Many processes in living organisms are subject to periodic oscillations at different hierarchical levels of their organization: from molecular-genetic to population and ecological. Oscillatory processes are responsible for cell cycles in both prokaryotes and eukaryotes, for circadian rhythms, for synchronous coupling of respiration with cardiac contractions, etc. Fluctuations in the numbers of organisms in natural populations can be caused by the populations’ own properties, their age structure, and ecological relationships with other species. Along with experimental approaches, mathematical and computer modeling is widely used to study oscillating biological systems. This paper presents classical mathematical models that describe oscillatory behavior in biological systems. Methods for the search for oscillatory molecular-genetic systems are presented by the example of their special case – oscillatory enzymatic systems. Factors influencing the cyclic dynamics in living systems, typical not only of the molecular-genetic level, but of higher levels of organization as well, are considered. Application of different ways to describe gene networks for modeling oscillatory molecular-genetic systems is considered, where the most important factor for the emergence of cyclic behavior is the presence of feedback. Techniques for finding potentially oscillatory enzymatic systems are presented. Using the method described in the article, we present and analyze, in a step-by-step manner, first the structural models (graphs) of gene networks and then the reconstruction of the mathematical models and computational experiments with them. Structural models are ideally suited for the tasks of an automatic search for potential oscillating contours (linked subgraphs), whose structure can correspond to the mathematical model of the molecular-genetic system that demonstrates oscillatory behavior in dynamics. At the same time, it is the numerical study of mathematical models for the selected contours that makes it possible to confirm the presence of stable limit cycles in them. As an example of application of the technology, a network of 300 metabolic reactions of the bacterium Escherichia coli was analyzed using mathematical and computer modeling tools. In particular, oscillatory behavior was shown for a loop whose reactions are part of the tryptophan biosynthesis pathway.

The use of CpGV strains as the basis for bioinsecticides is an effective and safe way to control Cydia pomonella. The research is aimed at the identification and study of new CpGV strains. Objects of identification and bioinformatic analysis: 18 CpGV strains. Sequencing was carried out on a NextSeq550. Genome assembly and annotation were carried out using Spades, Samtools 1.9, MinYS, Pilon, Gfinisher, Quast, and Prokka. Comparative genomic analysis was carried out in relation to the reference genome present in the «Madex Tween» strain-producer (biological standard) according to the average nucleotide identity (ANI) criterion. The presence/absence of IAP, cathepsin, MMP, and chitinase in the genetic sequences of the strains was determined using simply phylogeny. Entomopathogenic activity was assessed against C. pomonella according to the criterion of biological efficacy. Thus, molecular genetic identification revealed that 18 CpGV strains belong to a genus of Betabaculovirus. For all the strains under study ANI values of 99% or more were obtained, and the presence of the cathepsin, chitinase, IAP, and MMP genes was noted. The strains BZR GV 1, BZR GV 3, BZR GV 7, BZR GV 10, and BZR GV L-8 showed the maximum biological efficacy: 100% on the 15th day of observation. Strains BZR GV 4, BZR GV 8, and BZR GV 13 showed efficacy at the level of the «Madex Tween» preparation: 89.5% on the 15th day of observation. The strains with the highest mortality rate of the host insect were identified: BZR GV 9, BZR GV 10, BZR GV L-6, and BZR GV L-8.

Cydia pomonella granulovirus is a natural pathogen for Cydia pomonella that is used as a biocontrol agent of insect populations. The study of granulovirus virulence is of particular interest since the development of resistance in natural populations of C. pomonella has been observed during the long-term use of the Mexican isolate CpGV. In our study, we present the genomes of 18 CpGV strains endemic to southern Russia and from Kazakhstan, as well as a strain included in the commercial preparation “Madex Twin”, which were sequenced and analyzed. We performed comparative genomic analysis using several tools. From comparisons at the level of genes and protein products that are involved in the infection process of virosis, synonymous and missense substitution variants have been identified. The average nucleotide identity has demonstrated a high similarity with other granulovirus genomes of different geographic origins. Whole-genome alignment of the 18 genomes relative to the reference revealed regions of low similarity. Analysis of gene repertoire variation has shown that BZR GV 4, BZR GV 6, and BZR GV L-7 strains have been the closest in gene content to the commercial “Madex Twin” strain. We have confirmed two deletions using read depth coverage data in regions lacking genes shown by homology analysis for granuloviruses BZR GV L-4 and BZR GV L-6; however, they are not related to the known genes causing viral pathogenicity. Thus, we have isolated novel CpGV strains and analyzed their potential as strains producing highly effective bioinsecticides against C. pomonella.

Transcription regulation plays an important role in bacterial activity. The operon concept coined by François Jacob and Jacques Monod has had a considerable effect on investigations into gene expression regulation, including modeling. However, most such studies have considered the regulation models devised manually for one or several operons. For that reason, the objective of the present study was automated genome model reconstruction for different bacteria. The suggested algorithm accounted for all possible interactions of transcription factors and their binding sites in an operon’s promoter region. Transcription factor enumeration was performed using the deep-first search technique. The obtained models are of interest for those involved in the research of transcription factor regulatory effects on bacterial gene expression in microbiology and biotechnology.

We report the near-complete genome of Cydia pomonella granulovirus BZR GV 10. The genome sequence is 123,362 bp long and shows a degree of similarity of more than 99% to the reference isolate Mexico/1963.

Endophytic bacteria play a key role in agricultural ecosystems, as they can affect the availability of various compounds, crop yield and growth, and provide resistance to diseases and pests. Therefore, the study of endophytes of agriculturally important crop plants is a promising task in the field of biological plant protection. Understanding the mechanisms of interaction between endophytic bacteria and plants will allow the use of these microorganisms as bioagents in the future and thus reduce dependence on chemical pesticides. In this paper, samples obtained from the leaves and/or roots of wheat, rapeseed and soybean are considered. Whole-genome sequencing of the isolates was performed. Using an analytical pipeline, the genomes of 15 strains of endophyte bacteria of cultivated plants were assembled and characterized. Their insecticidal and fungicidal potential was analyzed. Gene repertoire analysis performed with GenAPI showed a high degree of correspondence between the gene repertoires of strain BZR 585 against Alcaligenes phenolicus , BZR 762 and BZR 278 against Alcaligenes sp ., BZR 588 and BZR 201P against Paenochrobactrum pullorum . All strains, with the exception of BZR 162, BZR 588 and BZR 201P, were found to contain genes encoding proteins with fungicidal activity, such as iturins, fengycins and surfactins. All strains also contained genes encoding proteins with insecticidal activity, namely GroEL, Spp1Aa1, Spp1Aa2, Vpb1Ab1, Vpb4Ca1, HldE, mycosubtilin, fengycin and bacillomycin. The obtained genomic data are confirmed by the results of previous experimental studies: high insecticidal activity of a number of strains (BZR 1159, BZR 936, BZR 920, etc.) against Galleria mellonella , T enebrio molitor and Cydia pomonella , as well as fungicidal properties against Fusarium, Alternaria, Trichothecium, was demonstrated. This shows the practical significance of the identified genetic determinants for the creation of new biocontrol agents.