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A cloned repeated DNA sequence in human chromosome heteromorphisms
Cytogenetics and Cell Genetics
|January 1, 1981
Summary
Researchers cloned human satellite DNA III sequences and used them to probe chromosomes. They found specific sequences predominantly bind to chromosome 1, aiding in chromosome-specific DNA analysis.
Area of Science:
- Molecular Biology
- Genetics
- Cytogenetics
Background:
- Human satellite DNA III comprises repetitive sequences with unknown chromosomal localization.
- Heterochromatic regions (C-bands) vary in size across human chromosomes.
Purpose of the Study:
- To clone and characterize a specific human satellite DNA III sequence.
- To determine the chromosomal distribution of this cloned sequence using in situ hybridization.
Main Methods:
- ECoRI restriction and cloning of human satellite DNA III into lambda gt WES.
- In vitro synthesis of complementary RNA (cRNA) from the cloned DNA.
- In situ hybridization of cRNA to human metaphase chromosomes with heterochromatic polymorphisms.
Main Results:
- The cloned satellite DNA III sequence predominantly hybridized to chromosome 1.
- Hybridization intensity on chromosome 1 correlated with C-band size.
- Hybridization to other chromosomes was not directly related to C-band size, unlike total satellite DNA.
Conclusions:
- Specific satellite DNA sequences can exhibit preferential localization to particular chromosome pairs.
- In situ hybridization is a valuable technique for distinguishing chromosome-specific sequences from bulk satellite DNA.
- Further analysis of satellite DNA may reveal sequences unique to each human chromosome pair.