title: First evidence for (TTAGG)n telomeric sequence and sex chromosome post-reduction in Coleorrhyncha (Insecta, Hemiptera).
abstract: Telomeric repeats are general and significant structures of eukaryotic chromosomes. However, nothing is known about the molecular structure of telomeres in the enigmatic hemipteran suborder Coleorrhyncha (moss bugs) commonly considered as the sister group to the suborder Heteroptera (true bugs). The true bugs are known to differ from the rest of the Hemiptera in that they display an inverted sequence of sex chromosome divisions in male meiosis, the so-called sex chromosome post-reduction. To date, there has been no information about meiosis in Coleorrhyncha. Here we report a cytogenetic observation of Peloridium pomponorum, a representative of the single extant coleorrhynchan family Peloridiidae, using the standard chromosome staining and fluorescence in situ hybridization (FISH) with a (TTAGG) n telomeric probe. We show that Peloridium pomponorum displays 2n = 31 (30A + X) in males, the classical insect (TTAGG) n telomere organization and sex chromosome post-reduction during spermatocyte meiosis. The plesiomorphic insect-type (TTAGG) n telomeric sequence is suggested to be preserved in Coleorrhyncha and in a basal heteropteran infraorder Nepomorpha, but absent (lost) in the advanced heteropteran lineages Cimicomorpha and Pentatomomorpha. The telomere structure in other true bug infraorders is currently unknown. We consider here the inverted sequence of sex chromosome divisions as a synapomorphy of the group Coleorrhyncha + Heteroptera.
authors.affiliation: Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia.
authors.forename: Valentina G
authors.initials: VG
authors.lastname: Kuznetsova
authors.affiliation: Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Blvd Tsar Osvoboditel 1, Sofia 1000, Bulgaria.
authors.forename: Snejana M
authors.initials: SM
authors.lastname: Grozeva
authors.affiliation: Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany; Staatliches Museum für Naturkunde Karlsruhe, Erbprinzenstraße 13, 76133 Karlsruhe, Germany.
authors.forename: Viktor
authors.initials: V
authors.lastname: Hartung
authors.affiliation: Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia.
authors.forename: Boris A
authors.initials: BA
authors.lastname: Anokhin
keywords: (TTAGG)n telomeric sequence; Coleorrhyncha; Hemiptera; Karyotype; Peloridiidae; Peloridium pomponorum; sex chromosome post-reduction