Next generation sequencing analysis reveals a relationship between rDNA unit diversity and locus number in Nicotiana diploids

Table 1 Summary of 454 sequencing data

Species	Number of loci1	Copies/1C2	Reads mapped		Coverage3		Number of clusters
			18S	ITS1	18S	ITS1	18S	ITS1
N. tomentosiformis	1	1400	1190	1592	0.9	1.1	204	190
N. sylvestris	3	5100	2657	3882	0.5	0.8	339	483
N. otophora	2	1500	1469	2308	1.0	1.5	105	303
N. kawakamii	3+dispersed	2200	998	1093	0.5	0.5	138	213

¹See Figure 6 and Plant rDNA database - http://www.plantrdnadatabase.com[42].
²The gene copies were initially determined by slot blot hybridisation [43] and later adjusted by calculation from the NGS data [22] using a http://w3lamc.umbr.cas.cz/profrep/ server. For N. kawakamii and N. otophora the copies were determined based on Southern blot signals (Figure 5).
³Mean read-depth: the number of aligned reads divided by rDNA copy number.

ISSN: 1471-2164