Supplementing a de novo assembly with additional transcriptomes. Supplementing a de novo assembly with contigs from either (A) a partial annotation or (B) related species improves clustering recall of the de novo assembled contigs. We show the recall and precision, calculated for Trinity contigs. (A) We randomly sampled transcripts from the human annotation from Ensembl at 100%, 50%, 25%, 12.5% and 6% of all transcripts to emulate a partial annotation, mapped the human RNA-seq reads to each set and clustered the reads together with those mapped to the Trinity assembly using Corset. (B) We mapped human RNA-seq reads onto the Ensembl annotation for chimp, orangutan, macaque, marmoset and bushbaby, then clustered the reads together with those mapped to the Trinity assembly using Corset. 'None' in both plots indicates the Trinity assembly on its own.