Keywords: models

Designing gene drives to limit spillover to non-target populations

G. Greenbaum, M. W. Feldman, N. A. Rosenberg and J. Kim,  PLOS Genetics,  17:e1009278. 2021.
We develop mathematical models of gene-drive dynamics that incorporate migration between a target and non-target populations to investigate the possibility of effectively applying a gene drive in the target population while limiting its spillovers to the non-target population ...
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Demographic feedbacks can hamper the spatial spread of a gene drive

L. Girardin and F. Débarre,  arXiv,  2021.
Our results indicate that taking into account the interplay between population dynamics and population genetics might actually be crucial, as it can effectively reverse the direction of the invasion and lead to failure. Our findings can be extended to other bistable systems, such ...
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Suppression gene drive in continuous space can result in unstable persistence of both drive and wild-type alleles

J. Champer, I. K. Kim, S. E. Champer, A. G. Clark and P. W. Messer,  Mol Ecol,  2021.
Using spatially explicit simulations, we show that the release of a suppression drive can result in what we term "chasing" dynamics, in which wild-type individuals recolonize areas where the drive locally eliminated the population. Despite the drive subsequently reconquering ...
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Making gene drive biodegradable

J. Zapletal, N. Najmitabrizi, M. Erraguntla, M. A. Lawley, K. M. Myles and Z. N. Adelman,  Philosophical Transactions of the Royal Society B: Biological Sciences,  376:20190804. 2020.
Here, we consider the inclusion of self-elimination mechanisms into the design of homing-based gene drive transgenes. This approach not only caused the excision of the gene drive transgene, but also generates a transgene-free allele resistant to further action by the gene drive. ...
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Evading resistance to gene drives

R. Gomulkiewicz, M. L. Thies and J. J. Bull,  bioRxiv,  2020.08.27.270611. 2020.
Our analyses suggest that among gene drives that cause moderate suppression, toxin-antidote systems are less apt to select for resistance than homing drives. Single drives of moderate effect might cause only moderate population suppression, but multiple drives (perhaps delivered ...
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Split drive killer-rescue provides a novel threshold-dependent gene drive

M. P. Edgington, T. Harvey-Samuel and L. Alphey,  Scientific Reports,  10. 2020.
Population genetics mathematical models are developed here to demonstrate the threshold-dependent nature of the proposed system and its robustness to imperfect homing, incomplete penetrance of toxins and transgene fitness costs, each of which are of practical significance given ...
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Modeling CRISPR gene drives for suppression of invasive rodents

S. E. Champer, N. Oakes, R. Sharma, P. García-Díaz, J. Champer and P. W. Messer,  bioRxiv,  2020.11.05.369942. 2020.
Here, we develop a high-fidelity model of an island population of invasive rodents that includes three types of suppression gene drive systems. The individual-based model is spatially explicit and allows for overlapping generations and a fluctuating population size. Our model ...
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MGDrivE 2: A simulation framework for gene drive systems incorporating seasonality and epidemiological dynamics

S. L. Wu, J. B. Bennett, H. M. Sanchez C, A. J. Dolgert, T. M. Leon and J. M. Marshall,  bioRxiv,  2020.10.16.343376. 2020.
We present MGDrivE 2 (Mosquito Gene Drive Explorer 2): an extension of and development from the MGDrivE 1 simulation framework that investigates the population dynamics of a variety of gene drive architectures and their spread through spatially-explicit mosquito populations.
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Dynamics of Wild and Sterile Mosquito Population Models with Delayed Releasing

L. M. Cai,  International Journal of Bifurcation and Chaos,  30:15. 2020.
We extend the previous ODE models to the delayed releasing models in two different ways of releasing sterile mosquitos, where both constant and exponentially distributed delays are considered, respectively. By applying the theory and methods of delay differential equations, the ...
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Vector genetics, insecticide resistance and gene drives: An agent-based modeling approach to evaluate malaria transmission and elimination

P. Selvaraj, E. A. Wenger, D. Bridenbecker, N. Windbichler, J. R. Russell, J. Gerardin, C. A. Bever and M. Nikolov,  PloS Computational Biology,  16:21. 2020.
Here, we investigate the reduced efficacy of current vector control measures in the presence of insecticide resistance and evaluate the likelihood of achieving local malaria elimination using gene drive mosquitoes released into a high transmission setting alongside other vector ...
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Modelling the suppression of a malaria vector using a CRISPR-Cas9 gene drive to reduce female fertility

A. R. North, A. Burt and H. C. J. Godfray,  BMC Biology,  18:98. 2020.
Gene drives based on CRISPR-Cas9 technology are increasingly being considered as tools for reducing the capacity of mosquito populations to transmit malaria, and one of the most promising options is driving endonuclease genes that reduce the fertility of female mosquitoes. Here, ...
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Modeling the suppression dynamics of Aedes mosquitoes with mating inhomogeneity

M. Huang and L. Hu,  Journal of Biological Dynamics,  14:656-678. 2020.
In this work, we introduce a delay differential equation model with mating inhomogeneity to discuss mosquito population suppression based on Wolbachia. Our analyses show that the wild mosquitoes could be eliminated if either the adult mortality rate exceeds the threshold δ∗A ...
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A One-Sided Competition Mathematical Model for the Sterile Insect Technique

