Scholarly Literature

This is a database of scholarly literature that concentrates currently on natural and engineered selfish genetic elements (gene drives).  The latest are shown here.
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Modeling the efficacy of CRISPR gene drive for snail immunity on schistosomiasis control

23810
R. E. Grewelle, J. Perez-Saez, J. Tycko, E. K. O. Namigai, C. G. Rickards and G. A. De Leo,  PLOS Neglected Tropical Diseases,  16:e0010894. 2022-10-31 09:02:03.
CRISPR gene drives could revolutionize the control of infectious diseases by accelerating the spread of engineered traits that limit parasite transmission in wild populations. Gene drive technology in mollusks has received little attention despite the role of freshwater snails as hosts of parasitic flukes causing 200 million annual cases of schistosomiasis. A successful drive in snails must overcome self-fertilization, a common feature of host snails which could prevents a drive's spread. Here we developed a novel population genetic model accounting for snails' mixed mating and population dynamics, susceptibility to parasite infection regulated by multiple alleles, fitness differences between genotypes, and a range of drive characteristics. We integrated this model with an epidemiological model of schistosomiasis transmission to show that a snail population modification drive targeting immunity to infection can be hindered by a variety of biological and ecological factors; yet under a range of conditions, disease reduction achieved by chemotherapy treatment of the human population can be maintained with a drive. Alone a drive modifying snail immunity could achieve significant disease reduction in humans several years after release. These results indicate that gene drives, in coordination with existing public health measures, may become a useful tool to reduce schistosomiasis burden in selected transmission settings with effective CRISPR construct design and evaluation of the genetic and ecological landscape.

Gene drive by Fusarium SKC1 is dependent on its competing allele

23833
J. M. Lohmar, N. A. Rhoades, T. M. Hammond and D. W. Brown,  Fungal Genetics and Biology,  163:103749. 2022-10-29 09:19:43.
The Fusarium verticillioides SKC1 gene driver is transmitted to offspring in a biased manner through spore killing. The mechanism that allows SKC1 to kill non-SKC1 offspring while sparing others is poorly understood. Here we report that gene drive by SKC1 is dependent on SKC1's competing allele. We propose that SKC1's competing allele influences the ability of a genome defense process to detect SKC1, and we provide evidence that this genome defense process is meiotic silencing by unpaired DNA (MSUD). Our findings suggest that the successful deployment of gene drivers to control pathogenic fungi will require researchers to consider how competing alleles influence the ability of gene drivers to be detected by genome defense processes.

Expression of mosquito miRNAs in entomopathogenic fungus induces pathogen-mediated host RNA interference and increases fungal efficacy

23853
C. Cui, Y. Wang, Y. Li, P. Sun, J. Jiang, H. Zhou, J. Liu and S. Wang,  Cell Reports,  41:111527. 2022-10-25 10:15:50.
Summary The growing threat of insecticide resistance prompts the urgent need to develop additional tools for mosquito control. Entomopathogenic fungi provide an eco-friendly alternative to chemical insecticides. One limitation to the use of mycoinsecticides is their relatively low virulence. Here, we report an approach for suppressing mosquito immunity and increasing fungal virulence. We engineered Beauveria bassiana to express Aedes immunosuppressive microRNAs (miRNAs) to induce host RNA interference (RNAi) immune responses. We show that engineered strains can produce and deliver the miRNAs into host cells to activate cross-kingdom RNAi during infection and suppress mosquito immunity by targeting multiple host genes, thereby dramatically increasing fungal virulence against Aedes aegypti and Galleria mellonella larvae. Importantly, expressing host miRNAs also significantly increases fungal virulence against insecticide-resistant mosquitoes, creating potential for insecticide-resistance management. This pathogen-mediated RNAi (pmRNAi)-based approach provides an innovative strategy to enhance the efficacy of fungal insecticides and eliminate the likelihood of resistance development.

