It has been shown that yeast telomeres can be replaced by artificial telomeres of the simple sequence repeat (TG1-3)n. Although these telomeres lack several features, including nearby origins of replication and sub-telomeric repeats, deleting them has so far revealed no major impact on chromosome stability or behavior. Even putting artificial telomeres at both ends of the same chromosome has led to only marginal effects on chromosomal stability. Synthetic chromosomes in the Sc2.0 project are thus designed to encode universal telomere caps (UTCs) at their termini, which are specified by ~350bp of the yeast telomere repeat sequence containing a single copy of the “X” consensus element. The deletion of endogenous sub-telomeric repeat regions typically accounts for a significant decrease in chromosome length of the synthetic as compared to native sequence and can be 10s of kilobases.