Ethics in Gene Editing

BackgroundThe views of people with genetic conditions are crucial to include in public dialogue around developing gene editing technologies. This qualitative study sought to characterize the attitudes of people with inherited retinal conditions (retinitis pigmentosa [RP] and Leber congenital amaurosis [LCA]) toward gene editing.MethodsIndividuals with RP (N = 9) and LCA (N = 8) participated in semi‐structured qualitative interviews about their experience with and attitudes toward blindness, and their views about gene editing technology for somatic, germline, and enhancement applications.ResultsParticipants saw potential benefits from gene editing in general, but views about its use for retinal conditions varied and were influenced by personal perspectives on blindness. Those who felt more negatively toward blindness, particularly those with later onset blindness, were more supportive of gene editing for retinal conditions. Concerns about both germline and somatic editing included: the importance of informed consent; impacts of gene editing on social attitudes and barriers affecting blind people; and worries about “eliminating” blindness or other traits.ConclusionPeople with RP and LCA have diverse attitudes toward gene editing technology informed by their own lived experience with disability, and many have concerns about how the ways in which it is discussed and implemented might affect them.

The farming of livestock has a critical role to play in global nutritional security and poverty alleviation. To meet these goals through more efficient, environmentally sustainable and animal welfare focused means, gene editing technologies could be integrated into current breeding programs. A common issue with gene editing in livestock zygotes is the high incidence of genetic mosaicism. Genetic mosaicism, characterised by a single individual carrying distinct genotypes in different cell lineages, can lead to inconsistent presentation of a desired trait phenotypically, or the absence of the intended genotype in the animal’s germline. This review explores the present status of genetic mosaicism associated with CRISPR-Cas9 gene editing in cattle, sheep, and pigs, and identifies four areas for refinement; (1) the type of CRISPR-Cas9 genome editor used; (2) the CRISPR-Cas9 formats and timing of gene editing during embryonic development; (3) the method used to deliver the genome editor and (4) the genetic screening strategies applied. We also discuss alternatives to direct zygote gene editing, including surrogate sire technology and blastomere separation, which circumvent the production of mosaic offspring. By exploring these avenues for reducing mosaicism, gene editing protocols in livestock could become more efficient and effective, which will ultimately pave the way for traits to be introduced that improve animal welfare standards and help address gaps in the security of global nutrition access.

U.S. Regulatory Challenges for Gene Editing

Researchers views about perceived harms and benefits of gene editing: A study from the MENA region

Gene editing technologies are playing an increasingly important role in the study of insect gene functions. Appropriate incubation humidity helps improve the hatching rate of insect eggs. However, to date, no study has evaluated the impact of humidity on the hatching rate of gene-edited eggs or the subsequent development of the larvae. Using the cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) as a model, we investigated the weight and hatching rate of microinjected eggs under different humidity conditions. We determined the larval development time and pupal weight and calculated the larval gene editing efficiency. The results showed that post-microinjection incubation under high humidity (RH = 95%) had a significant influence on CRISPR/Cas9 gene-edited eggs. The key research results indicate that, compared with the incubation environment with RH ≤ 80%, after 48 h of incubation under 95% RH, the hatching rate of H. armigera eggs increased by more than 27.5%, with higher egg saturation and greater egg weight; meanwhile, the larval developmental duration was shorter and the pupal weight was also greater. These results establish a humidity-regulated developmental recovery protocol for gene-edited insects, which provides theoretical and practical support for optimizing post-microinjection recovery processes in gene-edited insects.

Current development of gene editing

CRISPR-Cas9 studies have implicated gene editing of DNA sequences for medical treatment of diseases such as sickle cell anemia, thalassemia, AIDS, blindness, muscular dystrophy, Huntington’s disease, and cystic fibrosis. Moreover, gene editing technology has contributed to the detection of viruses responsible for the dissemination of communicable diseases such as COVID-19. Despite current scientific progress, many uses of gene editing of DNA sequences are ethically questionable, bordering upon antithetical to principles of human rights protections. The history of genetics, genetic modification of DNA sequences, and human rights has included pseudoscientific practices such as those of the eugenics movement, which dominated much of the nineteenth and early twentieth centuries. Later, United Nations measures such as the International Bill of Human Rights and the Universal Declaration on the Human Genome and Human Rights prompted improvements in human rights practices. Still, genetics rights and human rights in many nations required codification, as human rights standards—including the right to privacy and the protection of genetic data—have been challenged by a host of stakeholders and commercial entities. Ethical limits and international human rights protections relevant to the use of gene editing technology must be preserved. Considerable progress in disease diagnostics and therapeutics using gene editing and genetic engineering has bolstered the fight for the concurrent preservation of gene editing, ethics, and international human rights protections. As such, this chapter will examine the critical importance of upholding human rights as an essential component of the advancement of gene editing.

