Saco A , Rey-Campos M , Rosani U , Novoa B , Figueras A .

	Figure 1. Phylogenetic analysis of the 379 unique IL-17 sequences obtained from the 16 mussel genomes. The 379 unique IL-17 sequences retrieved from 16 mussel genomes were submitted to phylogenetic analysis with Bayesian phylogenetic inference using the Jukes and Cantor (JC) evolution model. The 23 different IL-17 clusters or isoforms obtained are indicated with ellipses that englobe all their unique variants. The figure shows branch posterior probabilities. It can be seen how isoforms IL17-3 and IL17-16 would be diverging from IL17-17, since the branch of the latter contains both isoforms. The distinction between these isoforms was maintained due to the homology criterion and to expression evidence.
	Figure 2. Phylogenetic analysis of the 96 unique IL-17R sequences obtained from the 16 mussel genomes. The 96 unique IL-17R sequences retrieved from 16 mussel genomes were submitted to phylogenetic analysis with Bayesian phylogenetic inference using the GTR+G evolution model. The 6 different IL-17 clusters or isoforms obtained are indicated. The figure shows branch posterior probabilities.
	Figure 3. Phylogenetic analysis of the IL-17 families found in Mytilidae species. Homologous sequences to the M. galloprovincialis IL-17 isoforms were found in several Mytilidae species and submitted to neighbor joining analysis using the Jukes–Cantor substitution model. Clustering was based on isoform homologs, and species are indicated with colors.
	Figure 4. Comparative genomics analysis of IL-17 gene families throughout evolution. IL-17 repertoires were analyzed in several species from different phyla and clustered with an 80% homology criterion. The evolutionary cladogram is presented, along with the extension of the IL-17 family from each species.
	Figure 5. IL-17 genes often appear in tandem repetitions in the genomes of marine invertebrates with expanded IL-17 repertoires. Examples of several scaffolds with IL-17 tandem duplications are presented for these species. IL-17s are indicated with the name of the cluster to which they belong in our analysis. Tandem repetitions can occur with genes from the same or different isoforms. Neighbor genes are represented with their functional annotations.
	Figure 6. Expression of the different mussel IL-17 isoforms in the gill transcriptome against a waterborne bacterial infection (A) and in the hemocyte transcriptome against a bacterial infection injected into the muscle (B). It is shown that the isoforms expressed in each transcriptome changed completely. Colored pie charts represent the diversity of expressed IL-17 isoforms in each individual mussel from the control (C1, C2, C3) and infected conditions (I1, I2, I3). The white pie charts below represent, for each experiment, the weight that the expression values of each of the upper graphs have (calculated by the sum of the expression values of every IL-17 form for each of the individual samples). Clear upregulation of IL-17 expression is seen in the gill transcriptome against infection but not in the hemocyte transcriptome. Expression of IL-17 receptors in the same gill (C) and hemocyte (D) transcriptomes. Regarding the IL-17 receptors, it can be seen that the expressed isoforms also varied between transcriptomes.
	Figure 7. Normalized expression by qPCR of IL-17 isoforms expressed in the gill (A) and in the adductor muscle hemocytes of the same individual mussels (B) after a 24-hour waterborne infection with Vibrio splendidus, as well as the expression of the receptors (C). In gills, upregulation of the expressed IL-17 isoforms occurred, whereas in hemocytes, there was downregulation. Receptors did not show the antagonistic regulation between hemocytes and gills seen with the IL-17 genes, but instead, the expression of each receptor was correlated in both gill and hemocyte samples.

