gut bugs affect mating

The Scientist | Differences in diet alter the composition of microbiota in Drosophila, which appears to in turn influence mate preferences -- and drive speciation. Drosophila seem to prefer to mate with other Drosophila raised on the same diet as a result of the bacteria that live in their guts, according to a study published this week in Proceedings of the National Academy of Sciences (PNAS).

These apparent mate preferences, which arose after just one generation, suggest that an organism's microbiota can facilitate rapid evolution and speciation.

"It's an interesting paper," said Patty Gowaty of the University of California, Los Angeles, who did not participate in the study. "The thought that these gut bacteria could be associated with the reproductive outcomes for individuals is fascinating."

"There's a lot of emerging research these days about the physiological effects of microbiota, and changes in microbiota in response to environmental conditions," added evolutionary geneticist Paul Hohenlohe of Oregon State University, who was also not involved in the research. "This study ties that into mating preference, too."

Twenty years ago, Diane Dodd of Yale University raised Drosophila melanogaster on different media for more than 25 generations and found that those raised on starch media were more likely to mate with other starch-raised flies, while those raised on maltose were more likely to mate with maltose-raised flies.

"Nobody understood the mechanism for this, but they understood it was important because mating preference is an early stage of sexual isolation and speciation," said microbiologist Eugene Rosenberg, a professor emeritus at Tel Aviv University in Israel and coauthor of the PNAS paper. "And nothing is more fundamental to evolution than the origin of species."