Acclimatory responses in enzymatic activity and metabolite concentrations in the tropical scorpion Heterometrus fulvipes

1. 1.|Changes in tissue metabolite concentrations and enzyme activities in the pedipalpal (PM) and heart (HM) muscles of the tropical scorpion Heterometrus fulvipes show that the metabolism in PM and HM is fundamentally reorganized following low (18°C) and high (38°C) temperature acclimation.

2. 2.|Changes in metabolite concentrations show that metabolite biosynthesis showed increases after cold acclimation but decreases after warm acclimation.

3. 3.|Similarly, changes in enzyme activities show a preponderance of glycolysis and HMP shunt activity after cold acclimation, while after warm acclimation glycogenolysis, oxidative metabolism and gluconeogenesis predominated.

4. 4.|Higher metabolite concentrations and enzyme activities both before and after thermal acclimation in HM reflect its greater compensatory abilities.

A novel class of antimicrobial peptides from the scorpion Heterometrus spinifer

The venom peptides from the scorpion Heterometrus spinifer have been poorly characterized so far. Here, we identified a novel class of antimicrobial peptides from the venom gland of H. spinifer, which were referred to as HsAp, HsAp2, HsAp3 and HsAp4, respectively. Each of the four peptides consists of 29 amino acid residues, and is cationic and weakly amphipathic. They display no significant homology to any other known peptides, and thus represent a new family of venom peptides from scorpions. Antimicrobial assay showed that HsAp is able to inhibit the growth of both Gram-negative and Gram-positive bacteria with the MIC values of 11.8–51.2 μM. HsAp is also able to inhibit the growth of the tested fungus. Genomic analysis indicated that the genes of all the four peptides are intronless. Our studies expand the families of antimicrobial peptides from scorpions.     

彼得异蝎捕食行为初步观察

在实验室条件下,观察研究了彼得异蝎Heterometrus petersii的捕食行为,统计分析了不同温度条件下蝎的捕食量.结果 显示,彼得异蝎捕食黄粉虫时仅使用螯,并不使用毒针,其捕食流程包括活跃、定位、尝试捕捉、捕捉失败、捕捉成功、来回走动、静止、摄取等环节.在一定温度(20～30～C)范围内,捕食量与环境温度成正比.温度为20℃时,蝎捕食量最小;温度为30℃时,蝎捕食量最大;温度为40℃时,蝎正常昼夜活动被打乱.经单因素方差分析,不同温度条件下彼得异蝎捕食量差异显著(P<0.05).