Copy number variation of ribosomal DNA and Pokey transposons in natural populations of Daphnia

Table 2 Correlations between Pokey and rRNA gene number in Daphnia from North America

Species	X-axis	Y-axis	slope	y-intercept	R²	P-value	Figure
All isolates	18S	28S	1.257	-12.69	0.690	0.000	3
D. pulex	28S	u28S¹	0.850	15.71	0.976	0.000	5a
	28S	rInserts²	0.150	-17.84	0.556	0.000	5a
	28S	rPokey³	-0.00002	2.14	0.000	0.995	5a
	gPokey⁴	rPokey	-0.016	2.29	0.0005	0.884	4b
D. pulicaria	28S	u28S	0.907	3.26	0.981	0.000	5b
	28S	rInserts	0.104	-12.80	0.475	0.0001	5b
	28S	rPokey	-0.011	9.54	0.020	0.493	5b
	gPokey	rPokey	1.475	-7.48	0.290	0.005	4b
D. pulicaria-3 ⁵	gPokey	rPokey	0.123	1.62	0.031	0.420	4b

1. Denotes uninserted 28S rRNA genes.
2. Denotes other rDNA inserts calculated as (t28S-u28S-rPokey) where t28S is total 28S genes.
3. Denotes Pokey in 28S genes.
4. Denotes Pokey in other genome sites. Calculated as (total Pokey - rPokey).
5. Results obtained after removing three D. pulicaria isolates with high Pokey load (see text).

ISSN: 1759-8753