Telomeres are the specialized DNA-protein complexes at eukaryotic chromosome ends. They are essential to protect linear chromosome ends from nucleolytic attack and chromosomal end-to-end fusions, which may lead to chromosomal abnormalities. Genomic instability, a hallmark for both cancer and aging, is majorly induced by chromosomal abnormalities. Therefore, telomere length and structure are equally important for the maintenance of genomic stability. Mammalian telomeres associate with a six-subunit, telomere-specific shelterin complex, as well as shelterin subcomplexes. In this study, I will visualize the structure of mammalian telomeres associated with the shelterin subcomplexes using electron microscopy (EM). In order to achieve this goal, I will examine the association of model telomeres with single-stranded and double-stranded telomeric DNA repeat binding proteins separately. This study will be extremely valuable for understanding the mechanistic details of the regulation of mammalian telomere structure and function by the shelterin complex subunits and subcomplexes
