Cephalopods are known to produce an extensive range of secretions including ink, mucus, and venom. Sepiadariidae, a family of small, benthic bobtail squids, are notable for the high volume of viscous slime they emit when stressed. One species, Sepioloidea lineolata (striped pyjama squid), is covered with glands along the perimeter of the ventral mantle, and these structures are hypothesized to be the source of its slime. Using label-free quantitative proteomics, we analyzed five tissue types (dorsal and ventral mantle muscle, dorsal and ventral epithelium, and ventral mantle glands) and the slime from four individuals. In doing so, we were able to determine the relationship between the slime and the tissues as well as highlight proteins that were specifically identified within the slime and ventral mantle glands. A total of 28 proteins were identified to be highly enriched in slime, and these were composed of 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. The ventral mantle glands also appear to be the tissue with the closest overall proteomic composition to the slime; therefore, it is likely that the slime originates, at least in part, from these glands.

中文翻译：

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条纹睡衣鱿鱼（Sepioloidea lineolata）的粘液和腹膜腺定量蛋白质组学分析。

已知头足类动物会产生广泛的分泌物，包括墨水，粘液和毒液。Sepiadariidae是小型底栖短尾鱿鱼的一个家庭，因压力大时散发出的粘稠粘液而著称。一种，线虫（条纹睡衣鱿鱼）在腹膜的周围覆盖有腺体，这些结构被认为是其粘液的来源。使用无标记的定量蛋白质组学，我们分析了五种组织类型（背侧和腹侧上皮肌，背侧和腹侧上皮以及腹侧皮腺）和来自四个个体的粘液。这样，我们就可以确定粘液和组织之间的关系，并确定在粘液和腹地幔腺中专门鉴定的突出蛋白。总共鉴定出28种高浓度粘液蛋白，这些蛋白由肽酶和蛋白酶抑制剂组成。这些蛋白质中有七个含有预测的信号肽，表明其经典分泌，四种蛋白质与任何已知蛋白质都没有可识别的结构域或相似性。腹幔腺也似乎是与粘液最接近的整体蛋白质组学组织。因此，粘液可能至少部分源自这些腺体。