Cross-kingdom RNAi to enhance the efficacy of insect pathogens

23851
S. Asgari,  Trends in Parasitology,  2022-10-25 10:11:07.
Insect pathogens play significant roles in the biocontrol of medical and agricultural pests. Cui et al. demonstrated that genetically modified (GM) fungi expressing host mosquito miRNAs could enhance the efficacy of the fungus by suppressing the host immune response. This opens avenues for utilisation of cross-kingdom RNAi in biocontrol.

Monotonicity properties arising in a simple model of Wolbachia invasion for wild mosquito populations

24568
D. Vicencio, O. Vasilieva and P. Gajardo,  Mathematical Biosciences and Engineering,  20:1148-1175. 2022-10-25 08:23:57.
Using tools borrowed from monotone dynamical system theory, in the proposed model, we prove the existence of an invariant threshold manifold that allows us to provide practical recommendations for performing single and periodic releases of Wolbachia-carrying mosquitoes, seeking the eventual elimination of wild insects that are capable of transmitting infections to humans. We illustrate these findings with numerical simulations using parameter values corresponding to the wMelPop strain of Wolbachia that is considered the best virus blocker but induces fitness loss in its carriers. In these tests, we considered multiple scenarios contrasting a periodic release strategy against a strategy with a single inundative release, comparing their effectiveness. Our study is presented as an expository and mathematically accessible tool to study the use of Wolbachia-based biocontrol versus more complex models.

Pulled, pushed or failed: the demographic impact of a gene drive can change the nature of its spatial spread

23805
L. Kläy, L. Girardin, V. Calvez and F. Débarre,  arXiv,  2022-10-25 07:50:10.
Understanding the temporal spread of gene drive alleles -- alleles that bias their own transmission -- through modeling is essential before any field experiments. In this paper, we present a deterministic reaction-diffusion model describing the interplay between demographic and allelic dynamics, in a one-dimensional spatial context. We focused on the traveling wave solutions, and more specifically, on the speed of gene drive invasion (if successful). We considered various timings of gene conversion (in the zygote or in the germline) and different probabilities of gene conversion (instead of assuming 100% conversion as done in a previous work). We compared the types of propagation when the intrinsic growth rate of the population takes extreme values, either very large or very low. When it is infinitely large, the wave can be either successful or not, and, if successful, it can be either pulled or pushed, in agreement with previous studies (extended here to the case of partial conversion). In contrast, it cannot be pushed when the intrinsic growth rate is vanishing. In this case, analytical results are obtained through an insightful connection with an epidemiological SI model. We conducted extensive numerical simulations to bridge the gap between the two regimes of large and low growth rate. We conjecture that, if it is pulled in the two extreme regimes, then the wave is always pulled, and the wave speed is independent of the growth rate. This occurs for instance when the fitness cost is small enough, or when there is stable coexistence of the drive and the wild-type in the population after successful drive invasion. Our model helps delineate the conditions under which demographic dynamics can affect the spread of a gene drive.

New self-sexing Aedes aegypti strain eliminates barriers to scalable and sustainable vector control for governments and communities in dengue-prone environments

23796
S. A. M. Spinner, Z. H. Barnes, A. M. Puinean, P. Gray, T. Dafa’alla, C. E. Phillips, C. Nascimento de Souza, T. F. Frazon, K. Ercit, A. Collado, N. Naish, E. Sulston, G. C. Ll. Phillips, K. K. Greene, M. Poletto, B. D. Sperry, S. A. Warner, N. R. Rose, G,  Frontiers in Bioengineering and Biotechnology,  10. 2022-10-25 07:35:02.
For more than 60 years, efforts to develop mating-based mosquito control technologies have largely failed to produce solutions that are both effective and scalable, keeping them out of reach of most governments and communities in disease-impacted regions globally. High pest suppression levels in trials have yet to fully translate into broad and effective Aedes aegypti control solutions. Two primary challenges to date–the need for complex sex-sorting to prevent female releases, and cumbersome processes for rearing and releasing male adult mosquitoes–present significant barriers for existing methods. As the host range of Aedes aegypti continues to advance into new geographies due to increasing globalisation and climate change, traditional chemical-based approaches are under mounting pressure from both more stringent regulatory processes and the ongoing development of insecticide resistance. It is no exaggeration to state that new tools, which are equal parts effective and scalable, are needed now more than ever. This paper describes the development and field evaluation of a new self-sexing strain of Aedes aegypti that has been designed to combine targeted vector suppression, operational simplicity, and cost-effectiveness for use in disease-prone regions. This conditional, self-limiting trait uses the sex-determination gene doublesex linked to the tetracycline-off genetic switch to cause complete female lethality in early larval development. With no female progeny survival, sex sorting is no longer required, eliminating the need for large-scale mosquito production facilities or physical sex-separation. In deployment operations, this translates to the ability to generate multiple generations of suppression for each mosquito released, while being entirely self-limiting. To evaluate these potential benefits, a field trial was carried out in densely-populated urban, dengue-prone neighbourhoods in Brazil, wherein the strain was able to suppress wild mosquito populations by up to 96%, demonstrating the utility of this self-sexing approach for biological vector control. In doing so, it has shown that such strains offer the critical components necessary to make these tools highly accessible, and thus they harbour the potential to transition mating-based approaches to effective and sustainable vector control tools that are within reach of governments and at-risk communities who may have only limited resources.