Albertin, The octopus genome and the evolution of cephalopod neural and morphological novelties. 2015, Pubmed

Albertin, The octopus genome and the evolution of cephalopod neural and morphological novelties. 2015, Pubmed
Almagro Armenteros, SignalP 5.0 improves signal peptide predictions using deep neural networks. 2019, Pubmed
Bailey, MEME SUITE: tools for motif discovery and searching. 2009, Pubmed
Balseiro, Mytilus galloprovincialis myticin C: a chemotactic molecule with antiviral activity and immunoregulatory properties. 2011, Pubmed
Benderdour, Interleukin 17 (IL-17) induces collagenase-3 production in human osteoarthritic chondrocytes via AP-1 dependent activation: differential activation of AP-1 members by IL-17 and IL-1beta. 2002, Pubmed
Buckley, IL17 factors are early regulators in the gut epithelium during inflammatory response to Vibrio in the sea urchin larva. 2017, Pubmed , Echinobase
Cao, Evolution and function analysis of interleukin-17 gene from Pinctada fucata martensii. 2019, Pubmed
Cua, Innate IL-17-producing cells: the sentinels of the immune system. 2010, Pubmed
Domeneghetti, Mortality occurrence and pathogen detection in Crassostrea gigas and Mytilus galloprovincialis close-growing in shallow waters (Goro lagoon, Italy). 2014, Pubmed
Dong, Genome-wide identification of interleukin-17 (IL17) in common carp (Cyprinus carpio) and its expression following Aeromonas hydrophila infection. 2019, Pubmed
Du, Characterization of grass carp (Ctenopharyngodon idella) IL-17D: molecular cloning, functional implication and signal transduction. 2014, Pubmed
Du, Identification and functional characterization of grass carp IL-17A/F1: An evaluation of the immunoregulatory role of teleost IL-17A/F1. 2015, Pubmed
Fu, CD-HIT: accelerated for clustering the next-generation sequencing data. 2012, Pubmed
Fu, Linear invariants under Jukes' and Cantor's one-parameter model. 1995, Pubmed
Gaffen, Biology of recently discovered cytokines: interleukin-17--a unique inflammatory cytokine with roles in bone biology and arthritis. 2004, Pubmed
Gaffen, Structure and signalling in the IL-17 receptor family. 2009, Pubmed
Gao, Repertoire and evolution of TNF superfamily in Crassostrea gigas: implications for expansion and diversification of this superfamily in Mollusca. 2015, Pubmed
Gerdol, An updated molecular basis for mussel immunity. 2015, Pubmed
Gerdol, Massive gene presence-absence variation shapes an open pan-genome in the Mediterranean mussel. 2020, Pubmed
Gerdol, The genome of the Pacific oyster Crassostrea gigas brings new insights on the massive expansion of the C1q gene family in Bivalvia. 2015, Pubmed
Gerdol, The C1q domain containing proteins of the Mediterranean mussel Mytilus galloprovincialis: a widespread and diverse family of immune-related molecules. 2011, Pubmed
Ghosh, Sp185/333: a novel family of genes and proteins involved in the purple sea urchin immune response. 2010, Pubmed , Echinobase
González-Fernández, Identification and Regulation of Interleukin-17 (IL-17) Family Ligands in the Teleost Fish European Sea Bass. 2020, Pubmed
Gunimaladevi, Identification, cloning and characterization of interleukin-17 and its family from zebrafish. 2006, Pubmed
Han, Characterization of Lamprey IL-17 Family Members and Their Receptors. 2015, Pubmed
Hata, IL-17 stimulates inflammatory responses via NF-kappaB and MAP kinase pathways in human colonic myofibroblasts. 2002, Pubmed
Hibino, The immune gene repertoire encoded in the purple sea urchin genome. 2006, Pubmed , Echinobase
Hirsch, Insights into the maize pan-genome and pan-transcriptome. 2014, Pubmed
Huang, Comparative and Evolutionary Analysis of the Interleukin 17 Gene Family in Invertebrates. 2015, Pubmed
Huang, CD-HIT Suite: a web server for clustering and comparing biological sequences. 2010, Pubmed
Huelsenbeck, MRBAYES: Bayesian inference of phylogenetic trees. 2001, Pubmed
Hymowitz, IL-17s adopt a cystine knot fold: structure and activity of a novel cytokine, IL-17F, and implications for receptor binding. 2001, Pubmed
Kolls, Interleukin-17 family members and inflammation. 2004, Pubmed
Kono, Genomics of fish IL-17 ligand and receptors: a review. 2011, Pubmed
Korenaga, Isolation of seven IL-17 family genes from the Japanese pufferfish Takifugu rubripes. 2010, Pubmed
Krogh, Predicting transmembrane protein topology with a hidden Markov model: application to complete genomes. 2001, Pubmed
Letunic, Interactive Tree Of Life (iTOL) v4: recent updates and new developments. 2019, Pubmed
Li, Cloning and characterization of IL-17B and IL-17C, two new members of the IL-17 cytokine family. 2000, Pubmed
Li, Genomic characterization and expression analysis of five novel IL-17 genes in the Pacific oyster, Crassostrea gigas. 2014, Pubmed
