title: Minifish shows high genetic variation in mtDNA size.
abstract: The genus Paedocypris is a newly described taxon of minifish species that are characterized by extensive chromosome evolution and one of the smallest known vertebrate nuclear genomes. Paedocypris features a tiny adult size, a short generation time, low fecundity and fragmented tropical habitats, which are factors that favor rapid speciation. Most recently, we have revealed that P. progenetica (Pp), the type species of the genus Paedocypris, has an unusual mtDNA bearing - within its D-loop - a tandem array of a 34-bp repeat sequence called the minifish repeat, which shows compromised replication efficiency in vitro. Here we report that Pp exhibits high genetic variation in mtDNA size. The efficiency of D-loop amplification was found to depend upon primers. Interestingly, Pp individuals of one and the same population differed drastically in mtDNA size resulting from varying copy numbers of the minifish repeat. We conclude that minifish has a high mutation rate and perhaps represents a rapidly evolving taxon of vertebrates.
authors.forename: X-W
authors.initials: XW
authors.lastname: Chen
authors.forename: Q-L
authors.initials: QL
authors.lastname: Li
authors.forename: X-J
authors.initials: XJ
authors.lastname: Hu
authors.forename: Y-M
authors.initials: YM
authors.lastname: Yuan
authors.forename: M
authors.initials: M
authors.lastname: Wen
authors.forename: L-Y
authors.initials: LY
authors.lastname: Peng
authors.forename: S-J
authors.initials: SJ
authors.lastname: Liu
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore. dbshyh@nus.edu.sg.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Hong
mesh_terms: D000818:Animals; D002681:China; D003531:Cypriniformes / Q000235:genetics*; D056915:DNA Copy Number Variations; D017931:DNA Primers / Q000737:chemistry; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D050259:Genes, Mitochondrial; D049810:Genetic Speciation; D059646:Genome Size; D008928:Mitochondria / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020080:Tandem Repeat Sequences
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial