Project description:Spiders have distinct capture prey behaviors selected along Araneae´s evolutive history, but mainly based on the use of venom for prey paralysis. Uloboridae spiders lost the venom glands secondarily in evolution. Due to that they extensively wrap prey with silk to paralyze and begin digestion. During the extra-oral digestion, the digestive fluid very efficiently performs the liquefaction of both the prey and the AcSp2 spidroins from the web fibers. Despite the efficiency of this process, the cocktail of enzymes involved in digestion in Uloboridae spiders is unknown. In this study, we evaluated the protein content in the midgut of Uloborus sp. using enzymatic, proteomic, and phylogenetic analysis approaches. Hydrolases as peptidases (endo and exopeptidases: cysteine, serine and metallopeptidases), carbohydrases (alpha-amylase, chitinase, alpha-mannosidase), and lipases were biochemically assayed; 50 proteins, annotated as enzymes, structural proteins, and toxins, were identified. This is the first characterization of the molecules involved in the digestive process and the midgut protein content of a nonvenomous spider.
2023-03-11 | PXD037345 | Pride
Project description:Expanded phylogeny of spiders using transcriptomes
| PRJNA663891 | ENA
Project description:Phylogeny and biogeography of Pterocarya
Project description:We compare levels of gene expression in predator (Tigrosa helluo) exposed female Pardosa milvina compared to unexposed spiders and the offspring of predator exposed spiders to the offspring of control spiders.
Project description:Lions and tigers, as dominant apex predators, likely became competitors when lions expanded from Africa into Eurasia approximately one million years ago (Ma), forming a lion–tiger transition belt from the Middle East through Central Asia to the Russian Far East. At the easternmost edge of this zone, the Japanese Archipelago has long been considered a Late Pleistocene tiger refugium, supported by large felid subfossils traditionally attributed to tigers (Panthera tigris), though their taxonomic identity remained unresolved. To clarify the origin, evolutionary history, and biogeography of Japan’s Pleistocene felids, we analyzed 26 ancient specimens previously assumed to be tigers. Using mitochondrial and nuclear genome hybridization capture and sequencing, paleoproteomics, Bayesian molecular dating, and radiocarbon dating, we found that all ancient Japanese “tiger” remains yielding molecular data were, unexpectedly, cave lions (Panthera spelaea). One specimen was radiocarbon dated to 31,060 ± 190 BP. These cave lions likely dispersed to the Japanese Archipelago between ~72.7 and 37.5 thousand years ago (ka), when a land bridge connected northern Japan to the mainland during the Last Glacial Period. Our findings challenge the long-held view that tigers once took refuge in Japan, showing instead that cave lions were widespread in northeast Asia during this period and were the Panthera lineage that colonized Japan, reaching even its southwestern regions despite habitats previously thought to favor tigers.
2026-01-26 | PXD065297 | Pride
Project description:Phylogeny of the Two-Clawed Spiders (Dionycha)