Adaptive Evolution of the Venom-Targeted vWF Protein in Opossums that Eat Pitvipers

The rapid evolution of venom toxin genes is often explained as the result of a biochemical arms race between venomous animals and their prey. However, it is not clear that an arms race analogy is appropriate in this context because there is no published evidence for rapid evolution in genes that might confer toxin resistance among routinely envenomed species. Here we report such evidence from an unusual predator-prey relationship between opossums (Marsupialia: Didelphidae) and pitvipers (Serpentes: Crotalinae). In particular, we found high ratios of replacement to silent substitutions in the gene encoding von Willebrand Factor (vWF), a venom-targeted hemostatic blood protein, in a clade of opossums known to eat pitvipers and to be resistant to their hemorrhagic venom. Observed amino-acid substitutions in venom-resistant opossums include changes in net charge and hydrophobicity that are hypothesized to weaken the bond between vWF and one of its toxic snake-venom ligands, the C-type lectin-like protein botrocetin. Our results provide the first example of rapid adaptive evolution in any venom-targeted molecule, and they support the notion that an evolutionary arms race might be driving the rapid evolution of snake venoms. However, in the arms race implied by our results, venomous snakes are prey, and their venom has a correspondingly defensive function in addition to its usual trophic role

The Indian cobra reference genome and transcriptome enables comprehensive identification of venom toxins

Snakebite envenoming is a serious and neglected tropical disease that kills ~100,000 people annually. High-quality, genome-enabled comprehensive characterization of toxin genes will facilitate development of effective humanized recombinant antivenom. We report a de novo near-chromosomal genome assembly of Naja naja, the Indian cobra, a highly venomous, medically important snake. Our assembly has a scaffold N50 of 223.35 Mb, with 19 scaffolds containing 95% of the genome. Of the 23,248 predicted protein-coding genes, 12,346 venom-gland-expressed genes constitute the \u27venom-ome\u27 and this included 139 genes from 33 toxin families. Among the 139 toxin genes were 19 \u27venom-ome-specific toxins\u27 (VSTs) that showed venom-gland-specific expression, and these probably encode the minimal core venom effector proteins. Synthetic venom reconstituted through recombinant VST expression will aid in the rapid development of safe and effective synthetic antivenom. Additionally, our genome could serve as a reference for snake genomes, support evolutionary studies and enable venom-driven drug discovery

Cholinesterase in different types of the muscle tissue during the early postmortem period for diagnosis of death coming

The purpose of the research: consisted in study of postmortem regularitiesin the content of cholinesterase in different types of muscle tissue (MT) for improving accuracy of determination of the prescription of death coming PDC.Materials and methods: The activity/level of cholinesterase was determined in homogenates of the myocardial (MMH), oesophageal (OMH), diaphragm (DMH) and intercostal muscles (IMH)within the early PMP (3-13 hours after the coming of death) on 30 human corpses. MT was sampled in conditions of postmortem biopsy with use of special instruments; MT homogenates were prepared following the standard technique with subsequent determination of cholinesterase content in MT homogenates. Results and discussion: The analysis of postmortem changes in the content of cholinesterase in MT depending upon PDC revealed that after 3 hours from the moment of death coming its highest content was in muscles of the oesophagus, the least one being in MT of the intercostal muscles (respectively, (2,717.1±37.1) and (883.5±6.2) U/g, р<0.001). Levels of cholinesterase content in MT of the myocardium and diaphragm were rather close, though they differed (respectively, (1,213.8±8.8) and (1,512.8±11.5) U/g, р<0.05), and occupied an intermediate place between the corresponding values of MT of the intercostal muscles and oesophagus.A common pattern for the content of cholinesterase in different types of MT was characterized by a decrease of this content with an increase in PDC terms; besides, the dynamic lines of its changes, that we obtained, became basic ones for substantiating quantitative time dependencies and construction of relevant nomograms for forensic diagnosis of PDC by cholinesterase content in MT. Conclusions: It was proved that the content of cholinesterase in all MT homogenates, which we studied, changed regularly (and nonlinearly), but the initial and final levels of cholinesterase content differed depending upon the type of MT. Besides, the dynamics in changes of the content of cholinesterase within the time period of 3÷13 hours from the moment of death coming differed upon the type of MT too. Advantages of the technique consist in theintegrity of biochemical examination of different types of MT and simplicity in interpretation of findings. The application of the nomogram technique for assessing PDC by cholinesterase content in MT makes it possible to improve the accuracy of diagnosis for terms of the coming of death up to 60 minutes

ВДОСКОНАЛЕННЯ ПІДХОДУ РОЗРОБКИ ПЛАНУ ЛОКАЛІЗАЦІЇ І ЛІКВІДАЦІЇ АВАРІЙНИХ СИТУАЦІЙ І АВАРІЙ (ПЛАС)

The existing regulatory framework which governs the development and implementation of PLAS is analyzed. The analysis is conducted concerning the enterprises of storage and processing of phytogenous products (grain). The proposal to include organizational and technical issues in PLAS is expressed and justified. The authors considered typical mistakes made by developers of the document, as well as approaches to elaborate PLAS grounding on two "relatively simple" components of an enterprise: a fuel storage and grain drying unit. The main accident causing factors, with the help of which the level of accident gravity can be determined, are identified in the article.Проаналізована існуюча нормативно правова база, що регламентує розробку і впровадження ПЛАС. Аналіз здійснено стосовно підприємств зберігання і переробки продукції рослинного походження (зерна). Висловлена і обгрунтована пропозиція про необхідність включення в ПЛАС організаційно-технічної частини. Розглянуто типові помилки розробників документу, а також підходи щодо розробки ПЛАС на прикладі двох «відносно простих» складових борошномельного підприємства: складу ПММ і зерносушильного агрегату. Виділені основні фактори ураження при аварії, на підставі яких можна зробити висновок про її рівень