# Selection for Plastic, Pathogen-Inducible Recombination in a Red Queen Model with Diploid Antagonists

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## Abstract

**:**

## 1. Introduction

## 2. Model and Methods

#### 2.1. Life Cycles

#### 2.2. Species Interaction

#### 2.3. Recombination Strategies

- prevention strategy—with recombination sensitive to the potential infection risk, so that recombination rate of each host class increases proportionally to the frequency $p$ of the dangerous (exactly for this class) parasite class:$${r}^{\mathrm{h}}={r}_{\mathrm{min}}^{\mathrm{h}}+p\cdot \left({r}_{\mathrm{max}}^{\mathrm{h}}-{r}_{\mathrm{min}}^{\mathrm{h}}\right).$$
- remediation strategy—with recombination sensitive to the actual infection status, so that the infected hosts display an increased recombination rate (${r}_{\mathrm{max}}^{\mathrm{h}}$) compared to their resistant counterparts (${r}_{\mathrm{min}}^{\mathrm{h}}$):$${r}^{\mathrm{h}}=\left(\right)open="\{">\begin{array}{cc}{r}_{\mathrm{min}}^{\mathrm{h}}\hfill & \mathrm{resistance}\\ {r}_{\mathrm{max}}^{\mathrm{h}}\hfill & \mathrm{infection}\end{array}$$

