What is Drosophila?
My laboratory uses the fruit fly Drosophila melanogaster as a model for biological processes, and in particular the biology of oxidative stress resistance and ageing. The value of this organism stems largely from its highly developed background of genetic research, and the sophisticated techniques of genome manipulation which are available.
Keeping Drosophila
One of the major attractions of working with Drosophila is the modest culture requirements.
We keep flies in plastic vials 8cm x 2cm, containing about 5-10 ml of food, and stoppered with cotton wool. The food is a mixture of dried yeast molasses sugar and cornmeal, thickened with agar (vegetarian jelly), though different labs use slight variations of the same basic recipe.
Drosophila breed quickly : at 25oC it take only 10 days from egg to adult!
Of course, to look at the flies under the microscope, we need to stop them moving (but not killing them, since we may need use them to set an experiment up). To do this, we place them in a stream of carbon dioxide, which rapidly puts them to sleep. They also recover very rapidly.
Genetics
Drosophila has been used as a subject of genetic research since early in the 20th century. It is ideally suited, many genetically distinct strains can be maintained in the lab, and large numbers can be examined readily. Mutations affecting a wide variety of characteristics can be identified for study, including mutants altering the fly”s appearance, viability, fertility or behaviour.
Modern molecular genetic techniques in Drosophila are very sophisticated, and we can relatively easily make “designer flies” with particular genetic characteristics.
Drosophila as a model system
Most biological processes are remarkably similar in comparisons between flies and other animals, such as humans. This conservation makes flies particularly useful at investigation fundamental biological processes of great relevance to human health and development, quite apart from the intrinsic interest in investigating biology.
Clicking here take you to a description of a genetic analysis of fly development. It may seem strange at first sight, but the genetic control of basic developmental processes are remarkably similar in flies and man. Some of the key figures in this research, Ed Lewis, Christiane Nusslein-Volhard and Eric Weischaus, were awarded the Nobel Prize for Physiology and Medicine in 1995, for their pioneering work on the genetics of development in Drosophila.
Flies and ageing
In my lab, we are using flies to investigate lifespan and ageing. Our flies live an average of about 50 days in the culture conditions we use. While this may seem trivial, it”s an extremely important factor, as you cannot complete many lifespan experiments with an animal which has a lifespan measured in years. An additional factor is that we can breed large numbers of flies, and the large sample sizes make statistical interpretation easier.
We have been studying the consequences of increasing the fly”s resistance to chemical damage, and evaluating the correlation with lifespan.
Links to online resources
FlyBase – the Drosophila genetics and molecular biology database
The Bloomington Stock Center – The largest Drosophila stock centre
The Szeged stock centre
The Tucson stock centre – Drosophila species
The FlyBase BLAST service
Berkeley Drosophila Genome Project (BDGP)
26th October 2008 at 12:48 am
Thank you for your interesting blog. I have read about this topic now in a few places and I would like to conduct my A-level coursework project on fruit flies and aging. Do you think that this would be possible and if so, could you suggest a good study hypothysis and rough study design that I could use?
Thank you
Storm
27th October 2008 at 5:27 am
Well, I suppose part of the course work is devising these things yourself! :-)
Assuming this is an experimental piece of work, there are several reasons why ageing might be a bit difficult for experimental reasons: you need considerable facilities and equipment to grow up enough flies; the experiments are a bit lengthy (100 day max per experiment); it's really quite complex to control for genetic variation between different fly stocks.
If a theoretical study, there is a large literature on the genetics and physiology of ageing in Drosophila – Google Scholar is your friend!
Robert
13th August 2009 at 2:27 am
Hi! Congratulations for your reserch and for your lab's site. I'm beggining my research in drosophila, initially with biochemical parameters of oxidative stress after exposure to agrotoxics but now I'm trying to standarize some protocols to study behaviour of drosophilas (mainly locomotor activity). Do you know some protocol with details that may be used by us in our research? Thank you…
13th August 2009 at 5:32 am
Well, Drosophila behaviour is an aspect I've not personally been involved in, thogh we've recently begun using locomotor tests (phototaxis/negative geotaxis) as a measure of age-related muscular decline. I think one needs to be careful to distinguish between behaviour and physiology. There's a huge and sophisticated literature out there, but I'm not familiar with it.