In Situ Hybridization Using Synthetic Oligomers as Probes for Centromere and Telomere Repeats

Telomeres and centromeres are critical structural and functional elements of eukaryotic chromosomes. Thus, they are important to our understanding of the organization and management of complex genomes. Termini of eukaryotic chromosomes are characterized by short, tandem repeats with a G-rich sequence on the 3′ end of the DNA strands. The telomeres of humans and all other vertebrates analyzed to date contain the same telomere repeat sequence, (TTAGGG)_n (1 , 2 ). In situ hybridization of telomere repeat probes has become a useful adjunct to the molecular analysis of eukaryotic chromosome ends. Fluorescence in situ hybridization confirmed the presence of the (TTAGGG)_n sequence at the chromosomal ends and provided a visual documentation that all telomeres in the genome have the same terminal repeat. During the last 5 years, in situ hybridization of the telomere sequence has been used for a variety of studies (1 – 17 ). The integrity of the telomere as a structural and functional necessity for accurate chromosomal distribution during cell division has been supported by these studies.