Fig. 4

Characteristics of plasma cfDNA fragmentation in 901 healthy human and 38 dog individuals. A The size distribution of cfDNA was inferred by paired-end sequencing of plasma samples from 901 healthy human subjects. The predominant peaks at 167 bp, and three additional peaks at 333 bp, 527 bp, and 719 bp were marked. B The enlarged view of the boxed areas in panel A, indicating the ten most distinguishable periodic subpeaks around 50, 60, 70, 81, 91, 102, 111, 122, 134, and 153 bp. C Proportions of the fragments representing mono-, di-, tri-, and tetra-nucleosomes are 85.0%, 12.1%, 2.3%, and 0.4%, respectively. D Human genome is composed of 29.5% A, 29.6% T, 20.4% C, and 20.5% G (reference). The proportion of fragments with 5′ A-, T-, C-, and G-ends in circulating cfDNA is 18.8%, 23.3%, 35.9%, and 22.0% in average in 901 healthy human individuals (Position 1). E C-end preference is found in all fragment sizes (50–250 bp) in 901 healthy human individuals. F The size distribution of cfDNA was inferred by paired-end sequencing of plasma samples from 38 healthy dogs. The predominant peaks at 163 bp, and three additional peaks at 362 bp, 547 bp, and 728 bp were marked. G The enlarged view of the boxed areas in panel F, indicating the ten most distinguishable periodic subpeaks around 50, 60, 70, 81, 92, 102, 112, 122, 133, 144, and 153 bp. H Proportions of the fragments representing mono-, di-, tri-, and tetra-nucleosomes are 74.2%, 17.2%, 6.9%, and 1.7%, respectively. I Dog genome is composed of 29.5% A, 20.5% T, 29.5% C, and 20.5% G (reference). The proportion of fragments with 5′ A-, T-, C-, and G-ends in circulating cfDNA is 23.7%, 23.3%, 30.3%, and 22.7% in average in 38 healthy dogs (Position 1). J C-end preference is in all fragment sizes (50–250 bp) in 38 healthy dogs