Female fly choice

Imagine, you are in a white room and it is quiet. And there is this guy with you and he is frantically running around you while he is strangely quiet. He is freaking you out, you want him to leave. But then you start to hear singing. It seems to come from this guy and it sounds beautiful. Someone who can sing that beautifully, can’t be that bad. Actually he is kind of cute in his frantic way. So you allow him to get closer, you allow him to touch you and end up having sex with him. It is a bit odd that he continues singing all along, but you don’t mind, you like his song.

This is the actual setting that a female fly finds herself in when I am doing my experiments. She is locked in a white room, which we call courtship chamber, together with a muted male, that she finds unattractive as she runs away from him and kicks him when he comes too close.  And then, at one point, I start playing back fly courtship song to them and the female’s behaviour changes. She slows down and allows the male to come close and finally copulates with him. However, females are picky, and do not copulate to any song, no, it needs to be the right one.

And I find that the right song needs to have the right song amplitude structure, that is the right way to vary in volume. In specific females like song amplitude structure typical for their own species, which you can see from these data that show what percentage of females copulate to their own species song and to a different species song:


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Strikingly females from both species, copulate more when hearing a song with their own species song amplitude structure, however they don’t like song with another species song amplitude structure. Actually the song is rendered as unattractive as silence, which when you think back to the beginning of this post must be really unattractive.

Disco Drosophila

Mark Jones and Keiran Foster from the Physics Department in Oxford helped me building a device which looks like a disco for fruit flies:

The video was made by my husband Christoph out of a recording I made. Keiran helped me by switching on and off the LED’s.

I will use the red and green LED‘s to depolarise genetically modified neurons in fruit flies. This technique is called optogenetics and was developed by Boris Zemelman and Gero Miesenböck. Gero’s name links to a TED talk of him about Optogenetics.

I call the disco device ‘song box’. This is because I will use it to record fly courtship song. In the video you can see a dark spot in the middle of the box - it is a highly sensitive microphone for recording fly courtship song. Male flies sing by extending and vibrating their wing. They do this when they see female flies. However they will not sit and wait on top of the microphone out of good will. I will restrain flies in a small chamber which fits on the microphone.