#### 2.4. Experimental Design

## 3. Results

#### 3.1. The System’s Dynamics and the Optimal Constant Recombination in the Host

#### 3.2. Selection for Plastic Recombination in the Host

## 4. Discussion

## Supplementary Materials

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability

## Acknowledgments

## Conflicts of Interest

## References

- Lotka, A.J. Analytical Note on Certain Rhythmic Relations in Organic Systems. Proc. Natl. Acad. Sci. USA
**1920**, 6, 410–415. [Google Scholar] [CrossRef] - Volterra, V. Fluctuations in the Abundance of a Species considered Mathematically1. Nat. Cell Biol.
**1926**, 118, 558–560. [Google Scholar] [CrossRef] - De Bach, P.; Smith, H.S. Are population oscillations inherent in the host-parasite relation? Ecology
**1941**, 22, 363–369. [Google Scholar] [CrossRef] - Stiven, A.E. Experimental Studies on the Epidemiology of the Host Parasite System, Hydra and Hydramoeba hydroxena (Entz). II. The Components of a Simple Epidemic. Ecol. Monogr.
**1964**, 34, 119–142. [Google Scholar] [CrossRef] - Van den Bosch, R.; Schlinger, E.I.; Lagace, C.F.; Hall, J.C. Parasitization of Acyrthosiphon pisum by Aphidius smithi, a density-dependent process in nature (Homoptera: Aphidae) (Hymenoptera: Aphidiidae). Ecology
**1966**, 47, 1049–1055. [Google Scholar] [CrossRef] - Haldane, J.B.S. Disease and Evolution. In Malaria: Genetic and Evolutionary Aspects; Springer: Berlin/Heidelberg, Germany, 2006. [Google Scholar]
- Van Valen, L. A new evolutionary law. Evol. Theor.
**1973**, 1, 1–30. [Google Scholar] - Bell, G. The Masterpiece of Nature: The Evolution and Genetics of Sexuality; University of California Press: Berkeley, CA, USA, 1982. [Google Scholar]
- Decaestecker, E.; Gaba, S.; Raeymaekers, J.A.M.; Stoks, R.; Van Kerckhoven, L.; Ebert, D.; De Meester, L. Host-parasite ‘Rd Queen’ dynamics archived in pond sediment. Nature
**2007**, 450, 870–873. [Google Scholar] [CrossRef] - Ebert, D. Host–parasite coevolution: Insights from the Daphnia–parasite model system. Curr. Opin. Microbiol.
**2008**, 11, 290–301. [Google Scholar] [CrossRef] - Dybdahl, M.F.; Lively, C.M. Host-parasite coevolution: Evidence for rare advantage and time-lagged selection in a natural population. Evolution
**1998**, 52, 1057–1066. [Google Scholar] [CrossRef] [PubMed] - Koskella, B.; Lively, C.M. Evidence for negative frequency-dependent selection during experimental coevolution of a freshwater snail and a sterilizing trematode. Evolution
**2009**, 63, 2213–2221. [Google Scholar] [CrossRef] - Wolinska, J.; Spaak, P. The cost of being common: Evidence from natural daphnia populations. Evolution
**2009**, 63, 1893–1901. [Google Scholar] [CrossRef] [PubMed] - Lively, C.M. A Review of Red Queen Models for the Persistence of Obligate Sexual Reproduction. J. Hered.
**2010**, 101, S13–S20. [Google Scholar] [CrossRef] - Hamilton, W.D. Sex versus Non-Sex versus Parasite. Oikos
**1980**, 35, 282. [Google Scholar] [CrossRef] - May, R.M.; Anderson, R. Epidemiology and genetics in the coevolution of parasites and hosts. Proc. R. Soc. London. Ser. B Boil. Sci.
**1983**, 219, 281–313. [Google Scholar] [CrossRef] - Hamilton, W.D.; Axelrod, R.; Tanese, R. Sexual reproduction as an adaptation to resist parasites (a review). Proc. Natl. Acad. Sci. USA
**1990**, 87, 3566–3573. [Google Scholar] [CrossRef] - Agrawal, A.F.; Lively, C.M. Infection genetics: Gene-for-gene versus matching-alleles models and all points in between. Evol. Ecol. Res.
**2002**, 4, 79–90. [Google Scholar] - Otto, S.P.; Nuismer, S.L. Species interactions and the evolution of sex. Science
**2004**, 304, 1018–1020. [Google Scholar] [CrossRef] - Engelstädter, J.; Bonhoeffer, S. Red Queen Dynamics with Non-Standard Fitness Interactions. PLoS Comput. Biol.
**2009**, 5, e1000469. [Google Scholar] [CrossRef] - Salathé, M.; Kouyos, R.D.; Bonhoeffer, S. The state of affairs in the kingdom of the Red Queen. Trends Ecol. Evol.
