Table 4.

Observed and expected densities of SSRs in different genic regions

	5'-UTR	Exon	Intron	3'-UTR
Arabidopsis
Mononucleotide	434.6 (12.3)	3.3 (4.8)	321.6 (65.7)	33.9 (3.2)
Dinucleotide	664.2 (20.4)	7.3 (12.9)	122.7 (33.9)	12.3 (3.1)
Trinucleotide	702.7 (7.7)	218.7 (4.5)	90.9 (17.6)	17.1 (1.4)
Tetranucleotide	105.8 (27.7)	3.3 (17.9)	58.7 (58.9)	8.7 (4.5)
Rice
Mononucleotide	248.1 (6.1)	4.2 (3.7)	132.9 (4.9)	222.8 (11.5)
Dinucleotide	500.6 (13.2)	16.1 (11.5)	70.9 (12.8)	88.5 (16.9)
Trinucleotide	1670.6 (4.5)	421.4 (3.9)	182.3 (4.4)	153.2 (6.5)
Tetranucleotide	337.4 (18.7)	7.6 (16.1)	46.2 (17.7)	121.6 (24.3)

The unit is per mega-base pairs. The numbers listed in parentheses are the expected densities of various periods in different regions.