Combining transgenesis with paratransgenesis to fight malaria

23802
W. Huang, J. Vega-Rodriguez, C. Kizito, S.-J. Cha and M. Jacobs-Lorena,  eLife,  11:e77584. 2022-10-25 06:30:55.
Malaria is among the deadliest infectious diseases, and Plasmodium, the causative agent, needs to complete a complex development cycle in its vector mosquito for transmission to occur. Two promising strategies to curb transmission are transgenesis, consisting of genetically engineering mosquitoes to express antimalarial effector molecules, and paratransgenesis, consisting of introducing into the mosquito commensal bacteria engineered to express antimalarial effector molecules. Although both approaches restrict parasite development in the mosquito, it is not known how their effectiveness compares. Here we provide an in-depth assessment of transgenesis and paratransgenesis and evaluate the combination of the two approaches. Using the Q-system to drive gene expression, we engineered mosquitoes to produce and secrete two effectors – scorpine and the MP2 peptide – into the mosquito gut and salivary glands. We also engineered Serratia, a commensal bacterium capable of spreading through mosquito populations to secrete effectors into the mosquito gut. Whereas both mosquito-based and bacteria-based approaches strongly reduced the oocyst and sporozoite intensity, a substantially stronger reduction of Plasmodium falciparum development was achieved when transgenesis and paratransgenesis were combined. Most importantly, transmission of Plasmodium berghei from infected to naïve mice was maximally inhibited by the combination of the two approaches. Combining these two strategies promises to become a powerful approach to combat malaria.

Ethics of gene drive mosquitoes for malaria elimination

24071
A. J. Roberts,  McMaster University,  2022-10-24 10:34:04.
This thesis is concerned with presenting analyses regarding key ethical issues regarding and arising from the development and potential use of gene drive modified mosquitoes for the purpose of malaria elimination. Each of the chapters constituting this thesis offers a rigorously researched analysis which attempts to answer questions thus far unanswered in the academic literature. Chapter one explores whether the development and use of this technology can be fairly considered unethical in principle; concluding it cannot be. Chapter two explores the appropriate relationship between this technology and the precautionary principle, a prominent regulatory and governance principle which has been invoked as ostensible support for an indefinite global moratorium on all gene drive technology. The chapter concludes that the precautionary principle, at least as articulated by UNESCO, does not provide justification for a global moratorium on gene drive technology. In fact, the precautionary principle is likely unfit as a regulatory norm for some kinds of gene drive products and purposes. Chapter three was co-authored with Delphine Thizy, Global Stakeholder Engagement Manager for Target Malaria, one of the leading consortiums working on research and development of gene drive biotechnology for malaria control. Together we articulate the ethical principles selected to guide Target Malaria’s stakeholder engagement, as well as provide the rationale for their selection and expound upon some early lessons from their implementation. Chapter four offers an analysis with the goal of locating the ethically appropriate locus of political organization from which to seek permission for a gene drive modified organism release into the shared environment. The chapter considers the appropriateness of each of the following levels of political organization: consent of individuals, local communities, nation states, and international governance institutions. The conclusion arrived at, with some caveats, is that such a decision is most appropriately issued by a nation state.

