Figure 1. Core, shared and unique transcriptome genes in four prymnesiophyte species: Prymnesium parvum, Chrysochromulina brevifilum, Chrysochromulina ericina and Phaeocystis antarctica.

A) Venn diagram showing the number of shared or unique genes (in italics) and gene clusters (in bold) among the four prymnesiophytes as classified by the orthomcl program. Among the genes unique to each of the four prymnesiophytes, multi-copy genes refer to genes that were present in gene clusters, single-copy genes refer to genes that did not cluster with any other gene. Pp: Prymnesium parvum, Cb: Chrysochromulina brevifilum, Ce: Chrysochromulina ericina, Pa: Phaeocystis antarctica. B) Proportion of annotated and unannotated genes in the “core” gene set, i.e. genes shared by all four species, and in the gene set unique to each species. C) Proportion of the transcripts that comprised core, shared and unique genes. Shared genes are genes present in two or three of the four species. Unique genes are genes that are only present in one species.