Transgenesis

Transgenesis encompasses the deliberate introduction, modification or disruption of genetic material in an organism’s genome. Beginning with the microinjection of viral genomes into pre-implantation embryos, the field rapidly advanced through the development of pronuclear injection to create mice carrying exogenous DNA constructs. Embryonic stem-cell-mediated gene targeting then enabled precise knock-out and knock-in mutations by harnessing homologous recombination, while site-specific recombinases (for example Cre-loxP) introduced conditional control over gene inactivation in selected tissues or at defined developmental times. The emergence of programmable nucleases—zinc-finger nucleases, TALENs and, most recently, RNA-guided CRISPR/Cas systems—has transformed transgenesis into a versatile toolkit that can edit, delete or insert DNA at virtually any locus across diverse species. Such methods underpin the generation of disease models, the engineering of biomanufacturing cell lines, the study of developmental processes and the development of novel therapeutics. Global applications span agriculture, biopharmaceutical production and fundamental research into gene function, while ongoing refinements continue to improve efficiency, specificity and safety.

Research from Nature Portfolio

Fanzor, a newly characterised eukaryotic RNA-guided endonuclease, expands the editing repertoire beyond prokaryotic systems. Structural and biochemical analyses reveal a Cas12-like core and guide-RNA recognition, and initial repurposing of Fanzor achieves precise genome edits in human cells, suggesting a next generation of programmable nucleases for complex genomic contexts. Real-time imaging of bacterial conjugation has mapped single-strand plasmid transfer and its conversion to double-stranded form in recipient cells. The leading region of the plasmid carries active single-strand promoters that drive immediate transgene expression, while subsequent double-strand promoters regulate maintenance and dissemination functions, offering new design principles for vectors with enhanced transfer kinetics and staged gene-expression programmes.

Research from all publishers

A comprehensive review of CRISPR/Cas9 therapeutics outlines the evolution of high-fidelity Cas9 variants, base and prime editors, and non-viral delivery vehicles tailored to disease-specific biomarkers. Clinical successes in monogenic disorders underscore the importance of vector design for tissue tropism and immunocompatibility, and highlight strategies to minimise off-target effects while maximising on-target efficiency. Analysis of off-target and on-target scoring algorithms integrated into the CRISPOR tool demonstrates that combining multiple predictive models markedly improves guide-RNA selection, reducing false positives and guiding the rational design of editing experiments in plant and animal genomes. In the arena of biopharmaceutical production, the SiMPl-GS system employs a split-intein glutamine synthase selection marker to enrich for cells expressing multiple transgenes. This AND-gate strategy streamlines the development of multispecific antibody-producing cell lines by coupling selection to the correct assembly and expression of all components in a single step, thereby accelerating the creation of next-generation biologics.

Transgenesis publication trend

The graph below shows the total number of articles in transgenesis across all publications each year (not limited to Nature Index journals).

Technical terms

Transgene: A DNA sequence introduced into an organism’s genome, often encoding a reporter, therapeutic protein or gene modification.

Pronuclear injection: Delivery of DNA directly into the male pronucleus of a one-cell embryo to generate transgenic offspring.

Embryonic stem cell (ESC): A pluripotent cell line derived from the inner cell mass of the blastocyst, capable of targeted genome modification and germline transmission.

Homologous recombination: A DNA repair pathway that uses a homologous donor sequence to mediate precise integration or correction of genetic changes.

Site-specific recombinase: An enzyme (for example Cre or Flp) that catalyses recombination between defined DNA recognition sites to activate or excise genomic segments.

Programmable nuclease: A designer endonuclease (such as ZFN, TALEN or CRISPR/Cas) that cleaves DNA at user-specified genomic locations.

Off-target effect: Unintended cleavage or modification at genomic sites that resemble the intended target sequence, posing a potential risk to specificity and safety.

References

1. Evolution of Transgenic Technology: From Random Transgenesis to Precise Genome Editing.
2. Fanzor is a eukaryotic programmable RNA-guided endonuclease. Nature (2023).
3. Real-time visualisation of the intracellular dynamics of conjugative plasmid transfer. Nature Communications (2023).
4. CRISPR/Cas9 therapeutics: progress and prospects. Signal Transduction and Targeted Therapy (2023).
5. Evaluation of off-target and on-target scoring algorithms and integration into the guide RNA selection tool CRISPOR. Genome Biology (2016).