Electroporation vs Zebrafish Embryonic Transfection

Electroporation is a transfection method to deliver substances such as DNA, RNA, proteomic material into cells by introducing an electrical pulse. While electroporation is an effective method for cells such as bacterial, yeast, mammalian, plant, insect, or primary cells, however, some cells are more sensitive where this method may negatively affect overall viability. For example, a popular application involving zebrafish embryonic transfection, it is not recommended to use electroporation. Some reasons this method is not beneficial for these embryonic cell types and their viability include the developmental stage of the embryo, the sensitivity of the embryo, and the embryo’s chorion.

Developmental Stage

Zebrafish embryos develop quickly, where gastrulation begins approximately 6-hours post-fertilization, and hatch after 2-days as a free-swimming larvae. The efficacy of electroporation can vary depending on the developmental stage of the cell. Electroporation may be less efficient at certain stages of development, further limiting the utility of this method for successful transfection.

However, it has been found that at the cleavage stage, electroporation may be used effectively (Zhang, et. al. 2020). It is important to note that depending on the material being delivered and the desired outcome, this stage of transfection of zebrafish embryos may not be preferable.

Sensitivity

Zebrafish embryos are small, fragile, and susceptible to outside stressors. Electrical pulses have been found to negatively affect development and again, viability. Their small size and fragility make the electroporation a risky method to use for transfection.

Chorion

Zebrafish embryos are confined within a protective chorion that serves as a barrier to peripheral molecules. The chorion is quite impermeable, where a higher voltage is required to open channels via electroporation, a voltage often detrimental to cell viability.

Alternative Techniques

Alternative methods to achieve successful transfection includes standard pressure-based microinjection. It has been found that transgenesis of vectors using Tol2 or other transposon-based systems promote stable expression. A standard pressure-based microinjection approach presents greater reliability, precision, and overall control when delivering material to embryos, often preferred over electroporation in zebrafish studies. Check out WPI’s line of Pressure-based microinjection systems for all your zebrafish embryonic modulation needs

Although electroporation is not often ideal for use in zebrafish embryos, it can be implemented for manipulating cells or tissues derived from zebrafish embryos or adults in certain research contexts. End-users should be cautious when structuring a protocol using electroporation for zebrafish models to optimize the results of their application.

Reference

Zhang, C., Ren, Z. & Gong, Z. (2020). Transgenic Expression and Genome Editing by Electroporation of Zebrafish Embryos. Mar Biotechnology, 22, 644–650. https://doi.org/10.1007/s10126-020-09985-0