Comparison of tandem repeats distribution in three species. See legend, Fig. 2, for information on database construction and other details. Arrows show centromere position (unknown for nematode). The Tandem Repeats Finder software identifies tandem repeats at a frequency of 415 per Mb for human chromosome 22, 445 per Mb for Arabidopsis thaliana chromosome 4, and 637 per Mb for Caenorhabditis elegans chromosome 1 (“No query” panel). Bottom panel: the query applied was U > = 10, N >= 3, L >  100, 0.3 >  = BGC >  = 0.55, %M >  = 70.

Chromosomes were fragmented in areas of comparable length: 1.73 Mb (20 areas), 1.78 Mb (10 areas), and 1.82 Mb (7 areas), for human chromosome 22, plant chromosome 4 and nematode chromosome 1, respectively. For human chromosome 22 and nematode chromosome 1, significant telomeric biases are observed. In contrast, the plant chromosome shows a bias toward the centromeric region.