Vol 21, No 1 (2023)

Studying the role of inositol phosphates in the regulation of signal exchange between leguminous plants and nodule bacteria is of great interest since it affects the regulation of calcium level in the root cells in response to bacterial signals during symbiosis development. The regulation of intracellular calcium content is one of the key events in the control of symbiosis development, but remains very poorly understood. In present work, we revealed a significant increase in the content of inositol hexasphosphate (IP₆), which occurs in response to the recognition of Nod factors and indicates that in plants, unlike animals, this form (along with the inositol triphosphate (IP₃)) may be important for signal transduction. This is consistent with the data that receptor for IP₃ in plants has not yet been found, despite numerous efforts.

Expression analysis of the genes encoding enzymes of two biosynthetic pathways for inositol phosphates showed stimulation of the PsITPK1 gene (Psat6g210960), which can control the phospholipid-independent pathway for synthesis of these compounds. Despite the fact that PsPIP5K (Psat5g134320) important for another pathway did not show increased expression in our experiments upon inoculation, the activation of the phospholipid-dependent pathway of inositol phosphate biosynthesis can be evidenced by stimulation of a number of genes encoding pospholipases C (PLCs) which were previously found in pea Pisum sativum as well as during analysis of transcriptome of Medicago truncatula root treated with Nod factors. Therefore, in plants, in contrast to animals, the pathways for the synthesis of inositol phosphates can be more diverse, which indicates the plasticity of signal pathways.

The dynamics of the composition of the populations of Adalia bipunctata L. in St. Petersburg and Yalta (Crimean Peninsula) for 47–32 years has been studied. The proportion of black individuals in them decreased by almost 2 times. Comparison of the composition of populations with climatic features of habitats (average annual temperature) showed that the proportion of black individuals in the population negatively correlates with the average annual temperature of the previous year. The observed change in the composition of geographically remote populations is probably the effect of global warming.

The expansion of the spectrum of use of food additives and, in particular, food dyes (FD), increases the risk of increasing human exposure to genotoxicants. Since in real life, not pure substances with proven genetic safety are in contact with a person, but complex mixtures of unknown composition, even minor impurities in which can become an additional source or modifier of genome instability effects. Of particular concern in this aspect are synthetic FD azo and diazo compounds which can be transformed by human intestinal microflora to some forms of genotoxicants. The purpose of the work is to evaluate the genotoxic effects of 0–2 mg/mL of Tartrazine FD (E102) purchased in a retail network in a micronucleus test on human blood cells cultured under cytokinetic block conditions in parallel in presence and without rat S9 hepatocyte metabolic activation system.

Genotoxic effects were found in cultures without metabolic activation at 0.0000256–0,00064 mg/mL and 0.4 mg/mL of tartrazine, and in the presence of S9 — at 0.0000256 mg/mL, 0,000128 mg/mL and 0.16 mg/mL of tartrazine. For the first time, a dose-dependent suppression of mitotic and proliferative activity of lymphocytes induced by the tested tartrazine sample was revealed, as well as a dose-dependent U-shaped curve in the frequency of apoptosis. The data obtained indicate the presence of genotoxic activity of the studied sample.

We discuss the necessity to create the system for evaluation the genotoxic safety of FD real mixtures from a retail network.

Background. The epigenome of gametes is formed under the control of the developmental programme and the influence of environmental factors. How cytosine oxidation patterns are formed and altered in human spermatogenesis remains obscure so far.

The aim of the study was to assess 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) patterns in human spermatogenic cells and spermatozoa.

Materials and Methods. The study was performed on testicular biopsy samples of 10 azoospermic patients and ejaculate samples of 5 sperm donors and 8 patients from infertile couples. The microscope slides were prepared for further indirect immunofluorescence to detect 5fC and 5caC and FISH to determine spermatogenic cell ploidy.   

Results. 5fC and 5caC were undetectable in mitotic and meiotic chromosomes of spermatogenic cells, and was present exclusively in some spermatogonia and spermatid interphase nuclei as well as in some ejaculated spermatozoa. The frequency of spermatozoa with 5fC and 5caC varied in a wide range and was higher in patients than in sperm donors (p=0,007, p=0,028). The increase in frequency of spermatozoa with 5fC and 5caC was accompanied with the decrease in frequency of morphologically normal and progressively motile spermatozoa.

Conclusions. 5fC and 5caC are differentially distributed in human spermatogenic cells and spermatozoa. The immunocytochemically detected increase of 5fC and 5caC in individual spermatozoa is most likely induced by oxidative stress caused by effects of internal and external factors rather than developmental programme. The evaluation of 5fC and 5caC in spermatozoa can be potentially used as an additional criterion of ejaculate quality.

Variability of terry flowers in buttercup Ranunculus acris from different populations demonstrates the anthropogenic impact on the environment. Schoolchildren carried out training works analyzing the frequency of occurrence of the trait “double” of a buttercup flower in the populations of the North-West Region of Russia. The data obtained made it possible to discuss questions about the mechanisms of action of environmental pollution by surfactants and unsaturated hydrocarbons. The article emphasizes the importance: of the direct joint participation of schoolchildren and university professional teachers in environmental research; of the visibility, evidence and significance of their results; of competent comprehensive discussion for the formation of a bio- and ecocentric worldview. The latter is especially important for the tuition of qualified scientific staff in the field of ecological genetics.

Demographic history reconstruction is based on the estimation of effective population size (N_e), which is inferred and interpreted in various fields of evolutionary and conservation biology. Interest in Ne estimation is growing, as the key evolutionary forces and their are linked to N_e, and genetic data become increasingly accessible. However, what is effective population size, and how can we obtain an estimate of effective population size? In this review, we describe the history of the term “N_e” and explore existing methods for obtaining historical and contemporary estimates of changes in effective population size. We provide a detailed overview of methods based on sequential Markovian coalescence (SMC), generalized phylogenetic coalescence (G-PhoCS), identity by descent (IBD) and identity by state (IBS) similarity, as well as methods using allele frequency spectrum (AFS). For each method, we briefly summarize the underlying theory and note its advantages and disadvantages. In the final section of the review, we present examples of the use of these methods for various non-model species with conservation status.