Heterochromatin protein 1 is involved in control of telomere elongation in Drosophila melanogaster.
Telomeres of Drosophila melanogaster contain arrays of the retrotransposon-like elements HeT-A and TART. Their transposition to broken chromosome ends has been implicated in chromosome healing and telomere elongation. We have developed a genetic system which enables the determination of the frequency of telomere elongation events and their mechanism. The frequency differs among lines with different genotypes, suggesting that several genes are in control. Here we show that the Su(var)2-5 gene encoding heterochromatin protein 1 (HP1) is involved in regulation of telomere length. Different Su(var)2-5 mutations in the heterozygous state increase the frequency of HeT-A and TART attachment to the broken chromosome end by more than a hundred times. The attachment occurs through either HeT-A/TART transposition or recombination with other telomeres. Terminal DNA elongation by gene conversion is greatly enhanced by Su(var)2-5 mutations only if the template for DNA synthesis is on the same chromosome but not on the homologous chromosome. The Drosophila lines bearing the Su(var)2-5 mutations maintain extremely long telomeres consisting of HeT-A and TART for many generations. Thus, HP1 plays an important role in the control of telomere elongation in D. melanogaster.
Savitsky
Mikhail
M
Department of Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 117334 Moscow, Russia.
Kravchuk
Oksana
O
Melnikova
Larisa
L
Georgiev
Pavel
P
D000818:Animals; D001483:Base Sequence; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D002869:Chromosome Aberrations; D003433:Crosses, Genetic; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004251:DNA Transposable Elements; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D005785:Gene Conversion; D020440:Gene Duplication; D005786:Gene Expression Regulation; D015683:Gene Products, gag; D017344:Genes, Insect / Q000235:genetics; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D009154:Mutation; D020161:Physical Chromosome Mapping; D016615:Telomere / Q000235:genetics / Q000378:metabolism*; D013698:Templates, Genetic
D002868:Chromosomal Proteins, Non-Histone; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D015683:Gene Products, gag; C103996:HeT-A-gag protein, Drosophila; D019476:Insect Proteins; C452193:heterochromatin protein 1, Drosophila; D004247:DNA