Finally, Snell and School of Biology research scientist Tonya Shearer demonstrated a direct connection between the hormone and the switch to sexual reproduction in the rotifers. They used RNA interference (RNAi) technology to silence the gene controlling the progesterone receptor, which reduced by nearly two-thirds the number of animals switching over to sexual reproduction in response to the progesterone signal.
"This suggests that progesterone is important in this switch from asexual to sexual reproduction," Stout said. "Progesterone is certainly involved in the process, though there may be more going on in a cascade process that we haven't yet seen."
Beyond explaining how chemical signaling mechanisms crucial to both rotifers and humans evolved over time, the research can also help researchers understand the interplay between the environment, metabolism, hormones and behaviors.
"We can learn things from working with rotifers that touch upon human biology, including in this case the universality of steroids in reproduction and how steroids are used differently in different animals," Kubanek said. "When we experiment with rotifers in the lab, we can manipulate their behavior, physiology and metabolic pathways to determine how these steroids are made and used."
Though the researchers were looking for progesterone in the rotifers, finding the same molecule that is essential to humans still came as a surprise.
"It's a very complex system for such a simple organism," said Stout, whose primary research focuses on complex potential pharmaceutical compounds produced by marine organisms su
|Contact: John Toon|
Georgia Institute of Technology Research News