Figure 4.

Maximum likelihood phylogenetic tree of SSU rRNA gene (626–660 bp). Clone library sequences from both years (2010 and 2011) are coded by symbol as follows: Siq—circles, SukB—hexagons, SukS—squares, and Ikroavik (Ikr)—stars, followed by their corresponding accession numbers. Note that only one representative sequence was included for each taxon in the phylogenetic tree, and all the other sequences are available (KY886013–KY886132). Silva database sequences with ≥97% identity to iTag sequences are shown as red ovals and sequences with ≤97% identity are shown as orange ovals. Environmental sequences or culture isolates in the GenBank that were ≥97% similar to Sanger sequences, and that were obtained from cold environments (e.g., Canadian Arctic, Laptev Sea, Alaska, Antarctica, and others) are represented in pink and nearest neighboring sequences obtained in GenBank or the SILVA database are in purple. Only bootstrap values ≥50 are shown, and bootstrap values ≥80% are represented by black circles. For a full description of the SSU rRNA gene sequences on the tree, including sequences from the JGI IMG database, see Figure S4.