The common laboratory worm Caenorhabditis elegans is one of nature's most widely studied creatures, yet scientists still aren't sure how it developed an amazing trick:
Some specimens are self-fertile hermaphrodites, meaning they can have kids all by themselves.
New research, at the University of Medicine and Dentistry of New Jersey, suggests it probably didn't take much to acquire this skill.
Scientists began with a related worm, called C. remanei, which consists of just regular males and females.
They were able to turn C. remanei females into self-fertile hermaphrodites by suppressing just two genes. The first step caused the worms to make sperm as well as eggs; the second caused the sperm to be activated.
These modified worms were indeed able to reproduce by themselves, says senior author Ronald E. Ellis, an associate professor in the school's molecular biology department, at the Stratford campus.
C. elegans may have evolved this ability with two similar steps, Ellis and his coauthors write in the current issue of Science.
Why reproduce without a partner?
"It's quite useful for colonizing environments," Ellis says. "This one worm can head off on its own."
On the other hand, don't write off the males just yet. If C. elegans didn't also reproduce the old-fashioned way, the genetic diversity of the species would suffer. The offspring of a hermaphrodite are copies of their parent.
Says Ellis: "The most intense form of inbreeding is mating with yourself."
- Tom Avril