title: The absence of Arabidopsis-type telomeres in Cestrum and closely related genera Vestia and Sessea (Solanaceae): first evidence from eudicots.
abstract: Using slot-blot and fluorescent in situ hybridization (FISH), we found no evidence for the presence of the Arabidopsis-type telomeric sequence (TTTAGGG)n at the chromosome termini in any of the Cestrum species we investigated. Probing for the human-type telomere (TTAGGG)n also revealed no signal. However, polymerase chain reaction experiments indicated that there are short lengths of the sequence TTTAGGG dispersed in the genome but that these sequences are almost certainly too short to act as functional telomeres even if they were at the chromosome termini. An analysis of related genera Vestia and Sessea indicates that they too lack the Arabidopsis-type telomere, and the sequences were lost in the common ancestor of these genera. We found that the Cestrum species investigated had particularly large mean chromosome sizes. We discuss whether this is a consequence of alternative telomere end maintenance systems.
authors.affiliation: School of Biological Sciences, Queen Mary University of London, UK.
authors.forename: Eva
authors.initials: E
authors.lastname: Sykorova
authors.forename: Kar Yoong
authors.initials: KY
authors.lastname: Lim
authors.forename: Mark W
authors.initials: MW
authors.lastname: Chase
authors.forename: Sandra
authors.initials: S
authors.lastname: Knapp
authors.forename: Ilia Judith
authors.initials: IJ
authors.lastname: Leitch
authors.forename: Andrew Rowland
authors.initials: AR
authors.lastname: Leitch
authors.forename: Jiri
authors.initials: J
authors.lastname: Fajkus
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D032301:Cestrum / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics; D015698:Genomic Library; D017404:In Situ Hybridization, Fluorescence; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017384:Sequence Deletion; D019657:Solanaceae / Q000235:genetics*; D016615:Telomere / Q000235:genetics*
chemical_list: D018744:DNA, Plant