Label-Free Quantiative Analysis of Sepioloidea lineolata

Sepioloidea lineolata, the striped pyjama squid (family Sepidariidae), is a small species of benthic squid distributed along the Southern Indo-Pacfic coast of Australia. All Sepiadariid squids are known to secrete large volumes of viscous slime when stressed. The proteome of the slime, dorsal and ventral mantle muscle, the dorsal and ventral mantle epithelium and ventral mantle glands was analysed by combining label-free quantitative analysis using high resolution mass spectrometry data with an S. lineolata transcriptome assembled from give tissues including slime. A total of 28 highly positively differentially expressed proteins were identified within the slime and were predominately comprised of a host of enzymes including peptidases and protease inhibitors. Seven of these proteins contained predicted signal peptides, indicating classical secretion, with four proteins having no identifiable domains or similarity to any known proteins.