DNA Packaging in Social Amoeba Reveals Insights into Multicellular Transition

Each human cell contains two meters of DNA, organized through intricate three-dimensional arrangements. Packaging irregularities are linked to diseases like leukemia, glioma, autism, and cancer. Scientists from Skoltech, the Institute of Gene Biology of the Russian Academy of Sciences, and other institutions studied chromatin organization in *Dictyostelium*, a social amoeba. This organism transitions from individual cells to multicellular aggregates under adverse conditions.

Professor Mikhail Gelfand noted the transition from unicellularity to multicellularity in *Dictyostelium*, where cells form a structure resembling a miniature fungus; some become spores, while others die. Experimental data indicated *Dictyostelium* chromosomes attach to a central point in the nucleus, differing from humans where each chromosome occupies a specific region.

Dr. Ekaterina Khrameeva explained that *Dictyostelium* lacks topologically associated domains found in human cells but possesses chromatin loops that change during the unicellular-to-multicellular transition. Genes forming these loops are oriented towards each other, with RNA polymerase likely involved in the loop formation mechanism. This process resembles knot formation when untangling a thread from both ends.