title: Presence of a functional (TTAGG)(n) telomere-telomerase system in aphids.
abstract: The structure of the telomeres of four aphid species (Acyrthosiphon pisum, Megoura viciae, Myzus persicae and Rhopalosiphum padi) was evaluated by Southern blotting and fluorescent in situ hybridization, revealing that each chromosomal end consists of a (TTAGG)(n) repeat. The presence of a telomerase coding gene has been verified successively in the A. pisum genome, revealing that aphid telomerase shares sequence identity ranging from 12% to 18% with invertebrate and vertebrate homologues, and possesses the two main domains involved in telomerase activity. Interestingly, telomerase expression has been verified in different somatic tissues suggesting that, in aphids, telomerase activity is not as restricted as in human cells. The study of telomeres in a M. persicae strain with a variable chromosome number showed that aphid telomerase can initiate the de novo synthesis of telomere sequences at internal breakpoints, resulting in the stabilization of chromosomal fragments.
authors.affiliation: Dipartimento di Biologia, Università di Modena e Reggio Emilia, Via Campi 213/D, 41125 Modena, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Monti
authors.forename: Monica
authors.initials: M
authors.lastname: Giusti
authors.forename: Davide
authors.initials: D
authors.lastname: Bizzaro
authors.forename: Gian Carlo
authors.initials: GC
authors.lastname: Manicardi
authors.forename: Mauro
authors.initials: M
authors.lastname: Mandrioli
mesh_terms: D000818:Animals; D001042:Aphids / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D059006:Chromosomes, Insect / Q000235:genetics; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D012091:Repetitive Sequences, Nucleic Acid; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D026801:Synteny; D019098:Telomerase / Q000235:genetics*; D016615:Telomere / Q000235:genetics*
chemical_list: D019098:Telomerase