Our world has been revolutionized by biotechnologies like CRISPR-based gene editing and mRNA vaccines. This vigorous advancement has been powered by female scientists, and the results have reshaped industries from medicine to agriculture.
The biological and biomedical sciences boast the highest concentration of women of all the scientific fields. For Women’s History Month, we’re shining a light on some of the women who have contributed world-altering work to the field. Despite these amazing achievements, women in STEM continue to face social and organizational challenges in their work. The extra effort, mental fortitude, and passion necessary to achieve greatness in the face of unfair resistance is a testament to the powerful minds featured here.
Emmanuelle Charpentier and Jennifer Doudna
CRISPR; need we say more? The public conversation about gene editing pivoted from futuristic pipe dream to realistic inevitability because of Dr. Charpentier and Dr. Doudna’s earth shattering work.
Bacteria and archaea have a primitive immune system that protects them from viruses. This CRISPR system works directly on DNA by recognizing specific DNA signatures characteristic of viral invaders and using molecular scissors to cut viral DNA out of the genome. In their research, Dr. Charpentier and Dr. Doudna saw the remarkable degree of precision in the CRISPR system and saw endless applications. The two developed methods to gain control of the scissors’ targeting system, a feat that would become the epicenter of a breakthrough in genetics.
All of the sudden, it was quick and easy to selectively cut any gene that researchers wanted to study, enabling billions of experiments. A flood of new data became available as researchers used these tools to observe how organisms fared without certain genes. For kicking off one of the biggest breakthroughs in genetics, Charpentier and Doudna were awarded the 2020 Nobel Prize in Chemistry. The worldwide influence of this iconic duo is both a sign of our entrance into the genetic age and a beacon of inspiration for the next generation of women in STEM.
At one point, the chemistry of life was unknown – but Rosalind Franklin’s work propelled science toward a mechanistic understanding of the chemistry that drives the human machine. Dr. Franklin’s expertise in X-ray crystallography (aka x-ray diffraction analysis) produced the famed Photograph 51 which illustrated the helical nature of DNA.
The data contained in Franklin’s crystallographic images illustrated the structure of DNA and quantitatively confirmed the Watson-Crick DNA model.
Franklin received her BA in physical chemistry from Cambridge University in 1941, a time when the events of World War II permeated the academic sciences. According to the NIH’s biographical overview:
“She had to decide whether to be drafted for more traditional war work or pursue a PhD-oriented research job in a field relevant to wartime needs. She chose the latter, and began work with the recently organized British Coal Utilisation Research Association (BCURA).”
As Franklin studied the structure of carbon-based materials like coal, she identified and measured microscopic pores that affected how permeable the coal was. Franklin earned her PhD for this work, which made it possible to very accurately classify coals by quality and predict their performance characteristics. After receiving her PhD, Franklin went on to apply her mastery of X-ray crystallography to resolve the structure of microscopic biological structures, namely DNA and the Tobacco Mosaic Virus (TMV). By altering the water content of DNA samples, Franklin demonstrated that wet and dry DNA had different forms but both were helical. In her TMV research, Franklin’s work helped prove that TMV’s genome is embedded into the inner wall of its capsid.
Franklin’s work on TMV opened the door to cooperation with virology groups in the United States, and Franklin made multiple lengthy trips to network with these groups. Her career was tragically cut short by ovarian cancer, and while her 19 publications propelled science forward in multiple fields, many argue that Franklin deserved much more credit for her work on DNA. Four years after her death in 1958, Watson, Crick and Wilson were awarded the 1962 Nobel Prize for Physiology or Medicine for their characterization of the DNA double helix. Franklin was not credited, and was later spoken poorly of by Watson in his memoir, leading to a controversial review of history that is still debated to this day.
Countless researchers have sought to understand how structurally complex organisms arise from a single cell. Embryonic development is a topic where the chemistry of genetics melds with the physics of structure. The complex cascade of events and interactions amongst an increasing diversity of cell types makes embryology feel almost un-knowable, which is why researchers like Nüsslein-Volhard are so important.
Nüsslein-Volhard’s educational journey exposed her to multiple topics in the sciences, but nothing struck her interest as much as microbiology and genetics. After earning her PhD at the Max Planck Institute for Virus Research, Nüsslein-Volhard pivoted her study of genetics from viruses to fruit flies. The lifespan and development speed of fruit flies make them excellent organisms to study embryology with. Simply observing them yields an insight to the mechanisms at play during the early stages of life, but Nüsslein-Volhard took the work much further.
Together with her research partner, Eric Wieschaus, Nüsslein-Volhard invented a new technique to alter the development of fruit flies: saturation mutagenesis. Through intense study, the two were able to resolve the ~20,000 genes that make up the chromosomes of fruit flies, and filter down to 15 critical genes which instruct the blob of embryonic cells to take the shape of a fly embryo. The lessons learned with fruit flies carried strong implications for embryology of multiple species, including humans. For their advancements, Nüsslein-Volhard and Wieschaus were awarded the Nobel Prize in Physiology or Medicine in 1995. Nüsslein-Volhard is famously quoted saying, “Creativity is combining facts no one else has connected before.” From all of us here at AGT, Where Creativity Cures, we couldn’t agree more.
We tend to think of the genetic code that defines an organism as static, but through Barbara McClintock’s work, a much more complex picture begins to emerge. By studying multi-colored Maize plants, McClintock discovered a peculiar feature of DNA – that it can rearrange.
Since each kernel on an ear of corn is a distinct zygote, it was possible to observe hundreds of a plant’s offspring and derive an inheritance pattern for complex phenomena. During her experiments, McClintock noticed that breakage was occurring at specific sites on the chromosomes, demonstrating that pieces of genetic information were moving within the genome.
These moving genetic elements are now known as transposons, transposable elements, or simply “jumping genes”. McClintock was able to explain the inheritance pattern caused by these transposons with the Ac/Ds system, but the conceptual impact of her work extends far beyond explaining how certain traits are passed on. Her discovery occurred over 40 years before epigenetics was considered a formal area of study, but had a profound influence on how scientists view the mechanics of genetic expression.
The modern view of epigenetics places weight on both the genetic code and the way the cell interacts with that code. An advanced understanding of the cell shows how DNA-DNA interactions can influence gene expression, transcription factors can preferentially localize to certain areas within the nucleus, and chromosomes have defined territories. In this model, it’s not just about what is written in the code, it’s also about where it’s written and how it interacts with its surroundings. For her contributions to the way we look at gene expression, Barbara McClintock was awarded the 1983 Nobel Prize in Physiology or Medicine.