An image of bacterial sex enjoyed a brief period of celebrity attention in 1956. Today’s readers may not recall the weekly periodical, Paris-Match. Think People. Now imagine a People expose featuring raw photos of bacteria caught “in the act.” Hmm, what were the French thinking?
American electron-microscopist, Tom Anderson, was on a Fullbright scholarship visiting the Pasteur Institute in 1956. He and his French colleagues, Francoise Jacob and Elie Wollman, succeeded in catching two mating bacteria in the conjugal act (below). At this point in the mating process, the male bacterium Left, is close enough to the female, bacterium Right, to start injecting his strand of DNA.
In order to easily distinguish males from females, Anderson and his colleagues used a virus-resistant strain of bacteria for the male; the female bacterium was sensitive to the virus. Just prior to mating, the females were “labelled” with inactivated virus particles (males are resistant, and therefore virus is unable to attache to male membranes). Notice the attached viruses are visible sticking to the outer edge of the bacterial membrane Right.
Over a decade earlier, Anderson recorded some of the first electron microscopic images of bacteriophages, the viruses that naturally infect bacteria.
Check out the electron microscopy image of bacteriophage Lambda below. It reminds me of the Martian Tripods in H. G. Wells’ 1898 science fiction book, War the Worlds. Another example of life imitating art!
This is the virus that Esther Lederberg discovered in 1951. Lambda normally hides out, as a prophage: the viral genome integrates within in the E. coli K-12 genome. When activated by UV light, it emerges as a biologically active virus, capable of replicating and killing the host bacterial cell.
Anderson recalled the unusual instance of celebrity status for bacterial sex, in an autobiographical memoir
” I documented with Franc;ois Jacob and Elie Wollman the conjugal bliss of bacteria. Somehow, news of this reached the editors of the weekly picture magazine, Paris-Match, alnd they used one of our pictures to illustrate a story by Ramond Cartier entitled simply, “La Vie.” The picture caption was, “Un Accouplement de Bacterie.” When I objected that very few readers would understand what “Accouplement” meant, I was told to have no fear. They would.How many American readers of Life magazine in 1956 would have known the meaning of the equivalent English word, coupling?”