Beetles and the genetics of parenthood

Most insects do not care for their young. But burying beetles take an extraordinarily active role - preparing food, protecting the brood and even feeding their offspring much in the same way that a bird feeds its hatchlings. New research published in the journal Nature Communications has identified many of the genetic changes that take place in burying beetles as they assume the role of parent:

"Parenting is a complex trait, but it's particularly complex in burying beetles," said the study's co-author Allen Moore, a Distinguished Research Professor of Genetics in UGA's Franklin College of Arts and Sciences. "Sometimes the male or female may care for the brood as a single parent, and sometimes they appear to work as a couple. By examining changes in genes associated with parenting, we got a clearer picture of what's really happening."

Scientists have long presumed that burying beetles were one of the few insect species to co-parent their offspring, but the research team's genetic tests cast serious doubt on that assumption, Moore said. The fundamental idea was that males and females that stayed together did so because they were compatible; they made up for individual weaknesses by joining forces.

"If that were true, you'd expect two parents to be better than one, but we didn't see that at all," Moore said. "Offspring raised by a single parent fared just as well as those that appeared to be raised by two parents."

The researchers allowed 269 pairs of male and female beetles to co-mingle in a closed environment complete with food sources, and they observed their behavior as they raised their offspring. About 50 percent of the time, males would abandon the nest after mating, leaving the female to care for the brood alone. Females, on the other hand, only abandoned the nest 5 percent of the time.

Regardless of its sex, when a single parent cared for the young, the researchers found that beetles expressed specific genes that control parenting behaviors. But when beetles appeared to act as a couple, the story was different.

The social dynamics of parenting and their genetic expression is an important part of the story of evolution, itself building the foundational chapters in the story of survival. Fundamental research that illuminates a better understanding of the world around us realizes an integral part of the university's mission, as exemplified by Dr. Moore and his extraordinary colleagues. Inquire into the nature of things.

Image: A female burying beetle feeds her begging young. The parent and offspring are in a mouse carcass prepared by the parent as food. (Credit: Allen Moore/UGA)