Stress exposure during the preimplantation period affects blastocyst lineages and offspring development

We found retardation of preimplantation embryo growth after exposure to maternal restraint stress during the preimplantation period in our previous study. In the present study, we evaluated the impact of preimplantation maternal restraint stress on the distribution of inner cell mass (ICM) and trophectoderm (TE) cells in mouse blastocysts, and its possible effect on physiological development of offspring. We exposed spontaneously ovulating female mice to restraint stress for 30 min three times a day during the preimplantation period, and this treatment caused a significant increase in blood serum corticosterone concentration. Microscopic evaluation of embryos showed that restraint stress significantly decreased cell counts per blastocyst. Comparing the effect of restraint stress on the two blastocyst cell lineages, we found that the reduction in TE cells was more substantial than the reduction in ICM cells, which resulted in an increased ICM/TE ratio in blastocysts isolated from stressed dams compared with controls. Restraint stress reduced the number of implantation sites in uteri, significantly delayed eye opening in delivered mice, and altered their behavior in terms of two parameters (scratching on the base of an open field test apparatus, time spent in central zone) as well. Moreover, prenatally stressed offspring had significantly lower body weights and in 5-week old females delivered from stressed dams, fat deposits were significantly lower. Our results indicate that exposure to stress during very early pregnancy can have a negative impact on embryonic development with consequences reaching into postnatal life.     

Identification of the molecular make-up of the Potato virus Y strain PVY(Z): genetic typing of PVY(Z)-NTN

Potato virus Y (PVY) strains were originally defined by interactions with different resistance genes in standard potato cultivars. Five distinct strain groups are defined that cause local or systemic hypersensitive responses (HRs) in genetic background with a corresponding N gene: PVY(O), PVY(N), PVY(C), PVY(Z), and PVY(E). The nucleotide sequences of multiple isolates of PVY(O) and PVY(N) differ from each other by ≈8% along their genomes. Additionally, complete genome sequences of multiple recombinant isolates are composed of segments of parental PVY(O) and PVY(N) sequences. Here, we report that recombinant isolate PVY-L26 induces an HR in potato 'Maris Bard' carrying the putative Nz gene, and is not recognized by two other resistance genes, Nc and Ny(tbr). These genetic responses in potato, combined with the inability of PVY-L26 to induce vein necrosis in tobacco, clearly define it as an isolate from the PVY(Z) strain group and provide the first information on genome structure and sequence of PVY(Z). The genome of PVY-L26 displays typical features of European NTN-type isolates with three recombinant junctions (PVY(EU-NTN)), and the PVY-L26 is named PVY(Z)-NTN. Three typical PVY(NTN) isolates and two PVY(N) isolates, all inducing vein necrosis in tobacco, were compared with PVY-L26. One PVY(NTN) isolate elicited HR reactions in Maris Bard, similar to PVY-L26, while two induced a severe systemic HR-like reaction quite different from the quasi-symptomless reaction induced by two PVY(N) isolates. 'Yukon Gold' potato from North America produced HR against several PVY(NTN) isolates, including PVY-L26, but only late and limited systemic necrosis against one PVY(N) isolate. Consequently, according to symptoms in potato indicators, both PVY(Z) and PVY(NTN) isolates appeared biologically very close and clearly distinct from PVY(O) and PVY(N) strain groups.     

Improvement of laboratory phytotest for the ecological evaluation of soils

Analysis of methodological documents, Russian and foreign standards, and scientific publications has been performed to reveal best global practices and current trends in the improvement of laboratory phytotesting. It is proposed to increase the number of simultaneously used test cultures and the range of simultaneously controlled test functions at the first (screening) stage of phytotest to increase the information value of laboratory phytotests. Attention is focused on the assurance of the statistical reliability of test results. The advisability of creating universal regulations of Russian Federation for phytotesting methods to unify approaches to the ecological evaluation of soils.     

Distribution of traffic-related contaminants in urban topsoils across a highway in Moscow

Purpose

The objective of this research is to find out the spatial distribution of different traffic-related contaminants in urban topsoils across a highway (125,000 vehicles per day) in the city of Moscow, Russia.

