Table 2.
Genomic Characteristics of Serratia Strains with Different Lifestyles
| Subfamily | Aphidinae |
Lachninae |
||||
|---|---|---|---|---|---|---|
| Tribe | Aphidini | Macrosiphini | Eulachnini |
Tuberolachnini | ||
| Serratia strain | Db11 | SAf | SAp | SCt | SCc | STs |
| Lifestyle | Free-living | Facultative endosymbiont | Facultative endosymbiont | Co-obligate endosymbiont | Co-obligate endosymbiont | Co-obligate endosymbiont |
| Genome size (Mb) | 5.11 | 3.58a | 2.76a | 2.49a | 1.76 | 0.65 |
| Plasmids | – | Unknown | Unknown | Unknown | Unknown | Unknown |
| Chromosome G+C content (%) | 59.5 | 52.1 | 48.4 | 52.0 | 29.2 | 20.7 |
| CDSs | 4,709 | 3,398 | 2,098 | 1,601 | 677 | 492 |
| Coding density (%) | 87.9 | 78.2 | 56.8 | 53.4 | 38.8 | 77.2 |
| Pseudogenes | 12 | 126 | 550 | 916 | 98 | 7 |
| tRNAs | 88 | 74 | 44 | 47 | 36 | 33 |
| rRNAs | 22 | 22 | 15 | 13 | 3 | 3 |
| Mobile elements | Yes (few) | Yes | Yes | Yes | No | No |
Note.—Comparison of genomic characteristics of Serratia genomes from the free living Serratia marcescens strain Db11 and endosymbionts from distinct aphid subfamilies. The various degrees of genomic reduction are evident and ordered from left to right. Db11, S. marcescens strain Db11 isolated as a pathogen from Drosophila melanogaster (Flyg et al. 1980); SAf, S. symbiotica strain CWBI-2.3T isolated from Aphis fabae (Aphidinae: Aphidini tribe) (Sabri et al. 2011); Sap, S. symbiotica strain Tucson from Ac. pisum (Burke and Moran 2011).
a
Genome size is reported as the total size of the assembled scaffolds for unclosed genomes.