Biology subjects

Sudweeks, J.

Publications and source records attributed to Sudweeks, J..

3 recordsLinked to original sources

bioRxiv2026

Environmental feedback maintains cooperation in viruses

Cooperators that pay a cost to provide benefits to others are vulnerable to exploitation by defectors that reap the benefits while avoiding the costs. Thus selection on the individual level can lead to loss of cooperators while lowering overall population fitness. Accordingly, the maintenance of cooperation is a key problem in evolutionary biology. The puzzle of cooperation extends to viruses: cooperative viruses produce gene products that can be shared, while defector viruses produce less and instead use products made by cooperators. In coinfection, defectors are always advantaged, predicting the loss of cooperation. However, the fitness of cooperator and defector phenotypes is context dependent. Though defectors are advantaged in coinfection, they suffer reduced replication in single infections. Environmental feedback is the process by which changes in population composition alter viral densities and rates of coinfection, which in turn feed back to affect the fitness of each type. We show that environmental feedback maintains cooperation in viruses. We also find that defector emergence may interfere with phage therapy by disrupting the phage dynamics that cause host extinction, and demonstrate that the introduction of defectors lowers viral densities and drives viral extinction, suggesting that defectors that replicate alone could function as antiviral therapies.

evolutionary biology↗

bioRxiv2019

Locally Fixed Alleles: A method to localize gene drive to island populations

Invasive species pose a major threat to biodiversity on islands. While successes have been achieved using traditional removal methods, such as toxicants aimed at rodents, these approaches have limitations and various off-target effects on island ecosystems. Gene drive technologies designed to eliminate a population provide an alternative approach, but the potential for drive-bearing individuals to escape from the target release area and impact populations elsewhere is a major concern. Here we propose the \"Locally Fixed Alleles\" approach as a novel means for localizing elimination by a drive to an island population that exhibits significant genetic isolation from neighboring populations. Our approach is based on the assumption that in small island populations of rodents, genetic drift will lead to multiple genomic alleles becoming fixed. In contrast, multiple alleles are likely to be maintained in larger populations on mainlands. Utilizing the high degree of genetic specificity achievable using homing drives, for example based on the CRISPR/Cas9 system, our approach aims at employing one or more locally fixed alleles as the target for a gene drive on a particular island. Using mathematical modeling, we explore the feasibility of this approach and the degree of localization that can be achieved. We show that across a wide range of parameter values, escape of the drive to a neighboring population in which the target allele is not fixed will at most lead to modest transient suppression of the non-target population. While the main focus of this paper is on elimination of a rodent pest from an island, we also discuss the utility of the locally fixed allele approach for the goals of population suppression or population replacement. Our analysis also provides a threshold condition for the ability of a gene drive to invade a partially resistant population.

evolutionary biology↗

bioRxiv2017

Anticipating complexity in the deployment of gene drive insects in agriculture

Insects cause substantial losses to agricultural crops each year and require intensive management approaches. Genetic pest management (GPM) has emerged as a viable, non-chemical alternative for managing insect pests. The development of engineered gene drives for agricultural use is promising, though unproven, and has the potential to impact farmers as well as broader socio-ecological systems in several ways. Drawing on lessons from the deployment of other pest control technologies, this paper considers how gene drive insects could intersect with some of the complexities that characterize agricultural systems. The development of gene drives is emerging in a landscape of pest management shaped by past and current approaches, experiences, regulations, public opinion and pest invasions. Because gene drive insects may spread well beyond their release area, stakeholder groups at different spatial scales need to be engaged in decisions about their deployment. This new paradigm both complicates and offers great promise for future pest management efforts.

ecology↗