Differential expression of DTSsa4 Tc1-like transposons in closely related populations of Baikal ciscoes

Two representatives of Baikal ciscoes—lake cisco and omul—diverged from a common ancestor as recently as 10–20 thousand years ago. We have found an increasing expression level of DTSsa4 Tc1-like DNA transposons in cisco and omul brains. The mapping of the sequences of these transposons from Salmo salar and Danio rerio genomes has shown that in some cases, these transposons are located in the 5′ and 3′ regions, as well as in the promoter regions of various genes. Probably, Tc1-like transposons affect the activity of neighboring genes, providing the adaptive divergence of the cisco population.     

Experimental study of the effects of amiridin and tacrine on learning and memory

The authors studied the influence of amiridin and tacrine on learning and memory in mice and rat by passive avoidance conditioning test at norm and under scopolamine induced amnesia as well as of their effect on acetylcholine esterase (AChE) activity in brain cortex homogenates. Amiridin in doses 0.1 and 0.2 mg/kg showed a beneficial action on conditioning in untreated animals, its effect being comparable with that of piracetam. Tacrine was ineffective. In scopolamine treated animals amiridin and tacrine showed anti-amnestic action at dose of 0.1 mg/kg which was found ineffective with respect to AChE activity. The data suggests that the ameliorating effect of amiridin and tacrine on cognitive abilities in patients with senile dementia is not related their anticholinesterase properties.     

Hydrolysis of Chitosan Sulfate with an Enzyme Complex from Streptomyces kurssanovii

The possibility of enzymatic hydrolysis of chitosan was shown. The optimum conditions for the process are sodium acetate buffer pH 6.0, 37°C, 24 h, and a chitosan sulfate–protein volume ratio of 500 : 1 in the enzyme preparation. During hydrolysis, the intrinsic viscosity of chitosan sulfate solution decreased by a factor of 2.7.     

Bacterioneuston Abundance and Physicochemical Properties of the Surface Microlayer of Lake Baikal

Biology Bulletin - Abstract—The aquatic surface microlayer at the interface between the atmosphere and the hydrosphere occupies 70% of the Earth’s surface, covering all water bodies....     

The use of the indirect hemagglutination reaction for the serodiagnosis of HIV infection

An assay system, based on the passive hemagglutination test and permitting the serodiagnosis of HIV infection with correct results in more than 99% of cases, has been developed. Three kinds of freeze-dried erythrocyte diagnostica (with shelf life exceeding 6 months), possessing high serological activity and sensitized with recombinant gene-engineering polypeptides, have been obtained. The proposed assay system is highly promising for mass examination of sera for the presence of antibodies to HIV due to the simplicity of assay techniques, the possibility of storing the diagnostica within a wide range of temperatures (4 degrees-30 degrees C) and obtaining results in a short time (3 hours).     

Single molecule detection of PARP1 and PARP2 interaction with DNA strand breaks and their poly(ADP-ribosyl)ation using high-resolution AFM imaging

PARP1 and PARP2 are implicated in the synthesis of poly(ADP-ribose) (PAR) after detection of DNA damage. The specificity of PARP1 and PARP2 interaction with long DNA fragments containing single- and/or double-strand breaks (SSBs and DSBs) have been studied using atomic force microscopy (AFM) imaging in combination with biochemical approaches. Our data show that PARP1 localizes mainly on DNA breaks and exhibits a slight preference for nicks over DSBs, although the protein has a moderately high affinity for undamaged DNA. In contrast to PARP1, PARP2 is mainly detected at a single DNA nick site, exhibiting a low level of binding to undamaged DNA and DSBs. The enhancement of binding affinity of PARP2 for DNA containing a single nick was also observed using fluorescence titration. AFM studies reveal that activation of both PARPs leads to the synthesis of highly branched PAR whose size depends strongly on the presence of SSBs and DSBs for PARP1 and of SSBs for PARP2. The initial affinity between the PARP1, PARP2 and the DNA damaged site appears to influence both the size of the PAR synthesized and the time of residence of PARylated PARP1 and PARP2 on DNA damages.     

Meadow Birds under Waning Traditional Pasture Animal Husbandry

Biology Bulletin - As a result of long-term studies in the areas of abandoned meadows and grasslands in Arkhangelsk, Novgorod, Ivanovo, and Moscow regions, we found the main peculiarities of bird...     

Morphology and ultrastructure of trichomes of intact and in vitro plants of stevia rebaudiana Bertoni with reference to biosynthesis and accumulation of steviol glycosides

The ultrastructure of trichomes of intact and in vitro plants of stevia were investigated under scanning and transmission electronic microscopy. Three types of trichomes were found on both the upper and lower surfaces of the leaf: viz. rounded glands and large and small trichome. The density of trichomes on the surface of upper leaves is higher than on lower leaves, while in vitro plants are characterized with lower density of trichomes than intact ones. The positive correlation between number of trichomes on leaves and content of steviol glycosides (SGs) in them was found. Three basic stages of ontogeny of gland cells were revealed which reflect the sequence of secrete accumulation.