Table 2. Distribution and amino-acid sequence identity of 13 gene clusters involved in the biosynthesis of secondary metabolites in the twelve Microcystis genomes (including the two previously available, PCC 7806 and NIES-843).
| Gene cluster | mcy | aer | mcn | mic | apt | mca | mdn | PKSImod/PKSIII | PKSI iterat | psm3 | MIC1 | MIC2 | MIC3 | ||
| Size (kb) | 51.8–54.6 | 12.9–24.8 | 21.8–30.2 | 19.6–20.5 | 23.4 | 10.7–11.5 | 4.7 | 25.3 | 15.2–16.1 | 28.4 | 37.2–39.6 | 25.8–28.8 | 30.0–30.6 | ||
| Strain | % of genome | Nb clust/strain | Aa seq ident (Detection$) | Aa seq ident (Detection$) | Aa seq ident (Detection$) | Aa seq ident | Aa seq ident | Aa seq ident | Aa seq ident for mdnB-E | Aa seq ident | Aa seq ident | Aa seq ident to AB279593 | Aa seq ident | Aa seq ident | Aa seq ident |
| PCC 7941 | 3.3 | 6 | 98.3 (+) | 94.9 (−) | 95.3 (+) | Ref. | - | - | 98.2 | 99.2 | - | - | - | - | - |
| PCC 9432 | 3.4 | 9 | - (−) | 94.8 (+) | 91.2 (+) | 89.9* | Ref. | 81.7# | 98.2 | 99.2 | partial£ | - | - | - | Ref. |
| PCC 9443 | 2.3 | 4 | 96.9 (na) | 95.5 (+) | mcnG-F £ (−) | - | - | - | 90.0 | - | 96.1 | - | - | - | - |
| PCC 9701 | 1.8 | 4 | - (na) | - (na) | 90.7* (+) | 85.5 | 97.3 | - | 98.5 | - | - | - | - | - | - |
| PCC 9717 | 2.8 | 6 | mcyA-C £ (na) | 93.4 (na) | 91.3* (+) | - | - | - | 98.1 | - | - | - | 98.2 | 95.5* | 98.6* |
| PCC 9806 | 1.0 | 2 | - (na) | - (na) | - (na) | - | - | 91.5 | mdnB, mdnD £ | - | - | - | - | Ref. | - |
| PCC 9807 | 2.9 | 5 | 97.6 (+) | 90.2 (+) | 96.1(+) | - | - | - | 96.2 | - | - | - | 96.3 | - | - |
| PCC 9808 | 3.2 | 6 | 96.7 (−) | 93.2 (−) | 92.3 (+) | - | - | - | 98.1 | - | - | 99.8 | - | - | 99.7 |
| PCC 9809 | 2.9 | 6 | 96.9 (+) | 93.5 (+) | 92.0*(+) | - | - | 95.6 | 98.6 | 99.3 | - | - | - | - | - |
| T1-4 | 1.6 | 3 | - (na) | - (na) | - (na) | - | - | - | 97.1 | - | - | - | 94.9 | 96.2 | - |
| PCC 7806 | 3.1 | 7 | Ref. (+) | Ref. (+) | Ref. (+) | - | - | Ref. | 96.6 | Ref. | Ref. | - | - | - | - |
| NIES-843 | 2.5 | 5 | 96.6 (+) | 93.8 (na) | 91.6 (na) | - | - | - | Ref. | - | - | - | Ref. | - | - |
| No of strains containing the complete gene cluster | 7 | 9 | 9 | 3 | 2 | 4 | 11 | 4 | 2 | 1 | 4 | 3 | 3 | ||
Mcy: Microcystins; Aer: Aeruginosins; mcn: Cyanopeptolins; Mic: Microginins; Apt: Anabaenopeptins; mca: Cyanobactins; mdn: Microviridins; PKSI iterat: PKSI iterative; % of genome: Proportion of genome; Nb clusters/strain: Number of clusters per strain. Aa seq ident: Amino-acid sequence identity; Ref.: Reference strain used for the estimation of the sequence identity.
£
: incomplete gene cluster;
*
: on adjacent contigs highly fragmented genome or region;
$
: metabolite detected in previous studies ([58]; Welker, unpublished);
#
: probably encodes for another cyanobactin; (+): positive detection of the metabolite in the strain; (−): negative detection of the metabolite in the strain; na: not analyzed.