Immunocompetence increases with larval body size in a phytophagous moth

Despite the obvious benefit of an immune system, its efficacy against pathogens and parasites may show great variation among individuals, populations and species. Understanding the causes of this variation is becoming a central theme in ecology. Many biotic and abiotic factors are known to influence immunocompetence (temperature, age, etc.). However, for a given age, size among individuals varies, probably as a result of accumulated resources. Thus, these variable resources could be allocated to immune defence and, consequently, body size may explain part of the variation in immune responsiveness. However, the influence of body size on immune defence is often overlooked. The present study investigates variations in haemocyte count and phenoloxidase activity in larvae of the phytophagous vine moth Eupoecilia ambiguella Hübner of the same age, although differing in body size. The measurements of immune function are made both when the insects are immunologically naïve and 24 h after a bacterial immune challenge. The base levels of these immune parameters do not covary with body size in naïve larvae. After the bacterial immune challenge, more haemocytes and phenoloxidase enzyme are mobilized, and the mobilization of these immune effectors is correlated positively with individual body size. Thus, larger larvae exhibit higher immunocompetence than smaller ones, suggesting that smaller larvae might be more vulnerable to infection. These results suggest that body size is probably an underestimated variable, which nevertheless modulates the insect immune system and should thus be considered as a covariate in insect immune system measurement. It is recommended therefore, that body size should be taken into account in ecological immunity studies with insects. © 2013 The Royal Entomological Society     

Distribution of Charges in Bacillus intermedins 7P Ribonuclease Determines the Number of Cooperatively Melting Regions of the Globule

Abstract

A correlation between the distribution of charged side groups in the globule of Bacillus intermedius 7P ribonuclease (binase) and the process of heat denaturation was studied at different pH values in order to estimate a relation between charge distribution in globular proteins and the character of cooperative thermodynamic transitions. As was shown by comparing the results of scanning microcalorimetric analysis of heat denaturation with the three-dimentional structure of binase, at optimal pH the molecule exists as a single cooperative system stabilized by hydrogen bonds, Van der Waals' contacts, and electrostatic interactions like salt bridges. At pH lower than 4.0 (below the physiological optimum) the cooperativity type of the system was found to change due to a reversible cooperative transition in the ternary structure of the protein globule. It has been concluded that the molecular architecture and the arrangement of atoms do not change considerably in different environments; thus the thermodynamic properties of the globule vary due to the alteration of charge distribution and the consequent changes in the size and number of cooperative regions of the globule. Thus, structural and energetic domains may be non-coincident in proteins.     

Possibilities of using MIGI-K protective activity under conditions of radionuclide contamination

Experimental studies of the mussel hydrolyzate (MIGI-K) have shown that this preparation can enhance both general and radiation resistance of the organism. Moreover, MIGI-K promotes elimination of incorporated radionuclides from the organism. Some properties of this preparation, in particular, the absence of toxicity or harmful side effects, have made it possible to apply MIGI-K as an adaptogen, that is, a food supplement oftherapeutic and preventive action used to increase radionuclide excretion in the Chernobyl emergency clean-up workers.     

The evaluation of viral load in patients with hemorrhagic fever with renal syndrome (HFRS) by real-time polymerase chain reaction

The system for real-time polymerase chain reaction was developed for detection of Puumala virus RNAand quantitative analysis of viral RNAload in clinical samples. Dynamics of viral load in blood samples from 12 patients with HFRS (from day 4 to day 17 of the disease) was studied. At day 4 viral RNA load varied from 4 x 10(4) to 1 x 10(6) copies/ml. During the period of observation viral load decreased by 10 - 200 times and was not detected in majority of patients to day 11 - 15 of the disease. The hantavirus persisted in blood of four patients to day 17 of the disease with viral load varied from 2.7 x 10(3) to 2 x 10(4) copies/ml. Developed method was characterized by highest sensitivity (100%) for HFRS detection from day 4 to day 8 of the disease.     

Membrane-modifying effect of taurine

The effect of taurine on membrane-associated processes was studied in rat erythrocytes and peritoneal mast cells. EPR with a spin probe 5-DS revealed a significant decrease in the order parameter S of membrane phospholipid acyl chains in vitro after incubation of erythrocytes with taurine (10 mM, 1 h). Increased susceptibility of the erythrocyte membrane to peroxide-induced lysis was also observed. These effects suggested decreased membrane microviscosity resulting from less dense packing of the phospholipids. The differential effects of taurine on stimulated Ca-dependent functional activity of peritoneal mast cells (histamine liberation) upon different ways of administration (oral, intraperitoneal, or intramuscular) suggest an indirect and complex mechanism of taurine action in the organism.     

Polymorphism of mitochondrial DNA and infection with symbiotic cytoplasmic bacterium <Emphasis Type="Italic">Wolbachia pipientis</Emphasis> in mosquitoes of the <Emphasis Type="Italic">Culex pipiens</Emphasis> (Diptera,Culicidae) complex from Russia

A total of 208 mosquitoes of the Culex pipiens complex from 15 basement and terrestrial populations collected in different regions of the European part of Russia and Siberia were examined by genetic methods. Among these, two major mitotypes, M and P, were identified. These mitotypes differed by six substitutions in the 246-bp mitochondrial DNA cytochrome oxidase I gene fragment examined. Urban basement mosquitoes C. pipiens (form molestus) were characterized by the presence of mitotype M and infection with the endosymbiotic bacteria of the genus Wolbachia. Mosquitoes of the C. pipiens complex inhabiting opened biotopes harbored mitotype P, or its variety, mitotype P1, and were not infected with Wolbachia. Thus, in natural conditions marked linkage disequilibrium between cytoplasmic elements, mitochondrial DNA and Wolbachia, can be observed. Similarity of mitotypes in form molestus mosquito from different geographical localities favors the hypothesis on the common ancestry of urban mosquitoes.Translated from Genetika, Vol. 41, No. 3, 2005, pp. 320–325.Original Russian Text Copyright © 2005 by Shaikevich, Vinogradova, Platonov, Karan, Zakharov.     

Insight into microevolution of Yersinia pestis by clustered regularly interspaced short palindromic repeats

Background

Yersinia pestis, the pathogen of plague, has greatly influenced human history on a global scale. Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR), an element participating in immunity against phages'' invasion, is composed of short repeated sequences separated by unique spacers and provides the basis of the spoligotyping technology. In the present research, three CRISPR loci were analyzed in 125 strains of Y. pestis from 26 natural plague foci of China, the former Soviet Union and Mongolia were analyzed, for validating CRISPR-based genotyping method and better understanding adaptive microevolution of Y. pestis.

Methodology/Principal Findings

Using PCR amplification, sequencing and online data processing, a high degree of genetic diversity was revealed in all three CRISPR elements. The distribution of spacers and their arrays in Y. pestis strains is strongly region and focus-specific, allowing the construction of a hypothetic evolutionary model of Y. pestis. This model suggests transmission route of microtus strains that encircled Takla Makan Desert and ZhunGer Basin. Starting from Tadjikistan, one branch passed through the Kunlun Mountains, and moved to the Qinghai-Tibet Plateau. Another branch went north via the Pamirs Plateau, the Tianshan Mountains, the Altai Mountains and the Inner Mongolian Plateau. Other Y. pestis lineages might be originated from certain areas along those routes.

Conclusions/significance

CRISPR can provide important information for genotyping and evolutionary research of bacteria, which will help to trace the source of outbreaks. The resulting data will make possible the development of very low cost and high-resolution assays for the systematic typing of any new isolate.