Biology subjects

Korol, A. B.

Publications and source records attributed to Korol, A. B..

10 recordsLinked to original sources

bioRxiv2025

Genetic basis of cuticular hydrocarbon variation in the desert ant

Cuticluar hydrocarbons (CHCs) are a ubiquitous component of insect cuticles that are used for a wide range of chemical signaling functions, especially recognition. Recognition and other signals are vital for the maintenance of insularity and cooperation in social insect colonies. Therefore, we expect natural selection on the composition and variabitlity of social insect CHC profiles. Selection on these signals may result in the evolution of genetic polymorphism affecting variation in CHC profiles. Here we tested for a genetic basis of CHC variation in the desert ant Cataglyphis niger. We applied a genomic mapping appraoch to a cohort of brothers from the same nest to reduce noise from environmental effects and achieve a clear statistical signal for association between the variation of CHCs and quantitative trait loci (QTL). This analysis identified 19 QTLs associated with 8 out of the 31 CHCs identified, and one QTL associated with total CHC quantity. These QTLs are located on 11 different chromosomes, including two cases where QTLs of different CHCs overlap. Each QTL explains between 13-25% of the variation in a specific CHC. We highlight several candidate genes in the QTLs identified, including fatty acid elongase and reductase genes. Our results reveal a polygenic genomic architecture underlying CHC variation in a population of the desert ant and open new research avenues into the genetic basis and evolution of chemical signaling in social insects.

ecology↗

bioRxiv2024

Transposable elements are entangled in rapid adaptation to climate change

Biodiversity conservation is urged at biodiversity hotspots that are under constant threat from anthropogenic development, yet a careful examination of the adaptive potential is a prerequisite for action. The Levant is considered a biodiversity hotspot and the distribution edge for many species, including important crop wild relatives. This region is under accelerated desertification and constantly disturbed by human activities, thus urging intervenient action. We collected and sequenced 300 wild barley plants along an eco-geographic gradient following a unique ecological-genetic sampling design. This scheme enabled to overcome the tight correlation between environmental and geographic distances. Phenotypic data was collected from 3600 progeny plants over three years and enabled to identify adaptive haplotype blocks comprised of phenological regulating genes tightly linked to drought and heat responsive genes. These haplotype blocks were highly enriched for transposable elements insertions, likely regulating genetic variation around adaptive genes, especially in stressed populations. Ecological and evolutionary models using over 2600 observations were combined to predict maladaptive risk, indicating that populations will be funneled into higher water availability refugia habitats while increasing isolation. Our findings highlight the main factors affecting rapid local adaptation and provide important recommendations for biodiversity management and conservation.

plant biology↗

bioRxiv2022

Statistical analysis and simulation allowing simultaneously positive, negative, and no crossover interference in multilocus recombination data

Crossover interference (COI) is a widespread feature of homologous meiotic recombination. It can be quantified by the classical coefficient of coincidence (CoC) `but this characteristic is highly variable and specific to the pair of chromosomal intervals considered. Several models were proposed to characterize COI on a chromosome-wise level. In the gamma model, the strength of interference is characterized by a shape parameter{nu} , while the gamma-sprinkled two-pathway model (GS) accounts for both interference-dependent and independent crossover (CO) events by fitting a mixture of gamma distributions with v>1 and v=1, correspondingly, and mixture proportions 1-p and p. In reality, COI can vary along chromosomes resulting in low compliance of the fitted model to real data. Additional inconsistency can be caused by common neglecting of possible negative COI in the model, earlier reported for several organisms. In this work, we propose an extension of the GS-model to take possible negative COI into account. We propose a way for data simulation and parameter estimation for such situations.

bioinformatics↗

bioRxiv2020

Fitness dependence preserves selection for recombination across diverse mixed mating systems

Meiotic recombination and the factors affecting its rate and fate in nature have inspired many theoretical studies in evolutionary biology. Classical theoretical models have inferred that non-zero recombination can be favoured under a rather restricted parameter range. Thus, the ubiquity of recombination in nature remains an open question. However, these models assumed constant (uniform) recombination with an equal rate across all individuals within the population. Models of fitness-dependent recombination, with the rate varying among genotypes according to their fitness have shown that such a strategy can often be favoured over the best constant recombination. Here we use simulations to show that across a range of mating systems with varying frequencies of selfing and clonality, fitness-dependent recombination is often favoured even when any non-zero constant recombination is disfavoured. This recombination-protecting effect of fitness dependence is strongest under intermediate rates of selfing or high rates of clonality.