Hidden endosymbionts: A male-killer concealed by another endosymbiont and a nuclear suppressor

23793
K. M. Richardson, P. A. Ross, B. S. Cooper, W. R. Conner, T. Schmidt and A. A. Hoffmann,  bioRxiv,  2022.10.19.512817. 2022-10-22 06:41:08.
Maternally transmitted endosymbiotic bacteria that cause male killing (MK) have only been described from a few insects, but this may reflect challenges in their detection rather than a rarity of MK. Here we identify MK Wolbachia in populations of Drosophila pseudotakahashii, present at a low frequency (around 4%) in natural populations and previously undetected due to a different fixed Wolbachia strain in this species expressing a different reproductive manipulation, cytoplasmic incompatibility (CI). The MK phenotype was eliminated after tetracycline treatment that removed Wolbachia. Molecular analyses indicated the MK phenotype to be expressed when a second Wolbachia strain was present alongside the CI Wolbachia. A genomic analysis highlighted Wolbachia regions diverged between the strains involving 17 genes and also identified the Wolbachia as representing an outgroup to a clade of Wolbachia infecting melanogaster-group species, including wRi-like and wMel-like strains. Doubly infected males induced CI with uninfected females but not females singly infected with CI-causing Wolbachia. The MK phenotype manifested at the larval stage and was transmitted maternally at a high fidelity but with occasional loss of the MK Wolbachia strain. A rapidly spreading dominant nuclear suppressor genetic element affecting MK was identified through backcrossing and subsequent analysis with ddRAD SNPs of the D. pseudotakahashii genome. These findings highlight the complexity of nuclear and microbial components affecting MK endosymbiont detection and dynamics in populations, and the challenges of making connections between endosymbionts and the host phenotypes affected by them.Competing Interest StatementThe authors have declared no competing interest.

Hurdles in responsive community engagement for the development of environmental biotechnologies

25089
A. M. Normandin, L. M. Fitzgerald, J. Yip and S. W. Evans,  Synthetic Biology,  7:ysac022. 2022-10-20 06:56:55.
Recent calls for engaging communities in biotechnology development do not draw enough attention to the hurdles that must be overcome for engagement strategies to effectively feed back into research design and conduct. These hurdles call into question many standard ways of operating and assessing in traditional scientific disciplines. The first steps in addressing these hurdles can be the most difficult. In reflecting on our own experiences in the early-stage development of environmental biotechnologies, we provide a set of techniques to help scientists and their collaborators learn to become more responsive to the needs and attitudes of communities with which they are engaging.Graphical Abstract

Driving down malaria transmission with engineered gene drives

23780
W. T. Garrood, P. Cuber, K. Willis, F. Bernardini, N. M. Page and R. E. Haghighat-Khah,  Frontiers in Genetics,  13. 2022-10-19 07:08:43.
The last century has witnessed the introduction, establishment and expansion of mosquito-borne diseases into diverse new geographic ranges. Malaria is transmitted by female Anopheles mosquitoes. Despite making great strides over the past few decades in reducing the burden of malaria, transmission is now on the rise again, in part owing to the emergence of mosquito resistance to insecticides, antimalarial drug resistance and, more recently, the challenges of the COVID-19 pandemic, which resulted in the reduced implementation efficiency of various control programs. The utility of genetically engineered gene drive mosquitoes as tools to decrease the burden of malaria by controlling the disease-transmitting mosquitoes is being evaluated. To date, there has been remarkable progress in the development of CRISPR/Cas9-based homing endonuclease designs in malaria mosquitoes due to successful proof-of-principle and multigenerational experiments. In this review, we examine the lessons learnt from the development of current CRISPR/Cas9-based homing endonuclease gene drives, providing a framework for the development of gene drive systems for the targeted control of wild malaria-transmitting mosquito populations that overcome challenges such as with evolving drive-resistance. We also discuss the additional substantial works required to progress the development of gene drive systems from scientific discovery to further study and subsequent field application in endemic settings.

