Figure 2.

Replication timing within Xq27 in normal and fragile X males. Replication patterns of several STSs within Xq27 are shown for a normal male lymphoblastoid cell line (FF) and two fragile X lymphoblasts (H6 and TL009). (A) Membrane hybridization signals are derived from BrdUrd incorporation into the analyzed locus at different portions of the cell cycle that correspond to flow cytometry fractions G₁, four fractions of S (S1, S2, S3, and S4), and G₂/M. Arrows designate regions that have a strong delay in replication. (B) Other examples of variability in the distal border of delayed replication in fragile X lymphoblasts.