Most people wouldn't think that making E. coli smarter is the best thing to do, but a group of students at the University of Tokyo have taught the microbes to solve logical puzzles, like Sudoku, reports New Scientist's Frank Swain. Beginning with 16 types of E. coli, the students assigned each colony a genetic identity based on which square it occupied on a four-by-four Sudoku grid, and the ability to express one of four colors representing the numerical value of that location, Swain says. Some bacteria were prodded into taking on a specific color, and then they used RNA recombinases packaged in viruses to send information about their color to undifferentiated microbes. "The E. coli are 'programmed' to accept RNA only from cells in the same row, column or block as themselves," Swain says. "The genetic information stored in the viral messages forbids the receiving bacteria from differentiating into the same color as the transmitting bacteria, so by a process of elimination the undifferentiated cells establish which color to adopt to 'solve' the grid." Thus, the more E. coli
At the Loom, Carl Zimmer takes a moment to "marvel anew at the sophistication" of E. coli. But, he adds, "let's just hope that all the E. coli in our guts don't figure this out on their own..."