Data from: High throughput techniques to reveal the molecular physiology and evolution of digestion in spiders

Background: Spiders are known for their predatory efficiency and for their high capacity of digesting relatively large prey. They do this by combining both extracorporeal and intracellular digestion. Whereas many high throughput (“-omics”) techniques focus on biomolecules in spider venom, so far this approach has not yet been applied to investigate the protein composition of spider midgut diverticula (MD) and digestive fluid (DF). Results: We here report on our investigations of both MD and DF of the spider Nephilingis (Nephilengys) cruentata through the use of next generation sequencing and shotgun proteomics. This shows that the DF is composed of a variety of hydrolases including peptidases, carbohydrases, lipases and nuclease, as well as of toxins and regulatory proteins. We detect 25 astacins in the DF. Phylogenetic analysis of the corresponding transcript(s) in Arachnida suggests that astacins have acquired an unprecedented role for extracorporeal digestion in Araneae, with different orthologs used by each family. The results of a comparative study of spiders in distinct physiological conditions allow us to propose some digestion mechanisms in this interesting animal taxon. Conclusion: All the high throughput data allowed the demonstration that DF is a secretion originating from the MD. We identified enzymes involved in the extracellular and intracellular phases of digestion. Besides that, data analyses show a large gene duplication event in Araneae digestive process evolution, mainly of astacin genes. We were also able to identify proteins expressed and translated in the digestive system, which until now had been exclusively associated to venom glands.背景：蜘蛛以其高效的捕食能力以及消化较大猎物的强大能力而闻名，它们通过结合体外消化与细胞内消化来实现这一过程。尽管诸多高通量组学（high throughput -omics）技术均聚焦于蜘蛛毒液中的生物分子，但迄今为止，该类方法尚未被用于探究蜘蛛中肠憩室（midgut diverticula, MD）与消化液（digestive fluid, DF）的蛋白质组成。 结果：本研究通过下一代测序（next generation sequencing）与鸟枪法蛋白质组学（shotgun proteomics），对血色络新妇（Nephilingis (Nephilengys) cruentata）的中肠憩室与消化液展开了研究。结果表明，消化液由多种水解酶组成，包括肽酶、糖酶、脂肪酶与核酸酶，同时还含有毒素与调控蛋白。我们在消化液中检测到25种星型蛋白酶（astacins）。对蛛形纲（Arachnida）中对应转录本的系统发育分析显示，蜘蛛目（Araneae）的星型蛋白酶已获得了前所未有的体外消化功能，且不同科类群使用不同的直系同源基因（orthologs）。针对不同生理状态蜘蛛的比较研究结果，使我们得以提出该有趣动物类群的部分消化机制。 结论：所有高通量数据均证实，消化液实为源自中肠憩室的分泌物。我们鉴定出了参与消化细胞外与细胞内阶段的酶类。此外，数据分析显示蜘蛛目在消化过程的演化中发生了大规模基因复制事件，尤以星型蛋白酶基因为甚。我们还鉴定出了在消化系统中表达并翻译的蛋白质，而此类蛋白质此前仅被认为与毒腺（venom glands）相关。