Fig. 2.

Schematics of telomere shortening (17). The length of the 3′ strand is shown to the right of each telomere. (A) Before replication, the length of the 3′ strand is l, and the length of the overhang is μ. (B) Immediately after replication, the lagging strand has a 3′ length of l and an overhang length determined by the position of the last RNA primer. The leading strand has a 3′ length l - μ and no overhang. (C) Processing of the 5′ strand by an exonuclease increases the length of the overhang, while keeping the length of the 3′ strands constant. In the deterministic model, μ = ν = ξ; in the stochastic model, these are random numbers.