Antimicrobial peptides of invertebrates. Part 1. structure,biosynthesis, and evolution

Antimicrobial peptides and proteins (AMPs) are among the most important components of the immune system of multicellular organisms. The role of AMPs is of particular importance for invertebrates which constitute the vast majority of species diversity of the living world, because these animals lack acquired immunity. The AMPs of animal origin are ribosomally-synthesized molecules that have, as a rule, a positive net charge and amphiphilic properties. They can act against bacteria, yeast and filamentous fungi, protozoa, and enveloped viruses. AMPs can also play a role of mediators of the immune system. Search and investigation for protective factors of the invertebrate host defense provide a better understanding of mechanisms of the innate immunity of humans and other mammals and give a key to a development of new medicines. The first part of this review focuses on special features of a structure, biosynthesis, regulation of gene expression, and molecular evolution of AMPs of invertebrates.     

Voice Prosthetic Biofilm Formation and Candida Morphogenic Conversions in Absence and Presence of Different Bacterial Strains and Species on Silicone-Rubber

Morphogenic conversion of Candida from a yeast to hyphal morphology plays a pivotal role in the pathogenicity of Candida species. Both Candida albicans and Candida tropicalis, in combination with a variety of different bacterial strains and species, appear in biofilms on silicone-rubber voice prostheses used in laryngectomized patients. Here we study biofilm formation on silicone-rubber by C. albicans or C. tropicalis in combination with different commensal bacterial strains and lactobacillus strains. In addition, hyphal formation in C. albicans and C. tropicalis, as stimulated by Rothia dentocariosa and lactobacilli was evaluated, as clinical studies outlined that these bacterial strains have opposite results on the clinical life-time of silicone-rubber voice prostheses. Biofilms were grown during eight days in a silicone-rubber tube, while passing the biofilms through episodes of nutritional feast and famine. Biofilms consisting of combinations of C. albicans and a bacterial strain comprised significantly less viable organisms than combinations comprising C. tropicalis. High percentages of Candida were found in biofilms grown in combination with lactobacilli. Interestingly, L. casei, with demonstrated favorable effects on the clinical life-time of voice prostheses, reduced the percentage hyphal formation in Candida biofilms as compared with Candida biofilms grown in absence of bacteria or grown in combination with R. dentocariosa, a bacterial strain whose presence is associated with short clinical life-times of voice prostheses.     

Larval Starvation Resistance in Invasive and Native Populations of the Multicolored Asian Ladybird,Harmonia axyridis (Pallas) (Coleoptera,Coccinellidae)

Entomological Review - Resistance of Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae) larvae to long-term (up to 8 days) starvation was studied under laboratory conditions. The experiments...     

The First Recombinant Viper Three-Finger Toxins: Inhibition of Muscle and Neuronal Nicotinic Acetylcholine Receptors

Genes encoding two three-finger toxins TFT-AF and TFT-VN, nucleotide sequences of which were earlier determined by cloning cDNA from venom glands of vipers Azemiops feae and Vipera nikolskii, respectively, were expressed for the first time in E. coli cells. The biological activity of these toxins was studied by electrophysiological techniques, calcium imaging, and radioligand analysis. It was shown for the first time that viper three-finger toxins are antagonists of nicotinic acetylcholine receptors of neuronal and muscle type.     

Weight dynamics in females of invasive and autochthonous populations of <Emphasis Type="Italic">Harmonia axyridis</Emphasis> (Pallas) (Coleoptera,Coccinellidae) during the induction of reproductive diapause

Under natural conditions, predatory insects often faced the shortage of food caused by an increase in the predator population density and/or a decrease in the prey population density. Experimental studies demonstrated that females of two laboratory strains that originated from autochthonous (the Russian Far East) and invasive (Krasnodar territory of Russia) populations of the aphidophagous ladybird beetle, Harmonia axyridis showed two responses to the absence or shortage of aphids. The first response, termination of oviposition, was observed in several days after transfer to the poor diet, it was independent of photoperiod, and it was stronger in females of the invasive line. The second response, induction of reproductive diapause, was observed in 20 days after transfer to the poor diet, it interacted with the long-day photoperiodic response, and it was stronger in females of the autochthonous line. The induction of reproductive diapause (in comparison with a simple termination of oviposition) is a more basic and less easily reversible physiological process. Thus, we conclude that under natural conditions, females of invasive populations terminate oviposition with the first signs of a shortage of aphids more quickly than females of autochthonous populations and also more quickly start oviposition again with an increase in prey population density. Possibly, these features can be considered as adaptations to new, less stable and less predictable environmental conditions. DOI: 10.1134/S0013873816080029     

Effect of diphtheria toxin on the release and extractability of histones from the liver cell nuclei of guinea pigs]

The release and extraction of histones from the nuclei of guinea pig liver under the influence of diphteria toxin was investigated in vivo and in vitro. A considerable loss of nuclear histones, increase of easily extracted arginine-rich histones and a more complete extraction of lysine-rich ones have been shown. A possible role of histones in the development of diphteria intoxication is discussed.     

An enhanced biodegradation of crude oil by <Emphasis Type="Italic">Psedomonas</Emphasis> plasmid-bearing strains in model soil systems

Oil biodegradation in sterile and nonsterile model soil systems has been studied. A comparison of process efficiency using indigenous microorganisms, introduced plasmid-free bacteria, and strains bearing various plasmids of naphthalene degradation was carried out. It was shown, in almost all variants of the experiment, that the total oil reduction in the nonsterile soil was higher than in the sterile soil. The highest level of degradation was observed in soil systems containing plasmid-bearing strains.     

Non-contiguous finished genome sequence of Aminomonas paucivorans type strain (GLU-3)

Aminomonas paucivorans Baena et al. 1999 is the type species of the genus Aminomonas, which belongs to the family Synergistaceae. The species is of interest because it is an asaccharolytic chemoorganotrophic bacterium which ferments quite a number of amino acids. This is the first finished genome sequence (with one gap in a rDNA region) of a member of the genus Aminomonas and the third sequence from the family Synergistaceae. The 2,630,120 bp long genome with its 2,433 protein-coding and 61 RNA genes is a part of the GenomicEncyclopedia ofBacteria andArchaea project.