J 2000

Analysis of the G-overhang structures on plant telomeres: evidence for two distinct telomere architectures

ŘÍHA, Karel, Thomas MCKNIGHT, Jiří FAJKUS, Boris VYSKOT, Dorothy E. SHIPPEN et. al.

Basic information

Original name

Analysis of the G-overhang structures on plant telomeres: evidence for two distinct telomere architectures

Authors

ŘÍHA, Karel (203 Czech Republic), Thomas MCKNIGHT, Jiří FAJKUS (203 Czech Republic, guarantor), Boris VYSKOT (203 Czech Republic) and Dorothy E. SHIPPEN

Edition

The Plant Journal, Velká Británie, Blackwell Science Ltd, 2000, 0960-7412

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

Genetics and molecular biology

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 5.629

RIV identification code

RIV/00216224:14310/00:00002407

Organization unit

Faculty of Science

UT WoS

000089401300007

Keywords in English

telomere; telomerase; Silene latifolia; Arabidopsis thaliana; DNA replication
Změněno: 24/6/2008 15:55, prof. RNDr. Jiří Fajkus, CSc.

Abstract

V originále

Telomeres are highly conserved structures essential for maintaining the integrity of eukaryotic genomes. In yeast, ciliates and mammals, the G-rich strand of the telomere forms a 3' overhang on the chromosome terminus. Here we investigate the architecture of telomeres in the dicot plants Silene latifolia and Arabidopsis thaliana using the PENT (primer extension/nick translation) assay. We show that both Arabidopsis and Silene telomeres carry G-overhangs longer than 20-30 nucleotides. However, in contrast to yeast and ciliate telomeres, only half of the telomeres in Silene seedlings possess detectable G-overhangs. PENT reactions using a variety of primers and reaction conditions revealed that the remaining fraction of Silene telomeres carries either no overhangs or overhangs less than 12 nucleotides in length. G-overhangs were observed in Silene seeds and leaves, tissues that lack telomerase activity. These findings suggest that incomplete DNA replication of the lagging strand, rather than synthesis by telomerase, is the primary mechanism for G-overhang synthesis in plants. Unexpectedly, we found that the fraction of telomeres with detectable G-overhangs decreased from 50% in seedlings to 35% in leaves. The difference may reflect increased susceptibility of the G-overhangs to nuclease attack in adult leaves, an event that could act as a precursor for the catabolic processes accompanying leaf senescence

Links

MSM 143100008, plan (intention)
Name: Genomy a jejich funkce
Investor: Ministry of Education, Youth and Sports of the CR, Genomes and their functions
VS97032, research and development project
Name: Analýza biologicky významných molekulárních komplexů
Investor: Ministry of Education, Youth and Sports of the CR, Analysis of biologically important molecular complexes