Background: Precision medicine has emerged with the development of science and technology and the rise of big data. This study first defines and presents the advantages of precision medicine and then introduces the development of three technologies: gene sequencing, cellular immunotherapy, and gene editing. The clinical applications of precision medicine in lung cancer, cervical cancer, breast cancer, and prostate cancer are thus analyzed. Lastly, the existing problems and future development directions of precision medicine are identified. The introduction of gene sequencing, bioanalytical techniques, and big data analysis tools has propelled medicine into the era of precision medicine. Key technologies in precision medicine form the foundation of its development. Therefore, this study elaborates on the development of key technologies in precision medicine, the current status of its clinical application, and the main problems that currently exist. This study also suggests solutions to the problems. Objective: To systematically explain the development and principle of three core technologies in precision medicine and to predict the main research trends of precision medicine. Results: Research in gene sequencing, cell immunotherapy, and gene editing technology has shown significant progress, and accurate medical treatment has achieved remarkable results, effectively prolonging the survival time and improving the quality of life of patients. Conclusion: Precision medicine has made significant achievements, but problems remain. Ensuring safety and efficiency in precision medicine should be the focus of future research.

In recent years, CRISPR/Cas9 gene editing technology has emerged as a powerful genetic tool with potential application in aquaculture. Crassostrea gigas, as a valuable species in aquaculture, holds promising potential for genetic enhancement and breeding through gene editing. However, the lack of efficient promoters for driving exogenous gene expression poses a major obstacle in bivalve gene editing. In this study, we isolated the promoter sequences of the β-tub and histone H3.3A genes from C. gigas. DNA expression constructs were generated by linking the promoters with the enhanced green fluorescent protein (EGFP) reporter and compared with the promoter activity of the endogenous EF-1α gene and an exogenous OsHV-1 promoter in C. gigas embryos. All four promoters effectively drive the expression of EGFP during early embryonic development in C. gigas. Among these four promoters, the β-tub promoter is the most potent promoter in driving EGFP expression in C. gigas embryos as early as 4.5h after fertilization. The OsHV-1 promoter showed similar activity as β-tub promoter and appeared to be more active than the EF-1α and histone H3.3A promoters in C. gigas embryos. Furthermore, we assessed their performance in other three C. gigas relatives (Crassostrea ariakensis, Crassostrea nippona, and Crassostrea sikamea) and similar results were found. Collectively, these data suggest that the β-tub promoter is an effective promoter in directing gene expression in directing gene expression in oyster embryos, thus offering a potential application for gene editing in bivalves.

Gene editing technology involves the modification of a specific target gene to obtain a new function or phenotype. Recent advances in clustered regularly interspaced short palindromic repeats (CRISPR)-Cas-mediated technologies have provided an efficient tool for genetic engineering of cells and organisms. Here, we review the three emerging gene editing tools (ZFNs, TALENs, and CRISPR-Cas) and briefly introduce the principle, classification, and mechanisms of the CRISPR-Cas systems. Strategies for gene editing based on endogenous and exogenous CRISPR-Cas systems, as well as the novel base editor (BE), prime editor (PE), and CRISPR-associated transposase (CAST) technologies, are described in detail. In addition, we summarize recent developments in the application of CRISPR-based gene editing tools for industrial microorganism and probiotics modifications. Finally, the potential challenges and future perspectives of CRISPR-based gene editing tools are discussed.

Gene editing technologies have revolutionized therapeutic development, offering potentially curative and preventative strategies for cardiovascular disease (CVD), which remains a leading global cause of morbidity and mortality. This review provides an introduction to the state-of-the-art gene editing tools-including ZFNs, TALENs, CRISPR/Cas9 systems, base editors, and prime editors-and evaluates their application in lipid metabolic pathways central to CVD pathogenesis. Emphasis is placed on targets such as PCSK9, ANGPTL3, CETP, APOC3, ASGR1, LPA, and IDOL, supported by findings from human genetics, preclinical models, and recent first-in-human trials. Emerging delivery vehicles (AAVs, LNPs, lentivirus, virus-like particles) and their translational implications are discussed. The review highlights ongoing clinical trials employing liver-targeted in vivo editing modalities (LivGETx-CVD) and provides insights into challenges in delivery, off-target effects, genotoxicity, and immunogenicity. Collectively, this review captures the rapid progress of LivGETx-CVD from conceptual innovation to clinical application, and positions gene editing as a transformative, single-dose strategy with the potential to redefine prevention and long-term management of dyslipidemia and atherosclerotic cardiovascular disease.

