Identification of several coding sequences of phospholipase A2 protein in the venom gland of the scorpion of Hemiscorpius lepturus using RNA-sequencing

The scorpion of Hemiscorpius lepturus is the deadliest scorpion in Iran, so it is very important from a medical point of view. Clinical symptoms caused by H. lepturus scorpion envenoming such as neurotoxic effects, skin burns, and some inflammatory reactions have been attributed to its phospholipase A2 activity. The aim of this study is to identify and categorize the genes encoding phospholipase A2 in H. lepturus scorpion venom gland. For this purpose, in this study, a cDNA library was produced from the venom glands of this scorpion using the Illumina RNA sequencing technique. The coding sequences of PLA2 were identified and extracted using the basic local alignment search tool (BLAST) and similarity searches between raw venom gland data with sequences recorded from other arthropods, especially the scorpion Centruroides sculpturatus. These searches led to the discovery of several homologs of PLA2 in the venom glands of this scorpion with sequence similarity to platelet acetylhydrolase-activating factor (PAFA), calcium-dependent PLA2s (cPLA2), secreted PLA2s (sPLA2), calcium-independent PLA2s (iPLA2) and, group III heterodimeric phospholipase A2 (hgPLA2). Most of the found sequences showed the most similarity with the PLA2 sequences from scorpions of C. sculpturatus and Androctonus crassicauda. This report is one of the few transcriptome sequencing efforts to identify, classify and analyze the physicochemical properties of PLA2 sequences form venom gland of H. lepturus, in which the phylogenetic relationships between different arthropods were investigated using the identified sequences of the genus Hemiscorpius.