uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rates and patterns of molecular evolution in liverwort genomes, with focus of Marchantiopsida.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
Biodiversity, Department of Biology, Lund University.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
(English)Manuscript (preprint) (Other academic)
National Category
Evolutionary Biology
Identifiers
URN: urn:nbn:se:uu:diva-392459OAI: oai:DiVA.org:uu-392459DiVA, id: diva2:1348616
Available from: 2019-09-05 Created: 2019-09-05 Last updated: 2019-09-05
In thesis
1. Rates and patterns of bryophyte molecular evolution
Open this publication in new window or tab >>Rates and patterns of bryophyte molecular evolution
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Plants have been growing on land for at least 450 million years. The bryophytes comprising the three phyla liverworts, mosses and hornworts, are considered to be the closest extant relatives to the plants that colonized land. Bryophytes has been described as evolutionary “unchanging sphinxes of the past” regarding both morphological and genetic potential. This suggestion has some support in limited studies of molecular evolution within bryophytes, but has also been questioned based on e.g., studies of species diversification rates. To shed more light on this controversy, the overall aim of this thesis is to investigate rates and patterns of bryophyte molecular evolution.

Our data suggest that the per nucleotide mutation rates in bryophytes are lower than those in angiosperms. Likewise, angiosperms are also more dynamic in terms of genome size, structural rearrangements, genome duplications and transposon activity. However, our data show that mutation rates of bryophytes are higher or at least on par with those of gymnosperms. Genome evolution in bryophytes is actually, in many aspects, similar to that of gymnosperms. Gymnosperms and bryophytes are both characterized by a low speciation rate, a low nucleotide mutation rate, low variation in chromosome numbers and relatively stable genome sizes. Studies have also suggested that macrosynteny is better conserved between conifer species compared with angiosperms, just as this study shows for bryophytes.

Hybridization and introgression has been suggested to affect speciation and evolution. Recent genomic data shows that hybridization and introgression in angiosperms is more common then previously thought, but the question is less well studied in bryophytes. The present study gave some support to the occurrence of introgression between Marchantia polymorpha subspecies, but refute a previous hypothesis that M. polymorpha subsp. ruderalis is a new stabilized hybrid between M. polymorpha montivagans and polymorpha.

An additional aspect of genome evolution and complexity is changes in gene regulatory networks. Gene regulatory networks generally appear more complex in angiosperms compared with bryophytes; also reflected in the circadian clock; with more gene components and more duplicated paralogous members, with possibly overlapping function, allowing a more robust and flexible system. Our studies of the plant circadian clock revealed that orthologs of most genes of the A. thaliana clock were present already in charophycean algae. Although gene numbers and complexity have generally increased during plant circadian clock evolution, our results suggest that gene loss has also been important in shaping the circadian clocks in the three bryophyte groups.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2019. p. 42
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1850
National Category
Evolutionary Biology
Research subject
Biology with specialization in Evolutionary Functional Genomics
Identifiers
urn:nbn:se:uu:diva-392462 (URN)978-91-513-0740-4 (ISBN)
Public defence
2019-10-23, Zootissalen, EBC, Villavägen 9, Uppsala, 10:00 (English)
Opponent
Supervisors
Available from: 2019-10-02 Created: 2019-09-05 Last updated: 2019-10-15

Open Access in DiVA

No full text in DiVA

By organisation
Plant Ecology and Evolution
Evolutionary Biology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf