title: Telomere elongation is under the control of the RNAi-based mechanism in the Drosophila germline.
abstract: Telomeres in Drosophila are maintained by transposition of specialized telomeric retroelements HeT-A, TAHRE, and TART instead of the short DNA repeats generated by telomerase in other eukaryotes. Here we implicate the RNA interference machinery in the control of Drosophila telomere length in ovaries. The abundance of telomeric retroelement transcripts is up-regulated owing to mutations in the spn-E and aub genes, encoding a putative RNA helicase and protein of the Argonaute family, respectively, which are related to the RNA interference (RNAi) machinery. These mutations cause an increase in the frequency of telomeric element retrotransposition to a broken chromosome end. spn-E mutations eliminate HeT-A and TART short RNAs in ovaries, suggesting an RNAi-based mechanism in the control of telomere maintenance in the Drosophila germline. Enhanced frequency of TART, but not HeT-A, attachments in individuals carrying one dose of mutant spn-E or aub alleles suggests that TART is a primary target of the RNAi machinery. At the same time, we detected enhanced HeT-A attachments to broken chromosome ends in oocytes from homozygous spn-E mutants. Double-stranded RNA (dsRNA)-mediated control of telomeric retroelement transposition may occur at premeiotic stages, resulting in the maintenance of appropriate telomere length in gamete precursors.
authors.affiliation: Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Savitsky
authors.forename: Dmitry
authors.initials: D
authors.lastname: Kwon
authors.forename: Pavel
authors.initials: P
authors.lastname: Georgiev
authors.forename: Alla
authors.initials: A
authors.lastname: Kalmykova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Gvozdev
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004251:DNA Transposable Elements; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000502:physiology; D005260:Female; D020868:Gene Silencing; D006579:Heterozygote; D006720:Homozygote; D009154:Mutation; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference / Q000502:physiology*; D018626:Retroelements / Q000235:genetics; D016615:Telomere / Q000235:genetics / Q000502:physiology*
chemical_list: D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D010448:Peptide Initiation Factors; D018626:Retroelements; C469435:TART-element-gag protein, Drosophila; C436124:aub protein, Drosophila; D000251:Adenosine Triphosphatases; C096355:spn-E protein, Drosophila