FISH validation of the nuclear localizations of sLAD and non-sLAD genes. (A) Representative DNA FISH images of five sLAD genes (Robo1, Sp4, Unc5c, Dyn2h1 and Myb) and a non-sLAD gene (Lmo7) in C2C12 myoblasts. Lamin B was labeled red and FISH signals were labeled green. Scale bars are 5 μm. (B) Cumulative distributions of the distances of FISH signals in (A) relative to the NL. Kolmogorov-Smirnov (K-S) test of FISH signal distances to the NL between any of the sLAD genes and Lmo7 (a non-sLAD gene): p < 0.001. MyoG was reported previously to be localized at the nuclear interior  and is also shown here as a reference. (C) Representative DNA FISH images of three sLAD-only regions and two LAD-only regions in 3T3 MEF cells. Lamin B was labeled green and FISH signals were labeled red. Scale bars are 5 μm. Genomic locations for these FISH probes are shown in Additional file 2: Figure S2. (D) Cumulative distributions of the distances of FISH signals in (C) relative to the NL. K-S test of FISH signal distances to the NL between sLAD-only regions and LAD-only regions: p < 0.001 in all cases (i.e., tests between any of the three sLAD-only regions and any of the two LAD-only regions).