Fig. 8

Patterns of Regucalcin, GULO and SVCT gene presence/absence within the animal kingdom. NB, PRO and DEU represent the non-bilaterian, protostomian and deuterostomian species, respectively. Circles are representative of the Regucalcin gene, while squares and triangles represent the GULO and SVCT genes, respectively. The figures’ fill is indicative of the percentage of species in which the given gene was identified relative to the total number of analysed species, while grey figures represent complete gene absence. The estimated GULO presence/absence frequency is based on previous reports [19, 21] where species for which no gene annotation is available, and thus where a manual gene annotation was performed, were also considered. The number of figures for each gene indicates the identified ancestral duplicates within each group/species. Numbers highlighted in the figures represent the inferred specific gene duplications found within the lineages. The purple colour outline within the Regucalcin Diptera section of the image represents the Sophophora Dca gene, while the dark blue, blue and orange represent the Drosophila Regucalcin, the Tephritidae Regucalcin-like and Culicidae Regucalcin-like genes, respectively. The four known SVCT genes within the vertebrates lineage are represented in red (SVCT1), orange (SVCT2), dark blue (SVCT3) and blue (SVCT4), while the putative SVCT5 is highlighted in light blue. The SVCTNB, SVCTP NL, SVCTP L and SVCT BD genes are represented in burnt yellow. The blue branches in the cladogram highlight the taxonomic groups represented by less than three species in the analyses. The last two columns summarize the current hypothesis regarding VC synthesis (via GULO pathway) and uptake from diet, respectively. Within these, the information highlighted in light pink represents possible correlations between loss of SVCT1 and GULO conservation, and vice-versa. The cladogram topology is depicted as in the Tree of Life web project [87]. The Euarchontoglires and Haplorrhini groups in the cladogram do not consider primates and H. sapiens, respectively, due to the subsequent taxa expansions