title: Repetitive transpositions of mitochondrial DNA sequences to the nucleus during the radiation of horseshoe bats (Rhinolophus, Chiroptera).
abstract: Transposition of mitochondrial DNA into the nucleus, which gives rise to nuclear mitochondrial DNAs (NUMTs), has been well documented in eukaryotes. However, very few studies have assessed the frequency of these transpositions during the evolutionary history of a specific taxonomic group. Here we used the horseshoe bats (Rhinolophus) as a case study to determine the frequency and relative timing of nuclear transfers of mitochondrial control region sequences. For this, phylogenetic and coalescent analyzes were performed on NUMTs and authentic mtDNA sequences generated from eight horseshoe bat species. Our results suggest at least three independent transpositions, including two ancient and one more recent, during the evolutionary history of Rhinolophus. The two ancient transpositions are represented by the NUMT-1 and -2 clades, with each clade consisting of NUMTs from almost all studied species but originating from different portions of the mtDNA genome. Furthermore, estimates of the most recent common ancestor for each clade corresponded to the time of the initial diversification of this genus. The recent transposition is represented by NUMT-3, which was discovered only in a specific subgroup of Rhinolophus and exhibited a close relationship to its mitochondrial counterpart. Our similarity searches of mtDNA in the R. ferrumequinum genome confirmed the presence of NUMT-1 and NUMT-2 clade sequences and, for the first time, assessed the extent of NUMTs in a bat genome. To our knowledge, this is the first study to report on the frequency of transpositions of mtDNA occurring before the common ancestry of a genus.
authors.affiliation: Institute of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
authors.forename: Huizhen
authors.initials: H
authors.lastname: Shi
authors.affiliation: Institute of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
authors.forename: David M
authors.initials: DM
authors.lastname: Irwin
authors.affiliation: College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China. Electronic address: syzhang@bio.ecnu.edu.cn.
authors.forename: Shuyi
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Institute of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China. Electronic address: xgmao@sklec.ecnu.edu.cn.
authors.forename: Xiuguang
authors.initials: X
authors.lastname: Mao
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002685:Chiroptera / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D008928:Mitochondria / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: NUMTs; Nuclear insertions; Phylogenetic analysis; Rhinolophus