Fig. 1: Heterogeneity of ecDNAs under the microscope.
From: Modern biology of extrachromosomal DNA: A decade-long voyage of discovery
a Representative metaphase spreads from the PC3 prostate cancer cell line and the SKNMCIXC Ewing sarcoma cell line, showing a dramatic contrast in ecDNA counts between two individual cells. ecDNAs within the same metaphase spread can display double-minute (orange arrowheads) or singlet (blue arrowheads) morphology. b Two-color fluorescent in situ hybridization (FISH) to visualize ecDNA identity. Images were taken from two metaphase spreads from the SNU16 stomach cancer cell line. Two ecDNA species carrying different oncogenes, FGFR2 (green) and MYC (red), may appear as individual particles (left) or as fusions (right), suggesting the ongoing evolution of ecDNAs. c Representative FISH images for MYC ecDNAs in interphase nuclei from COLO320DM colon cancer cell line and MSTO211H lung cancer cell line. MYC ecDNAs may cluster to form ecDNA hubs of different sizes (yellow arrowheads: large ecDNA speckle; cyan arrowhead: small ecDNA minim) in COLO320DM cells or appear as small to no aggregation in MSTO211H cells. Scale bars: 10 μm.
