Project description:Sepioloidea lineolata, the striped pyjama squid (family Sepiadariidae), is a small species of benthic squid distributed along the Southern Indo-Pacific coast of Australia. All sepiadariid squids are known to secrete large volumes of viscous slime when stressed. The proteome of S. lineolata slime was analysed by combining high resolution mass spectrometry data with an S. lineolata transcriptome assembled from five tissues including slime. The composition of S. lineolata slime was also compared to that of the closely related S. austrinum (southern bottletail squid). Of the 550 protein groups identified in S. lineolata slime, 321 had orthologs in S. austrinum, and the abundance of these (iBAQ) was highly correlated between species. Both slimes were dominated by a small number of highly abundant proteins and several of these were short secreted proteins that had no homologues outside the class Cephalopoda. The extent of N-glycosylation in the slime of S. lineolata was also studied via glycan cleavage with PNGase-F. Four proteins had strong evidence of N-glycosylated, with treatment with PNGase-F showing a slight increase in peptide identification rates.
Project description: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.