**2008**, 23, 439–445. [Google Scholar] [CrossRef] - Lively, C.M. Coevolutionary Epidemiology: Disease Spread, Local Adaptation, and Sex. Am. Nat.
**2016**, 187, E77–E82. [Google Scholar] [CrossRef] - Lively, C.M. Evidence from a New Zealand snail for the maintenance of sex by parasitism. Nat. Cell Biol.
**1987**, 328, 519–521. [Google Scholar] [CrossRef] - Lively, C.M.; Craddock, C.; Vrijenhoek, R.C. Red Queen hypothesis supported by parasitism in sexual and clonal fish. Nat. Cell Biol.
**1990**, 344, 864–866. [Google Scholar] [CrossRef] - Busch, J.W.; Neiman, M.; Koslow, J.M. Evidence for maintenance of sex by pathogens in plants. Evolution
**2004**, 58, 2584. [Google Scholar] [CrossRef] - Kumpulainen, T.; Grapputo, A.; Mappes, J. Parasites and sexual reproduction in psychid moths. Evolution
**2004**, 58, 1511–1520. [Google Scholar] [CrossRef] [PubMed] - Jokela, J.; Dybdahl, M.F.; Lively, C.M. The Maintenance of Sex, Clonal Dynamics, and Host-Parasite Coevolution in a Mixed Population of Sexual and Asexual Snails. Am. Nat.
**2009**, 174, S43–S53. [Google Scholar] [CrossRef] - Vergara, D.; Jokela, J.; Lively, C.M. Data from: Infection dynamics in coexisting sexual and asexual host populations: Support for the Red Queen hypothesis. Am. Nat.
**2017**, 184, 22–30. [Google Scholar] [CrossRef] - Koch, H.R.; Wagner, S.; Becks, L. Antagonistic species interaction drives selection for sex in a predator–prey system. J. Evol. Biol.
**2020**, 33, 1180–1191. [Google Scholar] [CrossRef] [PubMed] - Fischer, O.; Schmid-Hempel, P. Selection by parasites may increase host recombination frequency. Biol. Lett.
**2005**, 1, 193–195. [Google Scholar] [CrossRef] - Kerstes, N.A.G.; Bérénos, C.; Schmid-Hempel, P.; Wegner, K.M. Antagonistic experimental coevolution with a parasite increases host recombination frequency. BMC Evol. Biol.
**2012**, 12, 18. [Google Scholar] [CrossRef] [PubMed] - Plough, H.H. The effect of temperature on crossingover in Drosophila. J. Exp. Zool.
**1917**, 24, 147–209. [Google Scholar] [CrossRef] - Plough, H.H. Further studies on the effect of temperature on crossing over. J. Exp. Zool.
**1921**, 32, 187–202. [Google Scholar] [CrossRef] - Bomblies, K.; Higgins, J.; Yant, L. Meiosis evolves: Adaptation to external and internal environments. New Phytol.
**2015**, 208, 306–323. [Google Scholar] [CrossRef] - Modliszewski, J.L.; Copenhaver, G. Meiotic recombination gets stressed out: CO frequency is plastic under pressure. Curr. Opin. Plant Biol.
**2017**, 36, 95–102. [Google Scholar] [CrossRef] [PubMed] - Kathiria, P.; Sidler, C.; Golubov, A.; Kalischuk, M.; Kawchuk, L.; Kovalchuk, I. Tobacco Mosaic Virus Infection Results in an Increase in Recombination Frequency and Resistance to Viral, Bacterial, and Fungal Pathogens in the Progeny of Infected Tobacco Plants. Plant Physiol.
**2010**, 153, 1859–1870. [Google Scholar] [CrossRef] - Singh, N.D.; Criscoe, D.R.; Skolfield, S.; Kohl, K.P.; Keebaugh, E.S.; Schlenke, T.A. Data from: Fruit flies diversify their offspring in response to parasite infection. Science
**2016**, 349, 747–750. [Google Scholar] [CrossRef] - Zilio, G.; Moesch, L.; Bovet, N.; Sarr, A.; Koella, J.C. The effect of parasite infection on the recombination rate of the mosquito Aedes aegypti. PLoS ONE
**2018**, 13, e0203481. [Google Scholar] [CrossRef] - Singh, N.D. Wolbachia Infection Associated with Increased Recombination in Drosophila. G3 Genes Genomes Genet.
**2019**, 9, 229–237. [Google Scholar] [CrossRef] - Zhuchenko, A.A.; Korol, A.B.; Preigel, I.A.; Bronstein, S.I. The evolutionary role of the dependence of recombination on environment: Two and three loci models. Theor. Appl. Genet.
**1985**, 69, 617–624. [Google Scholar] [CrossRef] - Rybnikov, S.R.; Frenkel, Z.M.; Korol, A.B. What drives the evolution of condition-dependent recombination in diploids? Some insights from simulation modelling. Philos. Trans. R. Soc. B Biol. Sci.
