title: Developmentally regulated telomere addition in Tetrahymena thermophila.
abstract: To investigate the developmentally programmed telomere addition that accompanies chromosome fragmentation during macronuclear differentiation in Tetrahymena thermophila, five representative telomeric regions from the macronucleus were cloned and characterized in detail. The sequences adjacent to the telomeric (C4A2:T2G4) repeats on these five macronuclear ends had no significant sequence homology or shared secondary structure. Two developmentally independent examples of one macronuclear telomere had a 5 base pair difference in the position of the junction between the telomeric repeats and the adjacent sequences. A telomere-adjacent sequence, in the form of a synthetic oligonucleotide, was unable to prime the addition of telomeric repeats in vitro. The implications of these results for the mechanisms underlying developmentally programmed chromosome fragmentation and telomere addition in Tetrahymena are discussed.
authors.affiliation: Department of Molecular Biology, University of California, Berkeley 94720.
authors.forename: E A
authors.initials: EA
authors.lastname: Spangler
authors.forename: T
authors.initials: T
authors.lastname: Ryan
authors.forename: E H
authors.initials: EH
authors.lastname: Blackburn
mesh_terms: D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000502:physiology; D002875:Chromosomes / Q000502:physiology*; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D009710:Nucleotide Mapping; D013768:Tetrahymena / Q000235:genetics* / Q000254:growth & development
chemical_list: D004262:DNA Restriction Enzymes