Sigma B is a stress-induced transcription factor in Bacillus subtilis. Bacteria producing a sigma B-YFP fusion protein were exposed to constant energy stress, and fluorescence pulses emitted by individual cells were detected by time-lapse microscopy. Could this result have been obtained using a sigma B-b-gal fusion protein?

Question

Quizplus · Accepted Answer

The key difference between using a YFP (Yellow Fluorescent Protein) fusion protein and a b-gal (beta-galactosidase) fusion protein for detecting stress-induced activity of sigma B in Bacillus subtilis lies in the method of detection. YFP allows for real-time, single-cell level observation through fluorescence, enabling the detection of fluorescence pulses in individual cells using time-lapse microscopy. In contrast, beta-galactosidase activity, typically measured using substrates like X-Gal or ONPG, provides an average signal from the population, making it unsuitable for detecting dynamic changes at the single-cell level as described in the scenario.

Sigma B Is a Stress-Induced Transcription Factor in Bacillus Subtilis