Fig 1.
Schematic overview of the old method and the here presented new method for the generation of venom gland transcriptomes.
Comparison between the ‘traditional’ method and our newly developed method for the extraction of mRNA from the Vietnam forest scorpion (Heterometrus laoticus). The traditional method involves sacrificing the animal to extract the venom gland from the telson or to homogenize the entire telson in order to collect mRNA, whereas the newly developed method includes mRNA-extraction from scorpion venom, which overcomes the need of harming the animal.
Fig 2.
Relative expression levels of transcripts in the venom gland transcriptomes at different timepoints.
The graphs show expression rates for venom gland transcriptomes two days after start of venom replenishment (V2d) and four days after the start of venom replenishment (V4d) relative to the whole telson transcriptome five days after the start of venom replenishment (T5d). In the upper bar graphs the transcripts are labelled as “toxin”, “physiological” and “unknown” and are shown as a percentage of total expression. The lower graphs represent the relative expression levels across toxin families within the “toxin” transcripts in the venom gland transcriptomes. Abbreviations: NaTx (sodium-channel binding toxin); KTx (potassium-channel binding toxins); ClTx (chlorotoxin); BPP (bradykinin-potentiating peptide); MTX (Maurotoxin); BmK (Buthus martensii Karsch-toxin); PLA2 (phospholipase A2). Note: Some toxins are found at such low expression rates that these differentiated from the bar graphs, therefore these are not represented in the legend. These include α-NaTx, calcium-channel binding toxin and Kunitz-type toxin. Host defense proteins were classified under “other”.
Fig 3.
Schematic overview of the three secretion methods in the venom glands across the animal kingdom.
The left panel shows the various venomous lineages, clustered based on the method of secretion of their venom-producing cells. For some lineages the gland type depends on the species and therefore these are represented multiple times in this figure. Note that some clades are shown in grey, as literature does not provide sufficient information to properly categorize these based on their method of venom secretion. The middle column of this figure shows a cartoon of excretory cells surrounding the gland lumen and right part of the figure schematically illustrates how venomous secretions are being produced by a single cell (see text for further details).
Table 1.
Overview of different methods of venom gland secretion across all venomous lineages.