How can we elucidate the biology behind heat-shock bacterial transformation?
Shubhankar KulkarniFeb 26, 2021
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How does the bacterial heat-shock transformation work?
Bacterial transformation is the process of injecting a foreign nucleic acid (plasmid) inside a bacterial cell. Providing a heat-shock creates pores in the bacterial membrane, which facilitate the entry of the plasmid into the cell. Heat-shock is one of the methods to make cells competent for transformation.
Although the method is used widely and the biology behind the transformation is passed down from mentor to the students throughout history, there have been claims that the biology has not been studied and empirically demonstrated.
So, how can we elucidate the biology behind the heat-shock bacterial transformation? Have you studied it? Do you have a theory in mind? If yes, please mention it. If you also have experiments thought of to prove the theory, mention them, too. If not, others can help come up with experiments. Other methods (for example, electrical stimulation) to induce competence may also finally exploit the same pathway (making pores in the cells). Therefore, any thoughts on the biology behind these other methods of achieving cell competency are also welcome.
The positive-charged calcium ions weaken the cell wall and the heat induces the formation of pores
Shubhankar KulkarniFeb 26, 2021
Here is one explanation I found.
Cells are usually made competent by exposing them to a calcium-rich environment. "The positive charges of the calcium ions neutralize the negative charges of both the plasmid and the bacterial cell wall dissipating electrostatic repulsion and weakening the cell wall. By exposing cells to a sudden increase in temperature, or heat shock, a pressure difference between the outside and the inside of the cell is created, that induces the formation of pores, through which supercoiled plasmid DNA can enter. After returning the cells to a more normal temperature, the cell wall will self-heal."