Fig S3. Comparison of tetranucleotide frequencies and GC content between MCR / MTR operons and surrounding gene context in the scaffolds.

The principal component analysis was conducted based on the sliding window GC content and 4mer profile. Red and Blue circles indicate fragments within the MCR and MTR operons, respectively. To avoid statistical bias caused by small sample size, scaffolds with length less than 5kb were excluded from this analysis.