Mosquito Gene Drives and the Malaria Eradication Agenda

23731
Editor: R. Carballar-Lejarazu,,  Jenny Stanford Publishing,  2022-10-17 06:37:46.
Malaria is one of most serious infectious diseases today and has afflicted humankind for thousands of years. A significant number of people still die from this mosquito-borne disease, despite the use of various malaria prevention and control methods over hundreds of years and more than a century of coordinated global control efforts using modern tools, together with research into and development of new strategies for prevention, diagnosis, and disease treatment. Genetic approaches that focus on the vector mosquitoes to prevent malaria parasite transmission have been considered for many decades. Genetic control strategies received a significant boost with the successful development of gene-drive systems, genetic methods for rapidly spreading beneficial genes and phenotypes through mosquito populations. This book reviews some concepts of gene drive systems and describes pioneering applications to control mosquito populations and prevent parasite transmission.

Assessing single-locus CRISPR/Cas9-based gene drive variants in the mosquito Aedes aegypti via single generation crosses and modeling

23756
W. Reid, A. E. Williams, I. Sanchez-Vargas, J. Lin, R. Juncu, K. E. Olson and A. W. E. Franz,  G3 Genes|Genomes|Genetics,  2022-10-17 06:25:18.
Critical to the design of a single-locus autonomous GD is that the selected genomic locus is amenable to both GD and appropriate expression of the antiviral effector. In our study, we used reverse engineering to target two intergenic genomic loci, which had previously shown to be highly permissive for antiviral effector gene expression, and we further investigated the use of three promoters (nanos, β2-tubulin, or zpg) for Cas9 expression. We then quantified the accrual of insertions or deletions (indels) after single generation crossings, measured maternal effects, and assessed fitness costs associated with the various transgenic lines to model the rate of GD fixation. Overall, MGDrivE modeling suggested that when an autonomous GD is placed into an intergenic locus, the GD system will eventually be blocked by the accrual of GD blocking resistance alleles and ultimately be lost in the population. Moreover, while genomic locus and promoter selection were critically important for the initial establishment of the autonomous GD, it was the fitness of the GD line that most strongly influenced the persistence of the GD in the simulated population. As such, we propose that when autonomous CRISPR/Cas9 based GD systems are anchored in an intergenic locus, they temporarily result in a strong population replacement effect, but as GD-blocking indels accrue, the GD becomes exhausted due to the fixation of CRISPR resistance alleles.

Introgression of a synthetic sex ratio distortion transgene into different genetic backgrounds of Anopheles coluzzii

23760
P. Pollegioni, T. Persampieri, R. L. Minuz, A. Bucci, A. Trusso, S. Di Martino, C. Leo, M. Bruttini, M. Ciolfi, A. M. Waldvogel, F. Tripet, A. Simoni, A. Crisanti and R. Müller,  Insect Molecular Biology,  2022-10-17 06:14:10.
The development of genetically modified mosquitoes (GMM) and their subsequent field release offers innovative approaches for vector control of malaria. A non-gene drive self-limiting male-bias Ag(PMB)1 strain has been developed in a 47-year-old laboratory G3 strain of Anopheles gambiae s.l. When Ag(PMB)1 males are crossed to wild-type females, expression of the endonuclease I-PpoI during spermatogenesis causes the meiotic cleavage of the X chromosome in sperm cells, leading to fertile offspring with a 95% male bias. However, WHO states that the functionality of the transgene could differ when inserted in different genetic backgrounds of An. coluzzii which is currently a predominant species in several West-African countries and thus a likely recipient for a potential release of self-limiting GMMs. In this study, we introgressed the transgene from the donor Ag(PMB)1 by six serial backcrosses into two recipient colonies of An. coluzzii that had been isolated in Mali and Burkina Faso. Scans of informative SNP markers and whole-genome sequencing analysis revealed a nearly complete introgression of chromosome 3 and X, but a remarkable genomic divergence in a large region of the chromosome 2 between the later backcrossed (BC6) transgenic offspring and the recipient paternal strains. These findings suggested to extend the backcrossing breeding strategy beyond BC6 generation and increase the introgression efficiency of critical regions that have ecological and epidemiological implications through the targeted selection of specific markers. Disregarding of differential introgression efficiency, we concluded that the phenotype of the sex ratio distorter is stabile in the BC6 introgressed An. coluzzii strains. This article is protected by copyright. All rights reserved.

