[A simple and effective method for assessing chromatin diminution values in copepods using qPCR].

The value of chromatin diminution (CD) in different species of freshwater cyclopoid copepods can differ significantly. The biological and evolutionary roles of these differences remain unclear. To expand the knowledge on CD distribution and magnitude in this group of copepods, a quick method for its evaluation was required. This study proposes a simple approach for CD assessment in copepods using quantitative realtime PCR (qPCR). The magnitude of changes in the genome size was assessed by comparing fluorescence curves of qPCR fragments of target genes for pre- and post-diminution materials. The method was tested on four cyclopoid copepods species. In Cyclops kolensis, CD was assessed as 95.3 ± 1.2; in Acanthocyclops vernalis it was assessed at 94.6 ± 0.8%; at C. insignis, it was 82.3 ± 5.2%; and for the first time, CD was found in Megacyclops viridis at 91.1 ± 2.6%. The advantages of our approach are its rapidity, simplicity and minimal requirements of materials studied.

[Genetic polymorphism of a pelagic fish species, little Baikal oilfish Comephorus dybowski, deduced from analysis of microsatellite loci].

Intraspecific genetic polymorphism of a Baikal Lake endemic, little Baikal oilfish (Comephorus dybowski Korotneff, 1905), was evaluated based on microsatellite analysis. Six microsatellite loci designed for the European sculpin, Cottus gobio, were used. Each locus was typed using 25 to 35 individuals from each of the Baikal trenches (southern, middle, and northern). Analysis of genetic differentiation (F(ST) and R(ST)) revealed no statistical significant differences between the samples. The data showed that the target species was represented by a single panmictic stable population.

[Proliferative activity and the rate of differentiation of rat bone marrow cells in normal conditions and in early periods of acute radiation sickness]. / Proliferativnaia aktivnost' i skorost' differentsirovki kletok kostnogo mozga krys v norme i v rannie sroki ostroi luchevoi bolezni.

The autoradiographic method was used to study proliferative activity of cells of a myeloid and erythroid compartments of the bone marrow of intact and irradiated (a single exposure of 10 Gy) rats. The proliferative activity and differentiation rate of cells decreased at early times after irradiation. It was shown that giant neutrophils had heavy tracer nuclei, were formed from myeloblasts, being at the most active phase of the S stage at the time of irradiation, and had a very low differentiation rate.

[Effect of carminomycin on bone marrow cell proliferative activity and differentiation rate]. / Vliianie karminomitsina na proliferativnuiu aktivnost' i skorost' differentsirovki kletok kostnogo mozga.

Autoradiographic investigations with the use of 3H-thymidine were performed on 140 noninbred albino rats. The fate of the label in the cells of the myeloid series was followed in the experimental and control groups. The animals of the experimental group were treated with carminomycin in the LD50 30 minutes after injecion of 3H-thymidine. The mitotic cycle of the nondifferentiated cells and promyelocytes + myelocytes in the control animals was equal to 24 hours, the period and rate of the metamyelocyte maturation being 10 hours and 0.81 per cent/hour respectively. The mitotic cycle of the nondifferentiated cells and promyelocytes + myelocytes during the first division after carminomycin administration increased up to 48 hours due to the block of G2-period, the period and rate of the metamyelocyte maturation being 18 hours and 0.43 per cent/hour respectively. The myelotoxic effect of carminomycin was due to the damage of the dividing cells in G2-period of the mitotic cycle, decreased rate of differentiation and death of the cells after or during the first and second divisions.

[Kinetics of bone marrow cells under conditions of fractional x-irradiation]. / Kinetika kletok kostnogo mozga v usloviiakh fraktsionirovannogo rentgenovskogo oblucheniia

A study was made of the damaging effect of fractionating X-irradiation (12 rad a day, up to the sum total doses of 250, 500, 750, 1000 and 1500 rad) on the hemopoiesis in guinea pigs. A phasic character of the changes in the erythro- and myelopoiesis during the damage was revealed. The first phase was attented by the activation of the proliferation processes expressed in the increase of mitotic index, reduced duration of the mitotic cycle of the cells belonging to the erythroid and the myeloid series and their accelerated differentiation, this stipulating for a sufficient entrance of the cells into the blood flow and maintaining the erythrocyte and leukocyte content in the peripheral blood approaching the normal level. A reduction of the proliferative processes in the bone marrow was observed during the second phase; these were also a reduction of the mitotic index, prolongation of the mitotic cycle and of the rate cell diferentiation of the erythroid and myeloid series, this being accompanied by anemia and leukopenia in the peripheral blood.