Some of the more important new techniques of bioengineering seek to use pathways and processes that already exist in nature. In this case, the researchers looked into the ability of plasmids to transfer genetic information between different kinds of cells. This needs some explanation.
First, a smidgeon of Biology 101: A plasmid is a DNA molecule that functions in a cell outside of the nucleus (or outside of whatever aggregation of DNA the cell may have). A key point about plasmids is they are found in all three major forms of life (domains: Archea, Bacteria, and Eukarya), although they are most common in bacteria. In bacteria plasmids provide a mechanism for transferring DNA within a population of microbes. This is called horizontal gene transfer. The research, which uses the lab-friendly moss Physcomitrella, instead of the usual bacteria, has a formidably technical description:
Most episomal transformants quickly lose the plasmid in the absence of selection, but a semistable type of transformant that loses the plasmid at a much lower frequency was also observed. The consistent rescue of the original plasmid, or of predictable derivatives thereof, suggests that molecular genetics methods which rely on shuttle plasmids are feasible in Physcomitrella.
In general terms, plasmids can be used to introduce changed genetic material (DNA) into a cell (in this case, a moss cell). The cell then replicates the DNA, more or less faithfully, over many generations. Then the plasmid can be retrieved from the cell and studied to see what happened to the DNA.
Researchers from Uppsala University in Sweden have now demonstrated that plasmid-based methods, which had been limited to single-cell organisms such as bacteria and yeasts, can be extended to mosses, opening the door to applications of a number of powerful techniques in plant research.
The new study, which was led by Dr. Eva Murén and Ph.D. student Anders Nilsson, shows that plasmids introduced into moss cells can be rescued back to bacteria without affecting the plasmids’ original structures, provided that certain conditions are met. Up to now, various kinds of rearrangements have sharply limited the use of plasmids in animal- and plant-cell research.
“Our work with plasmids in moss suggests that it will be possible to use powerful methods such as gene cloning by complementation and overexpression directly in plant cells without recourse to single-cell organisms like bacteria or yeasts,” says Professor Hans Ronne. “This, in turn, may simplify basic and applied research and biotechnology involving plants.”
[Source: Uppsala University]
While plasmids are not extensively found among eukarya (plants, animals), there are enough examples to provide a workable basis for genetic research. Moving plasmids between kingdoms, especially plant and animal, may also be possible. Of course, much of this is speculative. In fact, the current research reveals mostly potential use of plasmids and only for one species. Nevertheless, because plasmids are a ‘natural’ means of incorporating genetic material in many kinds of cells, it is an avenue that could be used with less complication than other approaches.