Inverted repeats and genome architecture conversions of terrestrial isopods mitochondrial DNA.
Mitochondrial DNA (mtDNA) is usually depicted as a circular molecule, however, there is increasing evidence that linearization of mtDNA evolved independently many times in organisms such as fungi, unicellular eukaryotes, and animals. Recent observations in various models with linear mtDNA revealed the presence of conserved inverted repeats (IR) at both ends that, when they become single-stranded, may be able to fold on themselves to create telomeric-hairpins involved in genome architecture conversions. The atypical mtDNA of terrestrial isopods (Crustacea: Oniscidea) composed of linear monomers and circular dimers is an interesting model to study genome architecture conversions. Here, we present the mtDNA control region sequences of two species of the genus Armadillidium: A. vulgare and A. pelagicum. All features of arthropods mtDNA control regions are present (origin of replication, poly-T stretch, GA and TA-rich blocks and one variable domain), plus a conserved IR. This IR can potentially fold into a hairpin structure and is present in two different orientations among the A. vulgare populations: either in one sense or in its reverse complement. This polymorphism, also observed in a single individual (heteroplasmy), might be a signature of genome architecture conversions from linear to circular monomeric mtDNA via successive opening and closing of the molecules.
Equipe Ecologie Evolution Symbiose, Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Université de Poitiers, 40 Avenue du Recteur Pineau, 86022, Poitiers Cedex, France, vincent.doublet@zoologie.uni-halle.de.
Vincent
V
Doublet
Quentin
Q
Helleu
Roland
R
Raimond
Catherine
C
Souty-Grosset
Isabelle
I
Marcadé
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D054629:Genome, Mitochondrial; D055029:Inverted Repeat Sequences; D033321:Isopoda / Q000235:genetics*; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques; D009690:Nucleic Acid Conformation; D017422:Sequence Analysis, DNA
D004272:DNA, Mitochondrial