Materials and methods

The topsoils (0–3 cm depth) were sampled 1, 6, 10, 18, and 50 m perpendicular to the roadbed in three replicates 10 m apart. We analyzed total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH), heavy metals in total and phyto-available forms (HM; Cu, Zn, and Pb), and deicing salts (DS; Cl^?). The TPH were extracted with carbon tetrachloride and detected by spectrometry and PAH were extracted with methylene chloride, separated by high-performance liquid chromatography, and determined by fluorescence detector. Total HM were extracted by microwave acid digestion with aqua regia and phyto-available forms were extracted by NH₄OAc and determined by inductively coupled plasma mass spectrometry. The DS were analyzed using an ion liquid chromatograph with a conductometric detector.

Results and discussion

Heavy soil pollution was found within 1–6 m of the road. The TPH, B[a]P, and phyto-available HM concentrations exceeded permissible levels for Russia, while total HM and DS did not. The contaminant contents sharply decreased 10 m from the road. Within 10–50 m, they reached background levels, while PAH levels were elevated. We attribute this to the greater age of soils at 10–50 m than 1–6 m from the road. The different contaminant distribution patterns are attributed to their different transportation pathways: TPH, DS, and HM generally reach soils through road spray, splashes, melting snow moved from the road surface to roadsides, and aerosol sedimentation, whereas PAH are mainly transported as airborne particles and are thus able to reach more distant locations.

Conclusions

Traffic-related soil pollution creates ecotoxicological and human-health risks. Distribution patterns vary by type of soil contaminant. The influence of the road on soil contamination was greatest within 10 m from the roadbed for TPH, HM, and DS and within 50 m for PAH. The increased PAH concentration levels with increased distance from the road highlights the importance of PAH monitoring in roadside soils.

     

Thermodynamic analysis of the effect of strongly swelling polymer hydrogels on the physical state of soil and sediment samples

The effect of five Russian and foreign hydrogels on the water retention curve (WRC) and the related physical parameters of soils and sediments differing in their genesis and degree of dispersion has been considered on the basis of a proprietary version of the equilibrium centrifugation method. The new version of the method with the use of a high-speed centrifuge has allowed obtaining WRC in a wide range of matric potentials from 0 to 3000 J/kg (pF = 4.5) with the experimental estimation of almost all the soil-hydrological constants. The first analysis of strongly swelling polymer hydrogels (SSPHs) on WRC and the structural curves of the pore size distribution in heavy-textured soils has been performed, and the possibility has been shown of increasing their water capacity at the swelling of SSPHs in the region near water saturation. The most efficient is the use of SSPHs in light soils, which allows their water retention to be brought to the level of native loamy sands and loams in the SSPH content range of 0.1–0.3% of the enclosing coarse material. The best characteristics were observed for the Russian hydrogel VUM developed by the Institute of Technical Chemistry of the Urals Branch of the Russian Academy of Sciences and produced by the Urals Plant for Chemical Reagents.     

Antiviral activity of betulin,betulinic and betulonic acids against some enveloped and non-enveloped viruses

Antiviral properties of betulin, betulinic and betulonic acids were investigated in cell cultures infected with herpes simplex type I, influenza FPV/Rostock and ECHO 6 viruses. All studied triterpenes were active against herpes simplex virus. Betulin and especially betulinic acid also suppressed ECHO 6 virus reproduction.     

Position of the head is not associated with changes in horse vision

It has become accepted that the horse cannot see directly in front when the nose is lowered and must therefore rely on the rider. We tested the hypothesis that this conclusion would be correct only if the horse did not adjust the eyeball horizontal axis to changes of the head position. The results of the present study suggest that it is unlikely that horses have limited vision in relation to their head position when driven by the rider, and that the horse maintains the optimal horizontal eyeball position regardless of head position relative to the ground.     

Microorganisms in forest soils of central Yakutia

The population of saprotrophic, oligotrophic, and nitrogen-fixing microorganisms was determined in cryogenic forest soils of central Yakutia. The number of saprotrophic bacteria ranged between 10⁸ and 10¹⁰ cell/g of soil. In the soils of Buryatia, this parameter (10⁸) was 4 orders of magnitude as high as in the soils of European Russia (10⁶). According to the increase in the total number of microorganisms in the soils studied, the forests were arranged in the following sequence: pine forest—birch forest—larch forest. The main factor that determined the saturation of the studied frozen soils with microorganisms was the landscape, i.e., the forest type and the soil type. Of minor importance were the weather conditions of the year or season investigated, which defined the intra-and interspecies variation of the total population of the soil microorganisms.