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"Female and Male Flies"

no. 20161222_0098_male_female_fly

Caltech, CA

Female (left) and male (right) Drosophila melanogaster. The simple genetics of fruit flies—they only have 3 chromosomes compared to our 23—make them a popular model organism for studying the genetic and neural basis for how animals process sensory information and control their behavior. A binary genetic expression system called Gal4/UAS, originally derived from yeast in 1993, makes it possible to mate two genetically altered flies in order to express novel genetic constructs in relatively small subsets of neurons or tissues. These genetic constructs include light activated ion channels to activate neurons, fluorescent proteins such as GFP (green fluorescent protein) to image neurons, or neurotoxins to shut down neural activity.