title: Combined Transcriptomic and Proteomic Analysis of the Posterior Salivary Gland from the Southern Blue-Ringed Octopus and the Southern Sand Octopus.
abstract: This study provides comprehensive proteomic profiles from the venom producing posterior salivary glands of octopus (superorder Octopodiformes) species. A combined transcriptomic and proteomic approach was used to identify 1703 proteins from the posterior salivary gland of the southern blue-ringed octopus, Hapalochlaena maculosa and 1300 proteins from the posterior salivary gland of the southern sand octopus, Octopus kaurna. The two proteomes were broadly similar; clustering of proteins into orthogroups revealed 937 that were shared between species. Serine proteases were particularly diverse and abundant in both species. Other abundant proteins included a large number of secreted proteins, many of which had no known conserved domains, or homology to proteins with known function. On the basis of homology to known venom proteins, 23 putative toxins were identified in H. maculosa and 24 in O. kaurna. These toxins span nine protein families: CAP (cysteine rich secretory proteins, antigen 5, parthenogenesis related), chitinase, carboxylesterase, DNase, hyaluronidase, metalloprotease, phospholipase, serine protease and tachykinin. Serine proteases were responsible for 70.9% and 86.3% of putative toxin expression in H. maculosa and O. kaurna, respectively, as determined using intensity based absolute quantification (iBAQ) measurements. Phylogenetic analysis of the putative toxin serine proteases revealed a similar suite of diverse proteins present in both species. Posterior salivary gland composition of H. maculosa and O. kaurna differ in several key aspects. While O. kaurna expressed the proteinaceous neurotoxin, tachykinin, this was absent from H. maculosa, perhaps reflecting the acquisition of a potent nonproteinaceous neurotoxin, tetrodotoxin (TTX) produced by bacteria in the salivary glands of that species. The dispersal factor, hyaluronidase was particularly abundant in H. maculosa. Chitinase was abundant in both species and is believed to facilitate envenomation in chitinous prey such as crustaceans. Cephalopods represent a largely unexplored source of novel proteins distinct from all other venomous taxa and are of interest for further inquiry, as novel proteinaceous toxins derived from venoms may contribute to pharmaceutical design.
authors.affiliation: Department of Ecology, Environment and Evolution, School of Life Sciences, La Trobe University , Melbourne, Victoria 3086, Australia.|Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative , Carlton, Victoria 3053, Australia.
authors.forename: Brooke L
authors.initials: BL
authors.lastname: Whitelaw
authors.affiliation: Department of Ecology, Environment and Evolution, School of Life Sciences, La Trobe University , Melbourne, Victoria 3086, Australia.
authors.forename: Jan M
authors.initials: JM
authors.lastname: Strugnell
authors.affiliation: Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia.
authors.forename: Pierre
authors.initials: P
authors.lastname: Faou
authors.affiliation: The Bioinformatics Centre, Department of Biology, University of Copenhagen , Ole Maaløes Vej 5, 2200 København N, Denmark.
authors.forename: Rute R
authors.initials: RR
authors.lastname: da Fonseca
authors.affiliation: Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia.|Sciences, Museum Victoria , Carlton, Victoria 3053, Australia.
authors.forename: Nathan E
authors.initials: NE
authors.lastname: Hall
authors.affiliation: Sciences, Museum Victoria , Carlton, Victoria 3053, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Norman
authors.affiliation: Sciences, Museum Victoria , Carlton, Victoria 3053, Australia.
authors.forename: Julian
authors.initials: J
authors.lastname: Finn
authors.affiliation: Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia.|Comparative Genomics Centre and Department of Molecular and Cell Biology, James Cook University , Townsville, Queensland 4811, Australia.
authors.forename: Ira R
authors.initials: IR
authors.lastname: Cooke
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D008387:Marine Toxins / Q000032:analysis; D049831:Octopodiformes / Q000737:chemistry*; D040901:Proteomics; D012469:Salivary Glands / Q000737:chemistry*; D057057:Serine Proteases / Q000032:analysis; D013045:Species Specificity; D059467:Transcriptome; D014688:Venoms / Q000201:enzymology
chemical_list: D008387:Marine Toxins; D014688:Venoms; D057057:Serine Proteases
keywords: Hapalochlaena maculosa; Octopus kaurna; cephalopod; omics; proteogenomics; proteomics; tandem mass spectrometry; transcriptomics; venom; venomics