Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers
Ciliates provide a powerful system within microbial eukaryotes in which molecular genealogies can be compared to detailed morphological taxonomies. Two groups with such detailed taxonomies are the Colpodea and the Halteriidae. There are about 200 described Colpodea species that are found primarily i...
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ndltd-UMASS-oai-scholarworks.umass.edu-dissertations-56752020-12-02T14:30:30Z Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers Dunthorn, Micah Ciliates provide a powerful system within microbial eukaryotes in which molecular genealogies can be compared to detailed morphological taxonomies. Two groups with such detailed taxonomies are the Colpodea and the Halteriidae. There are about 200 described Colpodea species that are found primarily in terrestrial habitats. In Chapters 1 and 2, taxon sampling is increased to include exemplars from all major subclades using nuclear small subunit rDNA (nSSU-rDNA) sequencing. Much of the morphological taxonomy is supported, but extensive non-monophyly is found throughout. The conflict between some nodes of the nSSU-rDNA genealogy and morphology-based taxonomy suggests the need for additional molecular marker. In Chapter 3, character sampling is increased using mitochondrial small subunit rDNA (mtSSU-rDNA) sequencing. The nSSU-rDNA and mtSSU-rDNA topologies for the Colpodea are largely congruent for well-supported nodes, suggesting that nSSU-rDNA work in other ciliate clades will be supported by mtSSU-rDNA as well. Chapter 4 compares the underlying genetic variation within two closely related species in the Halteriidae with increased taxon and molecular sampling using nSSU-rDNA and internally-transcribed spacer (ITS) region sequencing. The morphospecies Halteria grandinella shows extensive genetic variation that is consistent with either a large effective population size or the existence of multiple cryptic species. This pattern contrasts with the minimal of genetic variation in the morphospecies Meseres corlissi. Chapter 5 discusses the congruence and incongruence among morphological and molecular data in ciliates. Most of the incongruence occurs where there is little statistical support for the molecules, or where molecular data is consistent with alternative morphological hypotheses. Chapter 6 reviews the data for sex, or lack thereof, in the Colpodea, a potentially ancient asexual group where sex was regained in a derived species. In Chapter 7, four ciliate clades are redefined using the PhyloCode. 2009-01-01T08:00:00Z text https://scholarworks.umass.edu/dissertations/AAI3379954 Doctoral Dissertations Available from Proquest ENG ScholarWorks@UMass Amherst Microbiology|Virology |
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ENG |
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Microbiology|Virology |
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Microbiology|Virology Dunthorn, Micah Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers |
description |
Ciliates provide a powerful system within microbial eukaryotes in which molecular genealogies can be compared to detailed morphological taxonomies. Two groups with such detailed taxonomies are the Colpodea and the Halteriidae. There are about 200 described Colpodea species that are found primarily in terrestrial habitats. In Chapters 1 and 2, taxon sampling is increased to include exemplars from all major subclades using nuclear small subunit rDNA (nSSU-rDNA) sequencing. Much of the morphological taxonomy is supported, but extensive non-monophyly is found throughout. The conflict between some nodes of the nSSU-rDNA genealogy and morphology-based taxonomy suggests the need for additional molecular marker. In Chapter 3, character sampling is increased using mitochondrial small subunit rDNA (mtSSU-rDNA) sequencing. The nSSU-rDNA and mtSSU-rDNA topologies for the Colpodea are largely congruent for well-supported nodes, suggesting that nSSU-rDNA work in other ciliate clades will be supported by mtSSU-rDNA as well. Chapter 4 compares the underlying genetic variation within two closely related species in the Halteriidae with increased taxon and molecular sampling using nSSU-rDNA and internally-transcribed spacer (ITS) region sequencing. The morphospecies Halteria grandinella shows extensive genetic variation that is consistent with either a large effective population size or the existence of multiple cryptic species. This pattern contrasts with the minimal of genetic variation in the morphospecies Meseres corlissi. Chapter 5 discusses the congruence and incongruence among morphological and molecular data in ciliates. Most of the incongruence occurs where there is little statistical support for the molecules, or where molecular data is consistent with alternative morphological hypotheses. Chapter 6 reviews the data for sex, or lack thereof, in the Colpodea, a potentially ancient asexual group where sex was regained in a derived species. In Chapter 7, four ciliate clades are redefined using the PhyloCode. |
author |
Dunthorn, Micah |
author_facet |
Dunthorn, Micah |
author_sort |
Dunthorn, Micah |
title |
Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers |
title_short |
Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers |
title_full |
Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers |
title_fullStr |
Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers |
title_full_unstemmed |
Ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers |
title_sort |
ciliate biodiversity and phylogenetic reconstruction assessed by multiple molecular markers |
publisher |
ScholarWorks@UMass Amherst |
publishDate |
2009 |
url |
https://scholarworks.umass.edu/dissertations/AAI3379954 |
work_keys_str_mv |
AT dunthornmicah ciliatebiodiversityandphylogeneticreconstructionassessedbymultiplemolecularmarkers |
_version_ |
1719364349337796608 |