Anopheles homing suppression drive candidates exhibit unexpected performance differences in simulations with spatial structure

23734
S. E. Champer, I. K. Kim, A. G. Clark, P. W. Messer and J. Champer,  eLife,  11:e79121. 2022-10-14 06:37:55.
Recent experiments have produced several Anopheles gambiae homing gene drives that disrupt female fertility genes, thereby eventually inducing population collapse. Such drives may be highly effective tools to combat malaria. One such homing drive, based on the zpg promoter driving CRISPR/Cas9, was able to eliminate a cage population of mosquitoes. A second version, purportedly improved upon the first by incorporating an X-shredder element (which biases inheritance towards male offspring), was similarly successful. Here, we analyze experimental data from each of these gene drives to extract their characteristics and performance parameters and compare these to previous interpretations of their experimental performance. We assess each suppression drive within an individual-based simulation framework that models mosquito population dynamics in continuous space. We find that the combined homing/X-shredder drive is actually less effective at population suppression within the context of our mosquito population model. In particular, the combined drive often fails to completely suppress the population, instead resulting in an unstable equilibrium between drive and wild-type alleles. By contrast, otherwise similar drives based on the nos promoter may prove to be more promising candidates for future development than originally thought.

Wolbachia wAlbB inhibit dengue and Zika infection in the mosquito Aedes aegypti with an Australian background

23714
L. E. Hugo, G. Rašić, A. J. Maynard, L. Ambrose, C. Liddington, C. J. E. Thomas, N. S. Nath, M. Graham, C. Winterford, B. M. C. R. Wimalasiri-Yapa, Z. Xi, N. W. Beebe and G. J. Devine,  PLOS Neglected Tropical Diseases,  16:e0010786. 2022-10-13 06:27:20.
Biological control of mosquito vectors using the endosymbiotic bacteria Wolbachia is an emerging strategy for the management of human arboviral diseases. We recently described the development of a strain of Aedes aegypti infected with the Wolbachia strain wAlbB (referred to as the wAlbB2-F4 strain) through simple backcrossing of wild type Australian mosquitoes with a wAlbB infected Ae. aegypti strain from the USA. Field releases of male wAlbB2-F4 mosquitoes resulted in the successful suppression of wild populations of mosquitoes in the trial sites by exploiting the strain’s Wolbachia-induced cytoplasmic incompatibility. We now demonstrate that the strain is resistant to infection by dengue and Zika viruses and is genetically similar to endemic Queensland populations. There was a fourfold reduction in the proportion of wAlbB2-F4 mosquitoes that became infected following a blood meal containing dengue 2 virus (16.7%) compared to wild type mosquitoes (69.2%) and a 6–7 fold reduction in the proportion of wAlbB2-F4 mosquitoes producing virus in saliva following a blood meal containing an epidemic strain of Zika virus (8.7% in comparison to 58.3% in wild type mosquitoes). Restriction-site Associated DNA (RAD) sequencing revealed that wAlbB2-F4 mosquitoes have > 98% Australian ancestry, confirming the successful introduction of the wAlbB2 infection into the Australian genomic background through backcrossing. Genotypic and phenotypic analyses showed the wAlbB2-F4 strain retains the insecticide susceptible phenotype and genotype of native Australian mosquitoes. We demonstrate that the Wolbachia wAlbB2-F4, in addition to being suitable for population suppression programs, can also be effective in population replacement programs given its inhibition of virus infection in mosquitoes. The ease at which a target mosquito population can be transfected with wAlbB2, while retaining the genotypes and phenotypes of the target population, shows the utility of this strain for controlling the Ae. aegypti mosquitoes and the pathogens they transmit.

