title: Intragenomic variations of multicopy ITS2 marker in Agrodiaetus blue butterflies (Lepidoptera, Lycaenidae).
abstract: The eukaryotic ribosomal DNA cluster consists of multiple copies of three genes, 18S, 5. 8S and 28S rRNAs, separated by multiple copies of two internal transcribed spacers, ITS1 and ITS2. It is an important, frequently used marker in both molecular cytogenetic and molecular phylogenetic studies. Despite this, little is known about intragenomic variations within the copies of eukaryotic ribosomal DNA genes and spacers. Here we present data on intraindividual variations of ITS2 spacer in three species of Agrodiaetus Hübner, 1822 blue butterflies revealed by cloning technique. We demonstrate that a distinctly different intragenomic ITS2 pattern exists for every individual analysed. ITS2 sequences of these species show significant intragenomic variation (up to 3.68% divergence), setting them apart from each other on inferred phylogenetic tree. This variation is enough to obscure phylogenetic relationships at the species level.
authors.affiliation: Department of Karyosystematics, Zoological Institute of Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia; Department of Entomology, Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg 199034, Russia.
authors.forename: Nazar A
authors.initials: NA
authors.lastname: Shapoval
authors.affiliation: Department of Karyosystematics, Zoological Institute of Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia; Department of Entomology, Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg 199034, Russia.
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Lukhtanov
keywords: Agrodiaetus; ITS2; Lycaenidae; Polyommatus; cloning; intraindividual variability; ribosomal DNA