GENOMES - Cyanobacteria - page 94

Table 2: Properties of genomes of P. marinus strains.
Isolate/Strain

Light adaptation Clade Genome No. of genes tRNAs %G+C

size (Mb)
MED4 (CCMP1986) HL I 1.68 1,929 37 30.8
MIT9515 HL I 1.70 1,908 30.8
MIT9301 HL II 1.64 1,907 31.4
AS9601 HL II 1.67 1,926 31.3
MIT9215 HL II 1.73 1,989 31.1
MIT9312 HL II 1.70 1,962 31.2
NATL1A LL I 1.86 2,201 35.1
NATL2A LL I 1.84 2,158 35.0
CCMP1375 (SS120) LL II 1.75 1,925 36.4
MIT9211 LL III 1.69 1,855 38.0
MIT9303 LL IV 2.68 3,022 50.1
MIT9313 LL IV 2.41 2,843 43 50.7
An international joint venture between Joint Genome Institute, J. Craig Venter Institute and Genoscope led to the sequencing
of 12 Prochlorococcus and 11 Synechococcus strains listed in Tables 2 and 3, respectively.

vi) Genomes of Synechococcus strains : The properties of eleven of the genomes of Synechococcus
strains are summarized in Table 3. The genomes of Synechococcus sp. strain WH8102 (Palenik et al .,
2003) and Synechococcus sp. strain CC9311 (Palenik et al ., 2006) sequenced earlier have been compared
by Dufresne et al . (2008) with the genomes of nine other strains of Synechococcus sequenced by them.
These strains have been isolated from the Mediterranean Sea, the Red Sea, the Pacifi c and Atlantic
oceans from varying depths of 5 m ( Synechococcus sp. strain CC9902 from the Pacifi c Ocean) to 1000
m ( Synechococcus sp. strain BL107 from the Mediterranean Sea). With the exception of Synechococcus
sp. strain WH5701 and Synechococcus sp. strain RCC307 that belong to Marine sub-cluster 5.2 and
5.3 respectively, the rest of the strains belong to marine sub-cluster 5.1 and cover nine of the ten
clades described by Fuller et al . (2003). [Cluster 5 was initially recognized by Herdman et al. (1979)
by combining the the former MC-A and MC-B defi ned by Waterbury and Rippka (1989). In cluster
5 Synechococcus strains from coastal, euryhaline and strictly marine habitats are included. Strictly
marine PE-containing strains have been grouped into sub-cluster 5.1, while euryhaline strains lacking
PE were put in subcluster 5.2 including strains WH5701 and WH8007]. The smallest genome is that
of Synechococcus sp. strain RCC307 with 2.22 Mbp while the largest genome is of Synechococcus sp.
WH5701 with 2.86 Mbp. The G+C contents vary from 52.5% ( Synechococcus sp. strain CC9311) to
66.0% ( Synechococcus sp. strain WH5701). There are two rRNA genes in all strains except in case of

Table 3: Properties of genomes of Synechococcus strains (Modifi ed from Dufresne et al ., 2008).
Strain Clade Pigment Genome No. of genes rRNAs %G+C

Type a Size (Mb)
1) CC9311 I 3d (CA) 2.61 2,944 2 52.5
2) CC9605 II 3c 2.51 2,645 2 59.2
3) WH8102 III 3c 2.43 2,583 2 59.4
4) CC9902 IV 3d (CA) 2.23 2,358 2 54.2
5) BL107 IV 3d (CA) 2.28 2,553 2 54.2
6) WH7803 V 3a 2.37 2,586 2 60.2
7) WH7805 VI 2 2.62 2,934 2 57.5
8) RS9917 VIII 1 2.58 2,820 2 64.8
9) RS9916 IX 3d (CA) 2.66 3,009 2 59.8
10) WH5701 NA 1 2.86 3,129 2 66.0
11) RCC307 X 3b 2.22 2,583 1 60.8
a-The pigment types are as per the classifi cation provided by Six et al. (2007); CA=Chromatic adapter; NA=Not applicable.