Fig. 5.

Genomic instability of T cells and B cells in Mof ^F/F /Lck-Cre ⁺ mice. (A) T cells from thymus of 3-week-old mice showing nuclei of different sizes. Telomere signals (green) are detected by using telomere-specific probe. DNA was stained with DAPI (4′,6-diamidino-2-phenylindole) (blue). (B) T cells from thymus of 12-week-old mice. (B-1) DAPI staining and (B-2) telomere signals detected by FISH. Red arrows indicate the fragmented nuclei with or without telomere signals. (C) Metaphases from B cells of 3-week-old mice (C-1) DAPI staining and (C-2) telomere FISH staining, red arrows showing loss of telomere signals and white arrow showing a fragment with telomere signal. (D) Metaphase from 6-week-old mouse B cells showing chromosome end-to-end associations (yellow arrow) and telomere fusion leading to Robertsonian mutation (white arrow). (E) Giemsa staining of metaphase from 12-week-old mouse B cells showing chromosome fragments. (F) Metaphase of B cells showing fragment with telomere signal and (G) metaphase of B cells with loss or reduced telomere signal (red arrows) and high frequency of telomere fusions (white arrows). (H) Metaphase segment from 15-week-old mouse B cells showing telomere fusions leading to Robertsonian mutations (H-1) DAPI staining, white arrows showing chromosome end fusions and (H-2) telomere FISH showing loss of telomere signal (red arrows) and telomere fusions without any telomere signals (white arrows).