CRISPR/Cas9 gene drive technology to control transmission of vector‐borne parasitic infections

Post-genomic era in agriculture and veterinary science: successful and proposed application of genetic targeting technologies

Gene editing tools have become an indispensable part of research into the fundamental aspects of cell biology. With a vast body of literature having been generated based on next generation sequencing technologies, keeping track of this ever-growing body of information remains challenging. This necessitates the translation of genomic data into tangible applications. In order to address this objective, the generated Next Generation Sequencing (NGS) data forms the basis for targeted genome editing strategies, employing known enzymes of various cellular machinery, in generating organisms with specifically selected phenotypes. This review focuses primarily on CRISPR/Cas9 technology in the context of its advantages over Zinc finger proteins (ZNF) and Transcription activator-like effector nucleases (TALEN) and meganucleases mutagenesis strategies, for use in agricultural and veterinary applications. This review will describe the application of CRISPR/Cas9 in creating modified organisms with custom-made properties, without the undesired non-targeted effects associated with virus vector vaccines and bioactive molecules produced in bacterial systems. Examples of the successful and unsuccessful applications of this technology to plants, animals and microorganisms are provided, as well as an in-depth look into possible future trends and applications in vaccine development, disease resistance and enhanced phenotypic traits will be discussed.

CRISPR/Cas advancements for genome editing, diagnosis, therapeutics, and vaccine development for Plasmodium parasites, and genetic engineering of Anopheles mosquito vector

Malaria as vector-borne disease remains important health concern with over 200 million cases globally. Novel antimalarial medicines and more effective vaccines must be developed to eliminate and eradicate malaria. Appraisal of preceding genome editing approaches confirmed the CRISPR/Cas nuclease system as a novel proficient genome editing system and a tool for species-specific diagnosis, and drug resistance researches for Plasmodium species, and gene drive to control Anopheles population. CRISPR/Cas technology, as a handy tool for genome editing can be justified for the production of transgenic malaria parasites like Plasmodium transgenic lines expressing Cas9, chimeric Plasmodium transgenic lines, knockdown and knockout transgenic parasites, and transgenic parasites expressing alternative alleles, and also mutant strains of Anopheles such as only male mosquito populations, generation of wingless mosquitoes, and creation of knock-out/ knock-in mutants. Though, the incorporation of traditional methods and novel molecular techniques could noticeably enhance the quality of results. The striking development of a CRISPR/Cas-based diagnostic kit that can specifically diagnose the Plasmodium species or drug resistance markers is highly required in malaria settings with affordable cost and high-speed detection. Furthermore, the advancement of genome modifications by CRISPR/Cas technologies resolves contemporary restrictions to culturing, maintaining, and analyzing these parasites, and the aptitude to investigate parasite genome functions opens up new vistas in the better understanding of pathogenesis.

Construction of PX-LmGP63 Using CRISPR-Cas9 as Primary Goal for GP63 gene Knockout in Leishmania major and Leishmanization

Background: Leishmania is an intracellular protozoan parasite that uses complex methods for destroying the innate immune response in mammalian host macrophage cells. Many factors have been identified that play a role in the severity of the parasite’s pathogenicity. One of the factors is the GP63, which is a group of metalloproteinases that disrupts the signaling mechanism of the host cell. Objectives: The aim of this study was to construct PX-LMGP63 vector through CRISPR-Cas9 for GP63 gene knockout in Leishmania major as a potential method for leishmanization. Methods: A pair of gRNAs were designed based on the mRNA sequence of the GP63. Then annealing primers were cloned into the linearized vector PX-459 and transformed into the DH5ɑ competent cells. Then, PCR assay was performed with gene-specific and vector primers to confirm the colonies. In addition, the constructed plasmid was sequenced for final confirmation. Results: The expected size band of 270 was confirmed by PCR. The plasmid sequence showed that the gRNA789 was ligated in the vector. The created structure was named PX-LMGP63 and will be transfected into the promastigote cell in the next step. Conclusions: Owing to the prevalence of cutaneous Leishman as a public health problem in most countries and the lack of an effective vaccine for leishmaniasis, the use of the CRISPR method may make it possible to achieve an effective vaccine in the future.

The evolution and history of gene editing technologies

Scientific enquiry must be the driving force of research. This sentiment is manifested as the profound impact gene editing technologies are having in our current world. There exist three main gene editing technologies today: Zinc Finger Nucleases, TALENs and the CRISPR-Cas system. When these systems were being uncovered, none of the scientists set out to design tools to engineer genomes. They were simply trying to understand the mechanisms existing in nature. If it was not for this simple sense of wonder, we probably would not have these breakthrough technologies. In this chapter, we will discuss the history, applications and ethical issues surrounding these technologies, focusing on the now predominant CRISPR-Cas technology. Gene editing technologies, as we know them now, are poised to have an overwhelming impact on our world. However, it is impossible to predict the route they will take in the future or to comprehend the full impact of its repercussions.