Dialectics—The Potential of Application Transformation on Solid Surface Technique

Some of my words might be illogical because of my poor writting. Of course, researchers concern about the factor - time. What I want to express is that few people concern on the time when transformants begin to accumulate on plates because they think that transformation occur only in liquid culture in transformation study. It is possible that this is true for other bacteria. But in E. coli, I have to keep this in mind that transformation occurs only on plates. To evaluate transformability, the number of transformants (transformation frequency and transformation efficiency) should not be the only index. There should be some other aspects which are ignored by others but we should take care . Goodgal published his paper in Nature about 35 years ago and mentioned that different types of H. influenzae mutants with transformation deficiency has different irregular shapes. However, this is just the property of the donor strain not be transfomed. Dubnau's group finds that many genes regulated by comK do not function in competence and DNA uptake and proposed K-state. But no little functions were found in these genes when the competence occur. Claverys' group claims that fratricide accompanies with competence and named X-state. This shows the effect of competence on other cells. No referrences can be found about the properties of transformants in themselves other than the transformation behavior. Is it possible that the transformants which have absorbed exogenous DNA has other abnormal phynotypes (e.g. shape, size) just during transformation? Can they be the indexs for transformation ability evaluation and classification. The transformation process might be dynamic and has an integral impact on the recipients.

We should not just think the black side of transformation on plates (not easy to monitor, not easy to be observed under microscopy and so it is difficult to assay with fluorescence or beta-gal). Nevertheless, we can see the in situ landscape: diversity of transformants just at the position where they were transformed. In liquid cultures, we have no way to discriminate the diversity, however, on plates we can open a window to see its original appearance. The techniques in developing transformation on solid surface could provide much transformation information unconscious before and in turn it calls for other novel techniques to overcome its shortcomings in that not be able to be assayed in liquid culture.