Related Experiment Videos
Molecular analysis of a novel subtelomeric repeat with polymorphic chromosomal distribution
A Martin-Gallardo1, J Lamerdin, P Sopapan
1Lawrence Livermore National Laboratory, Livermore CA, USA.
Cytogenetics and Cell Genetics
|January 1, 1995
Summary
Researchers characterized a yeast artificial chromosome (YAC) containing a human telomere. They discovered a novel low-copy DNA repeat element, HC1103, present in subtelomeric and interstitial regions, with polymorphic distribution at some telomeres.
Area of Science:
- Human Genetics
- Molecular Biology
- Genomics
Background:
- Human telomeres are repetitive DNA sequences at the ends of chromosomes.
- Yeast artificial chromosomes (YACs) are tools for cloning large DNA fragments.
- Understanding subtelomeric DNA is crucial for comprehending chromosome stability and evolution.
Purpose of the Study:
- To characterize DNA sequences within a human telomere-containing YAC.
- To identify and map novel repetitive elements near human telomeres.
- To investigate the distribution patterns of these elements in the human genome.
Main Methods:
- Somatic hybrid panel mapping to localize YAC sequences.
- Fluorescence in situ hybridization (FISH) for repeat element mapping.
- RecA-assisted restriction endonuclease (RARE) cleavage analysis to determine YAC insert proximity to termini.
Main Results:
- A novel low-copy repeat element, HC1103, was identified 19 kb from the telomeric end of the YAC.
- HC1103 was consistently found in specific subtelomeric regions (e.g., 3q, 12p) and an interstitial site (2q13-q14).
- Polymorphic distribution of HC1103 was observed at several other telomeres, and the YAC insert was located 50-70 kb from chromosome ends.
Conclusions:
- The cloned DNA segment in yRM2001 contains a novel low-copy DNA block.
- This DNA block is consistently present at some human telomeres but variably distributed at others.
- The findings contribute to the understanding of human subtelomeric DNA composition and variability.