What kind of virus was being studied when the word ‘transfection’ was first used (1964)?

In today’s TransMission, we bring you transfection trivia! Do you know when the word ‘transfection’ was coined?

The word ‘transfection’ is a portmanteau of ‘trans’ and ‘infection.’ Its origin is widely attributed to Drs. J. Földes and Thomas Trautner. In their 1964 article “Infectious DNA from a Newly Isolated B. Subtilis Phage” published in Zeitschrift für Vererbungslehre, they state:

“Infection of cells by the isolated nucleic acid from a virus, resulting in the production of a complete virus, will be termed Transfection.“¹

Földes and Trautner had isolated a bacteriophage they called SP50 which was capable of not only infecting Bacillus subtilis, but whose isolated DNA alone could also effectively infect the bacterial cells causing the production of more bacteriophage. At the time, scientists had already established that the hereditary material of life, genes, consisted of nucleic acids, not protein. Transformation of bacteria with purified DNA had been reported in the 40s and 50s – recall the pioneering Avery-MacLeod-McCarty and Hershey-Chase experiments.^2,3 And, furthermore, the first transformation/transfection of human and animal cells was reported by the Szybalskis in 1962, before the term ‘transfection’ had even entered common parlance.⁴ So, why and how did the word ‘transfection’ emerge as distinct from ‘transformation?’

Immediately following Földes’ and Trautner’s 1964 definition, ‘transfection’ was used to describe the uptake of viral DNA resulting in production of additional virus, whereas ‘transformation’ referred to the general phenomenon of cells expressing new genetic information (with no distinction being made between prokaryotic or eukaryotic cells).^{5, 6} To this day, these meanings are still widely used in prokaryotic literature. In contrast, by 1980 a quiet battle of words had begun for terminology to describe gene delivery to eukaryotic cells.

For example, in 1980 Hanahan et al. proposed the word ‘convection’ be used, aptly noting:

“The terms transfection and transformation each have distinct biological definitions that can be confusing when applied to describe the general acquisition of exogenous DNA sequences by the genome of a cell. Transfection has been used in the past to describe biochemically mediated absorption of viral DNA by cells, while transformation has a special meaning in the literature of mammalian cell culture, generally referring to the process by which cells change their normal patterns of growth regulation.“⁷

The pioneering molecular biologists of tissue culture needed a different word to distinguish transformation of cells as in carcinogenesis from the process of gene delivery. However, the word ‘convection’ never caught on, and over time ‘transfection’ in the context of animal cell culture came to mean delivery of any kind of nucleic acid, not just of viral origin. 

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