Evolutionary History of the Root Vole (Microtus oeconomus) as Revealed by Y Chromosome and Mitochondrial DNA sequences
(2003)- Abstract
- The root vole (<i>Microtus oeconomus</i>) is a rodent with Holarctic distribution. In fact, it is the only <i>Microtus</i> vole found in both Eurasia and North America. Phylogeographic analyses of the root vole from across its distribution range were performed using mitochondrial and Y chromosome DNA sequences. Mitochondrial cytochrome <i>b</i> gene data demonstrate that the root vole is divided into four geographically distinct and well supported mtDNA phylogroups. Concordance between phylogeographic patterns in the root vole and other species suggest similarities in these species' responses to large-scale climatic change. The result of Y chromosome sequence analyses in the root vole is congruent with... (More)
- The root vole (<i>Microtus oeconomus</i>) is a rodent with Holarctic distribution. In fact, it is the only <i>Microtus</i> vole found in both Eurasia and North America. Phylogeographic analyses of the root vole from across its distribution range were performed using mitochondrial and Y chromosome DNA sequences. Mitochondrial cytochrome <i>b</i> gene data demonstrate that the root vole is divided into four geographically distinct and well supported mtDNA phylogroups. Concordance between phylogeographic patterns in the root vole and other species suggest similarities in these species' responses to large-scale climatic change. The result of Y chromosome sequence analyses in the root vole is congruent with mtDNA, but the low sequence variability of the Y chromosome result in a phylogeographic pattern with much lower resolution. Differences between the mtDNA and Y chromosome phylogeographic patterns cannot be explained by differences in mutation rate alone, but is also affected by different evolutionary conditions and processes such as sex-biased dispersal, differences in male and female effective population sizes and local selective sweeps. Both mtDNA and Y chromosome data lend support for a subdivision of Fennoscandian root voles into two phylogroups with a complex history involving at least two colonization routes and, perhaps, glacial survival in northern Norway. These results contradict theoretical models that suggest low genetic diversity in previously glaciated areas. Analyses of two genetic markers, mtDNA and Y chromosome sequences, in concert have provided a more detailed picture of the evolutionary history of the root vole as well as the evolution of the two genetic systems. In addition, a phylogenetic study of 25 <i>Microtus</i> species based on mtDNA shows that the root vole belongs to an Asian group of <i>Microtus</i> voles. (Less)
- Abstract (Swedish)
- Popular Abstract in Swedish
Fylogeografiska analyser omfattar studier av släktskap mellan geografiskt skilda individer och populationer i en art. Målsättningen är att hitta genetiska spår av storskaliga biogeografiska händelser och historiska evolutionära processer. Min avhandling inbegriper fylogeografiska studier av mellansork (<i>Microtus oeconomus</i>), vars utbredningsområde omfattar stora delar av norra Eurasien och nordvästra Nordamerika. Arten är intressant att studera eftersom fossilfynd daterade till senaste istiden (115 000-10 000 år sedan) visar att den levde i Centraleuropa under hela denna period, till skillnad från många fylogeografiskt välstuderade arter som överlevde istiden i södra Europa. De... (More) - Popular Abstract in Swedish
Fylogeografiska analyser omfattar studier av släktskap mellan geografiskt skilda individer och populationer i en art. Målsättningen är att hitta genetiska spår av storskaliga biogeografiska händelser och historiska evolutionära processer. Min avhandling inbegriper fylogeografiska studier av mellansork (<i>Microtus oeconomus</i>), vars utbredningsområde omfattar stora delar av norra Eurasien och nordvästra Nordamerika. Arten är intressant att studera eftersom fossilfynd daterade till senaste istiden (115 000-10 000 år sedan) visar att den levde i Centraleuropa under hela denna period, till skillnad från många fylogeografiskt välstuderade arter som överlevde istiden i södra Europa. De fylogenetiska analyserna i avhandlingen är baserade på sekvensvariation i mitokondrie-DNA (mtDNA) och Y-kromosomen. MtDNA ärvs via mödernet (maternell nedärvning) medan Y kromosomen nedärvs paternellt. Eventuella skillnaderna i fylogeografiska mönster baserade på sekvensvariation i de två genetiska markörerna kan avspegla skillnader i mutationstakt, men också könsspecifika spridningsmönster och skillnader i effektiva populationsstorlekar mellan hanar och honor.