The wtf meiotic driver gene family has unexpectedly persisted for over 100 million years

23712
M. De Carvalho, G. S. Jia, A. Nidamangala Srinivasa, R. B. Billmyre, Y. H. Xu, J. J. Lange, I. M. Sabbarini, L. L. Du and S. E. Zanders,  eLife,  11. 2022-10-13 06:23:07.
Meiotic drivers are selfish elements that bias their own transmission into more than half of the viable progeny produced by a driver+/driver- heterozygote. Meiotic drivers are thought to exist for relatively short evolutionary timespans because a driver gene or gene family is often found in a single species or in a group of very closely related species. Additionally, drivers are generally considered doomed to extinction when they spread to fixation or when suppressors arise. In this study, we examine the evolutionary history of the wtf meiotic drivers first discovered in the fission yeast Schizosaccharomyces pombe. We identify homologous genes in three other fission yeast species, S. octosporus, S. osmophilus, and S. cryophilus, which are estimated to have diverged over 100 million years ago from the S. pombe lineage. Synteny evidence supports that wtf genes were present in the common ancestor of these four species. Moreover, the ancestral genes were likely drivers as wtf genes in S. octosporus cause meiotic drive. Our findings indicate that meiotic drive systems can be maintained for long evolutionary timespans.

Risk Assessment on the Release of Wolbachia-Infected Aedes aegypti in Yogyakarta, Indonesia

23707
D. Buchori, A. Mawan, I. Nurhayati, A. Aryati, H. Kusnanto and U. K. Hadi,  Insects,  13. 2022-10-12 08:16:52.
Wolbachia-infected Aedes aegypti is the latest technology that was developed to eliminate dengue fever. The Ministry of Research and Technology of the Republic of Indonesia (Kemenristekdikti) established an expert group to identify future potential risks that may occur over a period of 30 years associated with the release of Wolbachia-infected Ae. aegypti. The risk assessment consisted of identifying different hazards that may have impacts on humans and the environment. From the consensus among the experts, there were 56 hazards identified and categorized into 4 components, namely, ecological matters, efficacy in mosquito management, economic and sociocultural issues, and public health standards. There were 19 hazards in the ecological group. The overall likelihood in the ecology of the mosquito is very low (0.05), with moderate consequence (0.74), which resulted in negligible risk. For the efficacy in mosquito management group, there were 12 hazards that resulted in very low likelihood (0.11) with high consequence (0.85). The overall risk for mosquito management efficacy was very low (0.09). There were 14 hazards identified in the public health standard with very low likelihood (0.07), moderate consequence (0.50) and negligible risk (0.04). Lastly, 13 hazards were identified in the economic and sociocultural group with low likelihood (0.01) but of moderate consequence (0.5), which resulted in a very low risk (0.09). The risk severity level of the four components leading to the endpoint risk of “cause more harm” due to releasing Wolbachia-infected Ae. aegypti is negligible (0.01).

Improvement of Resistance in Plants Against Insect-Pests Using Genome Editing Tools

25205
S. Bhat and S. Kumar,  Genome Editing: Current Technology Advances and Applications for Crop Improvement,  2022-10-09 09:31:41.
During growth period plants are subjected to both biotic and abiotic stresses. Like other biotic stresses, insect-pests are the most serious challenge for the plants particularly in yield losses. Genome editing techniques are becoming an emerging technology bringing real revolution in genetic engineering and biotechnology. Editing of targeted gene provides ways to elucidate extensive ranges of aims for the improvement, protection, and increased yield of various crops. Researchers all over the world have unraveled the usage of numerous gene editing methods from endonuclease to CRISPR/Cas in various aspects of plants like plant growth and development, insect-pest control, and other biotic stresses. The key goal of this chapter is to highlight various techniques of genome editing approaches which can be used to develop resistance in plants against insect-pests. New crop-based methods that reiterate the effective utilization of these techniques in insect-pest management as well as plant in resistance against pests are highlighted. This chapter also highlights the implication of genome editing as well as framework for its specific regulation.

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