Why do we have fingers at the end of our arms? The answer lies in the way embryos develop and the genes that control the process. Our understanding of what happens in humans came from work done on the fruit fly, drosophila, which earned the Nobel Prize for Medicine in 1995 for Edward Lewis, Eric Wieschaus and Christiane Nüsslein-Volhard. Christiane is the most recent and only the tenth woman to win a Nobel Prize in the 100 years of the prizes. Gifted but lazy

School was fun and Christiane soon showed that she was a bright pupil but she only made an effort in the subjects she really liked. Her teachers reported that she was gifted but lazy and she only achieved average exam results.

Christiane found university studies in Frankfurt, rather dull until she rediscovered her love of biology. The chance came to join one of the first biochemistry courses at Tübingen so at the age of 22 she left her large family and settled in rooms in the old town with no hot water or central heating.

DNA and flies
Christiane was soon involved in the new methods of finding the sequence of genes in DNA, but by the end of her research for her doctorate in 1973 she was rather bored. She wanted to investigate how genes affected the development of organisms and found that the fruit fly, Drosophila, was a good subject to study. Christiane moved to Basel in Switzerland to work for Walter Gehring, a fruit fly expert, and met Eric Wieschaus. Wieschaus soon moved to Zurich while Christiane investigated the mutated fruit flies.

Five years later, Christiane was offered a post at the new European Molecular Biology Laboratory in Heidelberg, which was lead by the English molecular biologist, John Kendrew. There she shared a laboratory with Eric Wieschaus. It was a very small laboratory and they only had one assistant, Hildegard Kluding. After a while Christiane and Eric decided it would be easier if them and for Hildegard if they collaborated on a project.

A bold plan
Some years earlier Edward Lewis had discovered that the genes for controlling the formation of organs were arranged in order on the chromosomes. Christiane and Eric's plan was very ambitious, as they wanted to find out which genes controlled the early development of the fruit fly embryo at the stage when it started to show some structure. They exposed fruit flies to substances that caused mutations then examined the eggs that were produced when the flies mated. They spent many hours sat at a bench peering down a special microscope with two sets of eyepieces, both examining the same slide of fruit fly embryos. For two years they hunted for mutations in the embryos and then identified the genes on the chromosomes responsible for the changes. At last they isolated just fifteen genes that controlled how the insect embryo began to divide up into segments. They announced their results in 1980 and caused great excitement.

Flies, Fish and Humans
Eric moved to Princeton in the USA almost immediately and Christiane moved back to Tübingen in 1981 where in 1986 she became director of a division of the Max Planck Institute. She remains there today. While her work on fruit flies continues she has also done similar research on the development of fish embryos. The race to complete the sequencing of the Human Genome has been matched by the race to complete the Drosophila Genome. Humans may seem very different to tiny flies but in fact many of the genes involved in the development of embryos discovered by Christiane, are the same.

Fruit Flies on the Web

http://www.nobel.se/medicine/laureates/1995/nusslein-volhard-autobio.html
Christiane Nüsslein-Volhard's autobiography, which includes a detailed account of her work.

http://www.nobel.se/medicine/laureates/1995/press.html
The Nobel Prize announcement of 1995 with a summary of the work of the three winners.

http://www.ceolas.org/fly/intro.html
A site all about the fruit fly, drosophila

http://www.sciencedaily.com/releases/2000/03/000324095129.htm
News item announcing the completion of the fruit fly genome.

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