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.     

Effectiveness of potato cultivation using nanosized silica under conditions of Kamchatka krai

The results of trials of nanosized silica and its preparation forms under the conditions of Kamchatka krai are given. The dose and methods of silica usage for potato cultivation were identified. When introduced into the soil, silica improved productivity to 16.1–25.7% (2.8–3.6 t/ha). Treatment of tubers and plants with Miwa agro improved productivity to 12.4–16.9% (2.2–3.0 t/ha), with silica (gel) to 13.5–20.3% (2.4–3.6 t/ha) and silica (powder) to 10.7–16.4% (1.9–2.9 t/ha). We offer effective methods of using silica and Miwa agro to reduce the incidence of Rhizoctonia solani. Silica improves phosphorus-potassium nutrition of plants.     

Accumulation of Mn(II) in Deinococcus radiodurans facilitates gamma-radiation resistance

Deinococcus radiodurans is extremely resistant to ionizing radiation. How this bacterium can grow under chronic gamma radiation [50 grays (Gy) per hour] or recover from acute doses greater than 10 kGy is unknown. We show that D. radiodurans accumulates very high intracellular manganese and low iron levels compared with radiation-sensitive bacteria and that resistance exhibits a concentration-dependent response to manganous chloride [Mn(II)]. Among the most radiation-resistant bacterial groups reported, Deinococcus, Enterococcus, Lactobacillus, and cyanobacteria accumulate Mn(II). In contrast, Shewanella oneidensis and Pseudomonas putida have high iron but low intracellular manganese concentrations and are very sensitive. We propose that Mn(II) accumulation facilitates recovery from radiation injury.     

Psychrotolerant actinomycetes in soils of the tundra and northern taiga

Actinomycetes adapted to low-temperature conditions are present in the cold soils of the tundra and northern taiga in quantities comparable to mesophylic forms and dominate in the soil actinomycete complex. Actinomycetes isolated from cold soils were identified as Streptomyces. Most actinomycetes relate to psychrotolerant forms according to habitation temperature. Two of them are conditionally psychrophilic. Specific properties of the investigated populations were identified by multirespirometrical testing.     

嗜水气单胞菌ZN1攻击鳗鲡后的组织病理观察

采用1/2半致死剂量的嗜水气单胞菌ZN1对鳗鲡进行腹腔注射,在第0 d、1 d、3 d、7 d、14 d、21 d采集鳗鲡肝、脾、肾、肠,观察鳗鲡经嗜水气单胞菌活菌攻击后各脏器的组织病理变化及脏器的损伤修复情况。结果显示,嗜水气单胞菌活菌ZN1攻击后鳗鲡肝、肾、脾、肠等组织细胞均出现程度不同的病变,且持续时间长达14 d以上,同时血液中的血栓细胞急剧减少,甚至全部消失。上述结果表明嗜水气单胞菌攻击后可引发鳗鲡各脏器发生明显的病理变化,并提示在病原菌攻击引起鳗鲡血栓细胞的减少并恢复缓慢可能是嗜水气单胞菌导致宿主产生败血症状的重要病理机制。     

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.     

Small nuclear ribonucleoprotein remodeling during catalytic activation of the spliceosome

Major structural changes occur in the spliceosome during its activation just before catalyzing the splicing of pre-messenger RNAs (pre-mRNAs). Whereas changes in small nuclear RNA (snRNA) conformation are well documented, little is known about remodeling of small nuclear ribonucleoprotein (snRNP) structures during spliceosome activation. Here, human 45S activated spliceosomes and a previously unknown 35S U5 snRNP were isolated by immunoaffinity selection and were characterized by mass spectrometry. Comparison of their protein components with those of other snRNP and spliceosomal complexes revealed a major change in protein composition during spliceosome activation. Our data also suggest that the U5 snRNP is dramatically remodeled at this stage, with the Prp19 complex and other factors tightly associating, possibly in exchange for other U5 proteins, and suggest that after catalysis the remodeled U5 is eventually released from the postsplicing complex as a 35S snRNP particle.     

Results of endocrinologic studies in culture media after coculture of bovine oocytes with granulosa cells

The steroid hormones progesterone (P.), and testosterone (T.) were radio-immunologically determined in 108 medium samples, following co-culturing of bovine oocytes with granulosa cells. P. and T. values recorded from a control group were lower with significance than those recorded from co-culturing groups, that is 72 +/- 21 ng/ml and 264 +/- 84 pg/ml as compared to 208 +/- 138 ng/ml and 2,168 +/- 1,595 pg/ml in the oocyte plus fresh granulosa cell co-culturing group as well as 364 +/- 215 ng/ml and 825 +/- 233 pg/ml in the oocyte plus pre-incubated granulosa cell co-culturing group. These rises were accompanied by decline in maturation rate, increase in oocyte degeneration, and rises in the rates of fertilisation and segmentation.     

Bacteria able to control foot and root rot and to promote growth of cucumber in salinated soils

The aim of the present work was to test known bacterial plant growth-promoting strains for their ability to promote cucumber plant growth in salinated soil and to improve cucumber fruit yield by protecting these plants against soil-borne pathogens. Fifty-two plant-beneficial bacterial strains were evaluated for their ability to protect plants against cucumber foot and root rot after bacterization of the seeds and infestation of salinated soil with the isolated Fusarium solani pathogen. Based on the results of initial screenings, five efficient strains were selected, namely Serratia plymuthica RR-2-5-10, Stenotrophomonas rhizophila e-p10, Pseudomonas fluorescens SPB2145, Pseudomonas extremorientalis TSAU20, and P. fluorescens PCL1751. All five strains are salt tolerant since they grow well in a medium to which 3% NaCl was added. Infestation of the soil with F. solani resulted in an increase of the percentage of diseased plants from 17 to 54. Priming of seedlings with the five selected bacterial strains reduced this proportion to as low as 10%. In addition, in the absence of an added pathogen, all five strains showed a significant stimulatory effect on cucumber plant growth, increasing the dry weight of whole cucumber plants up to 62% in comparison to the non-bacterized control. The strains also increased cucumber fruit yield in greenhouse varying from 9% to 32%. We conclude that seed priming with the selected microbes is a very promising approach for improving horticulture in salinated soils. Moreover, allochthonous strains isolated from non-salinated soil, from a moderate or even cold climate, and from other plants than cucumber, functioned as well as autochthonous strains as cucumber-beneficial bacteria in salinated Uzbek soils. These results show that these plant-beneficial strains are robust and they strongly suggest they can also be used successfully in case the climate gets warmer and the soils will become more salinated. Finally, the mechanisms by which they may exert their plant-beneficial action are discussed.