A Roseate Spoonbill eating fish in a canal at KSC. Took this pic on my way home from work. I was quite impressed to see a pink bird hanging out there.
How did fruit flies end up on a rocket to help understand the human heart to begin with?
Well, I could take you through the long history of genetics, how Gregor Mendel unraveled the mystery of genetic inheritance and Thomas Hunt Morgan became the father of fruit fly research. If that sort of thing interests you, I highly recommend reading The Gene, by Siddhartha Mukherjee. He does an excellent job explaining the history of genetics and model organisms.
For those of you that want a simple answer, fruit flies are an incredible tool for understanding human disease. They share ~75% of disease causing genes with humans, and their simple genetic makeup of four chromosome pairs (compared to the 23 in humans) allow us to easily manipulate them to understand disease. Therefore, fruit flies are an ideal model organism. One of my teammates here at NASA put together an awesome video explaining this question as well. Check out Christina’s video, Why Do Scientists Use Fruit Flies in Research?
Here is a picture of Christina collecting flies today:
To add another layer to the onion, the fruit fly heart is ideal for studying defects for a few reasons. First, of all the model organisms, the fly shares the most similar genetic makeup to humans, even trumping the mouse model, which lacks certain ion channels that both humans and flies have in their heart tissue. Second, because flies are an insect, they have an exoskeleton. Their heart pumps “blood” or hemolymph around their entire body cavity, whereas vertebrates require blood to travel through veins and arteries to remain contained and get where it need to go. This is called an “open circulatory system,” and we have a “closed circulatory system.”
The open circulatory system means that the blood flow does not need to be as consistent or effective as ours for the fly to live. This makes them excellent candidates to ethically study disease models of the heart. If you knock out a gene that simulates a disease, the heart can function poorly, and you still have flies that live a happy life and reproduce more generations of flies for future studies.
When it was discovered that prolonged space travel caused astronauts to have heart problems, NASA sought to solve it. Naturally fruit flies had to get involved. So that’s the basic story for how we are now going to fly high with the fruit flies.
Also, here is another cool video put out by NASA explaining how fruit flies help with space research, How Fruit Flies Help us Understand Human Responses to Microgravity.