Figure 2.

Schematic of the 1-start crossed linker model of the chromatin fibre. The large open circle represents the start of a left-handed helical path rising towards the reader, on which both the odd (red sphere) and even (blue sphere) number nucleosomes reside. The ratio β /α determines the interdigitating pattern of the two series, which, in this example, gives rise to (1 3 5 7 9 ² 11 ⁴ 13 ⁶…) or alternatively (2 4 6 8 ¹ 10 ³ 12 ⁵…) because nucleosomes can interdigitate with either those above or below of the neighbouring stacks. The adjacent nucleosomes in this example are identified as (i±7, i, i±9).