Mina resultat visar att mellansorken är uppdelad i fyra geografiskt distinkta mtDNA fylogrupper som återfinns i Nordeuropa, Centraleuropa, Centralasien och Nordamerika. En god överensstämmelse mellan det fylogeografiska mönstret i mellansorken och en rad andra smågnagare tyder på att dessa arter påverkats på liknande sätt av storskaliga klimatförändringar under istider. Mellansorken uppvisar dessutom mycket mtDNA variation i hela dess utbredningsområde, vilket motsäger hypoteser om låg genetisk variation i nordliga populationer. Mina analyser av sekvensvariation i Y kromosomen stöder mtDNA resultaten, även om Y kromosomen är mindre variabel än mtDNA. Både mtDNA- och Y kromosom-resultaten uppvisar en uppdelning av nordeuropeiska mellansorkar i två undergrupper som förmodligen reflekterar varsin koloniseringshändelse efter senaste istiden. Resultaten kan kanske till och med avspegla överlevnad av mellansorkar i norra Norge under senaste istiden. Sekvensanalys av två genetiska markörer, mtDNA och Y kromosom, ger en mer detaljerad bild av den evolutionära historien i mellansork, men också evolution av de två genetiska systemen. Jag har också upprättat ett molekylärt släktträd för <i>Microtus</i>-sorkar baserat på mtDNA sekvenser. Detta träd visar att mellansorken är närmast släkt med flera asiatiska <i>Microtus</i>-arter. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/466175
- author
- Brunhoff, Cecilia LU
- supervisor
- opponent
-
- Dr Ettore Randi, Ettore Randi
- organization
- publishing date
- 2003
- type
- Thesis
- publication status
- published
- subject
- keywords
- Genetics, colonization history, phylogeography, root vole, cytogenetics, Genetik, cytogenetik
- pages
- 134 pages
- publisher
- Cecilia Brunhoff, Dept. of Cell and Organism Biology, Lund University, Sweden,
- defense location
- 2 October 2003, Genetics building, Sölvegatan 29, Lund
- defense date
- 2007-03-20 10:15:00
- ISBN
- 91-85067-06-7
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Genetics (Closed 2011) (011005100), Pathology (Malmö) (013031000)
- id
- 930252a3-f8b7-48c4-8b4b-2e4eec413411 (old id 466175)
- date added to LUP
- 2016-04-04 12:13:48
- date last changed
- 2018-11-21 21:09:45
@phdthesis{930252a3-f8b7-48c4-8b4b-2e4eec413411,
abstract = {{The root vole (<i>Microtus oeconomus</i>) is a rodent with Holarctic distribution. In fact, it is the only <i>Microtus</i> vole found in both Eurasia and North America. Phylogeographic analyses of the root vole from across its distribution range were performed using mitochondrial and Y chromosome DNA sequences. Mitochondrial cytochrome <i>b</i> gene data demonstrate that the root vole is divided into four geographically distinct and well supported mtDNA phylogroups. Concordance between phylogeographic patterns in the root vole and other species suggest similarities in these species' responses to large-scale climatic change. The result of Y chromosome sequence analyses in the root vole is congruent with mtDNA, but the low sequence variability of the Y chromosome result in a phylogeographic pattern with much lower resolution. Differences between the mtDNA and Y chromosome phylogeographic patterns cannot be explained by differences in mutation rate alone, but is also affected by different evolutionary conditions and processes such as sex-biased dispersal, differences in male and female effective population sizes and local selective sweeps. Both mtDNA and Y chromosome data lend support for a subdivision of Fennoscandian root voles into two phylogroups with a complex history involving at least two colonization routes and, perhaps, glacial survival in northern Norway. These results contradict theoretical models that suggest low genetic diversity in previously glaciated areas. Analyses of two genetic markers, mtDNA and Y chromosome sequences, in concert have provided a more detailed picture of the evolutionary history of the root vole as well as the evolution of the two genetic systems. In addition, a phylogenetic study of 25 <i>Microtus</i> species based on mtDNA shows that the root vole belongs to an Asian group of <i>Microtus</i> voles.}},
author = {{Brunhoff, Cecilia}},
isbn = {{91-85067-06-7}},
keywords = {{Genetics; colonization history; phylogeography; root vole; cytogenetics; Genetik; cytogenetik}},
language = {{eng}},
publisher = {{Cecilia Brunhoff, Dept. of Cell and Organism Biology, Lund University, Sweden,}},
school = {{Lund University}},
title = {{Evolutionary History of the Root Vole (<i>Microtus oeconomus</i>) as Revealed by Y Chromosome and Mitochondrial DNA sequences}},
year = {{2003}},
}