Li, A cytokine-like factor astakine accelerates the hemocyte production in Pacific oyster Crassostrea gigas. 2016, Pubmed
Li, Cd-hit: a fast program for clustering and comparing large sets of protein or nucleotide sequences. 2006, Pubmed
McInerney, Why prokaryotes have pangenomes. 2017, Pubmed
Mello, Estimating TimeTrees with MEGA and the TimeTree Resource. 2018, Pubmed
Milutinović, Immune memory in invertebrates. 2016, Pubmed
Monte, Cloning and characterization of rainbow trout interleukin-17A/F2 (IL-17A/F2) and IL-17 receptor A: expression during infection and bioactivity of recombinant IL-17A/F2. 2013, Pubmed
Nair, Macroarray analysis of coelomocyte gene expression in response to LPS in the sea urchin. Identification of unexpected immune diversity in an invertebrate. 2005, Pubmed , Echinobase
Nielsen, Identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites. 1997, Pubmed
Ottaviani, Cytokines and invertebrate immune responses. 1995, Pubmed
Oyanedel, Molecular characterization of an inhibitor of NF-κB in the scallop Argopecten purpuratus: First insights into its role on antimicrobial peptide regulation in a mollusk. 2016, Pubmed
Pappu, Regulation of epithelial immunity by IL-17 family cytokines. 2012, Pubmed
Pfaffl, A new mathematical model for relative quantification in real-time RT-PCR. 2001, Pubmed
Rey-Campos, Comparative Genomics Reveals a Significant Sequence Variability of Myticin Genes in Mytilus galloprovincialis. 2020, Pubmed
Rey-Campos, High individual variability in the transcriptomic response of Mediterranean mussels to Vibrio reveals the involvement of myticins in tissue injury. 2019, Pubmed
Roberts, Rapid accumulation of an interleukin 17 homolog transcript in Crassostrea gigas hemocytes following bacterial exposure. 2008, Pubmed , Echinobase
Romero, Occurrence, seasonality and infectivity of Vibrio strains in natural populations of mussels Mytilus galloprovincialis. 2014, Pubmed
Romero, Individual sequence variability and functional activities of fibrinogen-related proteins (FREPs) in the Mediterranean mussel (Mytilus galloprovincialis) suggest ancient and complex immune recognition models in invertebrates. 2011, Pubmed
Rosani, IL-17 signaling components in bivalves: Comparative sequence analysis and involvement in the immune responses. 2015, Pubmed
Rouvier, CTLA-8, cloned from an activated T cell, bearing AU-rich messenger RNA instability sequences, and homologous to a herpesvirus saimiri gene. 1993, Pubmed
Saco, Transcriptomic Response of Mussel Gills After a Vibrio splendidus Infection Demonstrates Their Role in the Immune Response. 2020, Pubmed
Saenz, Welcome to the neighborhood: epithelial cell-derived cytokines license innate and adaptive immune responses at mucosal sites. 2008, Pubmed
Secombes, The interleukins of fish. 2011, Pubmed
Simakov, Insights into bilaterian evolution from three spiralian genomes. 2013, Pubmed , Echinobase
Sonnhammer, A hidden Markov model for predicting transmembrane helices in protein sequences. 1998, Pubmed
Starnes, Cutting edge: IL-17D, a novel member of the IL-17 family, stimulates cytokine production and inhibits hemopoiesis. 2002, Pubmed
Toubiana, Toll signal transduction pathway in bivalves: complete cds of intermediate elements and related gene transcription levels in hemocytes of immune stimulated Mytilus galloprovincialis. 2014, Pubmed
Turner, Cytokines and chemokines: At the crossroads of cell signalling and inflammatory disease. 2014, Pubmed
Vizzini, Ciona intestinalis interleukin 17-like genes expression is upregulated by LPS challenge. 2015, Pubmed
Wang, The transcriptomic expression of pattern recognition receptors: Insight into molecular recognition of various invading pathogens in Oyster Crassostrea gigas. 2019, Pubmed
Wu, Interleukin-17 in pearl oyster (Pinctada fucata): molecular cloning and functional characterization. 2013, Pubmed
Xin, CgIL17-5, an ancient inflammatory cytokine in Crassostrea gigas exhibiting the heterogeneity functions compared with vertebrate interleukin17 molecules. 2015, Pubmed
Xin, The systematic regulation of oyster CgIL17-1 and CgIL17-5 in response to air exposure. 2016, Pubmed
Yang, Estimating the pattern of nucleotide substitution. 1994, Pubmed
Yao, Human IL-17: a novel cytokine derived from T cells. 1995, Pubmed
Zhang, Structure and function of interleukin-17 family cytokines. 2011, Pubmed
Zhang, Allograft inflammatory factor-1 stimulates hemocyte immune activation by enhancing phagocytosis and expression of inflammatory cytokines in Crassostrea gigas. 2013, Pubmed
Zhang, Cloning and characterization of allograft inflammatory factor-1 (AIF-1) from Manila clam Venerupis philippinarum. 2011, Pubmed