DNA Kromatin - Kromozom Kromozom ( ingilizce ) Fig. 1. Schematic drawing illustratin g different levels of chromatin condensation according to the dynamic matrix model. DNA (2nm) assembles with histone proteins, forming nucleosomes and the elementary fibril (10 nm) which winds up to a solenoid (30 nm). Solenoids attach to polymerizing matrix fibers by matrix fiber binding proteins. Dynamic matrix fibers associate and move anti-parallel to each other (arrows). As condensation progresses, attached solenoid loops are “ bunched ” into chromomeres (200 – 3 00 nm) which are stabilized by loop stabilizing proteins Fig. 2 . Scanning electron micrograph of a barley metaphase chromosome. The centromere and the two chromatids, which are partly separated, are clearly visible. The dominant substructure of the chro matids, at this low magnification level, are “ knobby ” chromomeres and a centromere with parallel fibers. Source: Wanner, G. et all. (2005). 3D Analysis of chromosome architecture: advantages and limitations with SEM, Cytogenet Genome Res 109:70 – 78