Today's Friday beautiful science comes from the TaMaRa lab (the lab of Francois Taddei, Ivan Matic and Miro Radman). They've worked on a lot of different projects, but these photos are intended to demonstrate that bacterial colonies are not made up of homogeneous cells. The first photo is of:
Cells expressing RFP undert rpoH and YFP under rpoS-dependent promoters.That is, they have RFP (red fluorescent protein) and YFP (yellow fluorescent protein) expressed under two different stress-dependent promoters. The colour of the cell will indicate which stresses that particular cell is being exposed to, protein folding stress, or starvation stress. As you can see, this group of 'homogeneous' cells is far from - and different cells are experiencing different stresses, depending on their position within the microcolony.
This second photo is of a
microcolony formed from a single cell (as above) with sublethal mytomycin concenration. Brightest cells (center) stopped growing after 3rd division and were engulfed by dividing cells.It is merely intended to show that different cells are responding to a sublethal dose of a DNA-damaging agent in different ways. This lab does all kinds of exciting work. I'll try to post on them more in the future.
P.S. I apologize for my absence. I had a massive hard drive meltdown a couple weeks ago, and I'm still recovering from it. I'm currently working on an ancient iMac while I wait for my machine to be fully repaired. Posting should pick up again shortly.