title: Telomere elongation (Tel), a new mutation in Drosophila melanogaster that produces long telomeres.
abstract: In most eukaryotes telomeres are extended by telomerase. Drosophila melanogaster, however, lacks telomerase, and telomere-specific non-LTR retrotransposons, HeT-A and TART, transpose specifically to chromosome ends. A Drosophila strain, Gaiano, that has long telomeres has been identified. We extracted the major Gaiano chromosomes into an Oregon-R genetic background and examined the resulting stocks after 60 generations. In situ hybridization using HeT-A and TART sequences showed that, in stocks carrying either the X or the second chromosome from Gaiano, only the Gaiano-derived chromosomes display long telomeres. However, in stocks carrying the Gaiano third chromosome, all telomeres are substantially elongated, indicating that the Gaiano chromosome 3 carries a factor that increases HeT-A and TART addition to the telomeres. We show that this factor, termed Telomere elongation (Tel), is dominant and localizes as a single unit to 69 on the genetic map. The long telomeres tend to associate with each other in both polytene and mitotic cells. These associations depend on telomere length rather than the presence of Tel. Associations between metaphase chromosomes are resolved during anaphase, suggesting that they are mediated by either proteinaceous links or DNA hydrogen bonding, rather than covalent DNA-DNA bonds.
authors.affiliation: Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Genetica e Biologia Molecolare, Universita' di Roma "La Sapienza," Rome, Italy.
authors.forename: Giorgia M
authors.initials: GM
authors.lastname: Siriaco
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cenci
authors.forename: Abdelali
authors.initials: A
authors.lastname: Haoudi
authors.forename: Larry E
authors.initials: LE
authors.lastname: Champion
authors.forename: Chun
authors.initials: C
authors.lastname: Zhou
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gatti
authors.forename: James M
authors.initials: JM
authors.lastname: Mason
mesh_terms: D000705:Anaphase; D000818:Animals; D015139:Blotting, Southern; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology; D002874:Chromosome Mapping; D015342:DNA Probes; D004251:DNA Transposable Elements / Q000235:genetics / Q000502:physiology; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics*; D005260:Female; D015683:Gene Products, gag; D005799:Genes, Dominant; D006570:Heterochromatin; D019476:Insect Proteins / Q000502:physiology; D008297:Male; D008677:Metaphase / Q000235:genetics / Q000502:physiology; D008938:Mitosis; D009154:Mutation; D011110:Polymorphism, Genetic; D016615:Telomere / Q000235:genetics* / Q000648:ultrastructure
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D015342:DNA Probes; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D015683:Gene Products, gag; C103996:HeT-A-gag protein, Drosophila; D006570:Heterochromatin; D019476:Insect Proteins; D000090266:Chromobox Protein Homolog 5