Fig. 1: Phylogenetic position of the novel Group 2 ice lineage (Group 2i) Isochrysidales.
From: Group 2i Isochrysidales produce characteristic alkenones reflecting sea ice distribution
Maximum-likelihood tree based on 18S rRNA gene from 99 sequences spanning three groups of Isochrysidales and 6 from the Coccolithales outgroup. The numbers shown on branches represent bootstrap support for the node (only those >50% are shown). Numbers in the parentheses represent numbers of sequences included in the collapsed groups, and the expanded version of this tree can be found in Supplementary Fig. 4. The scale bar represents substitution/site. Sequences generated from Canadian Arctic Archipelago surface sediments in this study are highlighted in red, and sea ice isolated strain RCC5486 cultured in this study is highlighted in blue. Sequences from reanalyzed NGS datasets are highlighted in brown, and other sequences were obtained from NCBI GenBank. The branches of the ice lineage are marked in red.
