Related Experiment Video
Updated: Aug 4, 2026
15:25
Examination of the Telomere G-overhang Structure in Trypanosoma brucei
Published on: January 26, 2011
Normal human chromosomes have long G-rich telomeric overhangs at one end
W E Wright1, V M Tesmer, K E Huffman
1Department of Cell Biology and Neuroscience, The University of Texas Southwestern Medical Center, Dallas, Texas 75235-9039 USA. wright@utsw.swmed.edu
Genes & Development
|November 14, 1997
Summary
Human telomeres have different terminal overhangs after replication. Lagging-strand synthesis may create a long 3' overhang, influencing telomere shortening rates in normal cells.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Telomeres protect chromosome ends and are implicated in aging and cancer.
- The precise structure of human telomeres, particularly their termini, remains largely uncharacterized.
Purpose of the Study:
- To investigate the structure of human telomere termini after replication.
- To analyze the terminal DNA overhangs in normal diploid telomerase-negative human fibroblasts.
Main Methods:
- Purification of telomeres from human fibroblasts.
- Analysis of telomere termini using electron microscopy.
Main Results:
- Daughter telomeres exhibit distinct terminal overhangs post-replication.
- Telomeres with long overhangs revealed approximately 200 +/- 75 nucleotides of single-stranded DNA.
- The observed overhang length is significantly greater than the telomere shortening rate per cell division.
Conclusions:
- Results support models where lagging-strand synthesis generates a G-rich 3' overhang.
- Variations in lagging-strand synthesis may regulate telomere shortening in human cells.
- Nuclease processing could also contribute to varied overhang lengths.
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