Biology subjects

Rybnikov, S. R.

Publications and source records attributed to Rybnikov, S. R..

4 recordsLinked to original sources

bioRxiv2025

Integrating gene drives with established pest controls to mitigate spillover risk

Gene drives--artificial genetic constructs that can rapidly spread in a population due to biased inheritance--are a promising tool for controlling disease vectors and invasive species. While gene drives can eradicate target populations within several generations, their unintended spillover into non-target populations poses serious ecological concerns. Here, we examine how integrating gene drives with established pest control methods, such as pesticide application and sterile-male release, can mitigate spillover risk. We develop optimal control models to identify cost-effective treatment strategies that minimize total eradication costs, accounting for actual investments and potential damage from spillover. We show that pesticides are most cost-effective at the intermediate stage of eradication when gene drives have already slowed population growth but do not yet substantially suppress the population. For sterile-male release, however, we observe two distinct types of optimal strategies, the choice of which depends on parameter values: intensive early-stage releases, or mild later-stage releases. Using established pest controls also relaxes requirements to gene drive design, favoring milder suppressive effects as the treatment intensifies.

ecology↗

bioRxiv2018

The evolutionary advantage of condition-dependent recombination in a Red Queen model with diploid antagonists

Antagonistic interaction, like those between a host and its parasite, are known to cause oscillations in genetic structure of both species, usually referred to as Red Queen dynamics (RQD). The RQD is believed to be a plausible explanation for the evolution of sex/recombination, although numerous theoretical models showed that this may happen only under rather restricted parameter values (selection intensity, epistasis, etc.). Here, we consider two diploid antagonists, each with either two or three selected loci; the interaction is based on matching phenotypes model. We use the RQD, whenever it emerges in this system, as a substrate to examine the evolution of one recombination feature, condition dependence in diploids, which still remains an underexplored question. We consider several forms of condition-dependent recombination, with recombination rates in the host being sensitive either to the parasites mean fitness, or to the hosts infection status, or to the hosts genotype fitness. We show that all form of condition-dependent recombination can be favored over the corresponding optimal constant recombination rate, even including situations in which the optimal constant recombination rate is zero.

evolutionary biology↗

bioRxiv2018

Desiccation-induced changes in recombination rate and interference in fruit flies: an evidence for fitness-dependent plasticity

Meiotic recombination is evolutionarily ambiguous, giving both benefits and costs to its bearers, with the resultant depending on a variety of conditions. The existing theoretical models explain why recombination does exist while the existence of its essential features remains underexplored. Here we test whether recombination plasticity and interference plasticity are fitness dependent. We compare effects of desiccation on recombination and interference in chromosome 3 in desiccation-sensitive and desiccation-tolerant Drosophila lines. We show that in desiccation-sensitive genotypes the treatment causes significant segment-specific increase in single- and double-crossover frequencies while in desiccation-tolerant genotypes changes are less pronounced, if seen at all. These results indicate that desiccation is a recombinogenic factor, and that desiccation-induced changes in both recombination and interference are fitness dependent, with a negative-feedback pattern implying the tendency of less fitted individuals to produce more variable progeny. Such dependence may play an important role in regulation of genetic variation in population experiencing environmental challenges.

genetics↗

bioRxiv2018

Fitness-dependent recombination can be evolutionarily advantageous in diploids: a deterministic mutation-selection balance model

Recombinations omnipresence in nature is one of the most intriguing problems in evolutionary biology. The question of why recombination exhibits certain general features is no less interesting than that of why it exists at all. One such feature is recombinations fitness dependence (FD). The so far developed population-genetics models have focused on the evolution of FD recombination mainly in haploids, although the empirical evidence for this phenomenon comes mostly from diploids. Using numerical analysis of modifier models for infinite panmictic populations, we show here that FD recombination can be evolutionarily advantageous in diploids subjected to purifying selection. This advantage is associated with benefits from the differential rate of disruption of lower- vs higher-fitness genotypes, that can be manifested in systems with at least three selected loci. We also show that in systems with linked modifier, an additional contribution to the evolutionary advantage of FD recombination may come from fitness-dependence of the intensity of modifier linkage to the selected system, although the contribution of the last effect vanishes with tighter linkage within the selected system. We also show that in systems with three selected loci, FD recombination may give rise to negative crossover interference, which may be beneficial by itself. Yet, the role of such FD-induced crossover interference in the evolutionary advantage of FD recombination is minor. Remarkably, FD recombination was often favored in situations where any constant non-zero recombination was rejected, implying a relaxation of the rather strict constraints on major parameters (e.g., selection intensity and epistasis) required for the evolutionary advantage of non-zero recombination formulated by classical models.

evolutionary biology↗