Fig. 5.

Genes encoding ferritins (FTNs) in diatom transcriptomes. Homologs of FTN were retrieved using a HMMER search within available diatom genomes and transcriptomes (see the caption of Fig. 3 for details). Pie charts summarize the presence and absence of FTN in raphid versus araphid pennate diatoms, and in polar versus radial centric species. It is important to note that the presence or absence of genes in a transcriptome may not be a true reflection of copy numbers in a genome, either because it was generated from iron-replete cultures or because it was not sequenced to sufficient depth.