Data from: Comparative venom analysis between melanistic and normally-colored phenotypes of the common adder (Vipera berus)
Data files
Sep 18, 2024 version files 5.53 MB
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README.md
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Supplemantary_Figure_S1.docx
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Supplemantary_Tables_S1-S4.xlsx
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Abstract
Snake venom is an ecologically relevant functional trait directly linked with a snake’s fitness and survival, facilitating predation and defence. Snake venom variation occurs at all taxonomic levels, but the study at the intraspecific level is still in its early stages. The common adder (Vipera berus) exhibits considerable variation in colour phenotypes across its distribution range. Melanistic (fully black) individuals are the subject of myths and fairytales, and in German folklore such ‘hell adders’ are considered more toxic than their normally coloured conspecifics despite any formal investigation. Here, we provide the first comparative analysis of venoms from melanistic and normally coloured common adders. Specifically, we compared the venom profiles by sodium dodecylsulfate polyacrylamide gel electrophoresis and reversed-phase high-performance liquid chromatography and tested the venoms’ protease, phospholipase A2 and cytotoxic activities. Phospholipase A2 activity was similar in both phenotypes, whereas general protease activity was higher in the melanistic venom, which was also more cytotoxic at two concentrations (6.25 and 12.5 µg ml−1). These minor differences between the venoms of melanistic and normally coloured adders are unlikely to be of clinical relevance in the context of human envenomation. In light of our results, the claim that melanistic adders produce more toxic venom than their normally coloured conspecifics appears rooted entirely in folklore.
README: Data from: Comparative venom analysis between melanistic and normally-colored phenotypes of the common adder (Vipera berus)
Here we provide the raw images of the reducing and non-reducing SDS-PAGE (Figure S1) as well as the normalized technical triplicates (1, 2, 3) of the protease activity assay (Table S1), phospholipase A2 assay (Table S2), cell viability assay (Table S3) and hemolytic activity assay (Table S4) by pooled venom of melanistic (MEL) and cryptic (CRY) Vipera berus in a five-fold dilution series (see below).
Description of the data and file structure
Abbrevations:
Tech. rep. = Technical replicates (1, 2, 3)
MEL = pooled venom of melanistic Vipera berus
CRY = pooled venom of cryptic Vipera berus
Pos. control = positive control
Neg. control = negative control
mean = Averaged normalized triplicates (%)
SD = Standard deviation of normalized, averaged triplicates (%)
Supplementary Figure:
Figure S1
SDS-PAGE raw images of pooled Vipera berus venom samples from melanistic (MEL) and cryptic (CRY) phenotypes under A) reducing and B) non-reducing conditions. Non-relevant lines, left and right of the section of interest, are cropped out.
Supplementary Tables:
Table S1
Phospholipase A2 activity of crude venom pools (concentrations: 3.125, 6.25, 12.5, 25 and 50 µg/ml) from melanistic (MEL) and cryptic (CRY) Vipera berus. The assay was performed in technical triplicates (1, 2, 3), subtracted by the buffer treatment (negative control, 0% activity) and normalized against 5 U/ml purified bee PLA2 treatment (positive control, 100% activity). Normalized activity was averaged (mean) and the standard deviation (SD) was calculated.
Table S2
Protease activity of crude venom pools (concentrations: 25, 50, 100, 200 and 400 µg/ml) from melanistic (MEL) and cryptic (CRY) Vipera berus. The assay was performed in technical triplicates (1, 2, 3), subtracted by the double-distilled water treatment (negative control, 0% activity) and normalized against 1.66 µg/ml Trypsin treatment (positive control, 100% activity). Normalized activity was averaged (mean) and the standard deviation (SD) was calculated.
Table S3
Cytotoxicity of crude venom pools (concentrations: 1.56, 3.125, 6.25, 12.5 and 25 µg/ml) from melanistic (MEL) and cryptic (CRY) Vipera berus against canine MDCKII cells. The assay was performed in technical triplicates (1, 2, 3), subtracted by the Media treatment (negative control, 100% growth) and normalized against 100 µM Ionomycin treatment (positive control, 0% growth). Normalized activity was averaged (mean) and the standard deviation (SD) was calculated.
Table S4
Hemolytic activity of crude venom pools (concentrations: 5, 10, 20, 40 and 80 µg/ml) from melanistic (MEL) and cryptic (CRY) Vipera berus against purified equine erythrocytes. The assay was performed in technical triplicates (1, 2, 3), subtracted by Buffer treatment (negative control, 0% lysis)and normalized against 1% Triton X-100 treatment (positive control, 100% lysis). Normalized activity was averaged (mean) and the standard deviation (SD) was calculated.