The dating of the divergence times among cyanobacteria.

<p>Maximum credibility chronogram based on 16S rRNA of cyanobacteria, with an emphasis on <i>Microcoleus vaginatus</i>. It is a continuation of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040153#pone-0040153-g005" target="_blank">Figure 5</a>. The mean ages and confidence intervals (95% HPD) are indicated at the nodes. The studied strains are in bold. The geographic origin of each strain is indicated as E – Europe, A – Asia, and NA – North America. A plus mark indicates the strains which have been identified anew because of previous incorrect determinations in the culture collection. An asterisk represents a node where <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040153#pone-0040153-g005" target="_blank">Figure 5</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040153#pone-0040153-g006" target="_blank">6</a> were originally connected.</p

Location of <i>M vaginatus</i> sampling sites.

<p>The locations of the North American strains were adopted from Boyer <i>et al.. </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040153#pone.0040153-Boyer1" target="_blank">[23]</a> and Siegesmund <i>et al.. </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040153#pone.0040153-Haler1" target="_blank">[25]</a>.</p

Maximum likelihood inferred phylogenetic tree based on the 16S-23S ITS of <i>M. vaginatus</i>.

<p>Maximum likelihood/neighbour joining bootstrap supports greater than 50% are shown at the nodes. The studied strains are in bold. The geographical origin of each strain is indicated as E – Europe, A – Asia, and NA – North America.</p

Principal coordinate analysis performed in Fast UniFrac based on the 16S-23S ITS of <i>M. vaginatus.</i>

<p>Principal coordinate 1 (P1) versus Principal coordinate 2 (P2) is shown. Group A consists of European strains, and group B of North American and Asian.</p

The dating of the divergence times among cyanobacteria.

<p>Maximum credibility chronogram based on 16S rRNA of cyanobacteria, with <i>Escherichia coli</i> as an outgroup. The mean ages and confidence intervals (95% HPD) are indicated at the nodes. An asterisk represents a node where <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040153#pone-0040153-g005" target="_blank">Figure 5</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040153#pone-0040153-g006" target="_blank">6</a> were originally connected.</p

Neighbour-net phylogenetic network based on the 16S-23S ITS of <i>M. vaginatus.</i>

<p>Bootstrap supports greater than 50% are indicated. The studied strains are in bold. The geographical origin of each strain is indicated as E – Europe, A – Asia, and NA – North America.</p

<i>Elainella</i> gen. nov.: a new tropical cyanobacterium characterized using a complex genomic approach

<p>Cyanobacteria represent an ancient, monophyletic lineage of bacteria with the ability to undertake oxygenic photosynthesis. Although they possess a relatively high degree of morphological variability compared with other prokaryotes and there is a wealth of molecular data, there are still significant gaps in our knowledge of cyanobacterial diversity, especially in tropical areas. Here, we present a novel, filamentous, tropical cyanobacterium, which could be classified as <i>Pseudophormidium</i> based on morphological criteria. A total evidence investigation employing ecological, morphological and genomic data, indicated that our strains form a new and ancient evolutionary lineage among cyanobacteria unrelated to <i>Pseudophormidium</i>. Based on this polyphasic assessment, our strains represent a novel, monospecific genus: <i>Elainella</i>. This new genus represents an example of phenotypic convergence, which seems to be a prevalent macroevolutionary pattern in cyanobacteria, a likely cause of the frequently cited polyphyly within a majority of genera.</p

Repeated evolution of uniparental reproduction in <i>Sellaphora</i> (Bacillariophyceae)

<div><p>Diatoms possess a remarkable life cycle in which cell size decreases slowly during vegetative cell division and then increases rapidly via special expanding cells called ‘auxospores’, which are usually formed as a result of biparental sexual reproduction. However, auxospores are sometimes produced by single unpaired cells, i.e. uniparentally. We examined the nature of uniparental auxosporulation in <i>Sellaphora</i> and used a two-gene dataset to study phylogenetic relationships between uniparental and biparental <i>Sellaphora</i> demes and species; we tested whether uniparental reproduction has evolved once or repeatedly in the genus. In at least two of the uniparental demes auxosporulation occurred through autogamy (i.e. intra-tetrad mating within an undivided cell). Maximum likelihood phylogenies indicated four lineages of uniparental <i>Sellaphora</i> and significance tests of alternative topologies, in which combinations of uniparental <i>Sellaphora</i> were constrained to be monophyletic, coupled with likelihood reconstruction of ancestral character states, led to rejection of the hypothesis that uniparental auxosporulation evolved only once in the genus. Uniparentally reproducing lineages appear to arise not infrequently in diatoms but do not persist. Two small extranuclear bodies, apparently containing DNA and lying outside the chloroplast (one close to each pole of the cell), were revealed by DAPI staining.</p></div

Multiple sequence alignment of 16S rRNA

Multiple sequence alignment of 16S rRNA of diverse cyanobacteria with focus on Synechococcus

16S rRNA phylogenetic tree

A phylogenetic tree constructed using MrBayes 3.2.