Table 2 Assignment of contigs to species of origina
ABCDE
Type of OrganismNo. by TopSortbNo. With Genomic EvidencecNo. Without Genomic EvidencecFalse-Positive Rate (%)d
Cnidarian28,02626,21918076.4
Dinoflagellate23,794112622,6684.7
Fungi1661814810.8e
Bacteria73118554625.3e
  • a The full list of assignments of individual contigs to their species of origin is provided in File S5.

  • b See text.

  • c Genomic evidence was defined as ≥10 paired-end reads aligning from Aiptasia genomic DNA libraries prepared from aposymbiotic anemones (see Materials and Methods).

  • d Classified as cnidarian by TopSort but lacking genomic evidence or classified as noncnidarian by TopSort but with apparent matches to Aiptasia genomic DNA.

  • e Many of these are presumably transcripts from contaminants that were present on the surfaces or in the gastric cavity of the anemones from which the genomic DNA was prepared. However, the high rate of apparent false-positives among the putatively bacterial and fungal sequences probably also reflects Bayes’ rule, whereby the ratio of false-positives to true-positives is high when the a priori probability of a true-positive is low.