**2017**, 372, 20160460. [Google Scholar] [CrossRef] - Otto, S.P. The Advantages of Segregation and the Evolution of Sex. Genetics
**2003**, 164, 1099–1118. [Google Scholar] [CrossRef] [PubMed] - Agrawal, A.F. Differences between selection on sex versus recombination in red queen models with diploid hosts. Evolution
**2009**, 63, 2131–2141. [Google Scholar] [CrossRef] [PubMed] - Mostowy, R.; Engelstädter, J. Host-parasite coevolution induces selection for condition-dependent sex. J. Evol. Biol.
**2012**, 25, 2033–2046. [Google Scholar] [CrossRef] - Kimura, M. A model of a genetic system which leads to closer linkage by natural selection. Evolution
**1956**, 10, 278–287. [Google Scholar] [CrossRef] - Nei, M. Modification of linkage intensity by natural selection. Genetics
**1967**, 57, 625–641. [Google Scholar] [CrossRef] - Jeffreys, A.J.; Kauppi, L.; Neumann, R. Intensely punctate meiotic recombination in the class II region of the major histocompatibility complex. Nat. Genet.
**2001**, 29, 217–222. [Google Scholar] [CrossRef] - Wegner, K.M. Clustering of Drosophila melanogaster Immune Genes in Interplay with Recombination Rate. PLoS ONE
**2008**, 3, e2835. [Google Scholar] [CrossRef] - Choi, K.; Reinhard, C.; Serra, H.; Ziolkowski, P.A.; Underwood, C.J.; Zhao, X.; Hardcastle, T.J.; Yelina, N.E.; Griffin, C.; Jackson, M.; et al. Recombination rate heterogeneity within Arabidopsis disease resistance genes. PLoS Genet.
**2016**, 12, e1006179. [Google Scholar] [CrossRef] - Dong, S.; Raffaele, S.; Kamoun, S. The two-speed genomes of filamentous pathogens: Waltz with plants. Curr. Opin. Genet. Dev.
**2015**, 35, 57–65. [Google Scholar] [CrossRef] - Dumont, B.L.; Devlin, A.A.; Truempy, D.M.; Miller, J.C.; Singh, N.D. No Evidence that Infection Alters Global Recombination Rate in House Mice. PLoS ONE
**2015**, 10, e0142266. [Google Scholar] [CrossRef] - Gratias, A.; Geffroy, V. Deciphering the Impact of a Bacterial Infection on Meiotic Recombination in Arabidopsis with Fluorescence Tagged Lines. Genes
**2020**, 11, 832. [Google Scholar] [CrossRef] - Holsinger, K.; Feldman, M.W. Linkage modification with mixed random mating and selfing: A numerical study. Genetics
**1983**, 103, 323–333. [Google Scholar] [CrossRef] - Sasaki, A.; Iwasa, Y. Optimal Recombination Rate in Fluctuating Environments. Genetics
**1987**, 115, 377–388. [Google Scholar] [CrossRef] - Hadany, L.; Beker, T. On the Evolutionary Advantage of Fitness-Associated Recombination. Genetics
**2003**, 165, 2167–2179. [Google Scholar] [CrossRef] - Agrawal, A.F.; Hadany, L.; Otto, S. The Evolution of Plastic Recombination. Genetics
**2005**, 171, 803–812. [Google Scholar] [CrossRef] - Korol, A.B.; Preigel, S.I. Host-parasite interaction as a factor of evolution of genetic recombination. Genetika
**1988**, 24, 1113–1120. (In Russian) [Google Scholar] - Preigel, S.I.; Korol, A.B. Evolution of recombination in systems of ‘host-parasite’ type: Multilocus models. Genetika
**1990**, 26, 349–358. (In Russian) [Google Scholar] - Agrawal, A.F. Similarity Selection and the Evolution of Sex: Revisiting the Red Queen. PLoS Biol.
**2006**, 4, e265. [Google Scholar] [CrossRef] - Hodgson, E.E.; Otto, S.P. The red queen coupled with directional selection favours the evolution of sex. J. Evol. Biol.
**2012**, 25, 797–802. [Google Scholar] [CrossRef] - Frenkel, V.; Ronin, Y.; Korol, A. The dynamics of the rec-system in variable environments: Haploid selection in a cyclical two-state environment. Theor. Popul. Biol.
**2006**, 70, 111–124. [Google Scholar] [CrossRef] - Rybnikov, S.; Frenkel, Z.; Korol, A.B. The evolutionary advantage of fitness-dependent recombination in diploids: A deterministic mutation–selection balance model. Ecol. Evol.
**2020**, 10, 2074–2084. [Google Scholar] [CrossRef] - Rybnikov, S.; Weissman, D.B.; Hübner, S.; Korol, A.B. Fitness dependence preserves selection for recombination across diverse mixed mating systems. bioRxiv
**2020**, 318238. [Google Scholar] [CrossRef]

