However, the third lineage was sympatric with the other two, had a worldwide distribution, and although highly clonal, showed a recombinant population structure. Our data could not reveal whether the signs of recombination resulted from rare recombination events due to the extreme low frequency of the other mating type or ancestral variation before the loss of sexual reproduction. However, investigation of Thamnolia’s green algal population showed that in different localities, different algal genotypes were associated with the same fungal genotype. Furthermore, data suggest that Thamnolia carried several algal genotypes ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Onuț-Brännström, Ioana |
author_facet |
Onuț-Brännström, Ioana |
author_sort |
Onuț-Brännström, Ioana |
title |
The puzzle of lichen symbiosis : Pieces from Thamnolia |
title_short |
The puzzle of lichen symbiosis : Pieces from Thamnolia |
title_full |
The puzzle of lichen symbiosis : Pieces from Thamnolia |
title_fullStr |
The puzzle of lichen symbiosis : Pieces from Thamnolia |
title_full_unstemmed |
The puzzle of lichen symbiosis : Pieces from Thamnolia |
title_sort |
puzzle of lichen symbiosis : pieces from thamnolia |
publisher |
Uppsala universitet, Systematisk biologi |
publishDate |
2017 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-319639 |
genre |
Tundra Aleutian Islands Siberia |
genre_facet |
Tundra Aleutian Islands Siberia |
op_relation |
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1503 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-319639 urn:isbn:978-91-554-9887-0 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766229637520687104 |