Periodic Reporting for period 1 - SpecSpiderVenom (Venomics of Prey-Specialised Spiders in the Evolutionary and Ecological Context)
Berichtszeitraum: 2022-04-01 bis 2024-03-31
The aim of this project is to investigate venomic adaptations of prey-specialised spiders more thoroughly. Specifically, we aim to elucidate the venom composition in selected specialists and the prey-specificity of selected toxins.
During the outgoing phase, the main objective was to analyse the venom composition of selected prey-specialised spiders. We focused on the proteomes of five spider species: three spider-eating spiders (Lampona sp., Palpimanus gibbulus and P. cypreus), one termite-eating spider (Ammoxenus amphalodes), and one ant-eating spider (Euryopis umbilicata). To analyse the venom composition, we utilized the combined proteo-transcriptomic approach.
The white-tailed spiders of the genus Lampona have been blamed for causing necrotic lesions after bite, although several studies have shown that this is not true. The main prey of the white-tailed spiders are other spiders. Our previous study showed that white-tailed spiders utilise several morphological and behavioural adaptations to capture spider prey. During this project, we focused on its venomic adaptations. We revealed the venom was more potent against the preferred spider prey than against alternative cricket prey. The venom composition analysis revealed 208 putative toxins. Smaller peptides (less than 10 kDa) were more abundant. Most lampotoxins belonged to one of two families characterized by unique scaffolds containing eight or ten cysteine residues. We also revealed that Lampona venom is more potent against spider prey than alternative cricket prey (Michálek et al., 2022).
The sand-diving spider A. amphalodes represents the only known monophagous predator, as it feeds on a single termite species, Hodotermes mossambicus. Previous research revealed the presence of unique predatory behaviour and fast prey paralysis, therefore we focused on its venom in more detail. We revealed the presence of 116 putative toxins. The most abundant venom components were six ammoxotoxins belonging to family 1, comprising over one-third of the venom proteome transcripts. These findings are congruent with the hypothesis that a few structurally similar toxins dominate venoms of predators with narrow diets.
The other datasets, including the venoms of two Palpipanus spiders and E. umbilicata, are currently being analysed. Besides the venom composition analyses, we also managed to produce several selected toxins of Lampona and Ammoxenus that will be further tested during the next phase of the project.
During the return phase of the project at Masaryk University, we will finish the bioinformatic processing of the proteotranscriptomic data of the Palpimanus and Euryopis. Moreover, we will start testing the potency of lampotoxins and ammoxotoxins on different prey. Our aim will be to test whether these toxins are prey-specific.