Male flies, fruit flies use a simple but effective strategy to find specimens of the weaker sex for mating — first they try to take care of all the females, but after failing to continue the kind of "Casanova" start to avoid the "ladies", fertilized by other males, say researchers in a paper published in the journal Nature.
Females of all kinds of flies, fruit flies mate only once in his entire life and keep the sperm of the male in the special internal organs to death. In other words, attempts to care for males fertilized females are doomed to failure. Because of this, developed a complex system of Drosophila chemical signals, alerting others of "marital status" of a fly.
Team of biologists led by Christina Keleman (Krystyna Keleman) of the Research Institute of Molecular Pathology in Vienna (Austria) studied the cellular mechanisms that control the behavior of adult male flies (Drosophila melanogaster).
As the scientists explain, the behavior of male controls mating pheromone cVA (cis vaktsenil acetate). During mating males applied to the abdomen of the female pheromone molecule layer, which notifies other flies on the "married" status of the individual. Mature males read this signal with Or67d receptor on the antennae and change their behavior depending on its concentration.
Keleman and colleagues examined how males behave in two unusual cases, impossible in nature. In the first case, the males tried to mate with the "old maid", who reject their advances even when unfertilized. In the second situation, the scientists removed the male portion of the genome of SP, is responsible for the synthesis of specific signaling agents, switching the body females are "married" mode.
In the experiment, the researchers put in a cell with adult males and females of some usual "old maids" and watched how their behavior has changed over time.
It was found that healthy males professed the same behavioral strategy — first, they tried to mate with all the females, but then move on to a more selective strategy and sensitively cVA molecules on the belly of the opposite sex. This means that a key role in changing the behavior of males played their experience — a series of unsuccessful mating increases the sensitivity of nerve cells to pheromone.
Biologists have tested this conclusion, they caught several females, fertilized by males with a remote gene SP, and applied to different portions of the abdomen substance SP. Then they put them in a container with other males, who had little or no experience of pairing, and tracked the reaction suitors.
As scientists expected, males with a strong tradition of pairing were more sensitive to pheromone than their inexperienced competitors. This confirms that the key factor in the marital behavior of male fruit flies is experience.
"To maximize the success of reproduction, the male has to take good features which distinguish the fertilized females from virgins. If the male is too selective, it may miss the chance to mate, while overly active courtship, he will not waste resources. Our study revealed an extremely simple and efficient algorithm — "everybody is fertilized, but the transition to electoral strategies in continuous failures" — the scientists conclude.