Mapping of the gene for the mouse telomerase rna component, Terc, to chromosome 3 by fluorescence in situ hybridization and mouse chromosome painting

The telomeres of human and mouse chromosomes contain repeated units consisting of the sequence TTAGGG and are considered to have an important function in sustaining chromosome stability. The maintenance of telomeric sequence is largely regulated by the enzyme telomerase, the activity of which is lost in normal somatic cells. Thus, it has been suggested that the limited proliferative life span of normal cells, referred to as replicative senescence, may be due to telomeric attrition. In addition, telomerase activity is detectable in both mouse and human tumors, suggesting that the expression of telomerase in cancer cells may be an important step in the neoplastic process. Telomerase is a ribonuclear protein, within which the RNA component acts as a template for the addition of the telomeric repeat sequences. Although the protein components of the mammalian telomerase enzyme have yet to be cloned, both the human and the mouse RNA component genes have been cloned. However, there may be some fundamental differences in the role of telomerase in the regulation of mouse and human telomere length. Thus, we have mapped the chromosomal location of the mouse telomerase RNA gene, Terc, as this information may be important in developing good mouse models for human disease and developmental processes.