<P> Following the pioneering work of Alfred Henry Sturtevant and others, Benzer and colleagues used sexual mosaics to develop a novel fate mapping technique . This technique made it possible to assign a particular characteristic to a specific anatomical location . For example, this technique showed that male courtship behavior is controlled by the brain . Mosaic fate mapping also provided the first indication of the existence of pheromones in this species . Males distinguish between conspecific males and females and direct persistent courtship preferentially toward females thanks to a female - specific sex pheromone which is mostly produced by the female's tergites . </P> <P> The first learning and memory mutants (dunce, rutabaga, etc .) were isolated by William "Chip" Quinn while in Benzer's lab, and were eventually shown to encode components of an intracellular signaling pathway involving cyclic AMP, protein kinase A, and a transcription factor known as CREB . These molecules were shown to be also involved in synaptic plasticity in Aplysia and mammals . </P> <P> Male flies sing to the females during courtship using their wings to generate sound, and some of the genetics of sexual behavior have been characterized . In particular, the fruitless gene has several different splice forms, and male flies expressing female splice forms have female - like behavior and vice versa . The TRP channels nompC, nanchung, and inactive are expressed in sound - sensitive Johnston's organ neurons and participate in the transduction of sound . </P> <P> The Nobel Prize in Physiology or Medicine for 2017 was awarded to Jeffrey C. Hall, Michael Rosbash, Michael W. Young for their works using fruit flies in understanding the "molecular mechanisms controlling the circadian rhythm". </P>

Which of the following are reasons why drosophila is considered a model system