10 Reasons to Thank the Fruit Fly: Insights into Human Disease
Copyright 2012 - Kris Heeter, Ph.D. (Reprinting, copying or reproducing this article in part or in full online or offline is prohibited.)
For well over a century now, some scientists have devoted their entire careers to understanding what most of us would consider pesky little flies – the fruit fly.
Yes, those annoying little flies that hitch a ride in on your fruit and that seem to rapidly appear out of nowhere.
Why in the world would any “sane” scientist want to study a fruit fly all of his/her life?
And, why should you care?
I’ll share 10 reasons why you should care and why you might begin looking at these annoying, buzzing, in-your-face, pests in a whole new appreciative light.
A Century of Fruit Fly Research
Fruit flies (genus Drosophila) have been studied for well over a hundred years. Their genome or genetic information was the first to be sequenced (decoded).
The little guys are easy to manipulate and breed. Scientists can easily induce mutations or make genetic changes to study the outcomes.
But why would someone want to spend so much time mutating a fly and breeding it?
It turns out that the fruit fly is a model for many human diseases.
It’s very hard and time consuming to study genetic changes in humans. And ethically there are, of course, limitations.
Fruit flies can get many of the same types of diseases as humans. Many of the genes that contribute to these diseases are conserved between humans and fruit flies.
Most people don’t care if fruit flies are mutated and killed in the name of science. So, for decades, scientists have been mutating them on a large scale in controlled environments to learn more about the genes involved in human diseases.
Over the time, this has unveiled some very interesting insights into human diseases.
How has fruit fly touched your life?
If you or a loved one have been affected by one more of the diseases listed, you can thank a fruit fly for some of the insights that have lead to understanding of these diseases.
1. Alzheimer’s Disease (AD) – yes, fruit flies can get AD and it can be measured and documented in a fly.
2. Parkinson’s Disease – fruit flies have emerged as a very valuable model organism to study both toxin-induced and genetically linked Parkinson’s.
3. Cancer – flies get cancer too.
4. Epilepsy – new research coming out shows that certain genetic mutations can induce epileptic seizures in flies.
5. Heart Disease - heart function can be studied in Drosophila. The fly's cardiac performance, like that of humans, has been shown to deteriorate with age and is now a model for human heart-related diseases.
6. Diabetes - fruit flies have paved the way for understanding insulin resistance.
7. Aggression and Mental Disease – fruit flies have become a model system for looking at the neuronal changes associated with aggression psychological diseases in humans.
8. Muscular Dystrophy – Drosophila are being used to characterize the mutations affecting neuromuscular function.
9. Kidney disease – flies can develop kidney stones (ouch!)
10. Obesity – flies have provided a great model for looking at the balance of energy intake and expenditure.
Studying a genetically tractable system like Drosophila gives scientists great insights to the basic processes underlying the onset and progression of diseases.
As I sit here as one of the scientists at the 53rd Annual Drosophila Research Conference, listening to latest coming out of the pipeline, I’m still in awe over how much these little guys have taught us over the past 100+ years!
Recent Fruit Fly and Human Disease Research
Catch some of the latest research using fruit flies as human disease models here (last updated June 28, 2012):
Fruit Flies Develop Insulin Resistance: Scientists at Southern Methodist University have recently shown that fruit flies fed too much protein and carbohydrates developed insulin resistance, gained weight and had a shorter life span.
This induced insulin resistance, a hallmark sign of Type 2 diabetes, allows scientists to easily study aspects of diabetes and other metabolic induced problems that result from overeating using the fruit fly.
Fruit Flies used as a model for studying Lou Gerhig's Disease or ALS
Recent research from the John Hopkins University School of Medicine has shown that when fruit flies are engineered to contain mutations in specific proteins that transport cargo (nutrients, etc.) within cells, the flies show a disruption in transport and cargo accumulates at nerve endings over time. The end result is disease that is analogous to ALS (Amyotrophic Lateral Sclerosis - a.k.a. Lou Gerhig's Disease) in humans.
This finding will allow researchers to study ALS more efficiently in the future and to provides an understanding of the genetics associated the disease.
Fruit flies used to identify two genes associated with Down Syndrome congenital heart defects
Congenital heart defect is the major cause of infant mortality in individuals with Down syndrome. Using the power of genetics in fruit flies, researcher have been able to identify two genes, when "over expressed" or are turned on at elevated levels, can disrupt cardiac development and function.
Sample References - Drosophila as a Model for Human Diseases:
Chan and Bonini. 2000. Drosophila models of human neurodegenerative disease. Cell Death and Differentiation. Vol 7: 1075-1080.
Chartier et al. 2006. A Drosophila model of oculopharyngeal muscular dystrophy reveals intrinsic toxicity of PABPN1. The EMBO Journal. Vol 25: 2253 - 226.
Ocurr et al. 2007. Age-related Cardiac Disease Model of Drosophila.Mech Age Dev; Vol.128: 112–116.