Fig. 1

a Project workflow: Samples corresponding to various stages of the life cycle (sporophyte, gametophyte, and gametes) and sub-cellular compartments of Ectocarpus sp. were prepared for MS analysis. PSTs were generated from the MS/MS data, mapped against the genome, and clustered. We classified each cluster according to their genomic annotation (whether one hit overlapped with or included at least one CDS of an identified protein) and the number of typical spectra and verified whether all hits were included in a CDS or not. The location of clusters of interest were written into GFF files to be integrated into a Genome viewer. The results of cluster qualification and visualization along the contig allowed us to select clusters for experimental characterization. b Illustration of PSTs obtained from an MS/MS spectrum. MS/MS spectra are composed of ions resulting from the fragmentation of peptides at their peptide bonds during tandem mass spectrometry analysis. The generated fragment ions differ in mass corresponding to their adjacent amino-acid masses within the peptide sequence. A PST is a partial element of information deduced from an MS/MS spectrum, defined as a small sequence of several probable adjacent amino acids from the original peptide and the masses of the flanking N- and C-terminal fragment ions of this small sequence