Mitotic loop arrays differ in average loop size between species. (A) Derivative of P(s) as a function of genomic separation in nonsynchronized chicken cells (DT40), human cells (HeLa), and mouse cells (mESCs, C2C12, and C127). The arrow highlights the average loop size mediated by cohesin in interphase in all cell types and species (B) Derivative plots of Hi-C data from chicken cells (DT40), human cells (HeLa), and mouse cells (mESCs, C2C12, and C127) synchronized in mitosis. (C) A zoom-in of the derivative plot shown in Figure 4B. The star highlights the average loop size observed in mitotic chicken cells (250 kb), the triangle highlights the average loop size in mitotic human cells (450 kb), and the circle highlights the average loop size in mitotic mouse cells (1.25 Mb). (D) Box plot of full chromosome lengths in chicken genome (galGal6), human genome (hg38), and mouse genome (mm10). Dots represent individual chromosomes. (E) Box plot of all q-arm lengths in chicken genome (galGal6), human genome (hg38), and mouse genome (mm10). Dots represent individual chromosomes. (F) Q-arm compaction as measured by microscopy as Mb/µM in mitotically synchronized HeLa cells (Chr 14) and C2C12 (Chr 18). Asterisk shows significant difference between arm compaction in mouse and human (n = 50, unpaired t-test).