A. Ben Dhahbi, Y. Chargui, S. M. Boulaaras and S. Ben Khalifa,  Complexity,  2020:12. 2020.
We study a simple mathematical model describing the dynamics of a wild-type pest insects population experiencing competition from sterile insects (one-sided competition).
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On Nonlinear Pest/Vector Control via the Sterile Insect Technique: Impact of Residual Fertility

M. S. Aronna and Y. Dumont,  Bulletin of Mathematical Biology,  82:29. 2020.
We consider a minimalist model for the Sterile Insect Technique (SIT), assuming that residual fertility can occur in the sterile male population.
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Field performance of sterile male mosquitoes released from an uncrewed aerial vehicle

J. Bouyer, N. J. Culbert, A. H. Dicko, M. G. Pacheco, J. Virginio, M. C. Pedrosa, L. Garziera, A. T. M. Pinto, A. Klaptocz, J. Germann, T. Wallner, G. Salvador-Herranz, R. A. Herrero, H. Yamada, F. Balestrino and M. J. B. Vreysen,  Science Robotics,  5:10. 2020.
Genetic control methods of mosquito vectors of malaria, dengue, yellow fever, and Zika are becoming increasingly popular due to the limitations of other techniques such as the use of insecticides. The sterile insect technique is an effective genetic control method to manage ...
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A spatially discrete, integral projection model and its application to invasive carp

R. A. Erickson, E. A. Eager, P. M. Kocovsky, D. C. Glover, J. L. Kallis and K. R. Long,  Ecological Modelling,  387:163-171. 2018.
Natural resource managers and ecologists often desire an understanding of spatial dynamics such as migration, dispersion, and meta-population dynamics. Network-node models can capture these salient features. Additionally, the state-variable used with many species may be ...
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Pest demography critically determines the viability of synthetic gene drives for population control

K. E. Wilkins, T. A. A. Prowse, P. Cassey, P. Q. Thomas and J. V. Ross,  Mathematical Biosciences,  305:160-169. 2018.
Synthetic gene drives offer a novel solution for the control of invasive alien species. CRISPR-based gene drives can positively bias their own inheritance, and comprise a DNA sequence that is replicated by homologous recombination. Since gene drives can be positioned to silence ...
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Daisyfield gene drive systems harness repeated genomic elements as a generational clock to limit spread

J. Min, C. Noble, D. Najjar and K. M. Esvelt,  bioRxiv,  104877. 2017.
Here we describe a novel form of gene drive based on the introduction of multiple copies of an engineered ‘daisy’ sequence into repeated elements of the genome. Each introduced copy encodes guide RNAs that target one or more engineered loci carrying the CRISPR nuclease gene ...
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Lethal Gene Drive Selects Inbreeding

J. J. Bull,  bioRxiv,  046847. 2016.
ere, population genetic models are used to consider the evolution of inbreeding (specifically selfing) as a possible response to a recessively lethal HEG with complete segregation distortion. Numerical analyses indicate a rich set of outcomes, but selfing often evolves in ...
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Global existence and asymptotic behavior of a model for biological control of invasive species via supermale introduction

R. D. Parshad, S. Kouachi and J. B. Gutierrez,  Communications in Mathematical Sciences,  11:971-992. 2013.
The purpose of this manuscript is to propose a model for the biological control of invasive species, via introduction of phenotypically modified organisms into a target population. We are inspired by the earlier Trojan Y Chromosome model [J.B. Gutierrez, J.L. Teem, J. Theo. Bio., ...
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Demographic effects on the use of genetic options for the control of mosquitofish, Gambusia holbrooki

R. E. Thresher, M. Canning and N. J. Bax,  Ecological Applications,  23:801-814. 2013.
This study tests the sensitivity of genetically based pest control options based on sex ratio distortion to intra-and intersexual aggressive interactions that affect male and female survival and fitness. Data on these interactions and their impacts were gathered for the ...
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Existence of global attractor for the Trojan Y Chromosome model

X. P. Zhao, B. Liu and N. Duan,  Electronic Journal of Qualitative Theory of Differential Equations,  2011.
This paper is concerned with the long time behavior of solution for the equation derived by the Trojan Y Chromosome (TYC) model with spatial spread. Based on the regularity estimates for the semigroups and the classical existence theorem of global attractors, we prove that this ...
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Analysis of the Trojan Y chromosome model for eradication of invasive species in a dendritic riverine system

J. B. Gutierrez, M. K. Hurdal, R. D. Parshad and J. L. Teem,  Journal of Mathematical Biology,  64:319-340. 2011.
The use of Trojan Y chromosomes has been proposed as a genetic strategy for the eradication of invasive species. The strategy is particularly relevant to invasive fish species that have XY sex determination system and are amenable to sex-reversal. In this paper we study the ...
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Can transposable elements be used to drive disease refractoriness genes into vector populations?

M. G. Kidwell and J. M. C. Ribeiro,  Parasitology Today,  8:325-329. 1992.
A number of biological procedures are currently being considered as alternatives to insecticide-based methods for the control of insect vectors of disease. Among these are the adaptation of various genetic mechanisms to drive genes of interest, such as refractoriness to malaria ...
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