Fig. 2

a-b Maximum intensity projections of confocal stacks of 3D-FISH experiments carried out with the three BAC probes representative of each MHC region co-hybridized on structurally preserved porcine (a) and human (b) macrophage nuclei: BAC containing class I is labeled in green with Alexa 488; BAC containing class II is labeled in red with Alexa 568; and BAC containing class III is labeled in yellow with Alexa 633. DNA was counterstained with DAPI. Bar scale: 10 μm. c-d Radial distribution of MHC genes in resting porcine (c) and human (d) macrophages. Cumulative frequency graphs of the radial position for each MHC class: SLA-1 and HLA-A for class I in green; SLA-DRA and HLA-DRA for class II in red; and TNFα for class III in blue. The cumulative frequency curve of a random distribution (P(X < d) = d3 for 0 < d < 1 where X is the random radial position) is shown in black in each graph for comparison. Pairwise comparisons (p-values) of cumulative radial distribution (Student’s t-test) are indicated in each graph. The center of the nucleus corresponds to 0 on the X-axis and the periphery to 1