Figure 4

mcyE sequencing. (a) Percentage of reads from mcyE amplicon sequencing that are derived from various potential toxin producing cyanobacterial genera from each U.S. river sample across various sampling months (indicated by shapes, see legend). Greater percentages are shown as dark red, lower percentages as dark blue. Samples that did not possess the mcyE sequence (see text) are not included. (b) Amplicon sequence variants (ASVs) assigned to each river sample. The legend for river and date of sample in (a) applies across the panels to (b). Each vertical line represents a unique ASV with bars placed along each line to indicate the presence of that ASV in the corresponding sample row. ASV lines are ordered left to right by abundance and grouped by genus of origin. Total ASV counts per sample are indicated on the left axis line. ASVs unique to a single sample are indicated along the top with purple dots. The color of each bar and the colors along the bottom indicate the genus to which each ASV was taxonomically assigned (legend at bottom). Replicates are indicated by a box around sample date shape. Samples with detectible microcystin toxin levels are indicated by an asterisk.