Drosophila melanogaster – better known to you and me as the common fruit fly – may seem an unlikely hero in the history of science. But this tiny insect has played a crucial role in helping us answer profound questions about the beginnings of life and how we become what we are.
While a fruit fly only has four chromosomes compared to a human’s 23, its genes are remarkably similar. Sequences of human genes can be matched with equivalent genes in the fly. For example, around 75% of genes that may cause hereditary diseases in humans can also be found in Drosophila.
All this makes them particularly attractive to scientists studying embryonic development. And for Christiane Nüsslein-Volhard and Eric Wieschaus, Drosophila helped them make an astounding discovery – that there are specific genes which control the development of the early fly embryo and do the same for other animals.
40,000 flies and the genes that build life
Born in Magdeburg, eastern Germany, Christiane Nüsslein-Volhard studied biology at the University of Tübingen, graduating with a PhD in biochemistry. In 1981, she began the project that would be recognized across the world – unraveling the mysteries of the embryo. In particular, she was interested in the genes that control the process by which the embryo forms and develops.
To decode these mysteries, Nüsslein-Volhard and her colleague Eric Wieschaus turned to the fruit fly. Lots of them. In all they bred nearly 40,000 flies. The two scientists developed a genetic screening process, which involved mutating the fruit fly genome and seeing which of the induced mutations affected embryonic development.
This process allowed the pair to identify those genes – ultimately whittled down to a crucial 120 genes – that directly controlled the shaping of Drosophila embryos – and by extension, other multicellular organisms.
“It turned out that the genes we had identified in flies also play a very important role in vertebrates. This was really the breakthrough which made it possible for the fly research to have an impact on human development,” explains Nüsslein-Volhard.
Their discovery has allowed us a much deeper understanding of the genetics of development. And in 1995 it won Nüsslein-Volhard, Wieschaus, and Edward B Lewis (whose earlier work on fruit flies underpinned their research) the Nobel Prize in Physiology or Medicine.
Christiane Nüsslein Volhard
momentum-photo.com/MPI für Entwicklungsbiologie Tübingen
Supporting young female scientists
Nüsslein-Volhard was just the sixth woman to win the Prize, a reflection not only of the significance of the discovery but also the relative lack of women in science for much of the century.
“When I started being a scientist in the '70s and early '80s, life was very different for women. We were a big exception” says Nüsslein-Volhard. “People didn’t know how to deal with us. This made life complicated, because the fact that you were a woman was just so unusual.”
Thankfully, times have changed. “People can no longer argue that women are exceptions and are in principle not suited to do good science,” she says. “In every field, there are women who are at least as good as the best men. There is no question about this anymore.”
However, challenges remain – particularly for women trying to juggle a science career with looking after young children. In light of these challenges, Christiane founded the CNV-Foundation in 2004, which provides financial grants for mothers at the beginning of their careers working in the natural sciences so they can continue their research.
“The idea for the foundation came when one wonders about the low percentage of women in science and how this could be improved. The most important difference, of course, between men and women is that women bear children. When you have a family, you have less time to devote to your research. It is just unavoidable that this costs time and energy.”
The recipients awarded grants are chosen purely on scientific merit. Nüsslein-Volhard explains, “we choose them on the basis of their achievements, on the basis of what they tell us about their research. This is not a social enterprise. It's meant for talented women, to support them in their career.”
It is this passion for scientific rigor and excellence that has been reflected throughout Nüsslein-Volhard’s career. From her ground-breaking discovery about how we develop to supporting the next generation of female scientists.