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New Study Findings about Fish Gene Editing

Spermatogonial stem cells (SSCs) are a type of reproductive stem cells with self-renewal and differentiation potential in adult male gonads. Using spermatogonial stem cell transplantation (SSCT) technology, it is possible to achieve cross-individual or even cross-species "parthenogenesis", that is, the use of individual (or species) B to produce functional gametes of individual (or species) A. SSCT "parochial reproduction" is an important technique to study gametogenesis and gonadal development, and it also has important and broad application value in rapid and efficient directional breeding. Whether SSCT "parochial reproduction" can be achieved among different species with large genetic distances (e.g., across subfamilies and above genetic distances) is a classical problem in this field.

Recently, Sun Yonghua, Institute of Aquatic Biology, Chinese Academy of Sciences, published a research paper entitled Surrogate production of genome edited sperm from a different by spermatogonial stem cell transplantation subfamily, using fish SSCT to achieve "loaner reproduction" among subfamily species for the first time, and genetically edited SSCT sperm derived from cross-subfamily species were obtained.

In the previous study, the Sun Yonghua team established and optimized the "parental-reproductive" technology of fish gene-edited gametes in zebrafish (J Genet Genomics, 2020) to quickly and efficiently obtain maternal zygotic mutants of homozygous mutant lethal genes, opening up new avenues for the functional study of zebrafish maternal genes. To further explore whether a "borrowed abdominal reproduction" technique for gene-edited gametes can be established between fish xenografts, the team selected two fish species across the subfamily, rare crucian carp and zebrafish, as SSCT donors and recipients, organically integrated and optimized germ-cell-targeted CRISPR/Cas9 gene editing and SSCT "borrowed abdominal reproduction" techniques, and rapidly and efficiently obtained genetically edited sperm derived from donor rare crucian carp using recipient zebrafish.

In order to trace the developmental fate of donor rare crucian carp SSCs in recipient zebrafish, researchers finely characterized the whole process of colonization, proliferation, and differentiation of transplanted SSCs in zebrafish gonads, and revealed that SSCT testis is a special recombinant gonad composed of donor rare crucian carp germ cells and recipient zebrafish gonadal somatic cells using genomics and experimental biology. The nuclear genome of SSCT sperm produced by zebrafish was completely derived from donor rare crucian carp and could only be fertilized with rare crucian carp eggs, but its morphological characteristics and swimming behavior were closer to those of recipient zebrafish sperm. Comparison of the transcriptomes of SSCT sperm and common rare crucian carp sperm revealed that some transcripts from zebrafish gonadal somatic cells may be transported into SSCT sperm cells in some way, thus affecting the morphological and behavioral characteristics of rare crucian carp sperm produced by "parental reproduction". This study is the first to use "borrowing abdominal reproduction" technology to produce gene-edited gametes of xenogeneic origin, which lays a solid theoretical and experimental foundation for further use of this technology to design and customize gametes for future farmed fish.

Collected by Lifeasible, which has been deeply involved in the field of fish gene editing for many years, and has accumulated a wealth of theoretical and practical experience. We can help customers perform gene editing on different fish species: Amphioxus, Lamprey, Danio rerio, Medaka, Tilapia, Monopterus, Ciona, Sturgeon, Salmon, Pelteobagrus Fulvidraco, and Pufferfish.
https://www.lifeasible.com/custom-solutions/animal/fish-gene-editing/