**Figure 1.**The effect of recombination rate in the parasite (${r}^{\mathrm{p}}$) on the estimation of the optimal constant recombination rate in the host (${r}_{\mathrm{opt}}^{\mathrm{h}}$). The colored curves show the lower (blue) and the upper (red) estimates. All simulations are conducted for the case of obligate parasitism (=1).

**Figure 2.**The evolutionary advantage of plastic recombination over non-zero optimal constant recombination, under in-phase (

**a**) and anti-phase (

**b**) dominance. The colored markers show regimes where the prevention (yellow) and the remediation (red) strategies are favored, either totally (circles) or partially (triangles).

**Figure 3.**The system’s dynamics under different regimes favoring plastic recombination. The plots show the last 500 out of 10,000 generations of the competition between the optimal constant recombination and plastic recombination; yet, the pattern is qualitatively similar also for other time windows. The colored curves stand for the host (green) and the parasite (orange). A, B and M denote, respectively, the two interaction-mediating loci and the modifier locus while W denotes the population’s mean fitness. All examples stand for anti-phase dominance and prevention strategy: (

**a**) A regime with strong overall selection: ${s}^{\mathrm{h}}\approx 0.88$, ${s}^{\mathrm{p}}\approx 0.91$. The optimal constant recombination in the host is high: ${r}_{\mathrm{opt}}^{\mathrm{h}}\approx 0.25.$ The oscillations are fairly regular. The modifier allele for plastic recombination generally increases in frequency, again with fairly regular oscillations; (

**b**) A regime with extremely strong overall selection: ${s}^{\mathrm{h}}\approx 0.98$, ${s}^{\mathrm{p}}>0.99$. The optimal constant recombination in the host is high: ${r}_{\mathrm{opt}}^{\mathrm{h}}=0.32.$ The oscillations are regular. The modifier allele for plastic recombination generally increases in frequency, again with fairly regular oscillations; (

**c**) A regime with weak overall selection due to weak selection in the host: ${s}^{\mathrm{h}}\approx 0.14$, ${s}^{\mathrm{p}}\approx 0.70$. The optimal constant recombination in the host is very low: ${r}_{\mathrm{opt}}^{\mathrm{h}}<0.01.$ The oscillations are irregular. Although the modifier allele for plastic recombination generally increases in frequency, its oscillations are substantially irregular; (

**d**) A regime with weak overall selection due to weak selection in the parasite: ${s}^{\mathrm{h}}\approx 0.85$, ${s}^{\mathrm{p}}\approx 0.16$. The optimal constant recombination in the host is very low: ${r}_{\mathrm{opt}}^{\mathrm{h}}<0.01.$ The oscillations are irregular. Although the modifier allele for plastic recombination generally increases in frequency, its dynamics are considerably irregular; in certain time windows (like here), the decline of the modifier allele for plastic recombination may even temporally prevail.

**Figure 4.**The evolutionary advantage of plastic recombination over zero optimal constant recombination, under in-phase (

**a**) and anti-phase (

**b**) dominance. The colored markers show regimes where the prevention (yellow) and the remediation (red) strategies are favored, either totally (circles) or partially (triangles).

**Figure 5.**The effect of the magnitude of recombination plasticity on the proportion of regimes favoring plastic recombination. The line styles stand for in-phase (sold) and anti-phase (dashed) dominance, while the marker colors stand for prevention (yellow) and remediation (red) strategies.

**Table 1.**Interaction matrix: the two possible outcomes of the interaction as a function of the antagonists’ genotypes. Red and green cells stand, respectively, for infection (I) and resistance (R).

Parasite Genotype | Host Genotype | ||||||||
---|---|---|---|---|---|---|---|---|---|

${\mathit{A}}_{1}^{\mathbf{h}}{\mathit{A}}_{1}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}$ | ${\mathit{A}}_{1}^{\mathbf{h}}{\mathit{A}}_{1}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}$ | ${\mathit{A}}_{1}^{\mathbf{h}}{\mathit{A}}_{1}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}$ | ${\mathit{A}}_{1}^{\mathbf{h}}{\mathit{A}}_{2}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}$ | ${\mathit{A}}_{1}^{\mathbf{h}}{\mathit{A}}_{2}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}$ | ${\mathit{A}}_{1}^{\mathbf{h}}{\mathit{A}}_{2}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}$ | ${\mathit{A}}_{2}^{\mathbf{h}}{\mathit{A}}_{2}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}$ | ${\mathit{A}}_{2}^{\mathbf{h}}{\mathit{A}}_{2}^{\mathbf{h}}{\mathit{B}}_{1}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}$ | ${\mathit{A}}_{2}^{\mathbf{h}}{\mathit{A}}_{2}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}{\mathit{B}}_{2}^{\mathbf{h}}$ | |

In-Phase Dominance (${A}_{1}^{\mathrm{p}}<{A}_{2}^{\mathrm{p}};{B}_{1}^{\mathrm{p}}<{B}_{2}^{\mathrm{p}};{A}_{1}^{\mathrm{h}}<{A}_{2}^{\mathrm{h}};{B}_{1}^{\mathrm{h}}<{B}_{2}^{\mathrm{h}}$) | |||||||||