evolutionary biology↗

bioRxiv2020

Seasonal changes in recombination rate, crossover interference, and their response to desiccation stress in a natural population of Drosophila melanogaster from India

Environmental seasonality is a potent evolutionary force, capable to maintain polymorphism, promote phenotypic plasticity, and cause bet-hedging. In Drosophila, it has been reported to affect life-history traits, tolerance to abiotic stressors, and immunity. Oscillations in frequencies of alleles underlying fitness-related traits were also documented alongside SNP alleles across genome. Here, we test for seasonal changes in recombination in a natural D. melanogaster population from India using morphological markers of the three major chromosomes. We show that winter flies (collected after the dry season) have significantly higher desiccation tolerance than their autumn counterparts. This difference proved to hold also for hybrids with three independent marker stocks, suggesting its genetic rather than plastic nature. Significant segment-specific changes are documented for recombination rate (in five of 13 intervals) and crossover interference (in five of 16 studied pairs of intervals); both single- and double-crossover rates tended to increase in the winter cohort. The winter flies also display weaker plasticity of recombination characteristics to desiccation. We ascribe the observed differences to indirect selection on recombination caused by directional selection on desiccation tolerance. Our findings suggest that changes in recombination can arise even after a short period of seasonal adaptation (~8-10 generations).

evolutionary biology↗

bioRxiv2019

Grain Protein Content QTLs Identified in a Durum x Wild Emmer Wheat Mapping Population Tested in Five Environments

AbstractWild emmer wheat (Triticum turgidum ssp. dicoccoides, WEW) was shown to exhibit high grain protein content (GPC) and therefore, possess a great potential for improvement of cultivated wheat nutritional value. A recombinant inbred line (RIL) population derived from a cross between T. durum var. Svevo and WEW acc. Y12-3 was used for construction of a high-density genetic map and genetic dissection of GPC. Genotyping of 208 F6 RILs with 15K wheat SNP array yielded 4,166 polymorphic SNP markers, of which 1,510 were designated as skeleton markers. A total map length of 2,169 cM was obtained with an average distance of 1.5 cM between SNPs. A total of 12 GPC QTLs with LOD score range of 2.7-35.9, and PEV of 2.6-26.6% were identified under five environments. Major QTLs with favorable alleles from WEW were identified on chromosomes 4BS, 5AS, 6BS and 7BL. The QTL region on 6BS coincided with the physical position of the previously cloned QTL, Gpc-B1. Comparisons of the physical intervals of the GPC QTLs described here with the results previously reported in other durumxWEW RIL population led to the identification of four common and two homoeologous QTLs. Exploration of the large genetic variation within WEW accessions is a precondition for discovery of exotic beneficial alleles, as we have demonstrated here, by the identification of seven novel GPC QTLs. Therefore, our research emphasizes the importance of GPC QTL dissection in diverse WEW accessions as a source of novel alleles for improvement of GPC in cultivated wheat.\n\nKey messageGenetic dissection of GPC in tetraploid durum x WEW RIL population, based on high-density SNP genetic map, revealed 12 QTLs, with favorable WEW allele for 11 QTLs.

genetics↗

bioRxiv2019

Variation in phosphorus and sulfur content shapes the genetic architecture and phenotypic associations within wheat grain ionome

Dissection of the genetic basis of ionome is crucial for the understanding of the physiological and biochemical processes underlying mineral accumulation in seeds, as well as for efficient crop breeding. Most of the elements essential for plants are metals stored in seeds as chelate complexes with phytic acid or sulfur-containing compounds. We assume that the involvement of phosphorus and sulfur in metal chelation is the reason for strong phenotypic associations within ionome. Thus, we adjusted element concentrations for the effect of variation in phosphorus and sulfur seed content. The genetic architecture of wheat grain ionome was characterize by QTL analysis using a cross between durum and wild emmer wheat. Adjustment for variation in P and S drastically changed phenotypic associations within ionome and considerably improved QTL detection power and accuracy, resulting in identification of 105 QTLs and 437 QTL effects for 11 elements. A search for candidate genes revealed some strong functional associations of genes involved in transport and metabolism of ions and elements. Thus, we have shown that accounting for variation in P and S is crucial for understanding of the physiological and genetic regulation of mineral composition of wheat grain ionome and can be implemented for other plants.

genetics↗

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↗