Genetic Engineering & Biotechnology NewsVol. 41, No. 11 Genome EditingHow Gene Editing Can Support Sustainable AgricultureEvolving environmental, social, and governance criteria suggest that gene editing technologies need to promote ethical innovation and an equitable futureIngrid FungIngrid FungIngrid Fung is an investment director at Finistere Ventures. Website: https://finistere.com.Search for more papers by this authorPublished Online:11 Nov 2021https://doi.org/10.1089/gen.41.11.21AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetails Volume 41Issue 11Nov 2021 Information© 2021 by GEN PublishingTo cite this article:Ingrid Fung.How Gene Editing Can Support Sustainable Agriculture.Genetic Engineering & Biotechnology News.Nov 2021.60-61.http://doi.org/10.1089/gen.41.11.21Published in Volume: 41 Issue 11: November 11, 2021PDF download

The rapid growth of the field of gene editing can largely be attributed to the discovery and optimization of designer endonucleases. These include zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regular interspersed short palindromic repeat (CRISPR) systems including Cas9, Cas12a, and structure-guided nucleases. Zebrafish (Danio rerio) have proven to be a powerful model system for genome engineering testing and applications due to their external development, high fecundity, and ease of housing. As the zebrafish gene editing toolkit continues to grow, it is becoming increasingly important to understand when and how to utilize which of these technologies for maximum efficacy in a particular project. While CRISPR-Cas9 has brought broad attention to the field of genome engineering in recent years, designer endonucleases have been utilized in genome engineering for more than two decades. This chapter provides a brief overview of designer endonuclease and other gene editing technologies in zebrafish as well as some of their known functional benefits and limitations depending on specific project goals. Finally, selected prospects for additional gene editing tools are presented, promising additional options for directed genomic programming of this versatile animal model system.

With recent advancements in gene editing technology using the CRISPR/Cas system, there is a demand for more effective gene editors. A key factor facilitating efficient gene editing is effective CRISPR delivery into cells, which is known to be associated with the size of the CRISPR system. Accordingly, compact CRISPR-Cas systems derived from various strains are discovered, among which Un1Cas12f1 is 2.6 times smaller than SpCas9, providing advantages for gene therapy research. Despite extensive engineering efforts to improve Un1Cas12f1, the editing efficiency of Un1Cas12f1 is still shown to be low depending on the target site. To overcome this limitation, we develop enhanced Cas12f1 (eCas12f1), which exhibits gene editing activity similar to SpCas9 and AsCpf1, even in gene targets where previously improved Un1Cas12f1 variants showed low gene editing efficiency. Furthermore, we demonstrate that eCas12f1 efficiently induces apoptosis in cancer cells and is compatible with base editing and regulation of gene expression, verifying its high utility and applicability in gene therapy research.

Stem cell technologies and gene editing techniques are two of the most promising recent developments in biomedicine. The ability to reprogram common human cells into induced pluripotent stem cells (hiPSCs) and turn them into the cells of interest has already become a powerful research tool, thus providing a unique platform for disease studies. In combination with the use of designer nucleases approach to repair or to introduce disease-causing mutations, both are valuable in developing personalized disease models. This chapter provides an overview on designer nucleases-based gene editing in hiPSCs, describing the principles of CRISPR/Cas systems along with consecutive methodological steps such as nucleases selection, isolation, and genotyping of modified hiPSC clones with emphasis on the crucial role of isogenic cell lines in disease modeling. Moreover, the production of rare or complex genotypes in patient cell lines requires efficient and streamlined gene editing technologies. However, precise genome editing applications rely on infrequent homology-directed repair (HDR), with the abundant nonhomologous end joining (NHEJ) formed indels presenting a barrier to achieving high rates of precise sequence modification. The methods presented here are supported by theoretical framework to allow for the incorporation of inevitable improvements to achieve either higher rates of gene editing by promotion of HDR over NHEJ or application of different CRISPR/Cas platforms for robust and multiplex gene editing, toward decoding of neurodevelopmental as well as for modeling of late onset disorders by fast-forwarding the biological clock. Due to easy in theory but laborious and inefficient in practice, the precise and efficient genome editing in hiPSCs could be only achieved by the proper combination of the described methods in the process. This eventually would lead to generation of wide range of disease models for decoding of sporadic, polygenic, undiagnosed, and rare disorders using the adequate experimental design following appropriate gene editing toolbox selection.