Table 1.
Main features of the two newly described bacterial species, as well as data of their hosts.
Figure 1.
Transmission electron microscopy images of “Candidatus Trichorickettsia mobilis”.
(A) “Candidatus Trichorickettsia mobilis” inside the macronucleus of P. multimicronucleatum PS23; several cylindrical electrondense particles, arranged in a regular way, are visible inside the bacterium; arrows indicate the flagella of the symbionts. (B) “Candidatus Trichorickettsia mobilis” inside the cytoplasm of P. nephridiatum PAR; icosahedral electrondense particles are visible. (C) Negative staining of “Candidatus Trichorickettsia mobilis” from P. multimicronucleatum LSA: numerous and long flagella are clearly visible. Bars: 0.5 µm.
Figure 2.
Transmission electron microscopy images of “Candidatus Gigarickettsia flagellata” in transverse (A) and longitudinal (B, C) sections.
Arrows indicate the flagella. Bars: 0.5 µm.
Figure 3.
FISH experiments performed on “Candidatus Trichorickettsia mobilis” and “Candidatus Gigarickettsia flagellata”.
Symbionts inside P. nephridiatum PAR (A) and inside P. multimicronucleatum LSA (C) with probe RickFla_430 (Cy3, red signal) together with eubacterial probe EUB338 (fluoresceine, green signal). Food bacteria, labeled only in green, are visible inside food vacuoles in LSA (C). FISH experiment performed on “Candidatus Gigarickettsia flagellata” with probe GigaRick_436 (green signal) is shown in B. Bars: 20 µm.
Figure 4.
Bayesian Inference tree of the family Rickettsiaceae.
The tree was built on the unmodified character matrix (see text) employing the GTR+I+G (8 gamma categories) model. Numbers associated to nodes represent Maximum Likelihood bootstraps and Posterior Probabilities, respectively (values below 70|0.85 are omitted). Taxa that received a formal or provisional binomial name are in bold. The bar stands for an inferred sequence divergence of 5%. “Ca.”, “Candidatus”; “bac.”, “bacterium associated to”.