Sepiadarium austrinum Slime MSMS

ABSTRACT: Sepiadarium austrinum, the southern bottletail squid, is a small squid that inhabits soft sediments along Australia’s south-east coast. When provoked this squid rapidly secretes large volumes of slime as a defense mechanism. Behavioral observations suggest that this slime may be toxic to crabs but its composition remains unknown. A reference transcriptome for S. austrinum using give tissues including slime was assembled and a database of 40,444 predicted proteins was created using the Trinotate annotation software with an addition 53 short proteins identified exclusively by proteogenomics. This database was used to identify 1736 proteins within the slime using bottom-up (shotgun) proteomics. The mechanism of slime secretion is likely to involve ejection of cell content with the presence of proteins involved in fundamental intracellular functions such as DNA binding and protein folding being highly abundant, along with few slime proteins containing a signal peptide. Putative toxic proteins were identified within the slime based on characteristics of known toxins, namely cysteine richness, short length, the existence of a signal peptide and homology to known toxins. Our study also adds a crucial layer of evidence for toxicity of these proteins by using direct proteomic measurement within toxic secretions (slime) rather than their parent glands. To our knowledge this is the first such study in cephalopods. Quantitative proteomics has allowed us to highlight two putative toxins within the top ten most abundant slime proteins. The slime secreted by S. austrinum may act as a carrier medium for these putative toxins and this may represent a novel toxin delivery mechanism for cephalopods.

OTHER RELATED OMICS DATASETS IN: PRJNA337893 PRJNA302677

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Sepiadarium Austrinum

SUBMITTER: Nikeisha Caruana  

LAB HEAD: Jan Marie Strugnell

PROVIDER: PXD003207 | Pride | 2016-08-08

REPOSITORIES: Pride