${A}_{1}^{\mathrm{p}}{A}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}$ | I | R | R | R | R | R | R | R | R |

${A}_{1}^{\mathrm{p}}{A}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | I | I | R | R | R | R | R | R |

${A}_{1}^{\mathrm{p}}{A}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | I | I | R | R | R | R | R | R |

${A}_{1}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}$ | R | R | R | I | R | R | I | R | R |

${A}_{1}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | I | I | R | I | I |

${A}_{1}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | I | I | R | I | I |

${A}_{2}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}$ | R | R | R | I | R | R | I | R | R |

${A}_{2}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | I | I | R | I | I |

${A}_{2}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | I | I | R | I | I |

Anti-Phase Dominance (${A}_{1}^{\mathrm{p}}<{A}_{2}^{\mathrm{p}};{B}_{1}^{\mathrm{p}}<{B}_{2}^{\mathrm{p}};{A}_{1}^{\mathrm{h}}>{A}_{2}^{\mathrm{h}};{B}_{1}^{\mathrm{h}}>{B}_{2}^{\mathrm{h}}$) | |||||||||

${A}_{1}^{\mathrm{p}}{A}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}$ | I | I | R | I | I | R | R | R | R |

${A}_{1}^{\mathrm{p}}{A}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | I | R | R | I | R | R | R |

${A}_{1}^{\mathrm{p}}{A}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | I | R | R | I | R | R | R |

${A}_{1}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}$ | R | R | R | R | R | R | I | I | R |

${A}_{1}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | R | R | R | R | I |

${A}_{1}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | R | R | R | R | I |

${A}_{2}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}$ | R | R | R | R | R | R | I | I | R |

${A}_{2}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{1}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | R | R | R | R | I |

${A}_{2}^{\mathrm{p}}{A}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}{B}_{2}^{\mathrm{p}}$ | R | R | R | R | R | R | R | R | I |

**Table 2.**The relative effects of the examined parameters (${s}^{\mathrm{h}}$, ${s}^{\mathrm{p}}$, and ${r}^{\mathrm{p}}$) and their combinations on the optimal constant recombination rate in the host (${r}_{\mathrm{opt}}^{\mathrm{h}}$).

Parameters/Combinations | In-Phase Dominance (n = 2856) | Anti-Phase Dominance (n = 3307) | ||||
---|---|---|---|---|---|---|

Model A | Model B | Model C | Model A | Model B | Model C | |

Selection Intensity in the Host (${s}^{\mathrm{h}}$) | 0.787 | - | 0.137 | 0.810 | - | 0.238 |

Selection Intensity in the Parasite (${s}^{\mathrm{p}}$) | 0.425 | - | −0.040 | 0.479 | - | 0.029 |

Recombination Rate in the Parasite (${r}^{\mathrm{p}}$) | 0.023 | 0.022 | 0.037 | 0.032 | 0.040 | 0.049 |

Overall Selection Intensity (${s}^{\mathrm{h}}\cdot {s}^{\mathrm{p}}$) | - | 0.974 | 0.889 | - | 0.970 | 0.775 |

R^{2}-Adjusted | 0.891 | 0.949 | 0.961 | 0.901 | 0.942 | 0.962 |

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**MDPI and ACS Style**

Rybnikov, S.; Frenkel, Z.; Korol, A.B.; Fahima, T.
Selection for Plastic, Pathogen-Inducible Recombination in a Red Queen Model with Diploid Antagonists. *Pathogens* **2021**, *10*, 898.
https://doi.org/10.3390/pathogens10070898

**AMA Style**

Rybnikov S, Frenkel Z, Korol AB, Fahima T.
Selection for Plastic, Pathogen-Inducible Recombination in a Red Queen Model with Diploid Antagonists. *Pathogens*. 2021; 10(7):898.
https://doi.org/10.3390/pathogens10070898

**Chicago/Turabian Style**

Rybnikov, Sviatoslav, Zeev Frenkel, Abraham B. Korol, and Tzion Fahima.
2021. "Selection for Plastic, Pathogen-Inducible Recombination in a Red Queen Model with Diploid Antagonists" *Pathogens* 10, no. 7: 898.
https://doi.org/10.3390/pathogens10070898