"Species that don't have this gene show more male-male courtship behavior than those that do have it," Long said. "The absence or presence of the sphinx gene appears to regulate the diversity of male-male courtship behavior among flies. This suggests that the genetic control of male courtship is an evolving system, which can recruit new genetic components and change courtship behaviors."
"This is the genetic interpretation," Long said. "Of course other factors, like the environment, are also likely to have an influence."
The scientists also noticed that groups of males without a working copy of sphinx tended to behave differently, often forming chains of flies positioned behind each other. This is a typical male-male courtship behavior, Long said, not seen in male-female relations.
Female flies without sphinx, on the other hand, did not show any changes in reproductive behavior compared to females with sphinx. This is not surprising, the authors say, since the sphinx gene is not expressed in female reproductive tissues.
Normal females were not able to attract the attentions of sphinxless males, which were more interested in each other than in females. But when these males could not complete the copulation process with other males, they would return to the females, Long said.
"Sphinx is not a protein-coding gene, but an RNA gene," Long said. "So, the question is: How do RNA genes interact and regulate other genes" We are exploring this in our lab."
|Contact: John Easton|
University of Chicago Medical Center