Sex in the Media

Indifferent to textbook dogma, some researchers have long suspected that bacteria really do have sex. They merge their genomes, research suggests, possibly by whole-cell fusion. Investigators liken the phenomenon to egg fertilization and distinguish it from conjugation, in which bacteria pass along bits of genetic material. A decade ago, Jean-Pierre Gratia, now at the Pasteur Institute of Brussels, Belgium, reported that mixing two nonconjugating Escherichia coli strains produced cells with both phenotypes, apparently diploid carriers of precursor genomes.

Recently, Gratia, who says he likes to "look freely at bizarre phenomena," and a colleague labelled one precursor strain with gold particles.¹ Some daughter cells had gold localized to one side, they found, suggesting that the parent cells had fused end to end. The researchers call the phenomenon spontaneous zygogenesis, or Z-mating, which may require a "Z-factor" transmitted by a bacteriophage.

Bharat Patel of Griffith University in Australia says, " [Gratia]...